CN212111688U - Switchgear test system protection device and switchgear test system - Google Patents

Abstract

The utility model discloses a protection device of a switch device testing system, which comprises a plurality of current monitoring units, an execution unit and a control unit. Several current monitoring units are capable of sensing the value of the current flowing through the test circuit. The execution unit can switch the test circuit on or off. The control unit is connected to several current monitoring units and execution units. The control unit is preset with standard data corresponding to the time change of the current value of the test circuit when the switching device operates normally. The control unit can continuously acquire the test circuits sensed by several current monitoring units. The current value of the switch device is compared with the standard data to determine whether the contacts of the switch device are blown or welded, and when it is judged that the contacts of the switch device are fused or welded, the execution unit is controlled to cut off the test circuit. The protection device can make the switchgear testing system stop testing automatically when contact welding or welding occurs in the switchgear. The utility model also provides a switchgear testing system with the above protection device.

Description

Switchgear test system protection device and switchgear test system

technical field

The utility model relates to a protection device, in particular to a protection device for a switchgear testing system, and a switchgear testing system with the protection device.

Background technique

In the process of testing the life or overload of the switchgear, the switchgear may have contacts blown and welded, and the test needs to be stopped immediately. The current test system automatically stops the test by adding a protection device when the contacts of the switch device are welded, but the reliability of the current protection device is insufficient, and the test cannot be automatically stopped when the contacts of the switch device are fused.

Utility model content

The purpose of the utility model is to provide a protection device for a switchgear testing system, which can make the switchgear testing system automatically stop testing when the switchgear has contact welding or welding.

Another object of the present invention is to provide a test system that can automatically stop the test when contact welding or welding occurs in the switch device.

The utility model provides a protection device for a switching device testing system, wherein the switching device testing system includes several testing circuits for testing the switching device. The protection device includes several current monitoring units, an execution unit and a control unit. Several current monitoring units are disposed on several test circuits in one-to-one correspondence, and can sense the current value flowing through the test circuits. The execution unit is arranged on several test circuits and can turn on or off the test circuits. The control unit is connected to several current monitoring units and execution units. The control unit is preset with standard data corresponding to the time change of the current value of the test circuit when the switching device operates normally. The control unit can continuously obtain the test circuits sensed by several current monitoring units. The current value of the switch device is compared with the standard data to determine whether the contacts of the switch device are blown or welded, and when it is judged that the contacts of the switch device are fused or welded, the execution unit is controlled to cut off the test circuit.

In the protection device of the switchgear testing system provided by the utility model, the control unit can continuously obtain the current values of the test circuits sensed by several current monitoring units, and judge whether the contacts of the switchgear are blown or fused according to preset standard data. welding, and control the execution unit to cut off the test circuit when it is judged that the contacts of the switch device are fused or welded. Thereby, the switchgear testing system can automatically stop the test when contact welding or welding of the switchgear occurs.

In another exemplary embodiment of the protection device, each current monitoring unit includes a Rogowski coil and an integrator. Each Rogowski coil is sleeved on the test circuit in a one-to-one correspondence. Each integrator is connected to the Rogowski coils in one-to-one correspondence. Thereby, the installation is convenient and the current value of the test circuit can be accurately sensed.

In another exemplary embodiment of the protection device, the control unit includes a programmable logic controller, and the integrator is connected to an analog input module of the programmable logic controller.

In another exemplary embodiment of the protection device, the control unit can also continuously monitor the analog value obtained by the analog input module, and control the execution when the analog value obtained by the analog input module exceeds the output value range of the integrator The unit cuts off the test circuit. This realizes the self-check function.

In another exemplary embodiment of the protection device, the actuating unit includes a DC contactor, a safety relay, a main circuit breaker and an undervoltage relay. The control coil of the DC contactor is connected to the digital output module of the programmable logic controller. The control terminal of the safety relay is connected to a group of contacts of the DC contactor. Each group of contacts of the main circuit breaker is connected to several test circuits in one-to-one correspondence. The control coil of the undervoltage relay and the contacts of the safety relay are connected to the power supply in series, and the contacts of the undervoltage relay are connected to the control circuit of the main circuit breaker. The reliability of the protection device is thereby increased.

In another exemplary embodiment of the protection device, the reset terminal of the safety relay is connected to another group of contacts of the DC contactor. Thereby, the reliability of the protection device is further improved.

In another exemplary embodiment of the protection device, the control coil of the undervoltage relay is connected to the power supply in series with the normally open contact of the safety relay. Thereby, the reliability of the protection device is further improved.

The utility model also provides a switching device testing system, which includes several testing circuits and the above protection device. Each test circuit is used to test the switchgear. Several current monitoring units are set in several test circuits in one-to-one correspondence, and execution units are set in several test circuits.

Description of drawings

The following drawings merely illustrate and explain the present invention schematically, and do not limit the scope of the present invention.

FIG. 1 is a schematic structural diagram for explaining an exemplary embodiment of a protection device.

FIG. 2 is a schematic diagram of a partial circuit structure for illustrating an exemplary embodiment of the protection device.

Label description

10 Current monitoring unit

12 Rogowski coil

14 Integrator

20 execution units

22 DC contactor

24 Safety relay

26 Main circuit breaker

28 Undervoltage relay

30 Control unit

40 Test circuit

50 Switchgear

Detailed ways

In order to have a clearer understanding of the technical features, purposes and effects of the utility model, the specific embodiments of the present utility model will now be described with reference to the accompanying drawings. The same reference numerals in each figure represent components with the same structure or similar structure but the same function.

As used herein, "schematic" means "serving as an example, instance, or illustration" and any illustration, embodiment described herein as "schematic" should not be construed as a preferred or advantageous one Technical solutions.

For the sake of brevity of the drawings, only the parts related to the present exemplary embodiment are schematically shown in each drawing, and they do not represent its actual structure as a product.

FIG. 1 is a schematic structural diagram for explaining an exemplary embodiment of a protection device. Referring to FIG. 1 , the switchgear testing system includes three test circuits 40 for testing the switchgear 50 . The switchgear testing system can perform life or overload tests on the switchgear 50 whose contacts are connected to the test circuit 40 . The protection device includes three current monitoring units 10 , one execution unit 20 and one control unit 30 .

Referring to FIG. 1 , three current monitoring units 10 are disposed on the three test circuits 40 in a one-to-one correspondence, and can sense the current value flowing through the test circuits 40 . Although there are three current monitoring units 10 in the exemplary embodiment, it is not limited thereto, and in other exemplary embodiments, the number of the current monitoring units 10 may be adjusted according to the number of the test circuits 40 . In the exemplary embodiment, each current monitoring unit 10 includes a Rogowski coil 12 and an integrator 14 . Each Rogowski coil 12 is sleeved on the test circuit 40 in a one-to-one correspondence. The integrators 14 are connected to the Rogowski coils 12 in a one-to-one correspondence. When there is current passing through the test circuit 40, the Rogowski coil 12 can induce the current and convert it into an analog signal of 4 to 20 mA by the integrator 14. The Rogowski coil 12 is easy to install, and can cooperate with the integrator 14 to accurately sense the current value of the test circuit 40 . However, it is not limited to this, and other types of current collecting devices may also be selected in other exemplary embodiments.

The execution unit 20 is disposed on the three test circuits 40 and can turn on or off the test circuits 40 . The control unit 30 is connected to the three current monitoring units 10 and the execution unit 20. The control unit 30 is preset with standard data corresponding to the time change of the current value of the test circuit 40 when the switching device 50 operates normally. When the switchgear test system tests the switchgear 50, the switchgear 50 will act within an expected time according to the specific item of the test, and this action will affect the on-off of the test circuit 40. The standard data simulates the switchgear 50 in During normal operation, the on-off state of the test circuit 40 within the expected time. The control unit 30 can continuously acquire the current values of the test circuits 40 sensed by the current monitoring units 10, and compare with the standard data to determine whether the contacts of the switching device 50 are fused or welded. The action causes the test circuit 40 to be disconnected, but the current monitoring unit 10 senses that the test circuit 40 still has a current value, which means that the contacts of the switch device 50 are welded; the switch device 50 should act to connect the test circuit 40 at the expected time. However, if the current monitoring unit 10 senses that there is no current value in the test circuit 40, it means that the contacts of the switch device 50 are fused. And the control unit 30 controls the execution unit 20 to cut off the test circuit 40 when judging that the contacts of the switch device 50 are fused or welded.

In the exemplary embodiment, the control unit 30 includes a programmable logic controller, and the integrator 14 is connected to an analog input module of the programmable logic controller and used to send to the programmable logic controller an analog representation representing the current value of the test circuit 40 quantity signal. The programmable logic controller makes logical judgments based on pre-input standard data.

FIG. 2 is a schematic diagram of a partial circuit structure for illustrating an exemplary embodiment of the protection device. 1 and 2 , the execution unit 20 includes a DC contactor 22 , a safety relay 24 , a main circuit breaker 26 and an undervoltage relay 28 . The control coil of the DC contactor 22 is connected to the digital output module of the programmable logic controller. The control terminal of the safety relay 24 is connected to a group of contacts of the DC contactor 22 . Each group of contacts of the main circuit breaker 26 is connected to several test circuits 40 in a one-to-one correspondence. The control coil of the undervoltage relay 28 and the contact of the safety relay 24 are connected to the power supply in series, and the contact of the undervoltage relay 28 is connected to the control circuit of the main circuit breaker 26 . During normal operation, each group of contacts of the main circuit breaker 26 is closed. When the programmable logic controller judges that the contacts of the switching device 50 are fused or welded, the programmable logic controller outputs the electrical signal through the digital output module. When the change occurs, the DC contactor 22 is driven to act to disconnect the control terminal of the safety relay 24, and then the safety relay 24 is driven to disconnect the power supply of the undervoltage relay 28, and the undervoltage relay 28 disconnects the control circuit of the main circuit breaker 26, and the main circuit is disconnected. Each set of contacts of the device 26 opens and disconnects the test circuit 40 . The execution unit 20 using the safety relay 24 can improve the reliability of the protection device.

In the protection device of the switch device testing system provided by the present invention, the control unit 30 can continuously acquire the current values of the test circuits 40 sensed by several current monitoring units 10, and judge whether the contacts of the switch device 50 are not according to preset standard data. Fusing or welding occurs, and the execution unit 20 is controlled to cut off the test circuit 40 when it is judged that the contacts of the switching device 50 are fused or welded. Thereby, the switchgear testing system can automatically stop testing when the switchgear 50 experiences contact welding or welding.

In the exemplary embodiment, the control unit 30 can also continuously monitor the analog value obtained by the analog input module. When the protection device is in use, such as the power supply of the integrator fails, the analog value obtained by the analog input module will exceed the output value range (4 to 20mA) of the integrator 14. At this time, the protection device will fail, and the control unit 30 will control The execution unit 20 switches off the test circuit 40 . Thereby, the self-checking function of the protection device is realized.

In an exemplary embodiment, referring to FIG. 2 , the reset terminal of the safety relay 24 is connected to another set of contacts of the DC contactor 22 . The action of the safety relay 24 is triggered only when the two sets of contacts of the DC contactor 22 are closed at the same time, thereby further improving the reliability of the protection device.

In an exemplary embodiment, referring to FIG. 2 , the control coil of the undervoltage relay 28 is connected to the power supply in series with the normally open contact of the safety relay 24 , and the test circuit 40 can be cut off directly when there is a problem with the power supply of the protection device. Thereby, the reliability of the protection device is further improved.

The present invention also provides a switching device testing system, which includes several testing circuits 40 and one of the above protection devices. Each test circuit 40 is used to test the switching device 50 . The plurality of current monitoring units 10 are disposed in the plurality of test circuits 40 in a one-to-one correspondence, and the execution units 20 are disposed in the plurality of test circuits 40 .

It should be understood that although this specification is described according to various embodiments, not each embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

A series of detailed descriptions listed above are only specific descriptions for the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalents made without departing from the technical spirit of the present invention Embodiments or modifications, such as combination, division or repetition of features, should all be included within the protection scope of the present invention.

Claims (8)

1. Protection device of switchgear test system, switchgear test system includes several test circuits that are used for testing switchgear, its characterized in that, protection device includes:

the current monitoring units (10) are arranged on the test circuits in a one-to-one correspondence manner, and can sense the current value flowing through the test circuits;

an execution unit (20) disposed in the plurality of test circuits and capable of switching on or off the test circuits; and

and the control unit (30) is connected with the plurality of current monitoring units (10) and the execution unit (20), standard data of the current value of the test circuit corresponding to time change when the switch device normally operates are preset in the control unit (30), the control unit (30) can continuously acquire the current value of the test circuit sensed by the plurality of current monitoring units (10), judge whether the contact of the switch device is fused or welded or not by comparing with the standard data, and control the execution unit (20) to cut off the test circuit when judging that the contact of the switch device is fused or welded.

2. The protection device according to claim 1, wherein each of said current monitoring units (10) comprises:

one Rogowski coil (12), each said Rogowski coil (12) is fitted in the said test circuit one to one correspondingly; and

and the integrators (14) are connected with the Rogowski coils (12) in a one-to-one correspondence mode.

3. A protection device according to claim 2, characterized in that said control unit (30) comprises a programmable logic controller, said integrator (14) being connected to an analog input module of said programmable logic controller.

4. The protection device according to claim 3, characterized in that the control unit (30) is further capable of continuously monitoring the analog value obtained by the analog input module and controlling the execution unit (20) to switch off the test circuit when the analog value obtained by the analog input module is out of the range of the output values of the integrator (14).

5. The protection device according to claim 3, wherein the execution unit (20) comprises:

a direct current contactor (22), the control coil of which is connected with the digital quantity output module of the programmable logic controller;

a safety relay (24) with a control end connected with a group of contacts of the direct current contactor (22);

a main circuit breaker (26) having respective sets of contacts connected to the plurality of test circuits in a one-to-one correspondence; and

and the control coil of the undervoltage relay (28) is connected with the contact of the safety relay (24) in series with a power supply, and the contact of the undervoltage relay (28) is connected with the control circuit of the main circuit breaker (26).

6. A protection device according to claim 5, characterized in that the reset terminal of the safety relay (24) is connected to the other set of contacts of the DC contactor (22).

7. The protection device according to claim 5, characterized in that the control coil of the undervoltage relay (28) and the normally open contact of the safety relay (24) are connected in series to a power supply.

8. A switchgear testing system, comprising:

a plurality of test circuits (40), each of the test circuits (40) for testing a switching device; and

a protection device according to any one of claims 1 to 7, wherein said plurality of current monitoring units (10) are disposed in one-to-one correspondence to said plurality of test circuits (40), and said execution unit (20) is disposed in said plurality of test circuits (40).

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