CN103901301B - The method for diagnosing faults of converter - Google Patents

Abstract

Disclose a kind of Converter Fault Diagnosis method.Described method for diagnosing faults includes: whether detection converter is in stopped status; when detecting that converter is shut down; controller starts the parts of converter one by one; and judge whether corresponding parts break down by the running status of the intrinsic sensor detection converter parts of described converter, and position the source of trouble.Converter Fault Diagnosis method according to present inventive concept, utilize the intrinsic controller of converter and sensor, by making converter work in fault diagnosis model, and start the parts of converter the most one by one, compare with classical feedback signal according to actual feedback signal and realize fault diagnosis, thus avoid influencing each other between converter subsystem, and then not only achieve Converter Fault Diagnosis, the most preferably take into account the requirement reducing cost with improving versatility.

Description

The method for diagnosing faults of converter

Technical field

The present invention relates to field of power electronics, more particularly, relate to a kind of Converter Fault Diagnosis method.

Background technology

Frequency conversion speed-adjusting system converts and uses digital frequency conversion controlling party by AC-DC-alternating electromotive force electronics Formula realizes rotating speed or the direct torque of accurate motor.This kind of control mode and traditional fixed-frequency control mode Compare, substantially reduce energy resource consumption.Therefore, frequency conversion speed-adjusting system be widely used in all kinds of electromotor, The control field of motor.

When faults such as in converter, generating device lost efficacy, cable connection is abnormal, converter can quit work And quote fault message.Due to the complexity of frequency changer, the fault of single part frequently can lead to become Frequently multiple component workings of device are abnormal, thus produce substantial amounts of fault message.Such as, the event of parts Barrier, can cause the parts being the most directly and/or indirectly connected all to quote fault.Substantial amounts of fault message can be covered Lid primary fault parts, increase the degree of difficulty searching fault.

In order to detect fault in prior art, the main following two fault detection approach that uses: 1) increase volume Outer sensor and fault monitoring device；2) frequency converter failure of expert system database debug is set up Information.First kind of way, although can preferably realize troubleshooting and can be at converter in theory Synchronous detecting in work process, but trouble-shooter and related sensor and the controller in converter Cost is substantially suitable, and therefore its deficiency is that economy is poor.The second way, fault detect structure is accurate Property depend on the experience of designer, and if converter recurring structure change, corresponding signal characteristic and therefore Barrier infologic relation also can change, and needs to re-establish principle of classification and Relational database, method Versatility is restricted.

In view of the above-mentioned problems in the prior art, need a kind of fault diagnosis technology succinct, efficient Quickly to position fault.

Summary of the invention

In view of the above-mentioned problems in the prior art, present inventive concept for Converter Fault Diagnosis side Method provides the controller intrinsic based on converter and sensor, runs each subsystem of converter one by one System (or parts) also compares with classical feedback signal according to actual feedback signal and realizes fault diagnosis.

The one side of the exemplary embodiment according to the present invention, it is provided that a kind of Converter Fault Diagnosis method. Described application of frequency converter is in the frequency conversion speed-adjusting system of motor-converter-electrical network composition, and described converter includes control Make the controller of described converter and intrinsic sensor.Described method for diagnosing faults comprises the steps: inspection Surveying whether converter is in stopped status, when detecting that converter is shut down, controller starts frequency conversion one by one The parts of device, and by described converter intrinsic sensor detection converter parts running status sentence Whether disconnected corresponding parts break down, and position the source of trouble.

Preferably, the motor side conversion that described converter also includes dc bus, is connected on dc bus Device and grid side changer, it is connected to the motor side chopper of motor side changer, is connected to grid side and becomes Precharge loop that the grid side chopper of parallel operation and grid side chopper are connected in parallel and dc bus Support Capacitor, wherein, stopped status represents that motor side chopper and grid side chopper are in disconnection shape State, motor side changer, grid side changer quit work.

Preferably, the step of the location source of trouble includes: whether detection electrical network breaks down；If it is determined that electrical network Not breaking down in side, then is pre-charged dc bus and Support Capacitor by described precharge loop, Whether detection dc bus and Support Capacitor break down；If it is determined that dc bus and Support Capacitor are not sent out Raw fault, then stop the precharge in described precharge loop, closes grid side chopper, and detects electrical network Whether side converter breaks down；If it is determined that grid side changer does not break down, then detection braking is single Whether unit breaks down, and if it is determined that brake unit does not break down, then detection motor side changer is No break down.

Preferably, the step of state of detection electrical network includes: the absolute value of three-phase voltage based on electrical network, The state of at least one the detection electrical network in mains frequency and electrical network electromotive force.

Preferably, the step of the state of detection dc bus and Support Capacitor includes: start based on precharge The magnitude of voltage of the dc bus at rear different time points calculates the capacitance of dc bus, and based on calculating Capacitance detection dc bus and the state of Support Capacitor.

Preferably, the step of detection grid side transducer status includes: when working based on grid side changer The state of detection of characteristic parameters grid side changer.

Preferably, the step of the state of detection brake unit includes: apply pulse PWM to brake unit Signal, and based on brake unit, described pwm signal is responded to the state of detection brake unit.

Preferably, the step of detection detection motor side transducer status includes: apply to motor side changer Pulse pwm signal, and flow through the electric current of motor side changer based in response to described pwm signal Detect the state of motor side changer.

Preferably, described method for diagnosing faults may further comprise the step of: display and the result of record detection.

Preferably, the motor side changer of described converter and grid side changer are for using full-control type merit The AC/DC Technics of Power Electronic Conversion circuit of rate device composition, described full-control type power device includes metal Oxide semiconductor field effect transistor (MOSFET), insulated gate bipolar transistor (IGBT), collection Become door pole stream-exchanging thyristor (IGCT), gate level turn-off thyristor (GTO), and described power electronics becomes Change circuit and include two Level Full Bridges, diode clamp bit-type three Level Full Bridge, striding capacitance type three Level Full Bridge.

Preferably, the changer of described converter forms frequency conversion speed-adjusting system, wherein, described electricity with motor Machine includes permagnetic synchronous motor, electric excitation synchronous motor, squirrel cage asynchronous motor, wire-wound asynchronous motor.

Converter Fault Diagnosis method according to present inventive concept, utilizes the intrinsic controller of converter and biography Sensor, by making converter work in fault diagnosis model, and starts converter the most one by one Parts, compare with classical feedback signal according to actual feedback signal and realize fault diagnosis, thus avoid Influencing each other between converter subsystem, and then not only achieve Converter Fault Diagnosis, the most preferably Take into account the requirement reducing cost with improving versatility.

Accompanying drawing explanation

By the description below in conjunction with the accompanying drawings embodiment carried out, these and/or other aspect of the present invention and Advantage will be made apparent from and be more readily understood.

Fig. 1 illustrates the frequency conversion speed-adjusting system schematic diagram of the exemplary embodiment according to the present invention.

Fig. 2 illustrates the flow chart of Converter Fault Diagnosis method according to an exemplary embodiment of the present invention.

Fig. 3. the equivalent circuit diagram of motor when being static state.

Detailed description of the invention

Being described in detail the embodiment of the present invention now, its example represents in the accompanying drawings, wherein, and phase Same label represents same parts all the time.It is described embodiment below with reference to the accompanying drawings to explain this Invention.

Converter Fault Diagnosis method according to present inventive concept, utilizes the intrinsic controller of converter and biography Sensor, by making converter work in fault diagnosis model, and starts converter the most one by one Parts, compare with classical feedback signal according to actual feedback signal and realize fault diagnosis, thus avoid Influencing each other between converter subsystem, and then not only achieve Converter Fault Diagnosis, the most preferably Take into account the requirement reducing cost with improving versatility.

Fault diagnosis model according to present inventive concept is the special running status of a kind of converter, its purpose It it is the fault of diagnosis converter.Converter is under described fault diagnosis model, it is impossible to carry out motor drag etc. Normal work.In other words, converter could enter described fault diagnosis model after should be at stopped status, Or converter stopped operation automatically or manually because of fault.

It addition, the motor as controlled device is not had according to the Converter Fault Diagnosis method of present inventive concept Having concrete restriction, described motor can be permagnetic synchronous motor, electric excitation synchronous motor, squirrel-cage asynchronism Motor, wire-wound asynchronous motor etc. are multiple.

Below, in conjunction with Fig. 1 and Fig. 2 describe in detail the converter according to the exemplary embodiment of the present invention and Converter Fault Diagnosis method.

Fig. 1 illustrates the frequency conversion speed-adjusting system diagram of the exemplary embodiment according to the present invention.As it is shown in figure 1, Converter 100 includes motor side chopper 102, motor side changer 103, dc bus 110, braking Unit 104, Support Capacitor 105, grid side changer 106, wave filter 107, precharge loop 108, Grid side chopper 109 and controller 120.

As it is shown in figure 1, motor side changer 103 and grid side changer 106 are connected to dc bus 110. Motor side changer 103 and grid side changer 106 comprise the three-phase bridge using full-control type power device Structure.The exchange that motor side changer 103 is connected to motor 200 by motor side chopper 102 is drawn On line 101.The brake unit 104 being connected between dc bus 110 prevents by consuming excess energy The overtension of dc bus 110.The Support Capacitor 105 being connected between dc bus 110 is for subtracting The voltage pulsation of little dc bus 110.Additionally, the precharge being connected in parallel with grid side chopper 109 Loop 108 is used for limiting the charging current of pre-charge process.

Additionally, motor side changer 103 and grid side changer 106 in described converter 100 are permissible It it is various structures form.Motor side changer 103 and grid side changer 106 should respond control Three-phase pulse width modulated (PWM) output that device 120 is given, and the operation of performer on/off.Meet this to want The motor side changer 103 asked and grid side changer 106, its power component can be metal-oxide half Conductor field-effect transistor (MOSFET), insulated gate bipolar transistor (IGBT), integral gate change The multiple wholly-controled device such as stream IGCT (IGCT), gate level turn-off thyristor (GTO), electric power electricity Subtopology form can be two Level Full Bridges, diode clamp bit-type three Level Full Bridge, striding capacitance type three level The various ways such as full-bridge.

There is the Converter Fault Diagnosis mode such as Fig. 1 structure as follows: a) controller 120 detects electrical network 300 Three-phase voltage, controller 120 uses phaselocked loop (PLL) algorithm measurement mains frequency and phase place, it is judged that electrical network The faults such as 300 short circuits, open circuit, phase sequence wrong；B) the precharge contact in Guan Bi precharge loop 108 Device, detection DC bus-bar voltage change over value, it is judged that pre-charge contactor operation irregularity fault and Support electric capacity 105 capacitance abnormal failure；C) grid side changer 106 is started, according to DC bus-bar voltage, electricity The parameters such as the electric current of grid side converter 106 judge grid side full-control type power device, grid side power measurement Fault；D) controller 120 sends pwm signal driving and braking units 104 and works, and detects and flow through system The electric current of moving cell 104, it is judged that braking power device fault and braking resistor resistance abnormal failure；E) inhale Closing motor side chopper 102, controller 120 sends PMW signal drive motor side converter 103 and works, By detecting the electric current of motor AC lead-out wire 101, calculate electric motor resistance, and judge motor side changer The fault of 103, motor AC lead-out wire 101 Wiring faults；F) show that the fault detected, prompting are used The method of family handling failure.

Below, describe frequency converter failure according to an exemplary embodiment of the present invention in detail in conjunction with Fig. 1 and 2 to examine Disconnected method, wherein, Fig. 2 illustrates Converter Fault Diagnosis method according to an exemplary embodiment of the present invention Flow chart.

Step S110, converter 100 enters fault diagnosis model.

Under fault diagnosis model, all internal parts of converter 100 quit work, and motor side breaks Road device 102 and grid side chopper 109 disconnect.

After entering fault mode, controller 120 is by the startup one by one as shown in step S120 to S160 The all parts of converter, to position the source of trouble.In step S120 to S160, however, it is determined that the source of trouble, Then report an error backed off after random, otherwise proceeds to next step.Below, based on step S120 to S160, each is described The fault detection approach of parts.

Step S120, whether detection electrical network 300 breaks down.

For the ease of describing, below with rated voltage as 690V, as a example by rated frequency is the electrical network of 50Hz. The three-phase voltage value of detection electrical network, if the continuous 20ms of the absolute value of three-phase line voltage is less than rated line voltage peak The 50%(specified line voltage 690V of value, then the 50% of rated line voltage peak value is 487.9V), then sentence It is set to electrical network Wiring faults.

It addition, phaselocked loop (PLL) algorithm well known to field of power electronics can be used, according to three-phase electricity Pressure input calculates mains frequency and electrical network electromotive force.If mains frequency is more than 150% or electricity of rated frequency Net frequency less than the 50% of rated frequency, is then judged to electrical network line phase sequence connection error fault；If electrical network The absolute value of electromotive force is less than the 90% of electrical network specified electromotive force absolute value, or the absolute value of electrical network electromotive force More than the 110% of the specified electromotive force of electrical network, then it is judged to electrical network electromotive force abnormal failure.

If detecting in step S120, electrical network 300 does not breaks down, then perform step S130, and adhesive is pre- Support Capacitor 105 is pre-charged by the pre-charge contactor in charge circuit 108.During by detecting zero Carve, and the DC bus-bar voltage of precharge Δ t judges whether are dc bus 110 and Support Capacitor 105 Break down

The capacitance computing formula of Support Capacitor 105 is:

$C=\frac{\mathrm{\Δt}}{R\ln \left(\frac{U^{*}-U_0}{U^{*}-U_t}\right)}---\left(1\right)$

In formula (1), C is the capacitance of Support Capacitor 105；Δ t is time difference；R is precharge loop The resistance of 108；U₀It is the voltage of the dc bus 110 in zero moment；U_tAfter charging Δ t Dc bus 110 voltage；U^*For the voltage of the dc bus 110 of stable state, this numerical value is determined by line voltage Fixed.Owing to resistance value R in precharge loop 108 is precognition, Support Capacitor can be calculated by (1) formula The capacitance of 105.

If calculated Support Capacitor 105 capacitance C is less than its theoretical capacitance 80%, then it is judged to The low fault of Support Capacitor；If calculated Support Capacitor 105 capacitance C is more than its theoretical capacitance 120%, then it is judged to Support Capacitor high fault.If the voltage of dc bus 110 is less than U*'s after 5 seconds 50%, then it is judged to the short trouble of dc bus 110.

If detecting in step s 130, dc bus 110 and Support Capacitor 105 do not break down, then Perform step S140, disconnect the pre-charge contactor in described precharge loop 108, close grid side Chopper 109, starts grid side changer 106, and detects whether it breaks down.

Characteristic parameter when controller 120 can be worked by grid side changer 106 judges that grid side converts Whether device 106 breaks down, characteristic parameter include DC bus-bar voltage, grid side changer 106 electric current, Grid side changer 106 power calculation value etc..When grid side changer 106 works, if dc bus The average voltage of 110 is not up to the predeterminated voltage of dc bus 110 or continues 10 seconds dc bus 110 Voltage standard difference is more than presetting the limit value that reports an error, it is determined that there occurs the electric voltage exception fault of dc bus 110； If any one phase current virtual value is more than 10A, it is determined that there occurs the power device of grid side changer 106 Part fault；If grid side active power is more than the 1% of rated power, it is determined that there occurs net side active power Metering fault；If grid side reactive power absolute value is more than the 1% of rated power, it is determined that there occurs electrical network Side reactive power metering fault.

If determining in step S140, grid side changer 106 does not break down, then perform step S150 Whether detection brake unit 104 breaks down.

Pwm signal is applied to brake unit 104 by controller 120, and believes based in response to this PWM Number and flow through the electric current of brake unit 104 to detect whether brake unit 104 breaks down.

Such as, the pwm signal that dutycycle is 50% is applied to braking list for continuous three times by controller 120 Unit 104, carries out switch motion with the full-control type power device in driving and braking units 104 and detection is flow through The electric current of brake unit 104.PWM drive signal is a kind of pulse-width signal, including " 0 " With " 1 " two level.Full-control type power device when being applied with level "0", in brake unit 104 Part is off；And the full-control type power device when being applied with level"1", in brake unit 104 Part is in the conduction state.When being applied with level "0", the electric current flowing through brake unit 104 is 0；And When being applied with level"1", the electric current flowing through brake unit 104 is I_chopper, can be by following (2) formula Calculate braking resistor.

R_chopper=U_dc/I_chopper (2)

Wherein, U_dcFor dc bus 110 voltage, I_chopperFor flowing through the electric current of brake unit 104, R_chopper Resistance for brake unit 104.If I_chopperLess than theoretical value 50%, or more than theoretical value 150%, then Determine generation brake unit power device fault；If calculated R_chopperLess than theoretical value 80% or More than theoretical value 120%, it is determined that occur as braking resistor abnormal failure.

If determining in step S150, brake unit 104 does not break down, then perform the detection of step S160 Whether motor side changer 103 breaks down.

Controller 120 sends pwm signal, drives the full-control type power device in motor side changer to enter Row switch motion, detection is flow through the electric current of described full-control type power device, is detected cable with this and connect fault And full-control type power device fault.

Fig. 3 show motor static time equivalent circuit.First to A phase full-control type power device and B Phase full-control type power device sends the pwm signal that dutycycle is constant, and C phase full-control type power device keeps Closing, current of electric formula is as shown in (3) formula:

$\left\{\begin{array}{c}{P}_{A1}{U}_{\mathrm{dc}}-R_{\mathrm{SA}}{i}_{a1}-L_A\frac{{\mathrm{di}}_{a1}}{\mathrm{dt}}=P_{B1}{U}_{\mathrm{dc}}-R_{\mathrm{SB}}{i}_{b1}-L_B\frac{{\mathrm{di}}_{a1}}{\mathrm{dt}}\\ i_{a1}=i_{b1}\end{array}\right.---\left(3\right)$

Wherein, U_dcFor DC bus-bar voltage, P_A1、P_B1A phase PWM of motor when being the 1st test Dutycycle and B phase PWM duty cycle；R_SA、R_SB、R_SCFor motor three-phase resistance；L_A、L_B、L_CFor Motor threephase stator inductance；i_a1、i_b1The stator current of motor 200 when being the 1st test.Owing to controlling The dutycycle that device 120 sends is constant, and obtained electric current is also steady state value, and inductance both end voltage is zero,

(3) formula can be reduced to:

$\left\{\begin{array}{c}{P}_{A1}{U}_{\mathrm{dc}}-R_{\mathrm{SA}}{i}_{a1}=P_{B1}{U}_{\mathrm{dc}}-R_{\mathrm{SB}}{i}_{b1}\\ i_{a1}=i_{b1}\end{array}\right.---\left(4\right)$

If i_a1=i_b1=0, it is determined that motor side exchange lead-out wire 101 open circuit fault occurs；If permitting in error I in the range of Xuing_a1≠i_b1, it is determined that motor side changer 103 full-control type power device fault.

After completing above-mentioned steps, respectively to B, C phase, A, C phase applies short-time pulse, obtains formula (5) (6)

$\left\{\begin{array}{c}{P}_{B2}{U}_{\mathrm{dc}}-R_{\mathrm{SB}}{i}_{b2}=P_{C2}{U}_{\mathrm{dc}}-R_{\mathrm{SC}}{i}_{c2}\\ i_{b2}=i_{c2}\end{array}\right.---\left(5\right)$

$\left\{\begin{array}{c}{P}_{A3}{U}_{\mathrm{dc}}-R_{\mathrm{SA}}{i}_{a3}=P_{C3}{U}_{\mathrm{dc}}-R_{\mathrm{SC}}{i}_{c3}\\ i_{a3}=i_{c3}\end{array}\right.---\left(6\right)$

Wherein, P_A*、P_B*、P_C*It is respectively the PWM duty cycle of A, B, C three-phase, i_a*、i_b*、i_c* It is respectively the electric current (*=1,2,3) of the full-control type power device of A, B, C three-phase, according to formula (4) (5) (6) R can be calculated_SA、R_SB、R_SC.If calculated resistance value is less than the theoretical resistance of stator 80% or more than stator theoretical resistance 120%, it is determined that occur motor 200 abnormal parameters fault.

During order as above performs step S120 to S160, determine the source of trouble, then proceed to Step S180, records and display reports an error backed off after random, otherwise proceeds to next step.If by step S120 To S160, it is not detected by fault, then shows detection process key data in step S170, and exit.

Although show and describing embodiments of the invention with reference to its exemplary embodiments, to illustrate this Bright principle, but the present invention is not limited to represent and the embodiment of description.It should be understood that without departing from by In the case of the spirit and scope of the present invention defined in the appended claims, those skilled in the art can enter Row various changes and modifications.It should therefore be understood that such variation, amendment and equivalent thereof all wrap Include within the scope of the invention.

Claims (10)

1. a Converter Fault Diagnosis method, described application of frequency converter is in the frequency conversion speed-adjusting system of motor-converter-electrical network composition, controller that described converter includes controlling described converter and intrinsic sensor, it is characterised in that described method for diagnosing faults comprises the steps:

Whether detection converter is in stopped status,

When detecting that converter is shut down, controller starts the parts of converter one by one, and judges whether corresponding parts break down by the running status of the intrinsic sensor detection converter parts of described converter, and positions the source of trouble.

2. the method for claim 1, wherein, described converter also includes dc bus, be connected on dc bus motor side changer and grid side changer, it is connected to the motor side chopper of motor side changer, is connected to precharge loop and the Support Capacitor of dc bus that the grid side chopper of grid side changer is connected in parallel with grid side chopper

Wherein, stopped status represents that motor side chopper and grid side chopper are off, and motor side changer, grid side changer quit work；

Wherein, the step of the location source of trouble includes:

Whether detection electrical network breaks down；

If it is determined that grid side does not break down, being then pre-charged dc bus and Support Capacitor by described precharge loop, whether detection dc bus and Support Capacitor break down；

If it is determined that dc bus and Support Capacitor do not break down, then stop the precharge in described precharge loop, close grid side chopper, and detect whether grid side changer breaks down；

If it is determined that grid side changer does not break down, then whether detection brake unit breaks down,

If it is determined that brake unit does not break down, then whether detection motor side changer breaks down.

3. method as claimed in claim 2, wherein, the step of the state of detection electrical network includes: the state of at least one the detection electrical network in the absolute value of three-phase voltage based on electrical network, mains frequency and electrical network electromotive force.

4. method as claimed in claim 2, wherein, the step of the state of detection dc bus and Support Capacitor includes:

Start the magnitude of voltage of dc bus at rear different time points based on precharge and calculate the capacitance of dc bus, and based on the capacitance detection dc bus calculated and the state of Support Capacitor.

5. method as claimed in claim 2, wherein, the step of detection grid side transducer status includes:

The state of detection of characteristic parameters grid side changer when working based on grid side changer.

6. method as claimed in claim 2, wherein, the step of the state of detection brake unit includes:

Apply pulse pwm signal to brake unit, and based on brake unit, described pwm signal is responded to the state of detection brake unit.

7. method as claimed in claim 2, wherein, the step of detection motor side transducer status includes:

Apply pulse pwm signal to motor side changer, and detect the state of motor side changer based on the electric current flowing through motor side changer in response to described pwm signal.

8. the method for claim 1, further comprises the steps of: display and the result of record detection.

9. method as claimed in claim 2, wherein,

The motor side changer of described converter and grid side changer are the AC/DC Technics of Power Electronic Conversion circuit using full-control type power device composition,

Described full-control type power device includes mos field effect transistor, insulated gate bipolar transistor, integrated gate commutated thyristor, gate level turn-off thyristor,

Described Technics of Power Electronic Conversion circuit includes two Level Full Bridges, diode clamp bit-type three Level Full Bridge, striding capacitance type three Level Full Bridge.

The changer of the most described converter forms frequency conversion speed-adjusting system with motor, and wherein, described motor includes permagnetic synchronous motor, electric excitation synchronous motor, squirrel cage asynchronous motor, wire-wound asynchronous motor.