CN217507957U - Circuit and device for preventing secondary current loop of high-voltage switch cabinet from operating in open circuit mode - Google Patents

Abstract

The utility model provides a prevent circuit and device of high tension switchgear secondary current return circuit operation of opening a way, including resistance detection subassembly, voltage detection subassembly, output normally open contact, and output normally closed contact, resistance detection subassembly establishes ties with high tension switchgear's vacuum circuit breaker normally closed contact, and connect at the current terminal both ends, a resistance for detecting the current terminal both ends, voltage detection subassembly connects at the current terminal both ends, a voltage for detecting the current terminal both ends, output normally open contact connects at the current terminal both ends, resistance detection subassembly, voltage detection subassembly and output normally open contact are parallelly connected each other, output normally closed contact establishes ties and inserts in the high tension switchgear combined floodgate return circuit. The utility model discloses not only can prevent the current transformer secondary side operation accident of opening a way in the operation, can also prevent the accident of the operation of opening a way in the high tension switchgear secondary current return circuit in the equipment starting process simultaneously.

Description

Circuit and device for preventing secondary current loop of high-voltage switch cabinet from operating in open circuit

Technical Field

The utility model relates to a high tension switchgear technical field, in particular to prevent that high tension switchgear secondary current return circuit from opening a way circuit and device of operation.

Background

In the operation of an electric power system, the current transformer plays a role in isolating a primary system, so that secondary relay protection, an automatic device and a measuring instrument can safely and accurately acquire the current information of an electric primary loop. According to the regulations of 10.13 in the electric power safety work regulations: when the current transformer works on a secondary circuit of an electrified current transformer, the secondary side of the current transformer is forbidden to be opened. When the secondary side of the current transformer is open-circuited, the primary current of the current transformer becomes the exciting current, the iron core is excessively saturated and magnetized, and high voltage is generated between the secondary winding terminals, so that the secondary system is damaged due to insulation, the protection device is mistakenly operated or refused to operate, the current transformer is overheated, magnetized, burnt and the personal safety of workers is also endangered, and therefore, the open-circuit operation of the secondary circuit of the current transformer is a serious accident which needs to be avoided at utmost.

In the electrical operation, when newly installed equipment or overhauled equipment recovers to operate due to out-of-position work and other reasons, a secondary circuit current terminal of a high-voltage switch cabinet is disconnected to cause a secondary side of a current transformer to be open, and the condition that the current terminal is burnt when the equipment is started occurs occasionally. In the prior art, corresponding protection measures are mainly taken for the open circuit of the secondary side of the current transformer in operation, so that the accident of the open circuit operation of the secondary current loop of the high-voltage switch cabinet in the starting process of the equipment cannot be avoided.

SUMMERY OF THE UTILITY MODEL

The utility model aims at: aiming at the defects existing in the prior art, the scheme for preventing the secondary current loop of the high-voltage switch cabinet from operating in an open circuit mode is provided, so that the accident of the secondary current loop of the high-voltage switch cabinet in the open circuit mode in the starting process of equipment can be prevented while the accident of the open circuit operation of the secondary side of the current transformer in the operation is prevented.

In order to achieve the above object, the utility model provides a prevent circuit of high tension switchgear secondary current return circuit operation of opening a way, including resistance detection subassembly, voltage detection subassembly, output normally open contact and output normally closed contact, resistance detection subassembly establishes ties with high tension switchgear's vacuum circuit breaker normally closed contact to connect at the current terminal both ends, be used for detecting the resistance at current terminal both ends, voltage detection subassembly connects the current terminal both ends, be used for detecting the voltage at current terminal both ends, output normally open contact connects the current terminal both ends, resistance detection subassembly voltage detection subassembly and output normally open contact is parallelly connected each other, output normally closed contact establishes ties and inserts in the high tension switchgear combined floodgate return circuit.

Further, the resistance detection assembly and the voltage detection assembly have preset values.

Further, after the high-voltage switch cabinet is switched on, the output normally-closed contact is disconnected, so that the resistance detection assembly is disconnected from the current terminal, and the resistance detection assembly is prevented from being damaged.

The utility model also provides a prevent that high tension switchgear secondary current return circuit from opening a way device of operation, including casing and the aforesaid prevent that high tension switchgear secondary current return circuit from opening a way the circuit of operation, the circuit is built-in the casing, the casing has binding post, through binding post and current transformer the current terminal switch-on passes through simultaneously binding post and high tension switchgear combined floodgate return circuit switch-on.

The above technical scheme of the utility model has following beneficial effect:

the utility model provides a prevent circuit and device of high tension switchgear secondary current return circuit open circuit operation, through the setting of resistance detection subassembly, voltage detection subassembly, output normally open contact and output normally closed contact, not only can prevent the current transformer secondary side open circuit operation accident in service, can also prevent the accident of high tension switchgear secondary current return circuit open circuit operation in the equipment starting process simultaneously to avoid the damage of equipment and staff's safety risk more effectively;

other advantageous effects of the present invention will be described in detail in the following detailed description.

Drawings

Fig. 1 is a schematic circuit diagram of the present invention;

fig. 2 is a schematic connection diagram of the present invention.

[ description of reference ]

1-a resistance detection component; 2-a voltage detection component; 3-output normally open contact; 4-output normally closed contact; 5-normally closed contact of vacuum circuit breaker; 6-current terminals; 7-a high-voltage switch cabinet closing loop; 8-connecting piece.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The various features and embodiments described in the detailed description may be combined in any suitable manner, for example, different embodiments may be formed by combining different features/embodiments, and various combinations of features/embodiments are not separately described in order to avoid unnecessary repetition in the present disclosure.

It should be noted that the terms "disposed" and "connected" should be interpreted broadly, and may be, for example, directly disposed, installed and connected, or indirectly disposed and connected through intervening components and intervening structures. In addition, the directions or positional relationships indicated in the present invention, such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are based on the directions or positional relationships shown in the drawings or the conventional placing states or using states, and are only for convenience of description and simplification of description, but do not indicate or imply that the structure, feature, device or element referred to must have a specific direction, be constructed and operated in a specific direction, and thus, should not be construed as limiting the present invention.

The utility model relates to a high tension switchgear technical field, in electrical operation, when equipment or the equipment after overhauing that leads to new installation because of work out of position and other reasons resumes the operation, high tension switchgear secondary circuit current terminal disconnection leads to current transformer secondary side open circuit, and the condition that current terminal burns out takes place occasionally when equipment starts. In the prior art, corresponding protective measures are mainly taken for the open circuit of the secondary side of the current transformer in operation, so that the accident of open circuit operation of the secondary current loop of the high-voltage switch cabinet in the starting process of the equipment cannot be avoided. Based on this, the utility model discloses an embodiment 1 provides a circuit that prevents high tension switchgear secondary current return circuit and open a way the operation, aims at solving above-mentioned problem.

Specifically, as shown in fig. 1 and 2, the circuit includes a resistance detection element 1, a voltage detection element 2, an output normally-open contact 3, and an output normally-closed contact 4. The resistance detection assembly 1 is connected in series with a normally closed contact 5 of a vacuum circuit breaker of a high-voltage switch cabinet and then connected to two ends of a current terminal 6, and is used for detecting the resistance at the two ends of the current terminal 6. The voltage detection component 2 is connected to two ends of the current terminal 6 and is used for detecting the voltage of two ends of the current terminal 6. The output normally open contact 3 is connected to both ends of the current terminal 6. The output normally closed contact 4 is connected in series into a closing loop 7 of the high-voltage switch cabinet.

When the high-voltage switch cabinet is in a switching-off state, if the connecting sheet 8 of the current terminal 6 is disconnected or not connected and fastened at the moment, and the resistance detection assembly 1 detects that the resistance exceeds a specified value, the current terminal 6 is judged to be open-circuited, and the output normally-closed contact 4 is disconnected. Because the output normally closed contact 4 is connected in series in the high-voltage switch cabinet closing loop 7, the high-voltage switch cabinet cannot be closed at the moment, and therefore the accident of open circuit operation of a secondary current loop of the high-voltage switch cabinet in the equipment starting process can be avoided.

If the connecting sheet 8 of the current terminal 6 is connected and fastened, and the resistance detection assembly 1 detects that the resistance is qualified, it is judged that the current terminal 6 is connected perfectly, the output normally-closed contact 4 is in a closed state, and at the moment, the high-voltage switch cabinet can be normally switched on. After closing the switch, the normally closed contact 5 of the vacuum circuit breaker of the high-voltage switch cabinet is disconnected, so that the resistance detection assembly 1 is disconnected from the current terminal 6, and the resistance detection assembly 1 is prevented from being damaged.

When high tension switchgear is located when closing a floodgate running state, if this moment because operation personnel maloperation or other reasons lead to the connection piece 8 disconnection of current terminal 6, current transformer will be in the state of opening a way the operation, and the voltage at current terminal 6 both ends will rise this moment, and the voltage that detects current terminal 6 both ends when voltage detection subassembly 2 exceeds the specified value, and output normally open contact 3 is closed, with the short circuit of current terminal 6 both ends to can avoid the current transformer secondary side open circuit operation accident in the operation.

In this embodiment, the resistance detecting assembly 1 may adopt a resistance detector with a model number TRMD1002-30M Ω -S, a measuring range is 30.000M Ω, and module communication is an RS485 interface. The voltage detection assembly can adopt a model of TMD3602-600V-S-M, the input impedance is more than or equal to 1M omega, the measurement range is +/-603.0V, and the module communication is an RS485 interface.

Example 2:

the embodiment 2 of the utility model provides a prevent that high tension switchgear secondary current return circuit from opening a way device of operation, including the circuit and the casing that prevent that high tension switchgear secondary current return circuit from opening a way operation that embodiment 1 provided, wherein the circuit is built-in the casing, and the casing has binding post, through binding post and current transformer's secondary current terminal switch-on, through another binding post and 7 switch-ons in high tension switchgear combined floodgate return circuits simultaneously.

The foregoing is a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims (4)

1. A circuit for preventing a secondary current loop of a high-voltage switch cabinet from operating in an open circuit is characterized by comprising a resistance detection assembly (1), a voltage detection assembly (2), an output normally open contact (3) and an output normally closed contact (4), the resistance detection component (1) is connected in series with a normally closed contact (5) of a vacuum circuit breaker of a high-voltage switch cabinet and is connected at two ends of a current terminal (6), the voltage detection component (2) is connected with the two ends of the current terminal (6), is used for detecting the voltage at two ends of the current terminal (6), the output normally open contact (3) is connected at two ends of the current terminal (6), the resistance detection component (1), the voltage detection component (2) and the output normally open contact (3) are connected in parallel, the output normally closed contact (4) is connected in series into a closing loop (7) of the high-voltage switch cabinet.

2. The circuit for preventing open circuit operation of a secondary current loop of a high voltage switchgear according to claim 1, wherein the resistance detection assembly (1) and the voltage detection assembly (2) have preset values.

3. The circuit for preventing the secondary current loop of the high-voltage switch cabinet from operating in an open circuit mode according to claim 1, wherein the normally closed contact (5) of the vacuum circuit breaker is opened after the high-voltage switch cabinet is closed, so that the resistance detection assembly (1) is disconnected from the current terminal (6).

4. An arrangement for preventing the open circuit operation of a secondary current circuit of a high-voltage switch cabinet, characterized in that it comprises a housing and a circuit for preventing the open circuit operation of a secondary current circuit of a high-voltage switch cabinet according to any one of claims 1 to 3, said circuit being embedded in said housing, said housing having a connection terminal through which it is connected to a current terminal (6) of a current transformer and through which it is connected to a closing circuit (7) of a high-voltage switch cabinet.

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