阅读说明：本技术 一种电动机差动保护电流互感器接线校验装置及方法 (Wiring checking device and method for motor differential protection current transformer ) 是由 章勇 薛杰 申雁鹏 佟小明 严皓翔 李剑秋 齐奥 吕泓瑄 孙凯 于霄 吴兴文 于 2020-12-04 设计创作，主要内容包括：本发明属于电气试验技术领域,具体涉及一种电动机差动保护电流互感器接线校验装置及方法,所述电流互感器接线校验装置包括：仪器控制显示面板、多通道测量选择模块、多通道测量采样接口、电源进线接口、可调电流源模块和电流源输出端口。本发明的电流互感器接线校验装置接线回路简单,所需设备少,能够有效缩短试验回路调试时间,降低试验过程中触电安全风险,提高试验的一次成功率。(The invention belongs to the technical field of electrical tests, and particularly relates to a wiring calibration device and method for a motor differential protection current transformer, wherein the wiring calibration device for the current transformer comprises the following components: the instrument control display panel, the multichannel measurement selection module, the multichannel measurement sampling interface, the power inlet wire interface, the adjustable current source module and the current source output port. The current transformer wiring calibration device disclosed by the invention is simple in wiring loop, needs less equipment, can effectively shorten the debugging time of the test loop, reduces the electric shock safety risk in the test process, and improves the one-time success rate of the test.)

1. A wiring calibration device for a current transformer of a motor differential protection is characterized by comprising: the device comprises an instrument control display panel (1), a multi-channel measurement selection module (2), a multi-channel measurement sampling interface (3), a power supply inlet wire interface (4), an adjustable current source module (5) and a current source output port (6); the third output end of the instrument control display panel (1) is connected with the first input end of the multichannel measurement selection module (2), the fourth output end of the instrument control display panel (1) is connected with the second input end of the adjustable current source module (5), the output end of the multichannel measurement sampling interface (3) is connected with the second input end of the multichannel measurement selection module (2), the output end of the power supply inlet wire interface (4) is connected with the first input end of the adjustable current source module (5), the output end of the adjustable current source module (5) is connected with the first input end of the current source output port (6), the second output end of the current source output port (6) is connected with the third input end of the multichannel measurement selection module (2), and the output end of the multichannel measurement selection module (2) is connected with the input end of the instrument control display panel (1).

2. The wiring verification device of the motor differential protection current transformer according to claim 1, wherein the instrument control display panel (1) comprises an LED display and operation screen (7), a USB interface (8) and a micro printer (9); the first output end of the LED display and operation screen (7) is connected with the input end of the micro printer (9); a second output end of the LED display and operation screen (7) is connected with an input end of the USB interface (8); the third output end of the LED display and operation screen (7) is connected with the first input end of the multi-channel measurement selection module (2); a fourth output end of the LED display and operation screen (7) is connected with a second input end of the adjustable current source module (5); the input end of the LED display and operation screen (7) is connected with the output end of the multi-channel measurement selection module (2).

3. The wiring verification device of the motor differential protection current transformer according to claim 2, wherein the multi-channel measurement selection module (2) comprises a measurement analysis module (10) and a measurement channel switch (11); a first input end of the measuring channel switch (11) is connected with a third output end of the LED display and operation screen (7), and a second input end of the measuring channel switch (11) is connected with an output end of the multi-channel measuring and sampling interface (3); a third input end of the measuring channel switch (11) is connected with a second output end of the current source output port (6); the output end of the measuring channel switch (11) is connected with the input end of the measuring and analyzing module (10), and the output end of the measuring and analyzing module (10) is connected with the input end of the LED display and operation screen (7).

4. The wiring verification device of the motor differential protection current transformer according to claim 3, wherein the multi-channel measurement sampling interface (3) comprises a current input terminal, an input end of the current input terminal is connected with an output end of the secondary side of the current transformer, and an output end of the current input terminal is connected with a second input end of the measurement channel switch (11).

5. The motor differential protection current transformer wiring verification device of claim 4, wherein the current input terminals comprise a1 input (12), a2 input (13), a0 input (14), b1 input (15), b2 input (16), b0 input (17), c1 input (18), c2 input (19), c0 input (20); the a1 input (12), the a2 input (13), the b1 input (15), the b2 input (16), the c1 input (18) and the c2 input (19) are used for collecting the secondary side current of the current transformer, and the a0 input (14), the b0 input (17) and the c0 input (20) are used for collecting the confluence of the current transformer.

6. The wiring verification device of the motor differential protection current transformer of claim 5, characterized in that the a1 input (12), the a2 input (13), the a0 input (14), the b1 input (15), the b2 input (16), the b0 input (17), the c1 input (18), the c2 input (19) and the c0 input (20) are respectively configured with clamp-shaped wiring ports.

7. The wiring verification device of the motor differential protection current transformer according to claim 6, wherein the power incoming line interface (4) comprises a power switch (21), a fuse A (22), a fuse B (23) and a ground terminal (24), an input end of the power switch (21) is connected with an output end of a power supply, an output end of the power switch (21) is connected with input ends of the fuse A (22) and the fuse B (23), output ends of the fuse A (22) and the fuse B (23) are connected with a first input end of the adjustable current source module (5), and the ground terminal (24) is grounded through a ground wire.

8. The wiring verification device of the motor differential protection current transformer according to claim 7, wherein the adjustable current source module (5) comprises an isolation transformer (25) and a voltage regulator (26), a first input end of the isolation transformer (25) is connected with output ends of a fuse A (22) and a fuse B (23), respectively, a second input end of the voltage regulator (26) is connected with a fourth output end of the LED display and operation screen (7), a third input end of the voltage regulator (26) is connected with an output end of the isolation transformer (25), and an output end of the voltage regulator (26) is connected with a first input end of the current source output port (6).

9. The wiring verification device of the motor differential protection current transformer according to claim 8, wherein the current source output port (6) comprises a current output terminal and a current input terminal, and the current output terminal and the current input terminal form a current source output loop.

10. The wiring verification device for the current transformer for motor differential protection according to claim 9, wherein the first input terminal of the current input terminal is connected to the output terminal of the voltage regulator (26), the first output terminal of the current input terminal is connected to the input terminal of the primary side of the current transformer, the second input terminal of the current output terminal is connected to the output terminal of the primary side of the current transformer, and the second output terminal of the current output terminal is connected to the third input terminal of the measurement channel switch (11).

11. A motor differential protection current transformer wiring verification device according to claim 10, wherein said current output terminals comprise an a output (27), a B output (29) and a C output (31); the current input terminals include an A input (28), a B input (30), and a C input (32).

12. The wiring verification device of the motor differential protection current transformer according to claim 11, wherein the a output (27), the a input (28), the B output (29), the B input (30), the C output (31) and the C input (32) are respectively provided with a wire clamp.

13. A method for verifying the wiring verification device of the motor differential protection current transformer of claim 12, wherein the method comprises the steps of:

the method comprises the following steps that (1) a connecting wire is used for connecting a current transformer wiring calibration device and a current transformer, and a grounding wire is used for connecting the current transformer wiring calibration device;

step (2), connecting the current transformer wiring calibration device and a power supply by using a power line;

selecting a channel to be tested and the required current in the current transformer wiring calibration device, and starting testing;

step (4), collecting and analyzing the current of the current transformer;

step (5), outputting a current analysis result of the current transformer, and finishing the test;

step (6), removing a power line connecting the current transformer wiring calibration device and a power supply;

and (7) removing a connecting wire for connecting the current transformer wiring calibration device and the current transformer, and removing a grounding wire for connecting the current transformer wiring calibration device.

14. The method of claim 13, wherein the step (1) comprises:

step (1.1), connecting a current output terminal of the power output port (6) with a primary side loop of a current transformer through a current output connecting wire through a wire clamp arranged on a current output terminal connected with the power output port (6);

step (1.2), connecting a current input terminal of the multi-channel measurement sampling interface (3) and a secondary side loop of a current transformer through a pincerlike wiring port arranged on a current input terminal of the multi-channel measurement sampling interface (3) by using a current collection connecting wire;

step (1.3), connecting a grounding terminal (24) on a power supply inlet wire interface (4) by using a grounding wire, and grounding the shell of the checking device;

15. the wiring verification method for the motor differential protection current transformer according to claim 13, wherein the step (2) is specifically as follows: and a power switch (21) of the power inlet wire interface (4) and a power and closed power switch (21) are connected by using a power line to supply power for the whole current transformer wiring calibration device.

16. The wiring verification method for the motor differential protection current transformer according to claim 13, wherein the step (3) is specifically as follows: the LED display and operation screen (7) of the instrument control display panel (1) is used for controlling the measurement channel switch (11), a channel to be tested is selected, the LED display and operation screen (7) of the instrument control display panel (1) is used for controlling the voltage regulator (26) of the adjustable current source module (5), and the current is adjusted.

17. The wiring verification method for the motor differential protection current transformer according to claim 13, wherein the step (4) is specifically as follows: the secondary side current and confluence of the current transformer are collected through a current input terminal of a multi-channel measurement sampling interface (3), the primary side current of the current transformer is collected through a current output terminal of a current source output port (6), then the collected currents of the primary side and the secondary side of the current transformer are analyzed through a measurement analysis module (10), and an analysis result is transmitted to an LED display and operation screen (7) of an instrument control display panel (1).

18. The wiring verification method of claim 13, wherein the outputting the current analysis result of the current transformer in the step (5) comprises: displaying the analysis result in an LED display and operation screen (7) of the instrument control display panel (1), and storing data; the USB interface (8) is controlled by the LED display and operation screen (7) of the instrument control display panel (1) to output an analysis result, and the analysis result is printed by the LED display and operation screen (7) of the instrument control display panel (1) and the micro printer (9).

19. The wiring verification method for the motor differential protection current transformer according to claim 13, wherein the step (6) is specifically as follows: disconnecting a power switch (21) of the power inlet wire interface (4) and stopping supplying power to the whole current transformer wiring calibration device; and (3) detaching a power switch (21) connected with the power inlet wire interface (4) and a power wire of the power supply.

20. The motor differential protection current transformer wiring verification method according to claim 13, wherein said step (7) comprises:

step (7.1), removing a current output connecting wire which is connected with a current output terminal of the power output port (6) and a primary side loop of the current transformer;

step (7.2), removing a current collecting connecting wire which connects a current input terminal of the multi-channel measuring and sampling interface (3) and a secondary side loop of the current transformer;

and (7.3) removing the grounding wire connected with the grounding terminal (24) on the power supply inlet wire interface (4).

Technical Field

The invention belongs to the technical field of electrical tests, and particularly relates to a wiring calibration device and method for a differential protection current transformer of a motor.

Background

The current transformer is a device for measuring by converting a large current on a primary side into a small current on a secondary side according to an electromagnetic induction principle, and is called CT for short. The motor differential protection current transformer refers to an electric device for sampling a motor differential protection current.

The large-scale motor needs to be subjected to primary electric through-flow and secondary current transformer wiring verification work (also called as motor through-flow test) before being started for the first time after overhaul so as to verify the wiring correctness and polarity of the current transformer for motor differential protection, and if the differential protection is in wrong wiring in the overhaul process, the primary electric through-flow test is an effective method which can be verified before the motor is started.

The method of the electric primary through-flow test used on the spot at present comprises the following steps: the power supply is led into the voltage regulator through the isolation transformer, large current is output to primary equipment, a loop is formed after the current passes through the motor body, and the phase meter is used for measuring on the secondary side of the current transformer so as to verify the phase and the polarity and judge whether the wiring of the current transformer is correct or not.

Currently, the following problems exist with this work:

(1) the motor through-flow test loop comprises an alternating-current power supply, an isolation transformer, a voltage regulator, an ammeter, a phase meter, a test wire and the like, and has more equipment and complex wiring;

(2) because leakage current exists at the moment of switching on the test loop, and the upstream power source leakage protection action trips frequently, the debugging time of the test loop is long;

(3) because the isolation transformer and the voltage regulator are both traditional equipment, and the wiring terminals are exposed outside, the potential safety hazard of electric shock of personnel is great;

(4) when the motor is subjected to a through-current test, a static contact valve of a circuit breaker chamber of a switch cabinet needs to be opened, and a jointing clamp is placed at the position of a lower static contact; because the bus section is in an electrified state, the fixed contact at the upper part of the cabinet is electrified, and personnel have great electric shock risk during operation;

(5) the through-flow test needs a plurality of persons to participate, usually high-voltage personnel manually operate a voltage regulator to add current, and then the current transformer secondary loop current is measured one by a maintainer; in the actual test process, because the manual pressure regulating of voltage regulator's reason, can't accurate impressed current to the success rate of through-flow test's one time has been reduced.

Disclosure of Invention

The invention aims to solve the problems that the existing large-scale motor through-flow test has complicated test loop wiring and long debugging time; the testing operation is complex, and the required manpower is much, so that the wiring calibration device and method for the motor differential protection current transformer can effectively shorten the debugging time of a testing loop, reduce the electric shock safety risk in the testing process, and improve the one-time success rate of the test.

The technical scheme for realizing the purpose of the invention is as follows:

a wiring verification device for a motor differential protection current transformer, comprising: the instrument control display panel, the multi-channel measurement selection module, the multi-channel measurement sampling interface, the power supply inlet wire interface, the adjustable current source module and the current source output port; the third output end of the instrument control display panel is connected with the first input end of the multichannel measurement selection module, the fourth output end of the instrument control display panel is connected with the second input end of the adjustable current source module, the output end of the multichannel measurement sampling interface is connected with the second input end of the multichannel measurement selection module, the output end of the power supply inlet wire interface is connected with the first input end of the adjustable current source module, the output end of the adjustable current source module is connected with the first input end of the current source output port, the second output end of the current source output port is connected with the third input end of the multichannel measurement selection module, and the output end of the multichannel measurement selection module is connected with the input end of the instrument control display panel.

Furthermore, the instrument control display panel comprises an LED display and operation screen, a USB interface and a micro printer; the first output end of the LED display and operation screen is connected with the input end of the micro printer; the second output end of the LED display and operation screen is connected with the input end of the USB interface; the third output end of the LED display and operation screen is connected with the first input end of the multi-channel measurement selection module; the fourth output end of the LED display and operation screen is connected with the second input end of the adjustable current source module; the input end of the LED display and operation screen is connected with the output end of the multichannel measurement selection module.

Further, the multi-channel measurement selection module comprises a measurement analysis module and a measurement channel switch; the first input end of the measuring channel selector switch is connected with the third output end of the LED display and operation screen, and the second input end of the measuring channel selector switch is connected with the output end of the multi-channel measuring and sampling interface; a third input end of the measuring channel selector switch is connected with a second output end of the current source output port; the output end of the measuring channel switch is connected with the input end of the measuring and analyzing module, and the output end of the measuring and analyzing module is connected with the input end of the LED display and operation screen.

Furthermore, the multichannel measurement sampling interface comprises a current input terminal, the input end of the current input terminal is connected with the output end of the secondary side of the current transformer, and the output end of the current input terminal is connected with the second input end of the measurement channel change-over switch.

Further, the current input terminals include a1 input, a2 input, a0 input, b1 input, b2 input, b0 input, c1 input, c2 input, c0 input; the input of a1, the input of a2, the input of b1, the input of b2, the input of c1 and the input of c2 are used for collecting the secondary side current of the current transformer, and the input of a0, the input of b0 and the input of c0 are used for collecting the confluence of the current transformer.

Further, clamp-shaped wiring ports are arranged for the a1 input, the a2 input, the a0 input, the b1 input, the b2 input, the b0 input, the c1 input, the c2 input, and the c0 input, respectively.

Further, the power supply incoming line interface comprises a power supply switch, a fuse A, a fuse B and a grounding terminal, the input end of the power supply switch is connected with the output end of the power supply, the output end of the power supply switch is respectively connected with the input ends of the fuse A and the fuse B, the output ends of the fuse A and the fuse B are connected with the first input end of the adjustable current source module, and the grounding terminal is grounded through a grounding wire.

Furthermore, the adjustable current source module comprises an isolation transformer and a voltage regulator, wherein a first input end of the isolation transformer is connected with output ends of the fuse A and the fuse B respectively, a second input end of the voltage regulator is connected with a fourth output end of the LED display and operation screen, a third input end of the voltage regulator is connected with an output end of the isolation transformer, and an output end of the voltage regulator is connected with a first input end of the current source output port.

Further, the current source output port comprises a current output terminal and a current input terminal, and the current output terminal and the current input terminal form a current source output loop.

Furthermore, the first input end of the current input terminal is connected with the output end of the voltage regulator, the first output end of the current input terminal is connected with the input end of the primary side of the current transformer, the second input end of the current output terminal is connected with the output end of the primary side of the current transformer, and the second output end of the current output terminal is connected with the third input end of the measurement channel change-over switch.

Further, the current output terminal includes an a output, a B output, and a C output; the current input terminals include an a input, a B input, and a C input.

Furthermore, the A output, the A input, the B output, the B input, the C output and the C input are respectively provided with a wire clamp.

A method for verifying wiring of a differential protection current transformer of an electric motor, the method comprising the steps of:

the method comprises the following steps that (1) a connecting wire is used for connecting a current transformer wiring calibration device and a current transformer, and a grounding wire is used for connecting the current transformer wiring calibration device;

step (2), connecting the current transformer wiring calibration device and a power supply by using a power line;

selecting a channel to be tested and the required current in the current transformer wiring calibration device, and starting testing;

step (4), collecting and analyzing the current of the current transformer;

step (5), outputting a current analysis result of the current transformer, and finishing the test;

step (6), removing a power line connecting the current transformer wiring calibration device and a power supply;

and (7) removing a connecting wire for connecting the current transformer wiring calibration device and the current transformer, and removing a grounding wire for connecting the current transformer wiring calibration device.

Further, the step (1) includes:

step (1.1), connecting a current output terminal of a power output port with a primary side loop of a current transformer through a wire clamp arranged on a current output terminal connected with the power output port by using a current output connecting wire;

step (1.2), connecting a current input terminal of the multi-channel measurement sampling interface and a secondary side loop of a current transformer through a pincerlike wiring port arranged on a current input terminal of the multi-channel measurement sampling interface by using a current acquisition connecting wire;

and (1.3) connecting a grounding terminal on the power supply inlet wire interface by using a grounding wire, and grounding the shell of the checking device.

Further, the step (2) is specifically: and a power switch of the power inlet wire interface, a power supply and a closed power switch are connected by using a power line to supply power for the whole current transformer wiring calibration device.

Further, the step (3) is specifically: the LED display and operation screen of the instrument control display panel controls the measuring channel switch, the channel to be tested is selected, the LED display and operation screen of the instrument control display panel controls the voltage regulator of the adjustable current source module, and the current is adjusted.

Further, the step (4) is specifically as follows: the method comprises the steps of collecting secondary side current and confluence of a current transformer through a current input terminal of a multichannel measurement sampling interface, collecting primary side current of the current transformer through a current output terminal of a current source output port, analyzing the collected primary side current and secondary side current of the current transformer through a measurement analysis module, and transmitting an analysis result to an LED display and operation screen of an instrument control display panel.

Further, the outputting the current analysis result of the current transformer in the step (5) includes: displaying the analysis result in an LED display and operation screen of an instrument control display panel, and storing data; the LED display and operation screen of the instrument control display panel controls the USB interface to output an analysis result, and the LED display and operation screen micro printer of the instrument control display panel prints the analysis result.

Further, the step (6) is specifically: disconnecting a power switch of a power inlet interface and stopping supplying power to the whole current transformer wiring calibration device; and (4) detaching a power switch connected with the power inlet wire interface and a power wire of the power supply.

Further, the step (7) includes:

step (7.1), removing a current output connecting wire which is connected with a current output terminal of the power output port and a primary side loop of the current transformer;

step (7.2), removing a current collecting connecting wire which connects a current input terminal of the multi-channel measuring and sampling interface and a secondary side loop of the current transformer;

and (7.3) removing the grounding wire connected with the grounding terminal on the power supply inlet wire interface.

The invention has the beneficial technical effects that:

1. the wiring calibration device for the motor differential protection current transformer is simple in wiring loop and few in required equipment, effectively solves the problems that a traditional test method is complex in wiring loop and needs more equipment, reduces the number of wire replacement times in the test process, reduces the number of personnel required for field test, and reduces the labor cost;

2. according to the wiring calibration device for the motor differential protection current transformer, the isolation transformer is arranged to realize self electrical isolation, the test loop debugging time is shortened, and the problems that field equipment frequently trips and the test loop debugging time is long are effectively solved;

3. according to the wiring calibration device for the motor differential protection current transformer, the voltage regulator is controlled through the LED display and operation screen, the required test current can be accurately controlled, and the one-time success rate of the test is improved;

4. the wiring calibration device for the motor differential protection current transformer can effectively reduce the safety risk of electric shock of personnel in the existing test method;

5. the wiring calibration device of the motor differential protection current transformer has the characteristics of integration, integration and intellectualization, and is convenient to operate and carry; the current transformer can be matched with various wiring modes on site, and has a wide application range.

Drawings

Fig. 1 is a schematic block diagram of a wiring verification device for a differential protection current transformer of a motor according to the present invention;

fig. 2 is a schematic diagram of an instrument control display panel in the wiring calibration apparatus for the current transformer for motor differential protection provided by the present invention;

fig. 3 is a schematic diagram of a multi-channel measurement selection module in the wiring verification apparatus for the current transformer for motor differential protection according to the present invention;

fig. 4 is a schematic view of a multi-channel measurement sampling interface in the wiring calibration apparatus for the motor differential protection current transformer provided by the present invention;

fig. 5 is a schematic diagram of a power inlet interface in the wiring calibration apparatus for the current transformer for the differential protection of the motor provided by the present invention;

fig. 6 is a schematic diagram of an adjustable current source module in the wiring calibration apparatus for the current transformer for motor differential protection according to the present invention;

fig. 7 is a schematic diagram of a current source output port in the wiring verification device for the motor differential protection current transformer provided by the invention;

in the figure: 1. an instrument control display panel; 2. a multi-channel measurement selection module; 3. a multi-channel measurement sampling interface; 4. a power inlet interface; 5. an adjustable current source module; 6. a current source output port; 7. an LED display and operation screen; 8. a USB interface; 9. a micro printer; 10. a measurement analysis module; 11. a measurement channel changeover switch; 12. a is₁Inputting; 13. a is₂Inputting; 14. a is₀Inputting; 15. b₁Inputting; 16. b₂Inputting; 17. b₀Inputting; 18. c. C₁Inputting; 19. c. C₂Inputting; 20. c. C₀Inputting; 21. a power switch; 22. a fuse 1; 23. a fuse 2; 24. a ground terminal; 25. an isolation transformer; 26. a voltage regulator; 27. a, outputting; 28. inputting; 29. b, outputting; 30. b, inputting; 31. c, outputting; 32. and C, inputting.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

As shown in fig. 1, the present invention provides a wiring verification device for a current transformer of a differential protection of an electric motor, the device comprising: the device comprises an instrument control display panel 1, a multi-channel measurement selection module 2, a multi-channel measurement sampling interface 3, a power supply inlet wire interface 4, an adjustable current source module 5 and a current source output port 6. The third output end of the instrument control display panel 1 is connected with the first input end of the multichannel measurement selection module 2, the fourth output end of the instrument control display panel 1 is connected with the second input end of the adjustable current source module 5, the output end of the multichannel measurement sampling interface 3 is connected with the second input end of the multichannel measurement selection module 2, the output end of the power supply incoming line interface 4 is connected with the first input end of the adjustable current source module 5, the output end of the adjustable current source module 5 is connected with the first input end of the current source output port 6, the second output end of the current source output port 6 is connected with the third input end of the multichannel measurement selection module 2, and the output end of the multichannel measurement selection module 2 is connected with the input end of the instrument control display panel 1.

As shown in fig. 2, the instrument control display panel 1 includes an LED display and operation panel 7, a USB interface 8, and a micro printer 9. The first output end of the LED display and operation screen 7 is connected with the input end of the micro printer 9 and is used for controlling the micro printer 9 to print and output the measured data result; a second output end of the LED display and operation screen 7 is connected with an input end of the USB interface 8 and is used for controlling the USB interface 8 to transmit data; the third output end of the LED display and operation screen 7 is connected with the first input end of the multi-channel measurement selection module 2; a fourth output end of the LED display and operation screen 7 is connected with a second input end of the adjustable current source module 5; the input end of the LED display and operation screen 7 is connected with the output end of the multi-channel measurement selection module 2.

As shown in fig. 3, the multi-channel measurement selection module 2 includes a measurement analysis module 10 and a measurement channel changeover switch 11. The measuring channel switch 11 is built-in, a first input end of the measuring channel switch 11 is connected with a third output end of the LED display and operation screen 7, and the measuring channel switch 11 is selectively controlled through the LED display and operation screen 7. The second input end of the measuring channel switch 11 is connected with the output end of the multi-channel measuring and sampling interface 3; a third input end of the measurement channel selector switch 11 is connected with a second output end of the current source output port 6; the output end of the measurement channel switch 11 is connected to the input end of the measurement and analysis module 10, and the secondary side current and the confluence of the current transformer collected by the multichannel measurement and sampling interface 3 and the primary side current of the current transformer collected by the current source output port 6 are respectively input to the measurement and analysis module 10. The output end of the measurement and analysis module 10 is connected with the input end of the LED display and operation screen 7, the current of the primary side and the secondary side of the current transformer collected by the current source output port 6 and the multichannel measurement and sampling interface 3 is analyzed, the analysis result is transmitted to the LED display and operation screen 7, and finally the analysis result is displayed in the LED display and operation screen 7.

As shown in fig. 4, the multi-channel measurement sampling interface 3 includes a current input terminal. The input end of the current input terminal is connected with the output end of the secondary side of the current transformer, and the output end of the current input terminal is connected with the second input end of the measurement channel change-over switch 11. The current input terminal is used for collecting the secondary side current and the confluence of the current transformer, and inputting the collected secondary side current and the confluence of the current transformer to the measurement analysis module 10 through the measurement channel change-over switch 11.

The current input terminals include a1 input 12, a2 input 13, a0 input 14, b1 input 15, b2 input 16, b0 input 17, c1 input 18, c2 input 19, c0 input 20. The a1 input 12, the a2 input 13, the b1 input 15, the b2 input 16, the c1 input 18 and the c2 input 19 are used for collecting secondary side current of the current transformer; the a0 input 14, b0 input 17 and c0 input 20 are used to collect the current transformer combined flow,

in the present embodiment, the a1 input 12, the a2 input 13, the a0 input 14, the b1 input 15, the b2 input 16, the b0 input 17, the c1 input 18, the c2 input 19, and the c0 input 20 are respectively provided with clamp-shaped connection ports for connecting the current collection lines, and further connected to the secondary-side current circuit of the current transformer or the merging circuit of the current transformer through the current collection lines.

As shown in fig. 5, the power inlet interface 4 includes a power switch 21, a fuse a22, a fuse B23, and a ground terminal 24. The input end of the power switch 21 is connected with the output end of the 220V power supply through a power line and used for supplying power to the whole checking device. The fuse a22 and the fuse B23 are used as overcurrent protection elements of the main circuit and are respectively arranged in the main circuit of the L line and the main circuit of the N line, the input ends of the fuse a22 and the fuse B23 are respectively connected with the output end of the power switch 21, and the output ends of the fuse a22 and the fuse B23 are connected with the first input end of the adjustable current source module 5. The ground terminal 24 completes grounding by a ground line for grounding the entire housing of the verification apparatus.

As shown in fig. 6, the adjustable current source module 5 includes an isolation transformer 25 and a voltage regulator 26. A first input terminal of the isolation transformer 25 is connected to output terminals of the fuse a22 and the fuse B23, respectively; the output end of the isolation transformer 25 is connected with the third input end of the voltage regulator 26; the power in the power inlet interface 4 is output to the voltage regulator 26 to achieve electrical isolation of the inlet power source from the output current source. The fourth output end of the LED display and operation screen 7 is connected to the second input end of the voltage regulator 26, and is used for controlling the voltage regulator 26 to adjust the current. The output end of the voltage regulator 26 is connected with the first input end of the current source output port 6, and the required current is supplied to the primary side of the current transformer through the current source output port 6.

As shown in fig. 7, the current source output port 6 includes a current output terminal and a current input terminal, which constitute a current source output loop. A first input end of the current input terminal is connected to the output end of the voltage regulator 26, a first output end of the current input terminal is connected to the input end of the primary side of the current transformer, a second input end of the current output terminal is connected to the output end of the primary side of the current transformer, and a second output end of the current output terminal is connected to the third input end of the measurement channel changeover switch 11. The current source output port 6 is used for supplying current to the primary side of the current transformer, collecting the current on the primary side of the current transformer, and inputting the collected current on the primary side of the current transformer to the measurement analysis module 10 through the measurement channel switch 11.

Wherein the current output terminals include an A output 27, a B output 29, and a C output 31; the current input terminals include an a input 28, a B input 30, and a C input 32; the A output 27 and the A input 28 form a current source output loop; b output 29 and B input 30 form a current source output loop; the C output 31 and the C input 32 constitute a current source output loop.

In the present embodiment, the a output 27, the a input 28, the B output 29, the B input 30, the C output 31, and the C input 32 are respectively provided with a clamp for connecting a current output line, and further connected to the primary side current loop of the current transformer through the current output line.

A method for verifying wiring of a differential protection current transformer of an electric motor, the method comprising the steps of:

step (1), connecting the current transformer wiring calibration device and the current transformer by using a connecting wire, and connecting the current transformer wiring calibration device by using a grounding wire

Step (1.1), connecting a current output terminal of the power output port 6 and a primary side loop of a current transformer by using a current output connecting wire through a wire clamp arranged on a current output terminal connected with the power output port 6;

step (1.2), connecting a current input terminal of the multi-channel measurement sampling interface 3 and a secondary side loop of a current transformer through a pincerlike wiring port arranged on a current input terminal of the multi-channel measurement sampling interface 3 by using a current collection connecting wire;

and (1.3) connecting a grounding terminal 24 on the power supply inlet wire interface 4 by using a grounding wire, and grounding the shell of the checking device.

Step (2), connecting the current transformer wiring calibration device and the power supply by using the power line

And a power supply wire is connected with the power supply switch 21 of the power supply inlet wire interface 4 and the power supply and closed power supply switch 21 to supply power for the whole current transformer wiring calibration device.

Step (3), selecting a channel to be tested and the required current in the current transformer wiring calibration device, and starting testing

The LED display and operation screen 7 of the instrument control display panel 1 controls the measuring channel switch 11, and the connection between the measuring channel switch 11 and the multi-channel measuring and sampling interface 3 or the connection between the measuring channel switch 11 and the current source output port 6 are switched and selected according to the requirements; and the LED display of the instrument control display panel 1 and the voltage regulator 26 of the adjustable current source module 5 are controlled by the operation screen 7, the current value of the primary side of the current transformer is adjusted, and the test is started.

Step (4) collecting and analyzing the current of the current transformer

The secondary side current and confluence of the current transformer are collected through a current input terminal of a multichannel measurement sampling interface 3, the primary side current of the current transformer is collected through a current output terminal of a current source output port 6, then the collected primary side and secondary side currents of the current transformer are analyzed through a measurement analysis module 10, and an analysis result is transmitted to an LED display and operation screen 7 of an instrument control display panel 1.

And (5) outputting a current analysis result of the current transformer, and finishing the test

And displaying the analysis result in an LED display and operation screen 7 of the instrument control display panel 1, storing the data and finishing the test.

According to the requirement, the USB interface 8 can be controlled by the LED display and operation screen 7 of the instrument control display panel 1 to output the analysis result.

According to the requirement, the micro printer 9 can also be used for printing the analysis result through the LED display and operation screen 7 of the instrument control display panel 1.

Step (6), power lines for connecting the current transformer wiring calibration device and the power supply are removed

Disconnecting the power switch 21 of the power inlet wire interface 4, and stopping supplying power to the whole current transformer wiring calibration device; and (3) detaching a power switch 21 connected with the power inlet wire interface 4 and a power wire of the power supply.

And (7) removing a connecting wire for connecting the current transformer wiring calibration device and the current transformer, and removing a grounding wire for connecting the current transformer wiring calibration device

Step (7.1), removing a current output connecting wire which is connected with a current output terminal of the power output port 6 and a primary side loop of the current transformer;

step (7.2), removing a current collecting connecting wire which connects a current input terminal of the multi-channel measuring and sampling interface 3 and a secondary side loop of the current transformer;

and (7.3) removing the grounding wire connected with the grounding terminal 24 on the power supply inlet wire interface 4.

The present invention has been described in detail with reference to the drawings and examples, but the present invention is not limited to the examples, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present invention. The prior art can be adopted in the content which is not described in detail in the invention.