WO2020039661A1 - Abnormality diagnosis device - Google Patents
Abnormality diagnosis device Download PDFInfo
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- WO2020039661A1 WO2020039661A1 PCT/JP2019/018486 JP2019018486W WO2020039661A1 WO 2020039661 A1 WO2020039661 A1 WO 2020039661A1 JP 2019018486 W JP2019018486 W JP 2019018486W WO 2020039661 A1 WO2020039661 A1 WO 2020039661A1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/34—Testing dynamo-electric machines
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P5/00—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors
- H02P5/46—Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors for speed regulation of two or more dynamo-electric motors in relation to one another
Definitions
- the present invention relates to an abnormality diagnosis device.
- Patent Document 1 discloses a technique for improving efficiency by effectively utilizing harmonic components of a magnetic flux distribution in a current control method for a rotating electric machine.
- An object of the present invention is to provide an abnormality diagnosis apparatus capable of diagnosing an abnormality in two or more electric motors or a power transmission mechanism of a mechanical facility using the electric motors as a power source at a low cost.
- the present disclosure relates to an abnormality diagnosis device that diagnoses an abnormality with a plurality of AC motors or a plurality of power transmission mechanisms that transmit power to a plurality of mechanical equipment connected to the plurality of AC motors as a plurality of diagnosis targets. At least one of the plurality of AC motors is operated at a different rotation speed from any one of the other AC motors.
- the abnormality diagnosis device includes: a classification storage unit configured to store a classification result obtained by classifying a plurality of diagnosis targets into a plurality of diagnosis target groups based on a rotation speed; a signal input unit receiving an electric signal related to a plurality of AC motors; A frequency analysis unit that performs frequency analysis on an electric signal obtained via the input unit, and an allocation unit that allocates one frequency band component of an output of the frequency analysis unit to each of the plurality of diagnostic control groups And a determination unit that determines whether or not an abnormality has occurred in each of the plurality of diagnostic target groups using the components of the frequency band allocated by the allocation unit.
- abnormality diagnosis of each diagnosis target is performed at a low cost because abnormality diagnosis of each diagnosis target is performed using a result of frequency analysis performed on electric signals related to a plurality of AC motors. be able to.
- FIG. 2 is a schematic configuration diagram illustrating a configuration and an installation state of the abnormality diagnosis device according to the first embodiment
- 5 is a graph showing the relationship between the magnitude of the current spectrum and the frequency when all the electric motors and the power transmission mechanisms of the mechanical equipment connected thereto are normal.
- 5 is a graph showing the relationship between the magnitude of the current spectrum and the frequency when any of the electric motors or the power transmission mechanism of the mechanical equipment connected thereto is abnormal.
- FIG. 3 is a block diagram illustrating a configuration of a classification storage unit 8.
- FIG. 2 is a block diagram illustrating a configuration of an assignment unit 10.
- 5 is a flowchart illustrating an abnormality diagnosis process in the diagnosis device according to the first embodiment.
- FIG. 3 is a typical configuration diagram of an abnormality diagnosis device 5 that executes the processing of the flowchart.
- FIG. 9 is a diagram for explaining another example to which the abnormality diagnosis method can be applied.
- FIG. 5 is a diagram showing a configuration of an abnormality diagnosis device 5 according to a modification of the first embodiment.
- 9 is a flowchart for describing a classification process performed in the second embodiment.
- 13 is a first flowchart illustrating an abnormality diagnosis process in the diagnosis device according to the third embodiment.
- 13 is a second flowchart illustrating the abnormality diagnosis processing in the diagnosis device according to the third embodiment.
- FIG. 17 is a block diagram illustrating a configuration of a determination unit 11 when performing past data storage processing according to a fourth embodiment.
- FIG. 17 is a block diagram illustrating a configuration of a determination unit when performing abnormality diagnosis during actual operation according to a fourth embodiment.
- FIG. 1 is a schematic configuration diagram showing a configuration and an installation state of the abnormality diagnosis device according to the first embodiment.
- AC power is supplied from a power supply 1 to a plurality of AC motors 2 via a common bus BL.
- Bus line BL includes three-phase power supply lines BL (U), BL (V), and BL (W).
- a current detector 3 is arranged on the power supply line BL (U) so that a current for driving each of the plurality of AC motors 2 can be collectively measured.
- Each of the AC motors 2 is an AC motor that rotates a rotor by generating a rotating magnetic field by flowing a supplied three-phase AC through a stator coil.
- Such an AC motor is basically a constant-speed motor whose synchronous rotation speed is determined by the power supply frequency and the number of poles.
- the plurality of AC motors 2 include the motors 2A to 2N.
- the electric motors 2A to 2N may be electric motors having different specifications from each other. At least one of the motors 2A to 2N is operated at a rotation speed different from that of any one of the other motors.
- Mechanical equipments 4A to 4N, which are loads driven by the motors 2A to 2N, are connected to the motors 2A to 2N, respectively. These may be different facilities.
- the abnormality diagnosis device 5 is configured to diagnose abnormality of a plurality of AC motors 2 collectively.
- the abnormality diagnosis device 5 includes an information input unit 6, a classification storage unit 8, a signal input unit 7, a frequency analysis unit 9, an assignment unit 10, and a determination unit 11.
- the information input unit 6 is used to input information on the specifications of the motor to be driven for each motor.
- the classification storage unit 8 classifies the plurality of AC motors 2 to be diagnosed into a plurality of groups based on the rotation speed calculated from the information on the specifications of the motor input via the information input unit 6.
- a group of electric motors classified according to the rotational speed is referred to as an “electric motor group”.
- the classification storage unit 8 stores a classification result obtained by classifying the plurality of AC motors 2 into a plurality of motor groups based on the rotation speed.
- FIG. 2 is a graph showing the relationship between the magnitude of the current spectrum and the frequency when all the motors are normal.
- FIG. 3 is a graph showing the relationship between the magnitude of the current spectrum and the frequency when any of the motors has an abnormality.
- the frequency f0 is the AC frequency of the power supply 1.
- the AC frequency of the power supply 1 is a frequency of a commercial power supply such as 50 Hz or 60 Hz.
- components of different frequencies f1, f2, and f3 correspond to characteristic amounts for determining the presence or absence of an abnormality for motors having different rotation speeds. Therefore, by classifying the motors by the rotation speed, it is possible to determine whether or not an abnormality has occurred in the motors with respect to the motor group of each rotation speed.
- the frequencies f1, f2, and f3 are frequencies corresponding to three motor groups in which each of the motors 2A, 2B,... 2N of the AC motor 2 is classified based on the rotation speed.
- Abnormality determination reference values fth1, fth2, fth3 are predetermined for the frequencies f1, f2, f3. As shown in FIG. 2, when all the motors are normal, the power spectrum peaks at the frequencies f1, f2, and f3 are less than the abnormality determination reference values fth1, fth2, and fth3, respectively. On the other hand, when an abnormality has occurred in any of the motors, the power spectrum peak exceeds the abnormality determination reference value fth3 at the frequency f3 corresponding to the motor in which the abnormality has occurred, as shown in FIG. As described above, by comparing the abnormality determination reference value with the power spectrum peak, it is possible to determine whether or not an abnormality has occurred in the motors in each motor group.
- the specification information of all motors in the AC motor 2 is input from the information input unit 6 in advance. Necessary information is the number of poles of each AC motor 2 and the power supply frequency. The number of poles and the power supply frequency can be known from the motor nameplate or specification sheet. When there are a plurality of operable power supply frequencies, the frequency of the power supply actually operated is input from the information input unit 6.
- FIG. 4 is a block diagram illustrating the configuration of the classification storage unit 8.
- the classification storage unit 8 includes a classification unit 12 and a storage unit 13 as shown in FIG.
- the classification unit 12 classifies the AC motor 2 based on the output of the information input unit 6.
- the storage unit 13 stores the output of the classification unit 12, and outputs the output to the allocation unit 10.
- the classification unit 12 classifies the AC motors 2 into motor groups based on the rotation speed of each motor of the AC motor 2.
- the rotation speed of the AC motor 2 is determined by a synchronous rotation speed Ns determined by the power supply frequency and the number of poles of each motor. Based on the rotation speeds of the electric motors thus obtained, the electric motors are classified into groups.
- the classifying unit 12 classifies the AC motors 2 into a group of motors during a trial operation before the original operation of the AC motors 2 and the mechanical equipment 4.
- the classification unit 12 performs the classification again.
- the change of the operating condition it is conceivable to change the output frequency of the power supply for driving the motor or to replace the motor with one having a different number of poles.
- the classification unit 12 specifies the range of rotation speeds that can be taken by each electric motor and classifies the motor group. At this time, there is no problem even if there is a portion overlapping the range of the rotational speed corresponding to each motor group. For example, when an abnormal peak is found in an overlapping portion between the range corresponding to the motor group A and the range corresponding to the motor group B, it may be determined that an abnormality has occurred in the motor group A or B. However, when the ranges of the rotational speeds corresponding to the plurality of motor groups completely match, the classification unit 12 re-classifies them as the same motor group.
- the plurality of AC motors 2 are supplied with power from a power supply through a bus common to the plurality of AC motors 2.
- the bus is a bus bar in a switchboard, and power is supplied to each AC motor 2 by a power cable branched from the bus bar.
- the signal input unit 7 receives, as an electric signal Smon, an output of the current detector 3 that collectively measures a current flowing through the bus BL.
- Power is supplied to each of the plurality of AC motors 2 by power supply lines BL (U), BL (V), BL (W) of a plurality of phases included in a bus BL.
- the current detector 3 collectively measures the current of the power supply line BL (U) for at least one of the plurality of phases for the plurality of AC motors 2.
- the signal input unit 7 receives the electric signals Smon related to the plurality of AC motors 2.
- the frequency analysis unit 9 performs a frequency analysis on the electric signal Smon obtained via the signal input unit 7.
- the output of the frequency analysis unit 9 is sent to the determination unit 11 via the allocation unit 10, and is used by the determination unit 11 to determine whether an abnormality has occurred in the motors in each motor group.
- the frequency analysis unit 9 acquires a power spectrum by using a fast Fourier transform (FFT) as a frequency analysis technique.
- the allocating unit 10 determines frequency band components corresponding to each of the plurality of motor groups from the power spectrum.
- FFT fast Fourier transform
- FFT is a method of measuring a current for a certain period of time, performing frequency analysis on the measured data, and outputting a spectrum with frequency on the horizontal axis and power on the vertical axis.
- the frequency analysis unit 9 may perform the frequency analysis by a method other than the FFT.
- a frequency analysis method other than FFT includes, for example, a discrete Fourier transform (DFT).
- the DFT is a method of sequentially calculating a product of a sinusoidal signal of one frequency generated inside the frequency analysis unit 9 and a current value measured by the current detector 3, and calculating an average value.
- the DFT has an advantage that the calculation cost can be reduced because only a predetermined frequency value is obtained.
- the entire corresponding frequency range is not analyzed as in the case of the FFT, if the rotational speed is expected to have uncertain uncertainty, it is necessary to calculate a plurality of frequency components, thereby increasing the calculation cost. I do.
- the assignment unit 10 assigns the output of the frequency analysis unit 9 to each motor group based on the output of the classification storage unit 8.
- the allocating unit 10 allocates one frequency band component of the output of the frequency analysis unit 9 to each of the plurality of motor groups.
- the output of the frequency analysis unit 9 is a set in which the magnitudes of a plurality of frequency components are put together, and the function of the assignment unit 10 is to link those values to each motor group.
- FIG. 5 is a block diagram illustrating a configuration of the allocating unit 10.
- Assignment section 10 includes frequency band calculation section 14 and frequency band extraction section 15.
- the motor groups classified in the classification storage unit 8 correspond to different rotational speeds. One or more motors belonging to one motor group are operated at the same rotation speed corresponding to the motor group.
- the frequency at which the peak increases when an abnormality occurs in each motor group can be calculated in advance from the rotation speed.
- the frequency band calculator 14 calculates the frequency at which the peak increases when an abnormality occurs, for each motor group based on the result of classification by the classification storage unit 8.
- the classifying unit 12 classifies the motors by giving a range to the rotation speed corresponding to the motor group
- the frequency band corresponding to the width of the rotation speed is also allocated in the frequency allocation in the allocation unit 10. .
- the diagnosis result may be that any one of the two motor groups has an abnormality.
- the frequency band extracting unit 15 allocates a part of the power spectrum output from the frequency analyzing unit 9 to each motor group based on the output of the frequency band calculating unit 14.
- the allocating unit 10 extracts the frequency component of the spectrum or the maximum value of the spectrum in the frequency range for each motor group from the result of the power spectrum obtained by the frequency analysis unit 9 by the FFT.
- the allocating unit 10 may generate a band-pass filter that passes a frequency component in a frequency range corresponding to each motor group, and extract the frequency component.
- the simplest example of the frequency at which the peak of the power spectrum increases when an abnormality occurs is the case where the rotation speed output from the classification storage unit 8 is directly represented by the frequency.
- the frequency band calculation unit 14 converts the rotation speed value corresponding to the motor group obtained from the classification storage unit 8 into a frequency as it is and outputs it.
- the frequency may be calculated focusing on a certain characteristic abnormality of the electric motor. For example, it is known that when an abnormality occurs in a bearing, characteristic vibration is generated based on the abnormality, and the frequency can be calculated in advance.
- the determination unit 11 determines whether or not an abnormality has occurred in a motor for each motor group based on the frequency component of the spectrum in the frequency range for each motor group output by the allocating unit 10 or its maximum value. More specifically, the determination unit 11 determines whether or not an abnormality has occurred in each of the plurality of motor groups using the components of the frequency band allocated by the allocation unit 10.
- the determination unit 11 determines whether there is an abnormality by comparing the frequency component of the spectrum or the maximum value thereof in the frequency range for each motor group output by the allocation unit 10 with a preset reference value. It is known that a component assigned to each motor group for detecting an abnormality increases when an abnormality occurs in the motor.
- the determination unit 11 determines whether any of the motors in the motor group It is determined that an abnormality has occurred, and a determination result is output. For example, as illustrated in FIG. 3, when the component of the frequency f3 exceeds the abnormality determination reference value fth3, the determination unit 11 causes an abnormality in one of the motors in the motor group corresponding to the frequency f3. Is determined.
- the determination unit 11 compares the reference value of each motor group with the characteristic frequency component, and It is determined that an abnormality has occurred in the motor group for the motor group that exceeds the threshold, and a determination result is output. At this time, when the plurality of motor groups exceed the reference, the determination unit 11 determines that an abnormality has occurred in the motors in all of the motor groups.
- FIG. 6 is a flowchart showing an abnormality diagnosis process in the diagnostic device of the first embodiment.
- the processing of this flowchart is executed in the abnormality diagnosis device 5 of FIG.
- FIG. 7 is a typical configuration diagram of the abnormality diagnosis device 5 that executes the processing of the flowchart.
- the abnormality diagnosis device 5 includes a processor 111, a memory 112, and an input / output interface 113.
- the memory 112 stores a program for executing the processing of the flowchart in FIG. This program is read by the processor 111, and the processor 111 operates as the abnormality diagnosis device 5.
- step S ⁇ b> 1 abnormality diagnosis device 5 receives, at signal input unit 7, a signal indicating a measured current obtained by measuring the drive current of AC motor 2 with current detector 3.
- step S2 the abnormality diagnosis device 5 performs frequency analysis on the signal received by the signal input unit 7 in the frequency analysis unit 9, and in step S3, a part of the frequency analysis result is classified for each motor group classified in advance. assign. It is assumed that the number of motor groups classified at this time is n.
- the abnormality diagnosis device 5 determines whether or not an abnormality has occurred in the motor based on the frequency components assigned to each motor group, and outputs a determination result. Specifically, the variable i is set to 1 in step S4, and the abnormality diagnosis device 5 evaluates the frequency component assigned in step S5 for the i-th motor group. In the evaluation, the abnormality diagnosis device 5 determines that an abnormality has occurred if the magnitude of the frequency component is equal to or greater than the reference value, and determines that the abnormality has occurred if the magnitude of the frequency component does not exceed the reference value. Then, in step S6, the abnormality diagnosis device 5 outputs the determination result from the determination unit 11 to the display unit 30.
- step S7 the variable i is incremented until it reaches n, and as a result, the processing of steps S5 and S6 is sequentially performed for the first to n-th motor groups.
- the abnormality diagnosis device 5 When the determination of all the motor groups is completed, the abnormality diagnosis device 5 outputs the entire result to the display unit 30 in step S8, and ends the operation in step S9.
- the abnormality diagnosis device 5 assigns a current waveform to a motor group using frequency analysis.
- Bus currents for supplying AC power to a plurality of electric motors are collectively measured, and it is determined whether an abnormality has occurred in the electric motors for each electric motor group classified by the rotational speed.
- one common current detector 3 is used for a plurality of AC motors 2. For this reason, in a system in which a large number of electric motors operate on the same power supply, the number of current detectors used for judging abnormalities of the plurality of AC motors 2 can be reduced, and the cost of the diagnostic device can be reduced.
- the abnormality diagnosis method executed by the abnormality diagnosis device 5 utilizes the fact that the rotation speed of the AC motor is determined by the AC power supply frequency and the number of poles of the motor, and thus the AC motor whose rotation speed is determined in this manner.
- a similar abnormality diagnosis method can be applied to general.
- a similar abnormality diagnosis method can be applied to a plurality of synchronous motors, a plurality of induction motors, or a composite system thereof, which are rotated by permanent magnets of a rotor.
- FIG. 8 is a diagram for explaining another example to which the abnormality diagnosis method can be applied.
- a single vibration sensor 16 is installed at a place where the vibrations of both motors can be detected.
- the same analysis can be performed by inputting an electrical signal indicating the vibration detected by the vibration sensor 16 to the abnormality diagnosis device 5.
- the signal input unit 7 in FIG. 1 receives the output of the vibration sensor 16 that collectively measures the vibration generated by the plurality of AC motors 2.
- FIG. 9 is a diagram showing a configuration of an abnormality diagnosis device 5A according to a modification of the first embodiment.
- the abnormality diagnosis device 5A automatically recognizes the power supply frequency f0 from the signal Smon instead of inputting the power supply frequency f0 from the information input unit 6.
- the abnormality diagnosis device 5A can send the information on the power supply frequency f0 from the output of the frequency analysis unit 9 to the classification storage unit 8 via the assignment unit 10 as shown in FIG.
- the frequency spectrum of the current measured by the current detector 3 is obtained, the largest is the frequency component of the power supply frequency f0 as shown in FIG. 2 and FIG. is there.
- the other operations of the abnormality diagnosis device 5A are the same as those of the abnormality diagnosis device 5, and thus the description will not be repeated.
- Embodiment 2 When the AC motor 2 is an induction motor, the rotation speed of each AC motor 2 cannot be determined only by the power supply frequency and the number of poles of the motor. In order to determine the rotation speed, slip information for each AC motor 2 is required in addition to the power supply frequency and the number of poles of the motor. Due to this slip, the rotation speed of the induction motor takes a different value for each AC motor 2.
- the motors can be classified into groups of motors smaller than those in the example in the first embodiment, and it is easy to specify the motor in which an abnormality has occurred.
- the AC motor 2 When the AC motor 2 is an induction motor, it is necessary to input information on the torque T, the current I, the slip s, and the operation status of the induction motor in addition to the number of poles P and the power supply frequency f to the information input unit 6. There is.
- the actual rotation speed N (min -1 ) can be expressed by the following equation (2) using the slip s, the number of poles P, and the power supply frequency f.
- the number of poles P and the power supply frequency f can be known from the nameplate of the electric motor.
- Information about the torque T, the current I and the slip s is available from the motor specification sheet. In the specification sheet of the electric motor, the relationship among the torque T, the current I, and the slip s is shown, and the rotation speed can be obtained from the information. For example, when there are a plurality of operable power supply frequencies such as 50 Hz and 60 Hz, the power supply frequency to be actually operated is input. When acquiring the power supply frequency value from the current as described in the modification of the first embodiment, all the information on the torque, current, and slip described in the specification sheet is input for each power supply frequency.
- the classifying unit 12 classifies the AC motors 2 into motor groups when the AC motors 2 and the mechanical equipment 4 are experimentally operated before the original operation. If a change in the operating condition of the equipment is input from the information input unit 6 and the rotational speed of the AC motor 2 is assumed to change with reference to the changed operating condition, the classifying unit 12 performs the classification again.
- FIG. 10 is a flowchart for describing the classification processing performed in the second embodiment.
- the classification is performed in consideration of the mechanical equipment connected to the motor as shown in FIG. 10 in addition to the power supply frequency f and the number of poles P.
- the classification unit 12 determines that all the induction motors are the same among the induction motors constituting the AC motor 2 and are connected to the induction motor. Judge whether all the installed machinery and equipment are the same. Specifically, in step S21, it is determined whether or not all combinations of the electric motor and the load connected to the electric motor, that is, the mechanical equipment are the same. If there is a different combination of the electric motor and the load in step S21, it is determined in step S22 whether all the electric motors are the same. At this time, if all the motors are the same, the motors are classified by the type of load in step S23.
- step S23 by utilizing this property, the induction motor can be classified into a group of motors for each connected mechanical facility.
- the classification unit 12 determines in step S24 that the type or specification of the mechanical equipment connected to the induction motor, that is, the type or specification of the load. It is determined whether all are the same.
- the classification unit 12 determines that the difference in torque required to drive the mechanical equipment for each equipment is greater than when the mechanical equipment itself is different. Judge as small. Therefore, the classifying unit 12 considers that the torques output from the induction motors are all the same, and obtains a difference in slip when the same torque is applied from the torque and slip information input as part of the operation information. From this, the difference in rotational speed can be determined. In step S25, the classification unit 12 classifies the induction motors into a group of motors based on the difference in the rotation speeds obtained in this manner.
- step S24 it means that there are different types of induction motors and different types of connected mechanical equipment. In this case, it is considered that the slip of the induction motor that drives the equipment differs for each combination of the induction motor and the mechanical equipment.
- the rotation speed of each induction motor can be estimated from the estimated torque value and the relationship between the torque and slip in the induction motor.
- the classification unit 12 can classify the plurality of induction motors into a group of motors based on the estimated rotation speed. If it is difficult to estimate the rotation speed, perform individual measurements as needed.
- step S21 to step S27 all the induction motors are the same induction motor, and all the mechanical equipment connected to the induction motor is the same. In this case, it is impossible to distinguish the rotation speed by the difference between the induction motor or the mechanical equipment. Also in this case, the rotation speed of the induction motor may be different depending on the operation state of the mechanical equipment.
- step S27 it is determined whether the electric motor can be measured individually.
- the case where the electric motors can be individually measured is a case where the individual electric motors are provided with a tachometer, a torque sensor, an ammeter, and the like, and can measure data such as a rotation speed and a torque. If the motors can be measured individually, the rotation speed can be calculated based on the results of the individual measurements.
- step S28 the abnormality diagnosis device 5 first determines whether or not the rotation speed can be measured. If the speed of each induction motor can be measured (YES in S28), in step S29, each induction motor can be classified into a motor group based on the measured value of the rotation speed.
- step S30 abnormality diagnosis device 5 determines whether it is possible to individually measure the torque of the electric motor. If the torque can be measured (YES in S30), in step S31, the rotation speed can be obtained from the specifications of the induction motor. If the torque cannot be measured (NO in S30), in step S32, abnormality diagnosis device 5 individually measures the current for driving the induction motor. In step S32, the slip and rotation speed of the induction motor can be obtained by referring to the information on the specification of the induction motor using the amplitude or the effective value of the drive current.
- step S33 all the induction motors are classified as one motor group.
- the range of rotation speeds that each induction motor can take may be specified and classified into a group of motors. it can.
- the range in which the torque can be taken when driving mechanical equipment or the range of the estimated value is known, the range in which the rotation speed can be taken from the range and the slip information in the specifications of the induction motor is determined. You can ask.
- the motors are classified in consideration of the operating state of the individual motor in more detail than in the first embodiment, so that the classification is subdivided and an abnormality occurs. It becomes easy to specify the motor.
- Embodiment 3 Power transmission mechanisms of mechanical equipment such as belts, gears, and chains sometimes generate characteristic frequency vibrations when an abnormality occurs.
- the power transmission mechanism of the mechanical equipment is set to “Power transmission mechanism group ".
- an index serving as a reference for classification is required.
- the vibration frequency of the power transmission mechanism is appropriate as this index. In order to calculate this vibration frequency in advance, in addition to the rotation speed of the electric motor that drives the power transmission mechanism, parameters characteristic of the power transmission mechanism are required.
- vibrations of the same frequency may be generated from different equipment depending on the combination of the mechanical equipment and its failure mode. Therefore, different types of power transmission mechanisms, such as a chain and a belt, may be classified into the same “power transmission mechanism group”.
- This abnormality diagnosis is an abnormality diagnosis for the “power transmission mechanism group” in the same manner as the abnormality diagnosis for a plurality of electric motors. That is, it is determined for each “power transmission mechanism group” whether there is any equipment in which an abnormality has occurred.
- the operation of the abnormality diagnosis device at this time is as shown in steps S51 to S59 in FIG. 11, and is the same as the procedure described in steps S1 to S9 in FIG. 6 in the first embodiment.
- a sign of a crack in the belt can be detected by measuring a current for driving the AC motor.
- a value of the diameter of the pulley connected to the electric motor is required as a characteristic parameter of the power transmission mechanism.
- the abnormality diagnosis for the power transmission mechanism group can be performed in parallel with the abnormality diagnosis for the motor group because the frequency analysis and the method of assigning each component are exactly the same as the abnormality diagnosis for the motor group. is there.
- the operation of the abnormality diagnosis device is as shown in steps S61 to S73 in FIG.
- a certain output may be assigned to both some motor groups and some power transmission mechanism groups.
- the abnormality determination (S68 to S71) of the power transmission mechanism group is performed after the abnormality determination (S64 to S67) of the motor group is performed first. Is also possible.
- Embodiment 4 FIG. In the fourth embodiment, how to determine a reference value for determining abnormality is specified.
- FIG. 13 is a block diagram showing a configuration of determination unit 11 and a flow of signals when processing for storing past data is performed in the fourth embodiment.
- the determination unit 11 determines the abnormality of the motor group by comparing with a normal case.
- the determination unit 11 includes a data storage unit 17 that stores past data as shown in FIG. 13 and a data comparison unit 18.
- the data storage unit 17 stores an amount allocated to each motor group obtained by processing a signal obtained by measurement of the motor in a normal case by the signal input unit 7, the frequency analysis unit 9, and the allocation unit 10. It is configured to
- FIG. 14 is a block diagram showing a configuration of a determination unit and a flow of signals when performing an abnormality diagnosis during actual operation in the fourth embodiment.
- the data comparison unit 18 compares the output of the data storage unit 17 with the output of the allocation unit 10 as shown in FIG. It is determined whether an abnormality has occurred.
- the determination may be made in consideration of the variation width.
- the data at the time of actual operation output from the allocating unit 10 is stored in the data storage unit 17, and information on the variation of the allocated frequency components is obtained.
- the data storage unit 17 periodically updates the reference value by reflecting the variation information.
- the updated reference value is provided from the data storage unit 17 to the data comparison unit 18 as shown in FIG.
- the determination unit 11 determines that an abnormality has occurred in the motor in the motor group. I do.
- determination unit 11 outputs data when no abnormality has occurred in the AC motors for each of the plurality of motor groups.
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Abstract
An abnormality diagnosis device (5) is provided with: a classification storage unit (8) for storing the result of classifying a plurality of AC electric motors (2) into a plurality of electric motor groups, or of classifying a plurality of power transmission mechanisms of machinery into a plurality of power transmission mechanism groups; a signal input unit (7) for receiving an electrical signal (Smon) relating to the plurality of AC motors (2); a frequency analysis unit (9) for performing frequency analysis of the electrical signal (Smon); an assignment unit (10) for assigning a single frequency band component from among the output of the frequency analysis unit (9) to each of the plurality of electric motor groups; and a determination unit (11) for determining the presence/absence of an abnormality for each of the plurality of electric motor groups or the plurality of power transmission mechanism groups using the frequency band component assigned by the assignment unit (10). Through this configuration, an abnormality diagnosis device is provided that is capable of diagnosing, at low cost, an abnormality in an electric motor or a power transmission mechanism of machinery connected to an electric motor.
Description
本発明は異常診断装置に関する。
The present invention relates to an abnormality diagnosis device.
特開2003-244992号公報(特許文献1)は、回転電機の電流制御方法において、磁束分布の高調波成分を有効に活用して効率を向上させる技術を開示する。
Japanese Patent Laying-Open No. 2003-244992 (Patent Document 1) discloses a technique for improving efficiency by effectively utilizing harmonic components of a magnetic flux distribution in a current control method for a rotating electric machine.
従来、電動機の駆動電流に基づいて電動機あるいは電動機を動力源とする機械設備の動力伝達機構における異常の有無を診断することが行なわれている。1台の電源から出力された、複数の電動機を同時に駆動する電流を一括して計測することは、個々の電動機ごとに電流を計測するよりもコスト面で有利である。特開2003-244992号公報では、このような電流計測手法が電動機の制御を目的として提案されている。しかし、この例では対象とする電動機が特殊な形状をしており、一般的な電動機を対象とするものではなく、また、同時に電流を計測する電動機の台数は2台に限られているため、異常診断に適用するには改善の余地がある。
Conventionally, diagnosis of abnormality in a motor or a power transmission mechanism of mechanical equipment using the motor as a power source has been performed based on a drive current of the motor. Collectively measuring currents output from one power supply and simultaneously driving a plurality of motors is more advantageous in terms of cost than measuring currents for individual motors. Japanese Patent Application Laid-Open No. 2003-244992 proposes such a current measuring method for the purpose of controlling an electric motor. However, in this example, the target motor has a special shape, not a general motor, and the number of motors that simultaneously measure current is limited to two. There is room for improvement when applied to abnormality diagnosis.
本発明の目的は、2台以上の電動機あるいは電動機を動力源とする機械設備の動力伝達機構における異常を少ないコストで診断することができる異常診断装置を提供することである。
An object of the present invention is to provide an abnormality diagnosis apparatus capable of diagnosing an abnormality in two or more electric motors or a power transmission mechanism of a mechanical facility using the electric motors as a power source at a low cost.
本開示は、複数の交流電動機、または複数の交流電動機にそれぞれ接続された複数の機械設備に動力を伝達する複数の動力伝達機構を複数の診断対象として異常を診断する異常診断装置に関する。複数の交流電動機のうちの少なくとも1台は、他のいずれか1台の交流電動機と異なる回転速度で運転される。異常診断装置は、複数の診断対象を回転速度に基づいて複数の診断対象群に分類した分類結果を記憶する分類記憶部と、複数の交流電動機に関連する電気信号を受ける信号入力部と、信号入力部を経由して得られた電気信号に対して周波数解析を行なう周波数解析部と、複数の診断対照群の各々に対して周波数解析部の出力のうち1つの周波数帯の成分を割り当てる割当部と、割当部によって割り当てられた周波数帯の成分を用いて複数の診断対象群の各々に対して異常の発生の有無を判定する判定部とを備える。
The present disclosure relates to an abnormality diagnosis device that diagnoses an abnormality with a plurality of AC motors or a plurality of power transmission mechanisms that transmit power to a plurality of mechanical equipment connected to the plurality of AC motors as a plurality of diagnosis targets. At least one of the plurality of AC motors is operated at a different rotation speed from any one of the other AC motors. The abnormality diagnosis device includes: a classification storage unit configured to store a classification result obtained by classifying a plurality of diagnosis targets into a plurality of diagnosis target groups based on a rotation speed; a signal input unit receiving an electric signal related to a plurality of AC motors; A frequency analysis unit that performs frequency analysis on an electric signal obtained via the input unit, and an allocation unit that allocates one frequency band component of an output of the frequency analysis unit to each of the plurality of diagnostic control groups And a determination unit that determines whether or not an abnormality has occurred in each of the plurality of diagnostic target groups using the components of the frequency band allocated by the allocation unit.
本発明によれば、複数の交流電動機に関連する電気信号に対して周波数解析を行なった結果を用いて個々の診断対象の異常診断を行なうため、複数の診断対象の異常診断を少ないコストで行なうことができる。
According to the present invention, abnormality diagnosis of each diagnosis target is performed at a low cost because abnormality diagnosis of each diagnosis target is performed using a result of frequency analysis performed on electric signals related to a plurality of AC motors. be able to.
以下、本発明の実施の形態について、図面を参照しながら詳細に説明する。以下では、複数の実施の形態について説明するが、各実施の形態で説明された構成を適宜組み合わせることは出願当初から予定されている。なお、図中同一または相当部分には同一符号を付してその説明は繰り返さない。
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a plurality of embodiments will be described, but it is planned from the beginning of the application to appropriately combine the configurations described in the embodiments. In the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.
実施の形態1.
図1は、実施の形態1の異常診断装置の構成およびその設置状況を示す概略構成図である。図1において、複数の交流電動機2に電源1から共通の母線BLを介して交流電力が供給される。母線BLは、三相の電源ラインBL(U),BL(V),BL(W)を含む。電源ラインBL(U)には複数の交流電動機2の各々を駆動する電流を一括して計測できるように電流検出器3が配置される。Embodiment 1 FIG.
FIG. 1 is a schematic configuration diagram showing a configuration and an installation state of the abnormality diagnosis device according to the first embodiment. In FIG. 1, AC power is supplied from apower supply 1 to a plurality of AC motors 2 via a common bus BL. Bus line BL includes three-phase power supply lines BL (U), BL (V), and BL (W). A current detector 3 is arranged on the power supply line BL (U) so that a current for driving each of the plurality of AC motors 2 can be collectively measured.
図1は、実施の形態1の異常診断装置の構成およびその設置状況を示す概略構成図である。図1において、複数の交流電動機2に電源1から共通の母線BLを介して交流電力が供給される。母線BLは、三相の電源ラインBL(U),BL(V),BL(W)を含む。電源ラインBL(U)には複数の交流電動機2の各々を駆動する電流を一括して計測できるように電流検出器3が配置される。
FIG. 1 is a schematic configuration diagram showing a configuration and an installation state of the abnormality diagnosis device according to the first embodiment. In FIG. 1, AC power is supplied from a
交流電動機2の各々は、いずれも供給される三相交流を固定子コイルに流すことにより回転磁界を発生させ、回転子を回転させる交流電動機である。このような交流電動機は、基本的には電源周波数と極数で同期回転速度が決定される定速の電動機である。
Each of the AC motors 2 is an AC motor that rotates a rotor by generating a rotating magnetic field by flowing a supplied three-phase AC through a stator coil. Such an AC motor is basically a constant-speed motor whose synchronous rotation speed is determined by the power supply frequency and the number of poles.
複数の交流電動機2は、電動機2A~2Nを含む。電動機2A~2Nは、互いに仕様の異なる電動機であってよい。電動機2A~2Nのうち少なくとも1台は、他のいずれか1台の電動機とは異なる回転速度で運転される。電動機2A~2Nには、それらが駆動する負荷である機械設備4A~4Nがそれぞれ接続されている。これらは互いに異なる設備であってもよい。
交流 The plurality of AC motors 2 include the motors 2A to 2N. The electric motors 2A to 2N may be electric motors having different specifications from each other. At least one of the motors 2A to 2N is operated at a rotation speed different from that of any one of the other motors. Mechanical equipments 4A to 4N, which are loads driven by the motors 2A to 2N, are connected to the motors 2A to 2N, respectively. These may be different facilities.
異常診断装置5は、複数の交流電動機2の異常を一括して診断するように構成される。異常診断装置5は、情報入力部6と、分類記憶部8と、信号入力部7と、周波数解析部9と、割当部10と、判定部11とを備える。
The abnormality diagnosis device 5 is configured to diagnose abnormality of a plurality of AC motors 2 collectively. The abnormality diagnosis device 5 includes an information input unit 6, a classification storage unit 8, a signal input unit 7, a frequency analysis unit 9, an assignment unit 10, and a determination unit 11.
最初に、故障診断のための準備に相当する処理を行なうための情報入力部6および分類記憶部8について説明する。
First, the information input unit 6 and the classification storage unit 8 for performing processing corresponding to preparation for failure diagnosis will be described.
情報入力部6は、駆動する電動機の仕様に関する情報を電動機ごとに入力するために用いられる。
The information input unit 6 is used to input information on the specifications of the motor to be driven for each motor.
分類記憶部8は、情報入力部6を介して入力された電動機の仕様に関する情報から算出された回転速度に基づいて診断の対象となる複数の交流電動機2を複数のグループに分類する。以下では、回転速度ごとに分類された電動機のグループを「電動機群」と呼ぶ。分類記憶部8は、複数の交流電動機2を回転速度に基づいて複数の電動機群に分類した分類結果を記憶する。
The classification storage unit 8 classifies the plurality of AC motors 2 to be diagnosed into a plurality of groups based on the rotation speed calculated from the information on the specifications of the motor input via the information input unit 6. Hereinafter, a group of electric motors classified according to the rotational speed is referred to as an “electric motor group”. The classification storage unit 8 stores a classification result obtained by classifying the plurality of AC motors 2 into a plurality of motor groups based on the rotation speed.
図1に示したような交流電動機2のいずれかに異常が発生した場合には、異常が発生した電動機に特徴的な周波数の振動が駆動電流に重畳される。この特徴的な周波数は、電動機の回転速度に依存することが知られている。
異常 When an abnormality occurs in any of the AC motors 2 as shown in FIG. 1, vibration having a frequency characteristic of the abnormal motor is superimposed on the drive current. It is known that this characteristic frequency depends on the rotation speed of the electric motor.
図2は、すべての電動機が正常である場合の電流スペクトルの大きさと周波数との関係を示したグラフである。図3は、いずれかの電動機に異常が発生している場合の電流スペクトルの大きさと周波数との関係を示したグラフである。
FIG. 2 is a graph showing the relationship between the magnitude of the current spectrum and the frequency when all the motors are normal. FIG. 3 is a graph showing the relationship between the magnitude of the current spectrum and the frequency when any of the motors has an abnormality.
図2、図3において、周波数f0は、電源1の交流周波数である。電源1の交流周波数は、たとえば50Hzまたは60Hzなどの商用電源の周波数である。
周波 数 In FIGS. 2 and 3, the frequency f0 is the AC frequency of the power supply 1. The AC frequency of the power supply 1 is a frequency of a commercial power supply such as 50 Hz or 60 Hz.
図2、図3に示すように、異なる回転速度の電動機に対しては異なる周波数f1,f2,f3の成分が異常の有無を判定する特徴的な量として対応する。そのため、電動機を回転速度で分類することで、それぞれの回転速度の電動機群に対して電動機に異常が発生しているか否かを判定できる。周波数f1,f2,f3は、交流電動機2の各電動機2A,2B,…2Nが回転速度に基づいて分類された3つの電動機群に対応する周波数である。
As shown in FIGS. 2 and 3, components of different frequencies f1, f2, and f3 correspond to characteristic amounts for determining the presence or absence of an abnormality for motors having different rotation speeds. Therefore, by classifying the motors by the rotation speed, it is possible to determine whether or not an abnormality has occurred in the motors with respect to the motor group of each rotation speed. The frequencies f1, f2, and f3 are frequencies corresponding to three motor groups in which each of the motors 2A, 2B,... 2N of the AC motor 2 is classified based on the rotation speed.
周波数f1,f2,f3に対して、異常判定基準値fth1,fth2,fth3が予め定められている。図2に示すように、すべての電動機が正常である場合には、周波数f1,f2,f3のパワースペクトルピークは、それぞれ異常判定基準値fth1,fth2,fth3未満である。一方、いずれかの電動機に異常が発生している場合には、図3に示すように、異常が発生した電動機に対応する周波数f3においてパワースペクトルピークが異常判定基準値fth3を超える。このように、異常判定基準値とパワースペクトルピークとを比較することによって、各電動機群において電動機に異常が発生しているか否かを判断することができる。
異常 Abnormality determination reference values fth1, fth2, fth3 are predetermined for the frequencies f1, f2, f3. As shown in FIG. 2, when all the motors are normal, the power spectrum peaks at the frequencies f1, f2, and f3 are less than the abnormality determination reference values fth1, fth2, and fth3, respectively. On the other hand, when an abnormality has occurred in any of the motors, the power spectrum peak exceeds the abnormality determination reference value fth3 at the frequency f3 corresponding to the motor in which the abnormality has occurred, as shown in FIG. As described above, by comparing the abnormality determination reference value with the power spectrum peak, it is possible to determine whether or not an abnormality has occurred in the motors in each motor group.
異常診断を行なう前に、予め情報入力部6から、交流電動機2におけるすべての電動機の仕様情報を入力しておく。必要な情報は各交流電動機2の極数と電源周波数である。極数と電源周波数は電動機の銘板またはスペックシートから知ることができる。動作可能な電源周波数が複数ある場合は、実際に稼動させる電源の周波数を情報入力部6から入力する。
(4) Before performing the abnormality diagnosis, the specification information of all motors in the AC motor 2 is input from the information input unit 6 in advance. Necessary information is the number of poles of each AC motor 2 and the power supply frequency. The number of poles and the power supply frequency can be known from the motor nameplate or specification sheet. When there are a plurality of operable power supply frequencies, the frequency of the power supply actually operated is input from the information input unit 6.
図4は、分類記憶部8の構成を示すブロック図である。分類記憶部8は、図4に示すように分類部12と記憶部13とを含む。分類部12は、情報入力部6の出力に基づいて交流電動機2を分類する。記憶部13は、分類部12の出力を記憶し、割当部10に出力する。
FIG. 4 is a block diagram illustrating the configuration of the classification storage unit 8. The classification storage unit 8 includes a classification unit 12 and a storage unit 13 as shown in FIG. The classification unit 12 classifies the AC motor 2 based on the output of the information input unit 6. The storage unit 13 stores the output of the classification unit 12, and outputs the output to the allocation unit 10.
分類部12は、交流電動機2の電動機群への分類を、交流電動機2の各電動機の回転速度に基づいて行なう。交流電動機2の回転速度は、電源周波数と各電動機の極数で決定される同期回転速度Nsで求められる。このようにして求められた各電動機の回転速度に基づき、電動機群への分類がなされる。
The classification unit 12 classifies the AC motors 2 into motor groups based on the rotation speed of each motor of the AC motor 2. The rotation speed of the AC motor 2 is determined by a synchronous rotation speed Ns determined by the power supply frequency and the number of poles of each motor. Based on the rotation speeds of the electric motors thus obtained, the electric motors are classified into groups.
一般に、交流電動機の同期回転速度Ns(min-1)は、電源周波数f(Hz)と極数Pとによって次式(1)で算出することができる。
Ns=120f/P …(1)
分類部12は、交流電動機2の電動機群への分類を交流電動機2および機械設備4の本来の稼動の前の試験的な稼働の際に実施する。情報入力部6から設備の稼動条件の変更が入力され、変更後の稼動条件を参照して交流電動機2の回転速度が変わると想定される場合は、分類部12は再度分類をやり直す。稼動条件の変更としては、電動機を駆動する電源の出力周波数の変更や電動機を極数の異なるものに取り替えることが考えられる。 Generally, the synchronous rotation speed Ns (min −1 ) of the AC motor can be calculated by the following equation (1) using the power supply frequency f (Hz) and the number of poles P.
Ns = 120f / P (1)
The classifyingunit 12 classifies the AC motors 2 into a group of motors during a trial operation before the original operation of the AC motors 2 and the mechanical equipment 4. When a change in the operating condition of the equipment is input from the information input unit 6 and the rotational speed of the AC motor 2 is assumed to change with reference to the changed operating condition, the classification unit 12 performs the classification again. As the change of the operating condition, it is conceivable to change the output frequency of the power supply for driving the motor or to replace the motor with one having a different number of poles.
Ns=120f/P …(1)
分類部12は、交流電動機2の電動機群への分類を交流電動機2および機械設備4の本来の稼動の前の試験的な稼働の際に実施する。情報入力部6から設備の稼動条件の変更が入力され、変更後の稼動条件を参照して交流電動機2の回転速度が変わると想定される場合は、分類部12は再度分類をやり直す。稼動条件の変更としては、電動機を駆動する電源の出力周波数の変更や電動機を極数の異なるものに取り替えることが考えられる。 Generally, the synchronous rotation speed Ns (min −1 ) of the AC motor can be calculated by the following equation (1) using the power supply frequency f (Hz) and the number of poles P.
Ns = 120f / P (1)
The classifying
上記の分類において、使用する回転速度の値が変動する場合または回転速度が不確かである場合には、分類部12は、各電動機が取り得る回転速度の範囲を指定して電動機群に分類する。その際に各電動機群に対応する回転速度の範囲に重なり合う部分があっても問題ない。たとえば電動機群Aに対応する範囲と電動機群Bに対応する範囲との重なり部分に異常ピークが見られた場合には、電動機群AまたはBに異常が発生したと判定すればよい。ただし、複数の電動機群に対応する回転速度の範囲が完全に一致する場合は、分類部12は、それらを同一の電動機群として分類しなおす。
(4) In the above classification, when the value of the rotation speed to be used fluctuates or the rotation speed is uncertain, the classification unit 12 specifies the range of rotation speeds that can be taken by each electric motor and classifies the motor group. At this time, there is no problem even if there is a portion overlapping the range of the rotational speed corresponding to each motor group. For example, when an abnormal peak is found in an overlapping portion between the range corresponding to the motor group A and the range corresponding to the motor group B, it may be determined that an abnormality has occurred in the motor group A or B. However, when the ranges of the rotational speeds corresponding to the plurality of motor groups completely match, the classification unit 12 re-classifies them as the same motor group.
次に、電源電流の計測から周波数解析までの説明を行なう。
複数の交流電動機2は、複数の交流電動機2に共通する母線によって電源から電力が供給される。たとえば、母線は配電盤中のバスバーであり、バスバーから分岐された電力ケーブルによって個々の交流電動機2に電力が供給される。信号入力部7は、母線BLを流れる電流を一括して計測する電流検出器3の出力を電気信号Smonとして受ける。複数の交流電動機2の各々には、母線BLに含まれる複数相の電源ラインBL(U)、BL(V),BL(W)によって電力が供給される。電流検出器3は、複数相のうちの少なくとも1相分の電源ラインBL(U)の電流を複数の交流電動機2について一括して測定する。 Next, a description will be given from the measurement of the power supply current to the frequency analysis.
The plurality ofAC motors 2 are supplied with power from a power supply through a bus common to the plurality of AC motors 2. For example, the bus is a bus bar in a switchboard, and power is supplied to each AC motor 2 by a power cable branched from the bus bar. The signal input unit 7 receives, as an electric signal Smon, an output of the current detector 3 that collectively measures a current flowing through the bus BL. Power is supplied to each of the plurality of AC motors 2 by power supply lines BL (U), BL (V), BL (W) of a plurality of phases included in a bus BL. The current detector 3 collectively measures the current of the power supply line BL (U) for at least one of the plurality of phases for the plurality of AC motors 2.
複数の交流電動機2は、複数の交流電動機2に共通する母線によって電源から電力が供給される。たとえば、母線は配電盤中のバスバーであり、バスバーから分岐された電力ケーブルによって個々の交流電動機2に電力が供給される。信号入力部7は、母線BLを流れる電流を一括して計測する電流検出器3の出力を電気信号Smonとして受ける。複数の交流電動機2の各々には、母線BLに含まれる複数相の電源ラインBL(U)、BL(V),BL(W)によって電力が供給される。電流検出器3は、複数相のうちの少なくとも1相分の電源ラインBL(U)の電流を複数の交流電動機2について一括して測定する。 Next, a description will be given from the measurement of the power supply current to the frequency analysis.
The plurality of
信号入力部7は、複数の交流電動機2に関連する電気信号Smonを受ける。周波数解析部9は、信号入力部7を経由して得られた電気信号Smonに対して周波数解析を行なう。周波数解析部9の出力は、割当部10を経由して判定部11に送られ、判定部11において各電動機群における電動機に異常が発生しているか否かの判定に使用される。
The signal input unit 7 receives the electric signals Smon related to the plurality of AC motors 2. The frequency analysis unit 9 performs a frequency analysis on the electric signal Smon obtained via the signal input unit 7. The output of the frequency analysis unit 9 is sent to the determination unit 11 via the allocation unit 10, and is used by the determination unit 11 to determine whether an abnormality has occurred in the motors in each motor group.
周波数解析部9は、周波数解析の手法として高速フーリエ変換(FFT:Fast Fourier Transform)を用いて、パワースペクトルを取得する。割当部10は、パワースペクトルから複数の電動機群の各々に対応する周波数帯の成分を決定する。
The frequency analysis unit 9 acquires a power spectrum by using a fast Fourier transform (FFT) as a frequency analysis technique. The allocating unit 10 determines frequency band components corresponding to each of the plurality of motor groups from the power spectrum.
FFTは、一定時間の電流を測定した後その計測データに周波数解析を実施し、周波数を横軸、パワーを縦軸としたスペクトルを出力する方式である。
FFT is a method of measuring a current for a certain period of time, performing frequency analysis on the measured data, and outputting a spectrum with frequency on the horizontal axis and power on the vertical axis.
複数の電動機の電源電流が重畳した電源ラインの電流をFFTすることによって着目する周波数帯全体の情報を一度に取得することができる。FFTを用いると、電動機を分類する回転速度に変動がある場合または不確かさに起因する幅がある場合に、着目する周波数成分の算出が容易となる。
情報 By performing FFT on the current of the power supply line on which the power supply currents of a plurality of electric motors are superimposed, it is possible to obtain information of the entire frequency band of interest at once. The use of the FFT makes it easy to calculate the frequency component of interest when the rotational speed for classifying the electric motor fluctuates or when there is a range due to uncertainty.
なお、周波数解析部9は、FFT以外の手法によって周波数解析をしても良い。FFT以外の周波数解析手法は、たとえば、離散フーリエ変換(DFT:Discrete Fourier Transform)が挙げられる。DFTは、周波数解析部9の内部で発生させた1つの周波数の正弦波信号と電流検出器3で測定した電流値の積を逐次的に求め、平均値を算出する手法である。DFTは、予め設定した1つの周波数の値のみを求めるため、計算コストが抑えられるという利点がある。その一方で、FFTのように対応する周波数範囲全体を解析するわけではないため、回転速度に無視できない不確かさが見込まれる場合には、複数の周波数成分を計算する必要が生じるため計算コストが増大する。
The frequency analysis unit 9 may perform the frequency analysis by a method other than the FFT. A frequency analysis method other than FFT includes, for example, a discrete Fourier transform (DFT). The DFT is a method of sequentially calculating a product of a sinusoidal signal of one frequency generated inside the frequency analysis unit 9 and a current value measured by the current detector 3, and calculating an average value. The DFT has an advantage that the calculation cost can be reduced because only a predetermined frequency value is obtained. On the other hand, since the entire corresponding frequency range is not analyzed as in the case of the FFT, if the rotational speed is expected to have uncertain uncertainty, it is necessary to calculate a plurality of frequency components, thereby increasing the calculation cost. I do.
続いて、割当部10と判定部11について説明する。割当部10は、周波数解析部9の出力を分類記憶部8の出力に基づいて各電動機群に割り当てる。割当部10は、複数の電動機群の各々に対して周波数解析部9の出力のうち1つの周波数帯の成分を割り当てる。周波数解析部9の出力は複数の周波数成分の大きさをまとめた組であるが、それらの値と各電動機群を結びつけるのが割当部10の機能である。図5は、割当部10の構成を示すブロック図である。割当部10は、周波数帯計算部14と周波数帯抽出部15とを含む。
Next, the assignment unit 10 and the determination unit 11 will be described. The assignment unit 10 assigns the output of the frequency analysis unit 9 to each motor group based on the output of the classification storage unit 8. The allocating unit 10 allocates one frequency band component of the output of the frequency analysis unit 9 to each of the plurality of motor groups. The output of the frequency analysis unit 9 is a set in which the magnitudes of a plurality of frequency components are put together, and the function of the assignment unit 10 is to link those values to each motor group. FIG. 5 is a block diagram illustrating a configuration of the allocating unit 10. Assignment section 10 includes frequency band calculation section 14 and frequency band extraction section 15.
分類記憶部8において分類された各電動機群は、互いに異なる回転速度に対応する。1つの電動機群に属する1つまたは複数の電動機は、その電動機群に対応する同じ回転速度で運転される。また各電動機群に異常が発生した場合にピークが増大する周波数は回転速度から予め計算可能である。周波数帯計算部14は、異常が発生した場合にピークが増大する周波数を分類記憶部8で分類された結果に基づいて電動機群ごとに計算する。
The motor groups classified in the classification storage unit 8 correspond to different rotational speeds. One or more motors belonging to one motor group are operated at the same rotation speed corresponding to the motor group. The frequency at which the peak increases when an abnormality occurs in each motor group can be calculated in advance from the rotation speed. The frequency band calculator 14 calculates the frequency at which the peak increases when an abnormality occurs, for each motor group based on the result of classification by the classification storage unit 8.
なお、分類部12が電動機群に対応する回転速度に幅を持たせて、電動機の分類を行なった場合は、割当部10における周波数の割当においても、回転速度の幅に対応した周波数帯を割り当てる。この場合の周波数帯の割当においては、それぞれの電動機群に対応する周波数帯に重なり合う部分が発生しても問題ない。2つの電動機群の周波数帯が重なる部分に異常ピークが認められた場合には、その2つの電動機群のいずれかに異常が発生している旨を診断結果とすればよい。
When the classifying unit 12 classifies the motors by giving a range to the rotation speed corresponding to the motor group, the frequency band corresponding to the width of the rotation speed is also allocated in the frequency allocation in the allocation unit 10. . In the assignment of the frequency bands in this case, there is no problem even if a portion overlapping the frequency band corresponding to each motor group occurs. If an abnormal peak is found in a portion where the frequency bands of the two motor groups overlap, the diagnosis result may be that any one of the two motor groups has an abnormality.
周波数帯抽出部15は、周波数帯計算部14の出力に基づいて周波数解析部9の出力するパワースペクトルの一部を各電動機群に割り当てる。割当部10は、周波数解析部9がFFTによってパワースペクトルを求めた結果に対して、電動機群ごとの周波数の範囲におけるスペクトルの周波数成分もしくはその最大値を取り出す。割当部10は、この手法の他に、各電動機群に対応する周波数範囲の周波数成分を通過させるバンドパスフィルタを生成し、周波数成分を取り出しても良い。
The frequency band extracting unit 15 allocates a part of the power spectrum output from the frequency analyzing unit 9 to each motor group based on the output of the frequency band calculating unit 14. The allocating unit 10 extracts the frequency component of the spectrum or the maximum value of the spectrum in the frequency range for each motor group from the result of the power spectrum obtained by the frequency analysis unit 9 by the FFT. In addition to this method, the allocating unit 10 may generate a band-pass filter that passes a frequency component in a frequency range corresponding to each motor group, and extract the frequency component.
異常が発生した場合にパワースペクトルのピークが増大する周波数として最も単純な例は、分類記憶部8から出力された回転速度をそのまま周波数で表す場合である。この場合、周波数帯計算部14は、分類記憶部8から得た電動機群に対応する回転速度の値をそのまま周波数に変換して出力する。この他、電動機のある特徴的な異常に着目した周波数の計算をしてもよい。たとえば、軸受で異常が発生した場合にはその異常に基づいて特徴的な振動が発生することが知られており、その周波数は予め計算可能である。
The simplest example of the frequency at which the peak of the power spectrum increases when an abnormality occurs is the case where the rotation speed output from the classification storage unit 8 is directly represented by the frequency. In this case, the frequency band calculation unit 14 converts the rotation speed value corresponding to the motor group obtained from the classification storage unit 8 into a frequency as it is and outputs it. In addition, the frequency may be calculated focusing on a certain characteristic abnormality of the electric motor. For example, it is known that when an abnormality occurs in a bearing, characteristic vibration is generated based on the abnormality, and the frequency can be calculated in advance.
判定部11は、割当部10が出力する電動機群ごとの周波数の範囲におけるスペクトルの周波数成分もしくはその最大値に基づき各電動機群ごとに電動機に異常が発生しているか否かを判定する。より具体的には、判定部11は、割当部10によって割り当てられた周波数帯の成分を用いて複数の電動機群の各々に対して異常の発生の有無を判定する。
The determination unit 11 determines whether or not an abnormality has occurred in a motor for each motor group based on the frequency component of the spectrum in the frequency range for each motor group output by the allocating unit 10 or its maximum value. More specifically, the determination unit 11 determines whether or not an abnormality has occurred in each of the plurality of motor groups using the components of the frequency band allocated by the allocation unit 10.
判定部11は、割当部10の出力する電動機群ごとの周波数の範囲におけるスペクトルの周波数成分もしくはその最大値を予め設定した基準値と比較することで異常の有無の判定を行なう。異常を検出するために各電動機群に割り当てられた成分は、電動機に異常が発生した場合に増加することが知られている。
The determination unit 11 determines whether there is an abnormality by comparing the frequency component of the spectrum or the maximum value thereof in the frequency range for each motor group output by the allocation unit 10 with a preset reference value. It is known that a component assigned to each motor group for detecting an abnormality increases when an abnormality occurs in the motor.
ある一つの電動機群に対応する周波数範囲において特徴的な周波数成分が発生し、かつそれがその電動機群の基準値を上回る場合には、判定部11は、その電動機群内のいずれかの電動機に異常が発生していると判定し、判定結果を出力する。たとえば、図3に示すように、周波数f3の成分が異常判定基準値fth3を超えた場合に、判定部11は、周波数f3に対応する電動機群内のいずれかの電動機に異常が発生していると判定する。
If a characteristic frequency component is generated in a frequency range corresponding to a certain motor group and exceeds a reference value of the motor group, the determination unit 11 determines whether any of the motors in the motor group It is determined that an abnormality has occurred, and a determination result is output. For example, as illustrated in FIG. 3, when the component of the frequency f3 exceeds the abnormality determination reference value fth3, the determination unit 11 causes an abnormality in one of the motors in the motor group corresponding to the frequency f3. Is determined.
また、特徴的な周波数成分が複数の電動機群の周波数帯が重なった部分に発生した場合には、判定部11はそれぞれの電動機群の基準値とその特徴的な周波数成分とを比較し、基準を上回った電動機群に対して電動機に異常が発生していると判定し、判定結果を出力する。このときに複数の電動機群において基準を上回った場合は、判定部11は、それらすべての電動機群において電動機に異常が発生していると判定する。
If a characteristic frequency component occurs in a portion where the frequency bands of a plurality of motor groups overlap, the determination unit 11 compares the reference value of each motor group with the characteristic frequency component, and It is determined that an abnormality has occurred in the motor group for the motor group that exceeds the threshold, and a determination result is output. At this time, when the plurality of motor groups exceed the reference, the determination unit 11 determines that an abnormality has occurred in the motors in all of the motor groups.
図6は、実施の形態1の診断装置における異常診断処理を示すフローチャートである。このフローチャートの処理は、図1の異常診断装置5において実行される。図7は、フローチャートの処理を実行する異常診断装置5の代表的な構成図である。異常診断装置5は、プロセッサ111とメモリ112と入出力インターフェース113とを備える。メモリ112には、図6のフローチャートの処理を実行するプログラムが記憶されている。このプログラムがプロセッサ111に読み込まれ、プロセッサ111が異常診断装置5として動作する。
FIG. 6 is a flowchart showing an abnormality diagnosis process in the diagnostic device of the first embodiment. The processing of this flowchart is executed in the abnormality diagnosis device 5 of FIG. FIG. 7 is a typical configuration diagram of the abnormality diagnosis device 5 that executes the processing of the flowchart. The abnormality diagnosis device 5 includes a processor 111, a memory 112, and an input / output interface 113. The memory 112 stores a program for executing the processing of the flowchart in FIG. This program is read by the processor 111, and the processor 111 operates as the abnormality diagnosis device 5.
図6を参照して、まずステップS1において、異常診断装置5は、交流電動機2の駆動電流を電流検出器3で計測した計測電流を示す信号を信号入力部7で受ける。ステップS2において、異常診断装置5は、信号入力部7で受けた信号に対して周波数解析部9において周波数解析を実施し、ステップS3において、周波数解析結果の一部をあらかじめ分類した電動機群ごとに割り当てる。このときに分類された電動機群の数がn個であったとする。
6, first, in step S <b> 1, abnormality diagnosis device 5 receives, at signal input unit 7, a signal indicating a measured current obtained by measuring the drive current of AC motor 2 with current detector 3. In step S2, the abnormality diagnosis device 5 performs frequency analysis on the signal received by the signal input unit 7 in the frequency analysis unit 9, and in step S3, a part of the frequency analysis result is classified for each motor group classified in advance. assign. It is assumed that the number of motor groups classified at this time is n.
その次に、異常診断装置5は、電動機群ごとに割り当てられた周波数成分から、電動機に異常が発生しているか否かを判定し、判定結果を出力する。具体的には、ステップS4において変数iが1に設定され、異常診断装置5は、i番目の電動機群についてステップS5において割り当てられた周波数成分を評価する。評価においては、異常診断装置5は、周波数成分の大きさが基準値以上の場合には異常発生と判定し、周波数成分の大きさが基準値を超えない場合には正常と判定する。そしてステップS6において異常診断装置5は、判定結果を判定部11から表示部30に出力する。
Next, the abnormality diagnosis device 5 determines whether or not an abnormality has occurred in the motor based on the frequency components assigned to each motor group, and outputs a determination result. Specifically, the variable i is set to 1 in step S4, and the abnormality diagnosis device 5 evaluates the frequency component assigned in step S5 for the i-th motor group. In the evaluation, the abnormality diagnosis device 5 determines that an abnormality has occurred if the magnitude of the frequency component is equal to or greater than the reference value, and determines that the abnormality has occurred if the magnitude of the frequency component does not exceed the reference value. Then, in step S6, the abnormality diagnosis device 5 outputs the determination result from the determination unit 11 to the display unit 30.
ステップS7では、変数iがnに到達するまでインクリメントされ、その結果、1番目からn番目の電動機群について、ステップS5,S6の処理が順次実行される。
In step S7, the variable i is incremented until it reaches n, and as a result, the processing of steps S5 and S6 is sequentially performed for the first to n-th motor groups.
すべての電動機群の判定が終了したら、異常診断装置5は、ステップS8において全体の結果を表示部30に出力し、ステップS9において動作を終了する。
When the determination of all the motor groups is completed, the abnormality diagnosis device 5 outputs the entire result to the display unit 30 in step S8, and ends the operation in step S9.
以上説明したように、実施の形態1の異常診断装置5は、周波数分析を用いて電流波形を電動機群に対応するように割り当てる。複数の電動機に交流電力を供給する母線電流を一括して測定し、回転速度で分類された電動機のグループごとに電動機に異常が発生しているか否かを判定する。このように本実施の形態においては共通する1つの電流検出器3を複数の交流電動機2に対して用いる。このため、多数の電動機が同一の電源で稼動するシステムにおいて、複数の交流電動機2の異常を判定するために使用される電流検出器の数を減らし、診断装置のコストを低減させることができる。
As described above, the abnormality diagnosis device 5 according to the first embodiment assigns a current waveform to a motor group using frequency analysis. Bus currents for supplying AC power to a plurality of electric motors are collectively measured, and it is determined whether an abnormality has occurred in the electric motors for each electric motor group classified by the rotational speed. Thus, in the present embodiment, one common current detector 3 is used for a plurality of AC motors 2. For this reason, in a system in which a large number of electric motors operate on the same power supply, the number of current detectors used for judging abnormalities of the plurality of AC motors 2 can be reduced, and the cost of the diagnostic device can be reduced.
なお、異常診断装置5において実行される異常診断方法では、交流電動機の回転速度が交流の電源周波数と電動機の極数によって定まることを利用しているため、このようにして回転速度が定まる交流電動機一般に対して同様な異常診断方法が適用可能である。たとえば、回転子の永久磁石によって回転する複数の同期電動機、複数の誘導電動機、あるいはそれらの複合系に対しても同様な異常診断方法が適用可能である。
The abnormality diagnosis method executed by the abnormality diagnosis device 5 utilizes the fact that the rotation speed of the AC motor is determined by the AC power supply frequency and the number of poles of the motor, and thus the AC motor whose rotation speed is determined in this manner. A similar abnormality diagnosis method can be applied to general. For example, a similar abnormality diagnosis method can be applied to a plurality of synchronous motors, a plurality of induction motors, or a composite system thereof, which are rotated by permanent magnets of a rotor.
また、上記の異常診断方法は、電流以外の稼働状況が複数台の電動機に対して一括して計測される場合にも適用可能である。図8は、異常診断方法が適用可能な他の例を説明するための図である。たとえば図8のように、2台の交流電動機2が隣接して稼動しており、かつ回転速度が異なる場合、単一の振動センサ16を両方の電動機の振動が検出可能な場所に設置し、振動センサ16によって検出された振動を示す電気信号が異常診断装置5に入力されることで同様の解析が可能になる。このときには、図1の信号入力部7は、複数の交流電動機2が発生する振動を一括して計測する振動センサ16の出力を受ける。
異常 The above-described abnormality diagnosis method can also be applied to a case where operating states other than the electric current are collectively measured for a plurality of electric motors. FIG. 8 is a diagram for explaining another example to which the abnormality diagnosis method can be applied. For example, as shown in FIG. 8, when two AC motors 2 are operating adjacent to each other and have different rotation speeds, a single vibration sensor 16 is installed at a place where the vibrations of both motors can be detected. The same analysis can be performed by inputting an electrical signal indicating the vibration detected by the vibration sensor 16 to the abnormality diagnosis device 5. At this time, the signal input unit 7 in FIG. 1 receives the output of the vibration sensor 16 that collectively measures the vibration generated by the plurality of AC motors 2.
(変形例)
図9は、実施の形態1の変形例における異常診断装置5Aの構成を示す図である。異常診断装置5Aは、情報入力部6から電源周波数f0を入力する代わりに、信号Smonから電源周波数f0を自動的に認識する。異常診断装置5Aは、電源周波数f0に関する情報を情報入力部6から入力する代わりに図9のように周波数解析部9の出力から割当部10を経由して分類記憶部8に送ることができる。電流検出器3で測定した電流の周波数スペクトルを求めたとき、図2、図3に示したように最も大きいのは電源周波数f0の周波数成分であるので、周波数解析時に電源周波数f0がわかるためである。なお、異常診断装置5Aの他の動作については、異常診断装置5と同様であるので、説明は繰り返さない。 (Modification)
FIG. 9 is a diagram showing a configuration of an abnormality diagnosis device 5A according to a modification of the first embodiment. The abnormality diagnosis device 5A automatically recognizes the power supply frequency f0 from the signal Smon instead of inputting the power supply frequency f0 from theinformation input unit 6. The abnormality diagnosis device 5A can send the information on the power supply frequency f0 from the output of the frequency analysis unit 9 to the classification storage unit 8 via the assignment unit 10 as shown in FIG. When the frequency spectrum of the current measured by the current detector 3 is obtained, the largest is the frequency component of the power supply frequency f0 as shown in FIG. 2 and FIG. is there. The other operations of the abnormality diagnosis device 5A are the same as those of the abnormality diagnosis device 5, and thus the description will not be repeated.
図9は、実施の形態1の変形例における異常診断装置5Aの構成を示す図である。異常診断装置5Aは、情報入力部6から電源周波数f0を入力する代わりに、信号Smonから電源周波数f0を自動的に認識する。異常診断装置5Aは、電源周波数f0に関する情報を情報入力部6から入力する代わりに図9のように周波数解析部9の出力から割当部10を経由して分類記憶部8に送ることができる。電流検出器3で測定した電流の周波数スペクトルを求めたとき、図2、図3に示したように最も大きいのは電源周波数f0の周波数成分であるので、周波数解析時に電源周波数f0がわかるためである。なお、異常診断装置5Aの他の動作については、異常診断装置5と同様であるので、説明は繰り返さない。 (Modification)
FIG. 9 is a diagram showing a configuration of an abnormality diagnosis device 5A according to a modification of the first embodiment. The abnormality diagnosis device 5A automatically recognizes the power supply frequency f0 from the signal Smon instead of inputting the power supply frequency f0 from the
このような手法で電源周波数f0を取得した際には、情報入力部6に対する電源周波数f0の入力が不要になり操作が簡便になる。加えて、電源周波数f0が変動した場合には周波数解析部9が検出するスペクトルの電源周波数f0の位置も変化するため、電源周波数f0の変動を反映してより正確に回転速度を求めることができる。
(4) When the power supply frequency f0 is obtained by such a method, the input of the power supply frequency f0 to the information input unit 6 becomes unnecessary, and the operation is simplified. In addition, when the power supply frequency f0 fluctuates, the position of the power supply frequency f0 in the spectrum detected by the frequency analysis unit 9 also changes, so that the rotation speed can be more accurately obtained by reflecting the change in the power supply frequency f0. .
実施の形態2.
交流電動機2が誘導電動機である場合、交流電動機2の各々の回転速度は、電源周波数および電動機の極数だけでは決定できない。回転速度を求めるには、電源周波数および電動機の極数に加えて、交流電動機2ごとのすべりの情報が必要である。このすべりのために、誘導電動機の回転速度は交流電動機2ごとに異なる値をとる。Embodiment 2 FIG.
When theAC motor 2 is an induction motor, the rotation speed of each AC motor 2 cannot be determined only by the power supply frequency and the number of poles of the motor. In order to determine the rotation speed, slip information for each AC motor 2 is required in addition to the power supply frequency and the number of poles of the motor. Due to this slip, the rotation speed of the induction motor takes a different value for each AC motor 2.
交流電動機2が誘導電動機である場合、交流電動機2の各々の回転速度は、電源周波数および電動機の極数だけでは決定できない。回転速度を求めるには、電源周波数および電動機の極数に加えて、交流電動機2ごとのすべりの情報が必要である。このすべりのために、誘導電動機の回転速度は交流電動機2ごとに異なる値をとる。
When the
実施の形態2では、すべりなどの個別の電動機によって異なる稼動の情報を電動機の分類に使用する。そのため、実施の形態1における例よりも細かな電動機群に分類することができるので、異常が発生した電動機の特定が容易になる。
In the second embodiment, information on operation that differs depending on individual motors, such as slips, is used to classify the motors. For this reason, the motors can be classified into groups of motors smaller than those in the example in the first embodiment, and it is easy to specify the motor in which an abnormality has occurred.
交流電動機2が誘導電動機である場合には、情報入力部6に極数Pと電源周波数fに加えてトルクT、電流I、すべりsに関する情報、および誘導電動機の稼動状況に関する情報を入力する必要がある。
When the AC motor 2 is an induction motor, it is necessary to input information on the torque T, the current I, the slip s, and the operation status of the induction motor in addition to the number of poles P and the power supply frequency f to the information input unit 6. There is.
実際の回転速度N(min-1)は、すべりs、極数P、電源周波数fを用いて次式(2)で表すことができる。
N=(1-s)Ns=120(1-s)f/P …(2)
極数Pと電源周波数fは、電動機の銘板から知ることができる。トルクT、電流Iおよびすべりsに関する情報は、電動機のスペックシートから入手可能である。電動機のスペックシートではトルクT、電流Iおよびすべりsの関係が示されており、これらの情報から回転速度を求めることができる。たとえば、50Hz、60Hzなど動作可能な電源周波数が複数ある場合は、実際に稼動させる電源周波数を入力する。実施の形態1の変形例で説明したような電流からの電源周波数値の取得を実施する場合、スペックシートに記載されているトルク、電流およびすべりに関する情報を電源周波数ごとにすべて入力する。 The actual rotation speed N (min -1 ) can be expressed by the following equation (2) using the slip s, the number of poles P, and the power supply frequency f.
N = (1-s) Ns = 120 (1-s) f / P (2)
The number of poles P and the power supply frequency f can be known from the nameplate of the electric motor. Information about the torque T, the current I and the slip s is available from the motor specification sheet. In the specification sheet of the electric motor, the relationship among the torque T, the current I, and the slip s is shown, and the rotation speed can be obtained from the information. For example, when there are a plurality of operable power supply frequencies such as 50 Hz and 60 Hz, the power supply frequency to be actually operated is input. When acquiring the power supply frequency value from the current as described in the modification of the first embodiment, all the information on the torque, current, and slip described in the specification sheet is input for each power supply frequency.
N=(1-s)Ns=120(1-s)f/P …(2)
極数Pと電源周波数fは、電動機の銘板から知ることができる。トルクT、電流Iおよびすべりsに関する情報は、電動機のスペックシートから入手可能である。電動機のスペックシートではトルクT、電流Iおよびすべりsの関係が示されており、これらの情報から回転速度を求めることができる。たとえば、50Hz、60Hzなど動作可能な電源周波数が複数ある場合は、実際に稼動させる電源周波数を入力する。実施の形態1の変形例で説明したような電流からの電源周波数値の取得を実施する場合、スペックシートに記載されているトルク、電流およびすべりに関する情報を電源周波数ごとにすべて入力する。 The actual rotation speed N (min -1 ) can be expressed by the following equation (2) using the slip s, the number of poles P, and the power supply frequency f.
N = (1-s) Ns = 120 (1-s) f / P (2)
The number of poles P and the power supply frequency f can be known from the nameplate of the electric motor. Information about the torque T, the current I and the slip s is available from the motor specification sheet. In the specification sheet of the electric motor, the relationship among the torque T, the current I, and the slip s is shown, and the rotation speed can be obtained from the information. For example, when there are a plurality of operable power supply frequencies such as 50 Hz and 60 Hz, the power supply frequency to be actually operated is input. When acquiring the power supply frequency value from the current as described in the modification of the first embodiment, all the information on the torque, current, and slip described in the specification sheet is input for each power supply frequency.
分類部12は、交流電動機2の電動機群への分類を交流電動機2および機械設備4の本来の稼動前の試験的な稼働の際に実施する。情報入力部6から設備の稼動条件の変更が入力され、変更後の稼動条件を参照して交流電動機2の回転速度が変わると想定される場合は、分類部12は再度分類をやり直す。
The classifying unit 12 classifies the AC motors 2 into motor groups when the AC motors 2 and the mechanical equipment 4 are experimentally operated before the original operation. If a change in the operating condition of the equipment is input from the information input unit 6 and the rotational speed of the AC motor 2 is assumed to change with reference to the changed operating condition, the classifying unit 12 performs the classification again.
図10は、実施の形態2で行なわれる分類処理を説明するためのフローチャートである。交流電動機2が誘導電動機である場合には、電源周波数fと極数Pに加えて、図10に示すように電動機に接続される機械設備を考慮して、分類を行なう。
FIG. 10 is a flowchart for describing the classification processing performed in the second embodiment. When the AC motor 2 is an induction motor, the classification is performed in consideration of the mechanical equipment connected to the motor as shown in FIG. 10 in addition to the power supply frequency f and the number of poles P.
まず、分類部12は、情報入力部6から与えられる設備情報および稼働条件に基づいて、交流電動機2を構成する誘導電動機において、すべての誘導電動機が同じ誘導電動機であり、かつ誘導電動機に接続された機械設備がすべて同じであるかを判断する。具体的には、ステップS21において、電動機と電動機に接続されている負荷すなわち機械設備との組み合わせがすべて同じか否かが判断される。ステップS21において電動機と負荷との組み合わせに異なる組み合わせがあった場合、ステップS22において電動機がすべて同じか否かが判断される。このとき電動機がすべて同じであった場合、ステップS23において負荷の種類で電動機の分類が行なわれる。電動機がすべて同じであれば、機械設備の駆動に必要なトルクの大小がすべりの大小に反映され回転速度の違いとして現れる。ステップS23では、この性質を利用して、接続された機械設備ごとに誘導電動機を電動機群に分類することができる。
First, based on the equipment information and the operating conditions provided from the information input unit 6, the classification unit 12 determines that all the induction motors are the same among the induction motors constituting the AC motor 2 and are connected to the induction motor. Judge whether all the installed machinery and equipment are the same. Specifically, in step S21, it is determined whether or not all combinations of the electric motor and the load connected to the electric motor, that is, the mechanical equipment are the same. If there is a different combination of the electric motor and the load in step S21, it is determined in step S22 whether all the electric motors are the same. At this time, if all the motors are the same, the motors are classified by the type of load in step S23. If the motors are all the same, the magnitude of the torque required to drive the mechanical equipment is reflected in the magnitude of the slip and appears as a difference in the rotational speed. In step S23, by utilizing this property, the induction motor can be classified into a group of motors for each connected mechanical facility.
一方、ステップS22において電源1が駆動する誘導電動機に異なる種類のものが存在する場合(S22でNO)、分類部12は、ステップS24において誘導電動機に接続された機械設備すなわち負荷の種類または仕様がすべて同じであるか否かを判断する。
On the other hand, when there is a different type of induction motor driven by the power supply 1 in step S22 (NO in S22), the classification unit 12 determines in step S24 that the type or specification of the mechanical equipment connected to the induction motor, that is, the type or specification of the load. It is determined whether all are the same.
誘導電動機に接続された機械設備がすべて同じであれば(S24でYES)、分類部12は、機械設備を駆動するために必要なトルクの設備ごとの違いは、機械設備そのものが異なる場合よりも小さいと判断する。したがって、分類部12は、誘導電動機が出力するトルクがどれも同じであるとみなし、稼動情報の一部として入力されたトルクとすべりに関する情報から同じトルクが加えられた場合のすべりの違いを求め、そこから回転速度の違いを求めることができる。ステップS25では、分類部12は、このようにして求められた回転速度の違いによって、誘導電動機を電動機群に分類する。
If all the mechanical equipment connected to the induction motor is the same (YES in S24), the classification unit 12 determines that the difference in torque required to drive the mechanical equipment for each equipment is greater than when the mechanical equipment itself is different. Judge as small. Therefore, the classifying unit 12 considers that the torques output from the induction motors are all the same, and obtains a difference in slip when the same torque is applied from the torque and slip information input as part of the operation information. From this, the difference in rotational speed can be determined. In step S25, the classification unit 12 classifies the induction motors into a group of motors based on the difference in the rotation speeds obtained in this manner.
一方、ステップS24においてNOと判断された場合は、誘導電動機に異なる種類のものが存在し、かつ接続された機械設備にも異なる種類のものが存在する場合である。この場合、誘導電動機と機械設備の組合せごとに設備を駆動する誘導電動機のすべりが異なると考えられる。各機械設備の駆動に必要なトルクの値を見積もることができる場合、見積もったトルクの値と誘導電動機におけるトルクとすべりの関係から各誘導電動機の回転速度を見積もることができる。ステップS26では、分類部12は、この見積もられた回転速度から複数の誘導電動機を電動機群に分類できる。回転速度の見積が困難な場合、必要に応じて個別の測定を実施する。
On the other hand, if NO is determined in step S24, it means that there are different types of induction motors and different types of connected mechanical equipment. In this case, it is considered that the slip of the induction motor that drives the equipment differs for each combination of the induction motor and the mechanical equipment. When the value of the torque required for driving each mechanical facility can be estimated, the rotation speed of each induction motor can be estimated from the estimated torque value and the relationship between the torque and slip in the induction motor. In step S26, the classification unit 12 can classify the plurality of induction motors into a group of motors based on the estimated rotation speed. If it is difficult to estimate the rotation speed, perform individual measurements as needed.
ステップS21からステップS27に処理が進んだ場合は、すべての誘導電動機が同じ誘導電動機であり、かつ誘導電動機に接続された機械設備がすべて同じである場合である。この場合は、誘導電動機または機械設備の違いによる回転速度の区別は不可能である。この場合にも、機械設備の稼働状況によっては誘導電動機の回転速度が異なる場合がある。
When the process proceeds from step S21 to step S27, all the induction motors are the same induction motor, and all the mechanical equipment connected to the induction motor is the same. In this case, it is impossible to distinguish the rotation speed by the difference between the induction motor or the mechanical equipment. Also in this case, the rotation speed of the induction motor may be different depending on the operation state of the mechanical equipment.
したがって、ステップS27においては、電動機を個別に計測可能か否かが判断される。電動機を個別に計測可能な場合とは、個別の電動機に回転速度計、トルクセンサ、電流計などが設けられており、回転速度、トルク等のデータを計測可能な場合である。電動機を個別に計測可能な場合、個別に計測した結果によって回転速度を算出することができる。
Therefore, in step S27, it is determined whether the electric motor can be measured individually. The case where the electric motors can be individually measured is a case where the individual electric motors are provided with a tachometer, a torque sensor, an ammeter, and the like, and can measure data such as a rotation speed and a torque. If the motors can be measured individually, the rotation speed can be calculated based on the results of the individual measurements.
個別に計測する場合、最も直接的なのは回転速度の計測である。したがってステップS28において、異常診断装置5は、まず回転速度の計測が可能か否かを判断する。各誘導電動機の速度が計測できれば(S28でYES)、ステップS29では回転速度の測定値に基づいて各誘導電動機を電動機群に分類することができる。
場合 When measuring individually, the most direct is the measurement of the rotational speed. Therefore, in step S28, the abnormality diagnosis device 5 first determines whether or not the rotation speed can be measured. If the speed of each induction motor can be measured (YES in S28), in step S29, each induction motor can be classified into a motor group based on the measured value of the rotation speed.
回転速度の計測が不可能な場合(S28でNO)、次にステップS30において異常診断装置5は、電動機のトルクの計測が個別に可能か否かを判断する。トルクが計測できれば(S30でYES)、ステップS31において、誘導電動機の仕様から回転速度を求めることができる。トルクの測定が不可能な場合(S30でNO)、ステップS32において、異常診断装置5は、誘導電動機を駆動する電流を個別に測定する。ステップS32では、駆動電流の振幅あるいは実効値を用いて、誘導電動機の仕様に関する情報を参照して誘導電動機のすべりおよび回転速度を求めることができる。
If the rotation speed cannot be measured (NO in S28), then in step S30, abnormality diagnosis device 5 determines whether it is possible to individually measure the torque of the electric motor. If the torque can be measured (YES in S30), in step S31, the rotation speed can be obtained from the specifications of the induction motor. If the torque cannot be measured (NO in S30), in step S32, abnormality diagnosis device 5 individually measures the current for driving the induction motor. In step S32, the slip and rotation speed of the induction motor can be obtained by referring to the information on the specification of the induction motor using the amplitude or the effective value of the drive current.
ステップS29,S31,S32のいずれかの計測を実施した場合、計測して得られた情報は、情報入力部6から分類部12に導入される。
(4) When any of the measurements in steps S29, S31, and S32 is performed, information obtained by the measurement is introduced from the information input unit 6 to the classification unit 12.
ステップS29,S31,S32のいずれかの計測がいずれも不可能な場合は(S27でNO)、誘導電動機の複数の電動機群への分類は、不可能と判断される。その場合、ステップS33においては、すべての誘導電動機が1つの電動機群として分類される。
If all of the measurements in steps S29, S31, and S32 are impossible (NO in S27), it is determined that classification of the induction motor into a plurality of motor groups is impossible. In that case, in step S33, all the induction motors are classified as one motor group.
なお、上記の分類において使用する回転速度の値が変動する場合、または回転速度の値が不確かである場合は、各誘導電動機が取りうる回転速度の範囲を指定して電動機群に分類することができる。
If the value of the rotation speed used in the above classification fluctuates, or if the value of the rotation speed is uncertain, the range of rotation speeds that each induction motor can take may be specified and classified into a group of motors. it can.
たとえば、機械設備を駆動する際のトルクの取りうる範囲の値またはそれを見積もった値の範囲がわかっている場合、その範囲と誘導電動機の仕様におけるすべりの情報から、回転速度の取りうる範囲を求めることができる。
For example, if the value of the range in which the torque can be taken when driving mechanical equipment or the range of the estimated value is known, the range in which the rotation speed can be taken from the range and the slip information in the specifications of the induction motor is determined. You can ask.
その際、各電動機群に対応する回転速度の範囲に重なり合う部分があっても問題ない。ただし複数の電動機群に対応する回転速度の範囲が完全に一致する場合は、それらを同一の電動機群として分類しなおす。
際 At this time, there is no problem even if there is a portion that overlaps the range of the rotational speed corresponding to each motor group. However, if the ranges of the rotational speeds corresponding to the plurality of motor groups completely match, they are reclassified as the same motor group.
以上説明したように、実施の形態2では、実施の形態1よりも個別の電動機の稼働状況を詳しく考慮して電動機の分類を行なうため、分類が細分化されるので、異常が発生している電動機を特定することが容易となる。
As described above, in the second embodiment, the motors are classified in consideration of the operating state of the individual motor in more detail than in the first embodiment, so that the classification is subdivided and an abnormality occurs. It becomes easy to specify the motor.
実施の形態3.
ベルト、ギヤ、チェーンなどの機械設備の動力伝達機構には、異常が発生した際に特徴的な周波数の振動を発生する場合がある。この振動の周波数に関する情報を情報入力部6から分類記憶部8に保存することで、電動機が駆動する機械設備の動力伝達機構に対する異常判定が可能になる。Embodiment 3 FIG.
Power transmission mechanisms of mechanical equipment such as belts, gears, and chains sometimes generate characteristic frequency vibrations when an abnormality occurs. By storing information on the frequency of this vibration from theinformation input unit 6 to the classification storage unit 8, it is possible to determine an abnormality in the power transmission mechanism of the mechanical equipment driven by the electric motor.
ベルト、ギヤ、チェーンなどの機械設備の動力伝達機構には、異常が発生した際に特徴的な周波数の振動を発生する場合がある。この振動の周波数に関する情報を情報入力部6から分類記憶部8に保存することで、電動機が駆動する機械設備の動力伝達機構に対する異常判定が可能になる。
Power transmission mechanisms of mechanical equipment such as belts, gears, and chains sometimes generate characteristic frequency vibrations when an abnormality occurs. By storing information on the frequency of this vibration from the
複数の機械設備の異常をそれらの動力源である電動機の電流を一括して測定することで実現する場合、実施の形態1のように機械設備の動力伝達機構を「電動機群」と同様に「動力伝達機構群」に分類する必要がある。このとき分類の基準となる指標が必要である。この指標としては当該動力伝達機構の振動周波数が適当である。この振動周波数を事前に計算するには、当該動力伝達機構を駆動する電動機の回転速度に加えて、当該動力伝達機構に特徴的なパラメータが必要である。
When an abnormality of a plurality of mechanical equipment is realized by collectively measuring the current of a motor as a power source of the equipment, the power transmission mechanism of the mechanical equipment is set to “ Power transmission mechanism group ". At this time, an index serving as a reference for classification is required. The vibration frequency of the power transmission mechanism is appropriate as this index. In order to calculate this vibration frequency in advance, in addition to the rotation speed of the electric motor that drives the power transmission mechanism, parameters characteristic of the power transmission mechanism are required.
ここで注意すべきは、電動機の異常判定の場合と同様に、機械設備およびその故障モードの組合せによっては異なる設備から同じ周波数の振動が発生する場合があることである。そのため同じ「動力伝達機構群」にチェーンとベルトなど、異なる種類の動力伝達機構が分類されることがある。
注意 It should be noted here that, as in the case of the motor abnormality determination, vibrations of the same frequency may be generated from different equipment depending on the combination of the mechanical equipment and its failure mode. Therefore, different types of power transmission mechanisms, such as a chain and a belt, may be classified into the same “power transmission mechanism group”.
このようにして計算した振動周波数ごとに動力伝達機構を分類することで実施の形態1および2と同様に複数の動力伝達機構の異常診断を実施できる。この異常診断は複数の電動機に対する異常診断と同様に「動力伝達機構群」に対する異常診断となる。すなわち、各「動力伝達機構群」ごとに異常が発生した設備が無いかの判定を行うものである。このときの異常診断装置の動作は図11のステップS51~S59に示すようになり、実施の形態1で図6のステップS1~S9で説明した手順と同様である。
分類 By classifying the power transmission mechanisms for each vibration frequency calculated in this way, it is possible to diagnose an abnormality of a plurality of power transmission mechanisms as in the first and second embodiments. This abnormality diagnosis is an abnormality diagnosis for the “power transmission mechanism group” in the same manner as the abnormality diagnosis for a plurality of electric motors. That is, it is determined for each “power transmission mechanism group” whether there is any equipment in which an abnormality has occurred. The operation of the abnormality diagnosis device at this time is as shown in steps S51 to S59 in FIG. 11, and is the same as the procedure described in steps S1 to S9 in FIG. 6 in the first embodiment.
機械設備の動力伝達機構として交流電動機にベルトが接続されている場合、交流電動機を駆動する電流の計測によってベルトの亀裂の兆候を検出することができる。この場合、動力伝達機構に特徴的なパラメータとして電動機に接続されたプーリの径の大きさの値が必要である。
場合 When a belt is connected to an AC motor as a power transmission mechanism of mechanical equipment, a sign of a crack in the belt can be detected by measuring a current for driving the AC motor. In this case, a value of the diameter of the pulley connected to the electric motor is required as a characteristic parameter of the power transmission mechanism.
なお、この動力伝達機構群に対する異常診断は、周波数解析および各成分の割り当ての手法が電動機群に対する異常診断と全く同等であることから、電動機群に対する異常診断と並行して実施することが可能である。その場合、異常診断装置の動作は図12のステップS61~S73に示すようになる。この場合、ある出力が一部の電動機群と一部の動力伝達機構群の両方に割当てられることもある。なお図12では先に電動機群の異常判定(S64~S67)を実施したあとに動力伝達機構群の異常判定(S68~S71)を実施しているが、これらの異常判定の順番を入れ替えた動作も可能である。
The abnormality diagnosis for the power transmission mechanism group can be performed in parallel with the abnormality diagnosis for the motor group because the frequency analysis and the method of assigning each component are exactly the same as the abnormality diagnosis for the motor group. is there. In this case, the operation of the abnormality diagnosis device is as shown in steps S61 to S73 in FIG. In this case, a certain output may be assigned to both some motor groups and some power transmission mechanism groups. In FIG. 12, the abnormality determination (S68 to S71) of the power transmission mechanism group is performed after the abnormality determination (S64 to S67) of the motor group is performed first. Is also possible.
実施の形態4.
実施の形態4では、異常を判定するための基準値の決め方を特定する。Embodiment 4 FIG.
In the fourth embodiment, how to determine a reference value for determining abnormality is specified.
実施の形態4では、異常を判定するための基準値の決め方を特定する。
In the fourth embodiment, how to determine a reference value for determining abnormality is specified.
異常を判定するための基準値として、基準値に対応する電動機群において電動機に異常が発生していないとわかっている場合の測定データを使用することができる。以下では、この「電動機群において電動機に異常が発生していない場合」を「正常な場合」と呼ぶ。
測定 As the reference value for determining the abnormality, measurement data obtained when it is known that no abnormality has occurred in the motor in the group of motors corresponding to the reference value can be used. Hereinafter, this “case where no abnormality has occurred in the electric motor in the electric motor group” is referred to as “normal case”.
電動機群に属する電動機に異常が発生しない限りは、その電動機群に割り当てられた周波数成分の大きさも変化しない。したがって、正常な場合の値との有意な差が電動機群に割り当てられた周波数成分に検出された場合に、その電動機群を異常と判定することができる。正常な場合のデータを基準に用いる手法は、各電動機群に対応した基準値を設定しやすいという利点がある。以下、図13、図14を用いて、過去のデータを記憶する処理を実行する場合と、実際の稼働時に異常診断を行なう場合とに分けて、判定部11の信号の流れをそれぞれ説明する。
(4) As long as no abnormality occurs in the motors belonging to the motor group, the magnitude of the frequency component assigned to the motor group does not change. Therefore, when a significant difference from the value in the normal case is detected in the frequency component assigned to the motor group, the motor group can be determined to be abnormal. The technique of using data in a normal case as a reference has an advantage that a reference value corresponding to each motor group can be easily set. The signal flow of the determination unit 11 will be described below with reference to FIG. 13 and FIG. 14 separately for a case where processing for storing past data is executed and a case where abnormality diagnosis is performed during actual operation.
図13は、実施の形態4において過去のデータを記憶する処理を行なう場合の判定部11の構成および信号の流れを示すブロック図である。判定部11は、正常な場合との比較によって電動機群の異常を判定する。判定部11は、図13のように過去のデータを記憶するデータ記憶部17と、データ比較部18とを含む。
FIG. 13 is a block diagram showing a configuration of determination unit 11 and a flow of signals when processing for storing past data is performed in the fourth embodiment. The determination unit 11 determines the abnormality of the motor group by comparing with a normal case. The determination unit 11 includes a data storage unit 17 that stores past data as shown in FIG. 13 and a data comparison unit 18.
データ記憶部17は、正常な場合の電動機に対する測定で得られた信号を信号入力部7、周波数解析部9、割当部10で処理することで得られた各電動機群に割り当てられた量を記憶するように構成される。
The data storage unit 17 stores an amount allocated to each motor group obtained by processing a signal obtained by measurement of the motor in a normal case by the signal input unit 7, the frequency analysis unit 9, and the allocation unit 10. It is configured to
この過去のデータの記憶処理における正常な場合のデータの取得は、分類部12による交流電動機2の電動機群への分類と同様に交流電動機2および機械設備4の本来の稼動の前に実施する。
取得 Acquisition of normal data in the past data storage process is performed before the original operation of the AC motor 2 and the mechanical equipment 4 in the same manner as the classification of the AC motors 2 into the motor group by the classification unit 12.
図14は、実施の形態4において実際の稼働時に異常診断を行なう場合の判定部の構成および信号の流れを示すブロック図である。正常な場合のデータを取得した後の実際の稼動時には、データ比較部18は、図14のようにデータ記憶部17の出力と割当部10の出力とを比較することで各電動機群において電動機に異常が発生しているか否かを判定する。
FIG. 14 is a block diagram showing a configuration of a determination unit and a flow of signals when performing an abnormality diagnosis during actual operation in the fourth embodiment. At the time of actual operation after acquiring data in a normal case, the data comparison unit 18 compares the output of the data storage unit 17 with the output of the allocation unit 10 as shown in FIG. It is determined whether an abnormality has occurred.
なお、各電動機群に割り当てられた成分の大きさにばらつきが見込まれる場合には、ばらつきの幅を見込んだ判定を実施してもよい。その場合は図13に示すように割当部10が出力する実際の稼動時におけるデータをデータ記憶部17に記憶させ、割り当てられた周波数成分のばらつきの情報を取得する。データ記憶部17は、このバラツキ情報を反映させて定期的に基準値を更新する。更新された基準値は、図14に示すようにデータ記憶部17からデータ比較部18に与えられる。割当部10の出力である電動機群に割り当てられた周波数成分が、ばらつき分のマージンを反映させた基準値を上回った場合、判定部11はその電動機群において電動機に異常が発生していると判定する。
If the magnitude of the component assigned to each motor group is expected to vary, the determination may be made in consideration of the variation width. In that case, as shown in FIG. 13, the data at the time of actual operation output from the allocating unit 10 is stored in the data storage unit 17, and information on the variation of the allocated frequency components is obtained. The data storage unit 17 periodically updates the reference value by reflecting the variation information. The updated reference value is provided from the data storage unit 17 to the data comparison unit 18 as shown in FIG. When the frequency component assigned to the motor group, which is the output of the allocating unit 10, exceeds the reference value reflecting the variation margin, the determination unit 11 determines that an abnormality has occurred in the motor in the motor group. I do.
以上説明したように、実施の形態4では、図13および図14に示すように、判定部11は、複数の電動機群の各々に対して、交流電動機に異常が発生していない場合のデータを記憶するデータ記憶部17と、データ記憶部17に記憶されたデータを判定の基準とし、データに対応するパワースペクトルと過去の状態よりも後に周波数解析部9が演算したパワースペクトルとを比較するデータ比較部18とを含む。
As described above, in the fourth embodiment, as shown in FIGS. 13 and 14, determination unit 11 outputs data when no abnormality has occurred in the AC motors for each of the plurality of motor groups. A data storage unit 17 to be stored, and data for comparing a power spectrum corresponding to the data with a power spectrum calculated by the frequency analysis unit 9 after the past state using the data stored in the data storage unit 17 as a criterion for determination. And a comparing unit 18.
このような構成とすることによって、回転速度で分類された電動機群ごとに異常を判定するための基準が設定しやすくなる。
With such a configuration, it is easy to set a reference for determining an abnormality for each motor group classified by the rotation speed.
今回開示された実施の形態は、すべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は、上記した実施の形態の説明ではなくて請求の範囲によって示され、請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。
実 施 The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description of the embodiments, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
1 電源、2 交流電動機、2A,2B,2N 電動機、3 電流検出器、4,4A,4N 機械設備、5 異常診断装置、6 情報入力部、7 信号入力部、8 分類記憶部、9 周波数解析部、10 割当部、11 判定部、12 分類部、13 記憶部、14 周波数帯計算部、15 周波数帯抽出部、16 振動センサ、17 データ記憶部、18 データ比較部、111 プロセッサ、112 メモリ、113 入出力インターフェース、BL 母線、BL(U),BL(V),BL(W) 電源ライン。
1 power supply, 2 AC motor, 2A, 2B, 2N motor, 3 current detector, 4, 4A, 4N mechanical equipment, 5 abnormality diagnosis device, 6 装置 information input unit, 7 signal input unit, 8 classification storage unit, 9 frequency analysis , 10 assignment unit, 11 judgment unit, 12 classification unit, 13 storage unit, 14 frequency band calculation unit, 15 frequency band extraction unit, 16 vibration sensor, 17 data storage unit, 18 data comparison unit, 111 processor, 112 memory, 113 {input / output interface, BL} bus, BL (U), BL (V), BL (W)} power supply line.
Claims (13)
- 複数の交流電動機、または複数の交流電動機にそれぞれ接続された複数の機械設備に動力を伝達する複数の動力伝達機構を複数の診断対象として異常を診断する異常診断装置であって、
前記複数の交流電動機のうちの少なくとも1台は、他のいずれか1台の交流電動機と異なる回転速度で運転され、
前記複数の診断対象を回転速度に基づいて複数の診断対象群に分類した分類結果を記憶する分類記憶部と、
前記複数の交流電動機に関連する電気信号を受ける信号入力部と、
前記信号入力部を経由して得られた前記電気信号に対して周波数解析を行なう周波数解析部と、
前記複数の診断対象群の各々に対して前記周波数解析部の出力のうち1つの周波数帯の成分を割り当てる割当部と、
前記割当部によって割り当てられた周波数帯の成分を用いて前記複数の診断対象群の各々に対して異常の発生の有無を判定する判定部とを備える、異常診断装置。 A plurality of AC motors, or an abnormality diagnosis device for diagnosing an abnormality with a plurality of power transmission mechanisms for transmitting power to a plurality of mechanical equipment connected to the plurality of AC motors as a plurality of diagnosis targets,
At least one of the plurality of AC motors is operated at a rotation speed different from any one of the other AC motors,
A classification storage unit that stores a classification result obtained by classifying the plurality of diagnosis targets into a plurality of diagnosis target groups based on a rotation speed;
A signal input unit for receiving an electric signal related to the plurality of AC motors;
A frequency analysis unit that performs frequency analysis on the electric signal obtained via the signal input unit,
An allocating unit that allocates a component of one frequency band among outputs of the frequency analysis unit to each of the plurality of diagnosis target groups;
An abnormality diagnosis device comprising: a determination unit configured to determine whether or not an abnormality has occurred in each of the plurality of diagnosis target groups using a component of a frequency band allocated by the allocation unit. - 前記複数の診断対象は、前記複数の交流電動機であり、
前記分類記憶部は、前記複数の交流電動機を回転速度に基づいて複数の電動機群に分類した分類結果を記憶し、
前記割当部は、前記複数の電動機群の各々に対して前記周波数解析部の出力のうち1つの周波数帯の成分を割り当て、
前記判定部は、前記割当部によって割り当てられた周波数帯の成分を用いて前記複数の電動機群の各々に対して異常の発生の有無を判定する、請求項1に記載の異常診断装置。 The plurality of diagnosis targets are the plurality of AC motors,
The classification storage unit stores a classification result obtained by classifying the plurality of AC motors into a plurality of motor groups based on a rotation speed,
The allocating unit allocates one frequency band component of the output of the frequency analysis unit to each of the plurality of motor groups,
The abnormality diagnosis device according to claim 1, wherein the determination unit determines whether or not an abnormality has occurred in each of the plurality of motor groups using a component of a frequency band allocated by the allocation unit. - 前記複数の交流電動機は、前記複数の交流電動機に共通する母線によって電源から電力が供給され、
前記信号入力部は、前記母線を流れる電流を計測する電流検出器の出力を前記電気信号として受ける、請求項2に記載の異常診断装置。 The plurality of AC motors are supplied with power from a power supply by a bus common to the plurality of AC motors,
The abnormality diagnosis device according to claim 2, wherein the signal input unit receives, as the electric signal, an output of a current detector that measures a current flowing through the bus. - 前記複数の交流電動機の各々は、前記母線に含まれる複数相の電源ラインによって電力が供給される誘導電動機であり、
前記電流検出器は、前記複数相のうちの少なくとも1相分の電流を前記複数の交流電動機について測定する、請求項3に記載の異常診断装置。 Each of the plurality of AC motors is an induction motor to which power is supplied by a multi-phase power line included in the bus,
4. The abnormality diagnosis device according to claim 3, wherein the current detector measures a current of at least one of the plurality of phases for the plurality of AC motors. 5. - 前記信号入力部は、前記複数の交流電動機が発生する振動が共に伝わる場所の振動を計測する振動センサの出力を前記電気信号として受ける、請求項2に記載の異常診断装置。 The abnormality diagnosis device according to claim 2, wherein the signal input unit receives, as the electric signal, an output of a vibration sensor that measures a vibration at a place where vibrations generated by the plurality of AC motors are transmitted together.
- 前記周波数解析部は、前記周波数解析の手法として高速フーリエ変換を用いて前記電気信号のパワースペクトルの取得を実行し、
前記割当部は、前記パワースペクトルから前記複数の電動機群の各々に対応する周波数帯の成分を決定する、請求項2~5のいずれか1項に記載の異常診断装置。 The frequency analysis unit executes the acquisition of the power spectrum of the electric signal using a fast Fourier transform as a method of the frequency analysis,
The abnormality diagnosis device according to any one of claims 2 to 5, wherein the allocating unit determines a frequency band component corresponding to each of the plurality of motor groups from the power spectrum. - 前記判定部は、
前記複数の電動機群の各々に対して、交流電動機に異常が発生していない過去の状態での前記周波数解析部の周波数解析の結果を示すデータを記憶するデータ記憶部と、
前記データ記憶部に記憶された前記データを判定の基準とし、前記データに対応するパワースペクトルと前記過去の状態よりも後に前記周波数解析部が演算したパワースペクトルとを比較するデータ比較部とを含む、請求項2~6のいずれか1項に記載の異常診断装置。 The determination unit includes:
For each of the plurality of motor groups, a data storage unit that stores data indicating a result of the frequency analysis of the frequency analysis unit in the past state where no abnormality has occurred in the AC motor,
The data stored in the data storage unit is used as a criterion for determination, and includes a data comparison unit that compares a power spectrum corresponding to the data with a power spectrum calculated by the frequency analysis unit after the past state. The abnormality diagnosis device according to any one of claims 2 to 6. - 前記分類記憶部は、前記複数の動力伝達機構をそれぞれ駆動する複数の交流電動機の回転速度および前記複数の動力伝達機構の特徴パラメータに基づいて、前記複数の動力伝達機構を複数の動力伝達機構群に分類した分類結果を記憶し、
前記割当部は、前記複数の動力伝達機構群の各々に対して前記周波数解析部の出力のうち1つの周波数帯の成分を割り当て、
前記判定部は、前記割当部によって割り当てられた周波数帯の成分を用いて前記複数の動力伝達機構群の各々に対して異常の発生の有無を判定する、請求項1に記載の異常診断装置。 The classification storage unit stores the plurality of power transmission mechanisms in a plurality of power transmission mechanism groups based on rotation speeds of a plurality of AC motors respectively driving the plurality of power transmission mechanisms and characteristic parameters of the plurality of power transmission mechanisms. Memorize the classification result classified into
The allocating unit allocates a component of one frequency band among outputs of the frequency analysis unit to each of the plurality of power transmission mechanism groups,
The abnormality diagnosis device according to claim 1, wherein the determination unit determines whether or not an abnormality has occurred in each of the plurality of power transmission mechanism groups using a component of a frequency band allocated by the allocation unit. - 前記複数の交流電動機は、前記複数の交流電動機に共通する母線によって電源から電力が供給され、
前記信号入力部は、前記母線を流れる電流を計測する電流検出器の出力を前記電気信号として受ける、請求項8に記載の異常診断装置。 The plurality of AC motors are supplied with power from a power supply by a bus common to the plurality of AC motors,
The abnormality diagnosis device according to claim 8, wherein the signal input unit receives, as the electric signal, an output of a current detector that measures a current flowing through the bus. - 前記複数の交流電動機に接続された機械設備の少なくとも1つが動力伝達機構としてベルトを備え、
前記分類記憶部は、前記ベルトを駆動する交流電動機の回転速度および前記ベルトの長さから定まる振動周波数に基づいて動力伝達機構を分類した分類結果を記憶する、請求項9に記載の異常診断装置。 At least one of the mechanical equipment connected to the plurality of AC motors includes a belt as a power transmission mechanism,
The abnormality diagnosis device according to claim 9, wherein the classification storage unit stores a classification result obtained by classifying a power transmission mechanism based on a rotation frequency of an AC motor driving the belt and a vibration frequency determined from a length of the belt. . - 前記信号入力部は、前記複数の動力伝達機構が発生する振動が共に伝わる場所の振動を計測する振動センサの出力を前記電気信号として受ける、請求項9に記載の異常診断装置。 The abnormality diagnosis device according to claim 9, wherein the signal input unit receives, as the electric signal, an output of a vibration sensor that measures a vibration at a place where the vibrations generated by the power transmission mechanisms are transmitted together.
- 前記周波数解析部は、前記周波数解析の手法として高速フーリエ変換を用いて前記電気信号のパワースペクトルの取得を実行し、
前記割当部は、前記パワースペクトルから前記複数の動力伝達機構群の各々に対応する周波数帯の成分を決定する、請求項9~11のいずれか1項に記載の異常診断装置。 The frequency analysis unit executes the acquisition of the power spectrum of the electric signal using a fast Fourier transform as a method of the frequency analysis,
The abnormality diagnosis device according to claim 9, wherein the allocating unit determines a frequency band component corresponding to each of the plurality of power transmission mechanism groups from the power spectrum. - 前記判定部は、
前記複数の動力伝達機構群の各々に対して、交流電動機に異常が発生していない過去の状態での前記周波数解析部の周波数解析の結果を示すデータを記憶するデータ記憶部と、
前記データ記憶部に記憶された前記データを判定の基準とし、前記データに対応するパワースペクトルと前記過去の状態よりも後に前記周波数解析部が演算したパワースペクトルとを比較するデータ比較部とを含む、請求項9~12のいずれか1項に記載の異常診断装置。 The determination unit includes:
For each of the plurality of power transmission mechanism group, a data storage unit that stores data indicating the result of the frequency analysis of the frequency analysis unit in the past state where no abnormality has occurred in the AC motor,
The data stored in the data storage unit is used as a criterion for determination, and includes a data comparison unit that compares a power spectrum corresponding to the data with a power spectrum calculated by the frequency analysis unit after the past state. An abnormality diagnosis device according to any one of claims 9 to 12.
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- 2019-05-09 JP JP2020538173A patent/JP6999823B2/en active Active
- 2019-05-09 WO PCT/JP2019/018486 patent/WO2020039661A1/en active Application Filing
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WO2014156386A1 (en) * | 2013-03-29 | 2014-10-02 | 三菱電機株式会社 | Electric motor diagnosis device and switching device |
WO2016151708A1 (en) * | 2015-03-20 | 2016-09-29 | 株式会社日立製作所 | Breakdown detection device and breakdown detection method for electrical appliance |
WO2018109993A1 (en) * | 2016-12-15 | 2018-06-21 | 三菱電機株式会社 | Abnormality diagnostic device for power transmission mechanism, and abnormality diagnostic method for power transmission mechanism |
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TWI772085B (en) * | 2020-07-01 | 2022-07-21 | 日商日立產機系統股份有限公司 | Power transmission mechanism management device and power transmission mechanism management method |
WO2022176730A1 (en) * | 2021-02-19 | 2022-08-25 | 三菱パワー株式会社 | Diagnosis system, diagnosis method, and program |
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JPWO2020039661A1 (en) | 2021-08-10 |
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