CN111751090A - A mechanical characteristic measuring device and measuring method of circuit breaker - Google Patents

Abstract

The invention discloses a device and a method for measuring mechanical characteristics of a circuit breaker, wherein the device comprises an FPGA processing module, a switching-on and switching-off control module, a test power supply module and a mechanical characteristic sampling module; the mechanical characteristic sampling module comprises a switching-on and switching-off time sampling unit, a switching-on and switching-off speed sampling unit, a switching-on and switching-off coil characteristic sampling unit, a first sampling plate and a second sampling plate, the switching-on and switching-off time sampling unit is connected with the FPGA processing module through the first sampling plate, and the switching-on and switching-off speed sampling unit and the switching-on and switching-off coil characteristic sampling unit are respectively connected with the FPGA processing module through the second sampling plate; the testing power supply module is connected with the FPGA processing module, and the opening and closing control module is connected with the FPGA processing module. The embodiment of the invention can effectively improve the test efficiency and the test precision of the mechanical characteristics of the circuit breaker and has better practicability.

Description

A mechanical characteristic measuring device and measuring method of circuit breaker

technical field

The invention relates to the field of electric power technology, and in particular, to a device and a method for measuring mechanical characteristics of a circuit breaker.

Background technique

High-voltage circuit breakers are the core equipment for controlling and protecting circuits in the primary power system, and their reliability directly affects the safe and stable operation of the power grid. As one of the tests of the routine testing items of high-voltage circuit breakers, how to improve the efficiency and reliability of the test still needs further research.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art, and the present invention provides a mechanical characteristic measuring device and measuring method of a circuit breaker, which facilitates simultaneous measurement of different mechanical characteristic parameters in the circuit breaker, and effectively improves the performance of the mechanical characteristic test. Test accuracy and test efficiency.

Correspondingly, an embodiment of the present invention provides a device for measuring mechanical characteristics of a circuit breaker, and the device includes an FPGA processing module, an opening and closing control module, a test power supply module, and a mechanical characteristic sampling module;

The mechanical characteristic sampling module includes an opening and closing time sampling unit, an opening and closing speed sampling unit, an opening and closing coil characteristic sampling unit, a first sampling board and a second sampling board, and the opening and closing time sampling unit passes the The first sampling board is connected to the FPGA processing module, and the opening and closing speed sampling unit and the opening and closing coil characteristic sampling unit are respectively connected to the FPGA processing module through the second sampling board;

The test power supply module is connected to the FPGA processing module, and the opening and closing control module is connected to the FPGA processing module.

Optionally, the opening and closing time sampling unit includes several differential signal processing circuits and several relays, and each differential signal processing circuit is correspondingly connected to an output end of a relay;

The circuit breaker includes a three-circuit circuit breaker group, the first input end of each relay in the plurality of relays is connected to the graphite contact of the circuit breaker corresponding to the circuit breaker, and each of the plurality of relays is connected. The second input end of the relay is connected to the metal contact of a circuit breaker corresponding to one of the circuit breakers.

Optionally, the opening and closing speed sampling unit includes a plurality of travel sensors, and each travel sensor in the plurality of travel sensors is installed on the operating mechanism link of the circuit breaker corresponding to the circuit breaker. The output end of each of the several stroke sensors is connected to the second sampling plate respectively.

Optionally, the opening and closing coil characteristic sampling unit includes a current signal processing circuit and three opening and closing relays;

The first input terminal of each of the three switching relays is connected to the closing coil of the corresponding circuit breaker in the circuit breaker, and the first input terminal of each switching relay in the three switching relays is connected. The two input terminals are connected to the opening coil of one circuit breaker corresponding to the circuit breaker, and the output terminal of each switching relay in the three switching relays is respectively connected to the input terminal of the current signal processing circuit. The output end of the current signal processing circuit is connected to the second sampling board.

Optionally, the opening and closing control module is an operating power supply, the input end of the operating power supply is connected to a peripheral mains power supply device, and the output end of the operating power supply is connected to each circuit breaker in the circuit breaker. The coil of the power supply is connected, and the control end of the operation power supply is connected with the FPGA processing module.

Optionally, the test power supply module is a 10A constant current power supply board.

Optionally, the FPGA processing module is connected to the communication interface of the EM9170 industrial control motherboard through a parallel bus.

In addition, an embodiment of the present invention also provides a method for measuring mechanical characteristics of a circuit breaker, the measuring method comprising:

Obtain the opening and closing stroke signal, coil current signal and main contact voltage signal generated during the opening and closing process of the circuit breaker;

The opening and closing stroke signal, the coil current signal and the main contact voltage signal are analyzed and processed, and the mechanical characteristic parameters of the circuit breaker are calculated.

Optionally, the obtaining of the opening and closing stroke signal, the coil current signal and the main contact voltage signal generated during the opening and closing process of the circuit breaker includes:

The circuit breaker is controlled to perform the opening and closing action by operating the power supply, at the same time, the opening and closing stroke signal of the circuit breaker is obtained through the opening and closing speed sampling unit, and the main contact of the circuit breaker is obtained through the opening and closing time sampling unit The voltage signal, the coil current signal of the circuit breaker is acquired through the opening and closing coil characteristic sampling unit.

Optionally, the mechanical characteristic parameters include the maximum value of the current of the opening coil, the maximum value of the current of the closing coil, the moment of just opening, the moment of just closing, the opening displacement and the closing displacement.

The invention proposes a mechanical characteristic measuring device of a circuit breaker, which is provided with a plurality of test units for the high-efficiency test requirements of the circuit breaker, which can realize the functions of real-time acquisition, analysis and calculation of the mechanical characteristic parameters of the circuit breaker, and can effectively improve the The test efficiency of the mechanical property test is high, and the reliability is high and has good practical value.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic structural diagram of a device for measuring mechanical characteristics of a circuit breaker disclosed in an embodiment of the present invention;

2 is a schematic diagram of the internal circuit principle of a device for measuring mechanical characteristics of a circuit breaker disclosed in an embodiment of the present invention;

3 is a schematic diagram of the internal circuit principle of the test power supply module disclosed in the embodiment of the present invention;

FIG. 4 is a schematic diagram of the internal circuit principle of the switching control module disclosed in the embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

1 is a schematic structural diagram of a mechanical characteristic measuring device of a circuit breaker according to an embodiment of the present invention. The measuring device includes an FPGA processing module, an opening and closing control module, a test power supply module and a mechanical characteristic sampling module, wherein the The mechanical characteristic sampling module includes an opening and closing time sampling unit, an opening and closing speed sampling unit, an opening and closing coil characteristic sampling unit, a first sampling board and a second sampling board.

Basically, the opening and closing time sampling unit is connected to the FPGA processing module through the first sampling board, and the opening and closing speed sampling unit and the opening and closing coil characteristic sampling unit pass through the second sampling unit respectively. The board is connected to the FPGA processing module; the test power supply module is connected to the FPGA processing module, and the opening and closing control module is connected to the FPGA processing module.

In the embodiment of the present invention, the opening and closing time sampling unit is used to obtain the dynamic changes of the dynamic and static contacts and the inherent opening and closing time of the graphite contact circuit breaker or the ordinary circuit breaker during the closing and opening process The opening and closing speed sampling unit is used to obtain the opening and closing displacement of the circuit breaker by using the travel sensor; the opening and closing coil characteristic sampling unit is used to obtain the maximum value that flows through the opening and closing coil of the circuit breaker. current signal; finally, the FPGA processing module performs AD signal reading and bulk data storage for each mechanical characteristic parameter mentioned above. Since the FPGA processing module is connected to the communication interface of the EM9170 industrial control mainboard through a parallel bus, the sampled data read by the FPGA processing module can be transmitted to the EM9170 industrial control mainboard, and then uploaded via the EM9170 industrial control mainboard. Go to the upper computer for software judgment. In the whole test process, a plurality of different mechanical characteristic parameters are obtained through measurement and sampling, and analyzed and judged by the upper computer, and the test efficiency is high.

FIG. 2 is a schematic diagram of the internal circuit principle of a device for measuring mechanical characteristics of a circuit breaker according to an embodiment of the present invention. Based on FIG. 2 , each module in the device for measuring mechanical characteristics is further described as follows:

Specifically, the opening and closing time sampling unit includes several differential signal processing circuits and several relays, and each differential signal processing circuit is correspondingly connected to an output end of a relay; wherein, the circuit breaker includes a three-circuit circuit breaker group , the first input end of each relay in the plurality of relays is connected to the graphite contact of the corresponding circuit breaker in the circuit breaker, and the second input end of each relay in the plurality of relays is connected to the circuit breaker the metal contacts of the corresponding circuit breaker in the device. It should be noted that the circuit breaker may actually be a graphite contact circuit breaker or a common circuit breaker, and the two input ends of the plurality of relays can provide measurement conditions for the above two relays, so that the measurement device has more good usability.

Regarding the working principle of the opening and closing time sampling unit, the embodiment of the present invention provides the test power supply module as a test auxiliary tool. According to the schematic diagram of the internal circuit principle of the test power supply module shown in FIG. 3 , the test power supply module is a 10A constant current power supply board, wherein the FPGA processing module controls the 10A constant current power supply board through an output control terminal and a charging control terminal In the charging state or constant current output state, and the 10A constant current power supply board is in the charging state to meet its own normal operation, the 10A constant current power supply board is in the constant current output state to make the metal of the circuit breaker dynamic and static contacts The current channel formed when the parts are in contact can generate 10A of DC power. It should be noted that the 10A constant current power board only works on the measurement of the graphite contact circuit breaker.

In the embodiment of the present invention, the opening and closing time sampling unit can measure two types of circuit breakers, namely a graphite contact circuit breaker and a closing/common contact circuit breaker. Among them, the four-wire wiring test method is used for the graphite contact circuit breaker, and the current channel and the fracture of the graphite contact circuit breaker form a circuit. The voltage sampled by the voltage sampling and analysis channel at the two ends of the breaker of the graphite contact circuit breaker is the power supply voltage when the current channel is no-load; then the metal parts of the moving and static contacts are in contact, and the 10A constant current circuit board goes to the Each phase fracture of the graphite contact circuit breaker is injected with a constant current source, that is, the DC channel generates a constant DC current of 10A. At this time, the fracture voltage value is obtained through the voltage sampling and analysis channel, and the fracture voltage value is passed through the full-wave sampling algorithm. After the power frequency interference is filtered out, the host computer will compare the voltage value of the fracture with the preset value, judge the change of the opening and closing action of the graphite contact, and record the corresponding contact time point and contact separation. point in time. Since the metal parts of the movable contact and the stationary contact in the graphite contact circuit breaker are in reliable contact, the accuracy of the measurement result can be guaranteed.

In addition, the two-wire wiring test method is adopted for the closing/common contact circuit breaker, the voltage sampling is used for each phase fracture of the closing/common contact circuit breaker, and 50mA is injected into the each phase fracture during the measurement process. The constant DC power supply, with the photoelectric isolation sampling method, records the on-off signal of the closing/common contact circuit breaker by identifying the high and low level changes by the upper computer, so as to record its opening and closing time, but this method is not suitable for The requirements for measurement accuracy are not high.

Specifically, the opening and closing speed sampling unit includes a plurality of travel sensors, and each travel sensor in the plurality of travel sensors is installed on the operating mechanism link of the circuit breaker corresponding to the circuit breaker. The output end of each of the several stroke sensors is respectively connected to the second sampling plate. Wherein, each travel sensor pair is used to collect the displacement information of the moving contact of each circuit breaker in the circuit breaker during the opening and closing operation and transmit it to the second sampling board for amplification and filtering processing, and then The processed displacement signal is uploaded to the upper computer, and the upper computer synthesizes the travel-time curve when the contact just opens/closes according to the displacement information, and calculates the time when the circuit breaker completes the opening and closing operation. Action time, average speed, etc.

Specifically, the opening and closing coil characteristic sampling unit includes a current signal processing circuit and three opening and closing relays; wherein, the first input end of each opening and closing relay in the three opening and closing relays is connected to the circuit breaker The closing coil of the corresponding circuit breaker, the second input end of each of the three switching relays is connected to the opening coil of the circuit breaker corresponding to the circuit breaker, the three The output terminal of each switching relay in the switching relay is respectively connected to the input terminal of the current signal processing circuit, and the output terminal of the current signal processing circuit is connected to the second sampling board.

The current signal processing circuit is an I/V conversion circuit, which mainly adjusts the current signal with fast change speed, small amplitude and interference on the opening and closing coil of each circuit breaker in the circuit breaker, and then adjusts the current signal. The second sampling board is used to perform amplification filtering and AD sampling processing to remove clutter and noise of the original current signal and improve the accuracy of data processing.

In addition, in the embodiment of the present invention, there are two triggering methods for the opening and closing operation of the circuit breaker: the first is to use the opening and closing control module inside the device, such as the opening and closing control shown in FIG. 4 . The schematic diagram of the internal circuit principle of the module, the opening and closing control module is an operating power supply, the input end of the operating power supply is connected to the peripheral mains power supply equipment, and the output end of the operating power supply is connected to each of the circuit breakers. The coils of one circuit breaker are connected, and the control end of the operating power supply is connected with the FPGA processing module. Specifically, the operating power supply adopts the principle of switching power supply. First, the mains 220V AC voltage provided by the mains power supply equipment is used as the input power supply, and is converted into a 0-260V DC operating power supply through rectification and filtering, and then processed based on the FPGA. The chopper signal output by the module is used to control the closing of the closing IGBT module or the opening IGBT module, so as to switch the opening and closing mode and test the power transmission. The second is to use the on-site AC power supply or DC power supply to operate the switch when the operating power supply is not working, and directly connect to the circuit breaker of each circuit breaker in the circuit breaker through the external closing and opening trigger wiring. On the coil, test the power transmission.

It should be noted that when a closing or opening action occurs on the coil of each circuit breaker in the circuit breaker, a corresponding closing signal or opening signal will be generated and fed back to the FPGA processing module as a coil characteristic. The time starting point of the measurement; in addition, the calculation of other mechanical characteristic parameters of the circuit breaker by the host computer is based on the feedback signal as the trigger basis.

Based on the above description of each module in FIG. 2 , an embodiment of the present invention further provides a method for measuring mechanical characteristics of a circuit breaker, and the measuring method includes:

(1) Obtain the opening and closing stroke signal, coil current signal and main contact voltage signal generated during the opening and closing process of the circuit breaker;

Specifically, the circuit breaker is controlled to perform the opening and closing action through the operating power supply, and the opening and closing stroke signal of the circuit breaker is obtained through the opening and closing speed sampling unit, and the opening and closing time sampling unit is used to obtain the opening and closing stroke signal of the circuit breaker. The main contact voltage signal of the circuit breaker is acquired, and the coil current signal of the circuit breaker is acquired through the opening and closing coil characteristic sampling unit.

(2) Analyze and process the opening and closing stroke signal, the coil current signal and the main contact voltage signal, and calculate the mechanical characteristic parameters of the circuit breaker, wherein the characteristic parameters include the opening coil current The maximum value, the maximum value of the closing coil current, the moment of just opening, the moment of just closing, the opening displacement and the closing displacement.

In the embodiment of the present invention, the analysis and processing of the opening and closing stroke signal, the coil current signal and the main contact voltage signal depend on the running of the software program of the upper computer: for the opening and closing stroke The analysis and processing of the signal, first denoise the opening and closing stroke signal by the wavelet threshold denoising method, and then use the median filter algorithm to further smooth the denoised signal to obtain the accurate contact stroke-time curve, and finally calculate the opening displacement and the closing displacement according to the contact travel-time curve analysis by using the data operation subprogram written in the host computer. Secondly, for the analysis and processing of the coil current signal, firstly, the wavelet transform algorithm is applied to extract two feature points useful for analysis from the coil current signal, and then the soft threshold method in wavelet analysis is used to remove noise from the coil current. A section of current signal is intercepted from the signal, and the current signal takes the above two characteristic points as the starting point, and finally the upper computer uses the data program operation subroutine to extract the maximum value of the current of the opening coil from the current signal and the closing coil current maximum value. In addition, for the analysis and processing of the main contact voltage signal, see the above description of the opening and closing time sampling unit.

The invention proposes a mechanical characteristic measuring device of a circuit breaker, which is provided with a plurality of test units for the high-efficiency test requirements of the circuit breaker, which can realize the functions of real-time acquisition, analysis and calculation of the mechanical characteristic parameters of the circuit breaker, and can effectively improve the The test efficiency of the mechanical property test is high, and the reliability is high and has good practical value.

In addition, the device and method for measuring the mechanical characteristics of a circuit breaker provided by the embodiments of the present invention have been described in detail above. Specific examples should be used in this paper to illustrate the principles and implementations of the present invention. The description is only used to help understand the method of the present invention and its core idea; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. , the contents of this specification should not be construed as limiting the invention.

Claims (10)

1. The mechanical characteristic measuring device of the circuit breaker is characterized by comprising an FPGA processing module, a switching-on and switching-off control module, a testing power supply module and a mechanical characteristic sampling module;

the mechanical characteristic sampling module comprises a switching-on and switching-off time sampling unit, a switching-on and switching-off speed sampling unit, a switching-on and switching-off coil characteristic sampling unit, a first sampling plate and a second sampling plate, the switching-on and switching-off time sampling unit is connected with the FPGA processing module through the first sampling plate, and the switching-on and switching-off speed sampling unit and the switching-on and switching-off coil characteristic sampling unit are respectively connected with the FPGA processing module through the second sampling plate;

the testing power supply module is connected with the FPGA processing module, and the opening and closing control module is connected with the FPGA processing module.

2. The mechanical characteristic measuring device of the circuit breaker according to claim 1, wherein the switching-on and switching-off time sampling unit comprises a plurality of differential signal processing circuits and a plurality of relays, and each differential signal processing circuit is correspondingly connected with an output end of one relay;

the circuit breaker comprises a three-way circuit breaker group, wherein the first input end of each relay in the plurality of relays is connected with the graphite contact of the corresponding circuit breaker in the circuit breaker, and the second input end of each relay in the plurality of relays is connected with the metal contact of the corresponding circuit breaker in the circuit breaker.

3. The device for measuring the mechanical characteristics of the circuit breaker according to claim 2, wherein the switching-on/off speed sampling unit comprises a plurality of stroke sensors, each of the plurality of stroke sensors is mounted on a corresponding one-way operating mechanism connecting rod of the circuit breaker, and an output end of each of the plurality of stroke sensors is connected to the second sampling plate.

4. The mechanical characteristic measurement device of a circuit breaker according to claim 3, wherein the opening and closing coil characteristic sampling unit includes a current signal processing circuit and three opening and closing relays;

the first input end of each on-off relay in the three on-off relays is connected the closing coil of the corresponding circuit breaker of the same kind in the circuit breaker, the second input end of each on-off relay in the three on-off relays is connected the opening coil of the corresponding circuit breaker of the same kind in the circuit breaker, the output end of each on-off relay in the three on-off relays is connected respectively the input end of the current signal processing circuit, and the output end of the current signal processing circuit is connected with the second sampling plate.

5. The device for measuring the mechanical characteristics of the circuit breaker according to claim 4, wherein the switching-on/off control module is an operating power supply, an input end of the operating power supply is connected with an external commercial power supply device, an output end of the operating power supply is connected with a coil of each circuit breaker of the circuit breakers, and a control end of the operating power supply is connected with the FPGA processing module.

6. The apparatus of claim 1, wherein the test power supply module is a 10A constant current power supply board.

7. The device for measuring the mechanical characteristics of the circuit breaker according to claim 1, wherein the FPGA processing module is connected with a communication interface of the EM9170 industrial control mainboard through a parallel bus.

8. A method of measuring a mechanical characteristic of a circuit breaker, the method comprising:

acquiring a switching-on and switching-off stroke signal, a coil current signal and a main contact voltage signal which are generated in the switching-on and switching-off process of the circuit breaker;

and analyzing and processing the opening and closing stroke signal, the coil current signal and the main contact voltage signal, and calculating the mechanical characteristic parameters of the circuit breaker.

9. The method for measuring the mechanical characteristics of the circuit breaker according to claim 8, wherein the acquiring the opening and closing stroke signal, the coil current signal and the main contact voltage signal generated by the circuit breaker in the opening and closing process comprises:

the circuit breaker is controlled by an operating power supply to execute opening and closing actions, opening and closing stroke signals of the circuit breaker are acquired through an opening and closing speed sampling unit, main contact voltage signals of the circuit breaker are acquired through an opening and closing time sampling unit, and coil current signals of the circuit breaker are acquired through an opening and closing coil characteristic sampling unit.

10. The method of claim 8, wherein the mechanical characteristic parameters include a maximum value of a current of the opening coil, a maximum value of a current of the closing coil, a moment of just opening, a moment of just closing, a displacement of opening and a displacement of closing.

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