CN215866963U - Auxiliary automatic testing device for voltage sag tolerance characteristics of sensitive equipment - Google Patents

Abstract

The utility model discloses an auxiliary automatic testing device for voltage sag tolerance characteristics of sensitive equipment, which comprises an upper computer, a programmable power supply, a data acquisition card, a single chip microcomputer, a relay and a push-pull electromagnet, wherein the upper computer is connected with the programmable power supply through an LAN (local area network) port and is responsible for controlling the output of the programmable power supply; the programmable power supply output end is connected to the tested device and is responsible for providing test voltage for the tested device; the upper computer is connected with the single chip microcomputer through an RS232 interface and sends a control instruction to the single chip microcomputer, the single chip microcomputer is connected with the relay, and the relay is controlled by the single chip microcomputer according to the instruction of the upper computer. The relay is connected with the push-pull electromagnet, click operation is simulated according to the instruction of the single chip microcomputer, and the tested equipment is started. The utility model can effectively and accurately carry out automatic test aiming at the sensitive equipment, and lays an experimental foundation for setting the test standard of the voltage sag tolerance characteristic of the equipment and pertinently adopting treatment and prevention measures for the industry and users.

Description

Auxiliary automatic testing device for voltage sag tolerance characteristics of sensitive equipment

Technical Field

The utility model belongs to the technical field of voltage detection of power equipment, and particularly relates to an auxiliary automatic testing device for voltage sag tolerance characteristics of sensitive equipment.

Background

The voltage sag is a condition that an effective value of an output voltage suddenly drops in a certain time period and is maintained for a certain time period, and then the output voltage is finally recovered to a normal output voltage, and the duration time of the voltage sag is mostly half cycle to several seconds. With the continuous development of the power industry, the requirements of high-end manufacturing such as semiconductor manufacturing, precision machining, aerospace equipment and the like on the quality of electric energy are higher and higher, and voltage sag accidents cause loss which is difficult to estimate in the aspects of equipment production, operation and maintenance and the like.

AC contactors (ACC), variable speed systems (ASD), Programmable Logic Controllers (PLC), and other devices are used in various applications in power systems. While the actual working efficiency of the devices is improved, the actual power system users are more easily influenced by the quality of the electric energy due to the intolerance of the devices to the voltage sag. A number of voltage sag event surveys have shown that when the associated equipment is subjected to a voltage sag, the associated process control system may be interrupted, thereby causing production line disruptions and significant economic losses to the user. In order to understand the tolerance capability of the sensitive devices to the voltage sag and to adopt an effective prevention and treatment scheme, a large number of mechanism, simulation and experimental researches are carried out on different voltage sag types and different devices by related organizations at home and abroad.

At present, a plurality of feature vectors such as voltage sag characteristics, sensitive device types, sensitive device attributes and load states are considered in a comprehensive manner in the existing standard test project and test scheme, and a common voltage sag tolerance characteristic test method of typical sensitive devices is listed. And finally, providing a probability statistical analysis method of the test result according to the problem of the test result. However, the test method considers that the number of feature vectors is too many, each feature vector needs to be manually tested for many times, meanwhile, the resetting of the equipment also needs to be manually reset, the test result also needs to be manually recorded, the labor and the time are wasted in practical occasions, and the test result also has artificial errors. Some people carry out voltage sag sensitivity tests on PLCs of current common brands, simulate a power supply by using a Chroma 61860 recovery type power grid, respectively examine the influence of factors such as basic characteristic quantity of voltage sag, odd harmonics and the like on the sag sensitivity of the PLCs, and manually draw voltage sag sensitivity curves of the PLCs. However, in this method, the output voltage needs to be manually modified every time the test vector is changed, and the manual reading of the test result consumes much time for the experiments with more test vectors and more equipment brands. The mechanism of the ASD voltage sag tolerance characteristics influenced by the ASD (protection and control mode), the load side (load characteristics), and the source side (voltage amplitude before/after voltage sag, sag shape) factors is also analyzed; and voltage sag tolerance curves of ASD were obtained by a number of experiments. However, the modification of the source-side voltage sag characteristic vector and the device fault resetting each time need manual processing, thousands of times of resetting are needed according to the international test standard, and the workload is huge.

At present, the research in the field is based on manual setting of voltage parameters, manual reading of test results, manual drawing of sag tolerance curves, huge labor consumption and time cost, and large errors in duration of normal operation of equipment under voltage sag calculated manually through oscilloscope waveforms. In order to complete the test of a single sensitive device, about one month is required from the editing of the voltage sag characteristic vector, the recording of the result by an oscilloscope, the manual calculation of the duration time and the manual drawing of a sag curve. Automatic testing of voltage sag tolerance of typical sensitive devices has not been documented to study.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects that the existing test experiments all need to manually change test vectors, manually read test results and manually reset, the utility model constructs the auxiliary automatic test device for the voltage sag tolerance characteristic of the sensitive equipment based on the alternating-current programmable power supply, and on the basis of the existing standard test items and test schemes, for typical test circuits of ACC, ASD and PLC, through changing the characteristic quantity of the voltage sag and simultaneously reading the tolerance time of the voltage sag of the equipment, the test accuracy is improved, the workload of people is reduced, the automatic test of the voltage sag tolerance experiment can be realized, and the blank that the existing tests are all manual test record results and cannot be automatically recorded is filled. The method provides an experimental foundation for quantifying the voltage sag tolerance of the equipment, and lays a foundation for understanding the tolerance level of the sensitive equipment and formulating the test standard of the tolerance level of the equipment.

In order to achieve the purpose, the utility model adopts the technical scheme that: an auxiliary automatic testing device for voltage sag tolerance characteristics of sensitive equipment comprises an upper computer, an adjustable power supply, a load, a data acquisition card, a single chip microcomputer, a relay and a push-pull electromagnet, wherein the upper computer is connected with the adjustable power supply through an LAN (local area network) port, the output end of the adjustable power supply is used for being connected with tested equipment, the upper computer is connected with the single chip microcomputer, the single chip microcomputer is connected with the relay, the relay is connected with the push-pull electromagnet, a contact of the push-pull electromagnet is aligned with a reset switch of the tested equipment, and the contact of the push-pull electromagnet can simulate click operation according to instructions of the single chip microcomputer and can be used for starting the tested equipment; the voltage probe is respectively connected with the output side of the power supply, the output end of the testing equipment and the data acquisition card, and the data acquisition card is connected with the data input end of the upper computer.

The adjustable power supply adopts a programmable power supply, and the upper computer is connected with the programmable power supply through an upper computer LAN port and a programmable power supply LAN port.

The upper computer is connected with the singlechip through an RS232 interface.

The I/O port of the singlechip is connected with a relay, and the relay is connected with a power supply loop of the push-pull electromagnet.

The voltage output of the device under test is connected to the voltage input of the load.

The tested equipment is single-phase equipment or three-phase equipment, and a reset switch is arranged on the tested equipment; the load is single phase or three phase.

When the tested equipment is three-phase equipment, the A phase and the C phase of the power supply voltage are respectively connected to the first channel analog input port and the third channel analog input port, and the equipment voltage is connected to the second channel analog input port.

And the ground wire interface of the programmable power supply, the ground wire interface of the tested device, the ground wire interface of the load and the ground wire interface of the data acquisition card are grounded together.

The data output port of the data acquisition card is connected with the data input port of the upper computer through a USB line.

Compared with the prior art, the utility model has at least the following beneficial effects: the programmable power supply can provide various test voltages, is beneficial to realizing automatic control and output, and accesses a tested device, the data acquisition card acquires corresponding voltage through the voltage probe, transmits the acquired voltage data to the upper computer in real time, and provides real-time and accurate data for the upper computer.

Furthermore, the voltage sag tolerance characteristic of the sensitive equipment is utilized to assist the automatic testing device to test the ASD, the resetting of the equipment is realized through the automatic resetting module, the manual waiting for resetting is not needed, and the productivity is greatly released.

Drawings

Fig. 1 is an overall structure of an auxiliary automatic test device for voltage sag tolerance characteristics of sensitive equipment.

Fig. 2 is a schematic diagram of a voltage sag.

Fig. 3 is a PLC voltage measurement waveform.

Fig. 4 is a measured voltage waveform of the frequency converter.

In the attached drawing, 1 is an upper computer, 2 is a programmable power supply, 3 is a device to be tested, 4 is a load, 5 is a single chip microcomputer, 6 is a relay, 7 is a push-pull electromagnet, 8 is a data acquisition card, and 9 is a voltage probe.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The auxiliary automatic testing device can realize automatic testing based on the voltage sag tolerance characteristic of sensitive equipment, automatically generates required voltage sag characteristic quantity for typical test circuits of ACC, ASD and PLC, simultaneously reads the tolerance time of the voltage sag of the equipment through a sliding window algorithm, and controls a travel switch to control the on-off of the tested equipment through a singlechip through the communication of the singlechip and an upper computer for the tested equipment needing to be reset, thereby realizing the automatic resetting of the equipment. And finally, importing the test data into an upper computer module to provide real-time data for automatically drawing a voltage sag tolerance curve. All tests can be automated, the test accuracy is improved, the workload of people is reduced, and the blank that the existing tests are manual test recording results and cannot be automatically tested is filled. The method provides a test foundation for quantifying the voltage sag tolerance of the equipment, and lays a foundation for understanding the tolerance level of the sensitive equipment and formulating the test standard of the tolerance level of the equipment.

Fig. 1 shows the general structural framework of the auxiliary automatic test device for the voltage sag tolerance characteristic of the sensitive equipment. The upper computer 1 is connected with the programmable power supply 2 through an upper computer LAN port 1.1 and a programmable power supply LAN port 2.1. The serial port 1.3 of the upper computer is connected with the serial port 5.1 of the single chip microcomputer, and the upper computer 1 is connected with the single chip microcomputer 5 through the serial port by an RS232 interface. The I/O port 5.2 of the singlechip is connected with a relay 6, and the relay 6 is connected with a power supply loop of the push-pull electromagnet 7. The ground wire interface 2.5 of the programmable power supply, the ground wire interface 3.7 of the tested device, the ground wire interface 4.4 of the load and the ground wire interface 8.4 of the data acquisition card are grounded together. The first power output port 2.2 of the programmable power supply, the second power output port 2.3 of the programmable power supply and the third power output port 2.4 of the programmable power supply are A, B and phase C, respectively.

The first voltage input port 3.1 of the device under test, the second voltage input port 3.2 of the device under test and the third voltage input port 3.3 of the device under test are A, B and a C-phase voltage input port of the device under test 3 respectively, and the first voltage output port 3.4 of the device under test, the second voltage output port 3.5 of the device under test and the third voltage output port 3.6 of the device under test are A, B and a C-phase voltage output port of 3 respectively; the second voltage input port 3.2, the third voltage input port 3.3, the second voltage output port 3.5, and the third voltage output port 3.6 on the device under test 3 are dashed boxes, which indicate that they may not exist, when these four ports do not exist, the device under test 3 is a single-phase device, and when the dashed boxes exist, the device under test 3 is a three-phase device. The reset switch 3.8 is a dashed line box, when the reset switch 3.8 does not exist, the reset switch 3 can be automatically reset, and when the reset switch exists, the reset switch 3 needs to be manually reset. The load first voltage input port 4.1, the load second voltage input port 4.2 and the load third voltage input port 4.3 are A, B and C-phase voltage input ports of the load, the load second voltage input port 4.2 and the load third voltage input port 4.3 on the load are dotted lines to indicate that the load 4 may not exist, the load 4 is a single-phase load when two ports of the load second voltage input port 4.2 and the load third voltage input port 4.3 indicated by dotted lines do not exist, and the load 4 is a three-phase load when the load second voltage input port 4.2 and the load third voltage input port 4.3 indicated by dotted lines exist.

The data acquisition card 8 is provided with a first channel analog input port 8.1, a second channel analog input port 8.2 and a third channel analog input port 8.3. The programmable power supply first power output port 2.2 and the third power output port 2.4 are connected with a voltage probe 9, and the voltage probe 9 is connected with a first channel analog input port 8.1 and a third channel analog input port 8.3 after measuring the voltages of the first power output port 2.2 and the third power output port 2.4. The first voltage output port 3.4 of the tested device is connected with the voltage probe 9, and the voltage probe 9 measures the voltage of the first voltage output port 3.4 and then is connected with the analog input port 8.2 of the second channel. The first power output port 2.2 and the first voltage input port 3.1, the second power output port 2.3 and the second voltage input port 3.2, the third power output port 2.4 and the third voltage input port 3.3, the first voltage output port 3.4 and the load first voltage input port 4.1, the second voltage output port 3.5 and the load second voltage input port 4.2, and the third voltage output port 3.6 and the load third voltage input port 4.3 are connected, a dotted line in the figure represents that the dotted line does not exist, when the dotted line does not exist, the dotted line represents a test connection of single-phase equipment, and when the dotted line exists, the dotted line represents a test connection of three-phase equipment. The contact of the push-pull electromagnet 7 is in contact alignment with a reset switch 3.8 of the tested device. The data output port 8.5 of the data acquisition card is connected with the data input port 1.2 of the upper computer through a USB line. The transformer has a transformation ratio of 200.

Manual test processing flow

During manual testing, the background splices the parameters transmitted from the front end into character strings according to corresponding formats according to the parameters transmitted from the front end and a programmable power supply communication protocol, the character strings are transmitted to the programmable power supply by utilizing a TCP/IP protocol, the programmable power supply outputs corresponding voltage quantity according to the set parameters after receiving information, the voltage is added to test equipment, meanwhile, the background calls a data acquisition card to acquire data, a data processing algorithm is called to process the data after the test is finished, the time for the equipment to continuously and normally work under the condition of sag is calculated, the data is stored in a database, the data is returned to a browser after the storage is finished, and the processing is finished when the request is finished.

Automatic test processing flow

The automatic test is similar to the manual test, corresponding test parameters are gradually generated according to the initial amplitude and the reduced step length, the corresponding test parameters are spliced into character strings according to a protocol and are transmitted to a programmable power supply, then the test is started, the data acquisition card starts to acquire data, the data acquisition card acquires the data after each step of test is finished, if the equipment fails, if the equipment cannot be automatically restarted, a corresponding instruction is automatically transmitted to the single chip microcomputer through an RS232 serial port, the single chip microcomputer controls the push-pull type electromagnet to restart the equipment after receiving the instruction, and if the equipment can be automatically restarted, the step is not needed. And when the test amplitude is reduced to 0, ending the test, storing the analyzed data into the database, returning the data to the browser after the storage is ended, and ending the processing of the request.

(1) Power sag starting point discrimination

The data collected by the data acquisition card is analyzed by using a sliding window algorithm, taking the output voltage sag waveform of the programmable power supply shown in FIG. 2 as an example, when the voltage sag occurs, the voltage value of the phase relative to the voltage value of the same phase of the voltage of the last cycle will suddenly change,

(2) selection of criteria for equipment failure

1) ACC and PLC fault discrimination

The ACC and the PLC do not need manual reset, when voltage sag is recovered, the ACC and the PLC automatically recover to normal work from a fault state, when voltage sag occurs, equipment only has two states of normal work and fault, an ACC contact is closed during normal work, output voltage in a circuit is voltage of a main circuit voltage source, the ACC is disconnected during fault, and the output voltage in the circuit is zero; when the PLC works normally, a normally closed terminal in the PLC is selected, the output of the main circuit is voltage source voltage connected to the main circuit, the terminal is disconnected when a fault occurs, and the output voltage of the main circuit is zero. Therefore, the output voltage of the main circuit is detected as the criterion for judging whether the ACC and the PLC work normally or not, the voltage values of the previous cycle and the next cycle are always equal in normal time, the voltage at the same position of the current voltage cycle and the previous cycle at the moment generates a large difference value when a fault occurs, and the fault is considered to occur as long as the difference value is larger than a set threshold value.

Referring to fig. 3, point a is the initial time of the power supply voltage sag, point B is the PLC fault time, and the time between the two is analyzed, i.e., the duration.

2) Discrimination of ASD equipment fault

According to the analysis of the ASD working principle, the output voltage in the normal working state is high-frequency PWM modulation voltage, for the PWM modulation voltage, the difference value of the front data point and the rear data point of the data collected by the data collection card is very large, because the frequency converter is provided with a large capacitor, the frequency converter can still work for a period of time after the capacitor power supply occurs after the temporary drop, once the capacitor voltage can not provide enough voltage, the frequency converter stops working, because the load carried by the frequency converter is a motor, the motor rotates due to inertia, and finally the rotating speed is stopped to zero, the equipment voltage slowly drops to zero in the process, as shown in figure 4, the difference value of the front data point and the rear data point of the collected voltage is very small. According to the characteristic, the voltage difference value of the front data point and the rear data point of the data acquisition card is judged, when the difference value is smaller than a threshold value, the equipment is considered to be in a fault state, and when the difference value is larger than the threshold value, the equipment is in a normal working state.

As shown in fig. 4, point a is the starting point of the power supply voltage sag, it can be seen that after the voltage sag, the inverter is still performing PWM modulation, and after a period of time, the inverter stops PWM modulation when reaching point B, and the motor is still rotating due to inertia, that is, point B is considered as the failure point of the inverter.

Automatic reset device design

The automatic reset device comprises a singlechip 5, a relay 6 and a push-pull electromagnet 7, and in the auxiliary automatic test device for the voltage sag tolerance characteristic of the sensitive equipment, an instruction sent by an upper computer is transmitted to the singlechip module through a standard RS232 communication port. After receiving the corresponding instruction, the single chip controls the on-off of the corresponding relay so as to control the action of the push-pull type electromagnet, and the electromagnet completes the 'clicking' operation on the equipment reset button to realize the reset operation on the sensitive equipment. For the equipment needing power failure before resetting, the power supply loop can be controlled by the relay.

The control core of the control panel is formed by an 8051 single chip microcomputer of STC15W4K32S4 series. And a standard RS232 interface on the control panel is used for communicating with an upper computer. The power supply voltage of the control panel is DC 24V which is commonly used in engineering, and the control panel and the relay are isolated by an optical coupler, so that the anti-interference capability is enhanced. The push-pull electromagnet mainly comprises a magnetic core and an electromagnetic ring, and the magnetic core is driven to complete the actions of pushing and pulling through the power on and off of the electromagnetic ring. The push-pull speed is high, and the 'click' operation during manual reset can be simulated. The reset device does not use complex hardware equipment, and the control panel core is also composed of a single chip microcomputer, so that the reset device is suitable for engineering application.

The intelligent analyzer consists of an upper computer, a programmable power supply, tested equipment, a data acquisition card, a singlechip, a relay and a push-pull electromagnet. The upper computer is connected with the programmable power supply through the LAN port and is responsible for controlling the output of the programmable power supply; the programmable power supply output end is connected to the tested device and is responsible for providing test voltage for the tested device; the upper computer is connected with the single chip microcomputer through the RS232 interface and sends a control instruction to the single chip microcomputer, the single chip microcomputer is connected with the two relays and controls the relays according to the instruction of the upper computer, the relays are connected with the push-pull type electromagnets, contacts of the push-pull type electromagnets are aligned with reset switches of the equipment to be tested, clicking operation is simulated according to the instruction of the single chip microcomputer, and the equipment to be tested is started. The voltage probe is respectively connected with the programmable power supply output side and the output end of the tested device, the voltage is measured and then connected with the data acquisition card, wherein the device voltage is connected with the second interface of the analog input quantity of the data acquisition card, and the phases A and C of the power supply voltage are respectively connected with the first interface and the third interface of the analog input quantity of the data acquisition card. The data acquisition card is connected with the upper computer and directly uploads the acquired data to the upper computer.

Claims (9)

1. An auxiliary automatic testing device for voltage sag tolerance characteristics of sensitive equipment is characterized by comprising an upper computer (1), an adjustable power supply, a load (4), a data acquisition card (8), a single chip microcomputer (5), a relay (6) and a push-pull electromagnet (7), wherein the upper computer (1) is connected with the adjustable power supply through an LAN port, the output end of the adjustable power supply is used for being connected with tested equipment (3), the upper computer (1) is connected with the single chip microcomputer (5), the single chip microcomputer (5) is connected with the relay (6), the relay (6) is connected with the push-pull electromagnet (7), a contact of the push-pull electromagnet is aligned with a reset switch of the tested equipment, and the contact of the push-pull electromagnet can simulate clicking operation according to instructions of the single chip microcomputer and can be used for starting the tested equipment (3); the voltage probe (9) is respectively connected with the output side of the adjustable power supply, the output end of the tested device (3) and the data acquisition card, and the data acquisition card (8) is connected with the data input end of the upper computer (1).

2. The auxiliary automatic test device for the voltage sag tolerance characteristic of the sensitive equipment according to claim 1, wherein the adjustable power supply adopts a programmable power supply (2), and the upper computer (1) and the programmable power supply (2) are connected through an upper computer LAN port (1.1) and a programmable power supply LAN port (2.1).

3. The auxiliary automatic test device for the voltage sag tolerance characteristic of the sensitive equipment according to claim 1, wherein the upper computer (1) is connected with the singlechip (5) through an RS232 interface.

4. The auxiliary automatic test device for the voltage sag tolerance characteristic of the sensitive equipment according to claim 1, wherein the I/O port (5.2) of the single chip microcomputer is connected with a relay (6), and the relay (6) is connected with a power supply loop of the push-pull electromagnet (7).

5. The device-sensitive voltage sag tolerance characteristic-assisted automatic test apparatus according to claim 1, wherein a voltage output of the device under test (3) is connected to a voltage input of the load (4).

6. The auxiliary automatic test device for the voltage sag tolerance characteristic of the sensitive equipment according to claim 1, characterized in that the tested equipment (3) is single-phase equipment or three-phase equipment, and a reset switch (3.8) is arranged on the tested equipment (3); the load (4) is single-phase or three-phase.

7. The auxiliary automatic test device for the voltage sag tolerance characteristic of the sensitive equipment according to claim 6, wherein when the tested equipment (3) is a three-phase equipment, the phase A and the phase C of the power supply voltage are respectively connected to the first channel analog input port (8.1) and the third channel analog input port (8.3), and the equipment voltage is connected to the second channel analog input port (8.2).

8. The auxiliary automatic test device for the voltage sag tolerance characteristic of the sensitive equipment according to claim 1, wherein a ground wire interface (2.5) of a programmable power supply, a ground wire interface (3.7) of the tested equipment, a ground wire interface (4.4) of a load and a ground wire interface (8.4) of a data acquisition card are commonly grounded.

9. The auxiliary automatic test device for the voltage sag tolerance characteristic of the sensitive equipment according to claim 1, wherein a data output port (8.5) of the data acquisition card is connected with a data input port (1.2) of the upper computer through a USB (universal serial bus) line.

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