Control circuit for a disconnector or earthing switch and GIS device

Abstract

The application provides a control circuit for an isolating switch or grounding switch and GIS equipment, and belongs to the field of GIS equipment, comprising a disconnecting control branch and a closing control branch, wherein the disconnecting control branch is connected with a disconnecting contactor coil in series, is connected with a disconnecting signal input end, and is further connected with a disconnecting holding branch, and the disconnecting holding branch is connected with a positive pole of a control power supply through a normally open contact of a protection relay; the closing control branch is connected with a closing signal input end, is further connected with a closing holding branch, and the closing holding branch is connected with the positive pole of the control power supply through the normally open contact of the protection relay. A protection relay coil and a switch module are connected in series between positive and negative poles of a motor power supply, and the switch module comprises a disconnecting contactor first normally open contact and a closing contactor first normally open contact which are connected in parallel with each other. The starting time of the protection relay is greater than the reset time of the disconnecting contactor and the closing contactor.

Description

Technical Field

[0001] This invention provides a control circuit and GIS equipment for disconnecting switches or grounding switches, belonging to the field of GIS equipment, and particularly relates to a control circuit to prevent maloperation of the mechanical contacts of the contactors of disconnecting switches and grounding switches when mechanical vibration is caused by opening and closing operations. Background Technology

[0002] Gas-insulated metal-enclosed switchgear (GIS) is one of the most common power equipment in China, mainly composed of circuit breakers, disconnectors, grounding switches, instrument transformers, and busbars. As a crucial component of gas-insulated metal-enclosed switchgear, the correct and reliable operation of the disconnector is a key factor in ensuring the safety of maintenance personnel during on-site operations.

[0003] For gas-insulated metal-enclosed switchgear with voltage levels of 550kV and above, the circuit breaker generates significant mechanical vibration during opening and closing operations, with vibration amplitudes reaching several Gs. This vibration exceeds the vibration resistance of the mechanical contacts of the opening and closing contactors of the disconnecting and grounding switches. The mechanical vibration is transmitted to the nearby disconnecting or grounding switch mechanism box, causing the entire mechanism box to shake. Since the opening and closing contactors installed in the nearby disconnecting or grounding switch mechanism box are generally electromagnetic contactors, these contactors typically consist of coils and large mechanical contacts. The shaking of the mechanism box can cause the normally open mechanical contacts of the opening and closing contactors in the mechanism box to malfunction, causing the normally open auxiliary contacts in the corresponding disconnecting or grounding switch opening and closing control circuit to close, thus forming a self-holding mechanism. This leads to the disconnecting or grounding switch being opened or closed incorrectly, failing to meet the operating requirements and safety specifications of the disconnecting or grounding switch, and easily endangering the safety of equipment and personnel.

[0004] Currently, there are two main solutions: one is to place materials that can buffer mechanical vibration, such as adding shock-absorbing rubber pads, between the contactor and the mechanism box during the design and installation of the disconnector or grounding switch mechanism box; the other is to adjust the installation direction of the opening and closing contactors during the design and installation of the disconnector and grounding switch mechanism boxes, so that the closing direction of their normally open mechanical contacts is perpendicular to the direction of the circuit breaker's maximum vibration, such as horizontally or vertically. These two solutions can reduce the impact of mechanical vibration on the contactor to some extent. However, in actual use, even with these measures, it is still impossible to completely eliminate the phenomenon of malfunction caused by mechanical vibration of the disconnector or grounding switch; it only reduces the probability of problems.

[0005] Alternatively, the opening and closing control circuits of disconnecting switches or grounding switches can be completely moved out of the vibrating mechanism box and installed in the GIS control cabinet. However, since a GIS bay typically requires one circuit breaker, two disconnecting switches, and three grounding switches, and disconnecting switches and grounding switches generally use phase-by-phase control, this includes 15 disconnecting switch and grounding switch operating mechanisms, each with two contactors. If the opening and closing control circuits and all contactors are installed in the control cabinet, it not only increases the size of the control cabinet, affecting the space utilization of the substation, but also requires a large number of electrical components to be connected in the control cabinet, making the incoming and outgoing wiring of the control cabinet more complex, which is not conducive to further modification and maintenance of the existing mechanism box. Furthermore, this solution requires designing a larger control cabinet, resulting in higher costs.

[0006] In summary, the circuit breakers of existing GIS equipment generate mechanical vibrations during opening and closing operations, which may lead to the erroneous opening or closing of disconnecting switches and grounding switches, easily endangering equipment and personnel safety. Modifying the control cabinet of existing GIS equipment to solve this problem is costly. Summary of the Invention

[0007] The purpose of this invention is to provide a control circuit and GIS equipment for disconnecting switches or grounding switches, which solves the problem that mechanical vibrations generated during the opening and closing operations of existing GIS equipment cause malfunctions of the contactor mechanical contacts of disconnecting switches and grounding switches, endangering equipment and personnel safety.

[0008] To achieve the above objectives, the present invention provides a control circuit for a disconnector or grounding switch, comprising a tripping control branch and a closing control branch. A tripping contactor coil is connected in series in the tripping control branch, and a closing contactor coil is connected in series in the closing control branch. One end of the tripping control branch is connected to a tripping signal input terminal and is also connected to the positive control power supply through a tripping holding branch. One end of the closing control branch is connected to a closing signal input terminal and is also connected to the positive control power supply through a closing holding branch. The circuit also includes a protection relay and a switch module. The protection relay coil and the switch module are connected in series between the positive and negative terminals of the motor power supply. Both the tripping holding branch and the closing holding branch are connected to the positive control power supply through normally open contacts of the protection relay. The switch module includes first normally open contacts of the tripping contactor and first normally open contacts of the closing contactor connected in parallel. The start-up time of the protection relay is greater than the reset time of the tripping contactor and the reset time of the closing contactor.

[0009] The present invention provides a control circuit for opening and closing a disconnecting switch or grounding switch, comprising an opening control branch and a closing control branch. The opening control branch contains an opening contactor coil connected in series, is connected to the opening signal input terminal, and is also connected to an opening holding branch, which is connected to the positive terminal of the control power supply via a normally open contact of a protective relay. The closing control branch contains a closing contactor coil connected in series, is connected to the closing signal input terminal, and is also connected to the closing holding branch, which is connected to the positive terminal of the control power supply via a normally open contact of a protective relay. The protective relay coil and the switching module are connected in series between the positive and negative terminals of the power supply. The switching module includes a first normally open contact of the opening contactor and a first normally open contact of the closing contactor connected in parallel. The activation time of the protection relay is longer than the reset time of the opening and closing contactors. Therefore, under the influence of vibration during the circuit breaker's opening and closing operation, even if the mechanical contacts of the contactors in the isolating switch mechanism box or the grounding switch mechanism box malfunction, the normally open contacts of the protection relay will still be unable to close when the mechanical contacts of the opening and closing contactors are open, preventing the opening and closing contactor coils from being energized and thus preventing the opening and closing control circuit from being effectively connected, thereby eliminating vibration interference.

[0010] Furthermore, in the above circuit, the second normally open contact of the trip contactor is connected in series in the trip holding branch, and the second normally open contact of the closing contactor is connected in series in the closing holding branch; after one end of the trip holding branch and one end of the closing holding branch are connected, they are connected to the positive control power supply through the normally open contact of the protection relay.

[0011] The normally open contact of the trip contactor, connected in series in the trip holding branch, forms a self-holding mechanism when the trip command activates the trip control. It continuously supplies power to the trip contactor coil via the control power supply, allowing the motor to rotate continuously. Similarly, the normally open contact of the closing contactor, connected in series in the closing holding branch, forms a self-holding mechanism when the closing command activates the closing control. It also continuously supplies power to the closing contactor coil via the control power supply, allowing the motor to rotate continuously. The trip holding branch and the closing holding branch are connected in series with a normally open contact of a protection relay, and then connected to the positive terminal of the control power supply. This reduces costs compared to each holding branch having its own normally open contact of a protection relay connected to the positive terminal of the control power supply.

[0012] Furthermore, the above circuit also includes a motor drive circuit connected in series with the switch module. The motor drive circuit includes a first rotary branch for opening the circuit and a second rotary branch for closing the circuit. The third normally open contact of the opening contactor, the stator winding of the motor, and the rotor winding of the motor are connected in series to form the first rotary branch. The third normally open contact of the closing contactor, the stator winding of the motor, and the rotor winding of the motor are connected in series to form the second rotary branch. The protective relay coil is connected in parallel with the motor drive circuit.

[0013] The existing motor drive circuit includes a first rotation branch and a second rotation branch. The motor drive circuit is connected in series with the switch module. Therefore, by connecting the protection relay coil in parallel across the two ends of the motor drive circuit, and connecting the protection relay coil and the switch module in series between the positive and negative terminals of the motor power supply, the function of the present invention can be successfully realized, and the additional switch module can be avoided, thus saving costs.

[0014] Furthermore, in the above circuit, the normally closed contact of the closing contactor is connected in series in the tripping control branch, and the normally closed contact of the tripping contactor is also connected in series in the closing control branch.

[0015] The normally closed contact of the closing contactor connected in series in the opening control branch can be opened when the closing contactor coil is energized, so that the isolating switch and grounding switch cannot be opened. The normally closed contact of the opening contactor connected in series in the closing control branch can be opened when the opening contactor coil is energized, so that the isolating switch and grounding switch cannot be closed, thus ensuring the safety of equipment and personnel during opening and closing operations.

[0016] Furthermore, in the above circuit, a tripping limit switch is connected in series in the tripping control branch, and a closing limit switch is connected in series in the closing control branch.

[0017] The trip limit switch connected in series in the trip control branch opens when the motor completes the tripping operation, thus stopping the motor's rotation. The closing limit switch connected in series in the closing control branch opens when the motor completes the closing operation, thus stopping the motor's rotation. This prevents the motor from continuing to rotate, which could cause excessive travel of the tripping and closing contacts, affecting equipment and personnel safety.

[0018] This invention also provides a GIS device, including a control circuit for a disconnector or grounding switch. The control circuit includes a tripping control branch and a closing control branch. A tripping contactor coil is connected in series in the tripping control branch, and a closing contactor coil is connected in series in the closing control branch. One end of the tripping control branch is connected to a tripping signal input terminal and is also connected to the positive control power supply through a tripping holding branch. One end of the closing control branch is connected to a closing signal input terminal and is also connected to the positive control power supply through a closing holding branch. The device also includes a protection relay and a switch module. The protection relay coil and the switch module are connected in series between the positive and negative terminals of the motor power supply. Both the tripping holding branch and the closing holding branch are connected to the positive control power supply through normally open contacts of the protection relay. The switch module includes first normally open contacts of the tripping contactor and first normally open contacts of the closing contactor connected in parallel. The start time of the protection relay is greater than the reset time of the tripping contactor and the reset time of the closing contactor.

[0019] Furthermore, in the above-mentioned equipment, the second normally open contact of the trip contactor is connected in series in the trip holding branch, and the second normally open contact of the closing contactor is connected in series in the closing holding branch; after one end of the trip holding branch and one end of the closing holding branch are connected, they are connected to the positive control power supply through the normally open contact of the protection relay.

[0020] Furthermore, the aforementioned device also includes a motor drive circuit connected in series with the switch module. The motor drive circuit includes a first rotary branch for opening the circuit and a second rotary branch for closing the circuit. The third normally open contact of the opening contactor, the motor stator winding, and the motor rotor winding are connected in series to form the first rotary branch. The third normally open contact of the closing contactor, the motor stator winding, and the motor rotor winding are connected in series to form the second rotary branch. The protective relay coil is connected in parallel with the motor drive circuit.

[0021] Furthermore, in the above-mentioned equipment, the tripping control branch is also connected in series with a normally closed contact of a closing contactor, and the closing control branch is also connected in series with a normally closed contact of a tripping contactor.

[0022] Furthermore, in the above-mentioned equipment, a tripping limit switch is connected in series in the tripping control branch, and a closing limit switch is connected in series in the closing control branch. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the opening and closing control circuit of the control circuit inside the disconnector switch mechanism box in the prior art.

[0024] Figure 2 This is a schematic diagram of the motor drive circuit of the control circuit inside the disconnector mechanism box in the prior art;

[0025] Figure 3 This is a schematic diagram of the opening and closing control circuit of the control circuit inside the disconnector switch mechanism box in the embodiment of the control circuit of the present invention;

[0026] Figure 4 This is a schematic diagram of the motor drive circuit of the control circuit inside the isolating switch mechanism box in an embodiment of the control circuit of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0028] In gas-insulated metal-enclosed switchgear (GIS), the disconnecting switch, grounding switch, and fast grounding switch consist of the main unit and a mechanism box. The mechanism box is mounted on the outer shell of the main unit, and the switch body completes the opening and closing actions under the drive of the mechanism box's drive shaft. The control circuits of the disconnecting switch and the grounding switch are similar in principle. Taking the disconnecting switch as an example, this paper explains the existing disconnecting switch opening and closing control circuit within the disconnecting switch mechanism box and the grounding switch opening and closing control circuit within the grounding switch mechanism box. Figure 1 As shown, in the prior art, the control circuit inside the disconnector mechanism box includes a disconnector opening and closing control circuit and a motor drive circuit. The disconnector opening and closing circuit includes a disconnector opening control branch and a disconnector closing control branch.

[0029] One end of the disconnector switch tripping control branch is connected to the tripping command input terminal X3, and the other end is connected to the control power supply neutral line N through the control power supply negative terminal X2. The disconnector switch tripping control branch includes the normally closed contact CX (71-72) of the closing contactor, the tripping contactor coil TX (A1-A2), and the normally closed contact LSA (3-4) of the tripping limit switch connected in series. It also includes a tripping holding branch, in which the normally open contact TX (23-24) of the tripping contactor is connected in series. One end of the normally open contact TX (23-24) of the tripping contactor is connected to the control power supply live line L through the control power supply positive terminal X1, and the other end is connected between the tripping command input terminal X3 and the normally closed contact CX (71-72) of the closing contactor.

[0030] One end of the isolating switch closing control branch is connected to the closing command input terminal X4, and the other end is connected to the control power supply neutral line N through the control power supply negative terminal X2. The isolating switch closing control branch includes the normally closed contact TX (71-72) of the opening contactor, the closing contactor coil CX (A1-A2), and the normally closed contact LSB (3-4) of the closing limit switch connected in series. It also includes a closing holding branch, in which the normally open contact CX (23-24) of the closing contactor is connected in series. One end of the normally open contact CX (23-24) of the closing contactor is connected to the control power supply live wire terminal L through the control power supply positive terminal X1, and the other end is connected between the closing command input terminal X4 and the normally closed contact TX (71-72) of the opening contactor.

[0031] like Figure 2As shown, the motor drive circuit includes a first rotation branch and a second rotation branch. The normally open contacts TX (33-34) of the trip contactor, the stator windings M (D1-D2) of the motor, the normally open contacts TX (43-44) of the trip contactor, the rotor windings M (Z1-Z2) of the motor, and the normally open contacts TX (13-14) of the trip contactor are connected in sequence to form the first rotating branch. One end of the first rotating branch is connected to the live wire L of the motor power supply through the positive terminal X5 of the motor power supply, and the other end is connected to the neutral wire N of the motor power supply through the negative terminal X6 of the motor power supply. The normally open contacts CX (33-34) of the closing contactor, the stator windings M (D2-D1) of the motor, the normally open contacts CX (43-44) of the closing contactor, the rotor windings M (Z1-Z2) of the motor, and the normally open contacts CX (13-14) of the closing contactor are connected in sequence to form the second rotating branch. One end of the second rotating branch is connected to the live wire L of the motor power supply through the positive terminal X5 of the motor power supply, and the other end is connected to the neutral wire N of the motor power supply through the negative terminal X6 of the motor power supply.

[0032] When a circuit breaker performs opening and closing operations, it generates significant mechanical vibration, causing the normally open contacts in the opening and closing control circuits of the disconnecting switch, the grounding switch, and the motor drive circuit to close, thus forming a self-holding mechanism. This can lead to the disconnecting switch and the grounding switch opening or closing incorrectly.

[0033] Control loop example:

[0034] The control circuit of the present invention for a disconnecting switch or a grounding switch can be used for the opening and closing control of both disconnecting switches and grounding switches or fast grounding switches. Taking a disconnecting switch as an example, the control circuit includes a disconnecting switch opening and closing control branch and a motor drive circuit. The disconnecting switch opening and closing control branch includes a disconnecting switch opening control branch and a disconnecting switch closing control branch.

[0035] Specifically, such as Figure 3 As shown, one end of the disconnector switch tripping control branch is connected to the tripping command input terminal X3, and the other end is connected to the control power supply neutral line N through the control power supply negative terminal X2. The disconnector switch tripping control branch includes the normally closed contact CX (71-72) of the closing contactor, the tripping contactor coil TX (A1-A2), and the normally closed contact LSA (3-4) of the tripping limit switch connected in series. It also includes a tripping holding branch, in which the normally open contact TX (23-24) of the tripping contactor is connected in series with the normally open contact MX (13-14) of the protection relay to form the tripping holding branch. One end of the tripping holding branch is connected to the control power supply live wire L through the control power supply positive terminal X1, and the other end is connected between the tripping command input terminal X3 and the normally closed contact CX (71-72) of the closing contactor.

[0036] One end of the isolating switch closing control branch is connected to the closing command input terminal X4, and the other end is connected to the control power supply neutral line N through the negative terminal X2 of the control power supply. The isolating switch closing control branch includes the normally closed contact TX (71-72) of the opening contactor, the coil CX (A1-A2) of the closing contactor, and the normally closed contact LSB (3-4) of the closing limit switch connected in series. It also includes a closing holding branch, in which the normally open contact CX (23-24) of the closing contactor is connected in series with the normally open contact MX (13-14) of the protection relay to form the closing holding branch. One end of the closing holding branch is connected to the control power supply live line L through the positive terminal X1 of the control power supply, and the other end is connected between the closing command input terminal X4 and the normally closed contact TX (71-72) of the opening contactor.

[0037] like Figure 4 As shown, the motor drive circuit includes a first rotation branch and a second rotation branch. The normally open contact TX (33-34) of the trip contactor, the stator winding M (D1-D2) of the motor, the normally open contact TX (43-44) of the trip contactor, the rotor winding M (Z1-Z2) of the motor, and the normally open contact TX (13-14) of the trip contactor are connected in sequence to form the first rotation branch. The normally open contact CX (33-34) of the closing contactor, the stator winding M (D2-D1) of the motor, the normally open contact CX (43-44) of the closing contactor, the rotor winding M (Z1-Z2) of the motor, and the normally open contact CX (13-14) of the closing contactor are connected in sequence to form the second rotation branch. One end of the first rotating branch is connected to the live wire L of the motor power supply via the positive terminal X5, and the other end is connected to the neutral wire N of the motor power supply via the negative terminal X6; one end of the second rotating branch is connected to the live wire L of the motor power supply via the positive terminal X5, and the other end is connected to the neutral wire N of the motor power supply via the negative terminal X6.

[0038] The normally open contacts TX (13-14) of the trip contactor and CX (13-14) of the closing contactor are connected in parallel to form a switch module. The motor drive circuit also includes a protection relay coil MX (A1-A2). The protection relay coil MX (A1-A2) is connected in series with the switch module to form a protection branch. One end of the protection branch is connected to the live wire L of the motor power supply through the positive terminal X5 of the motor power supply, and the other end is connected to the neutral wire N of the motor power supply through the negative terminal X6 of the motor power supply.

[0039] The control power supply live wire L and control power supply neutral wire N are connected to the control power supply and are always energized; the trip command input terminal X3 and the closing command input terminal X4 are used as input ports for trip and closing commands, and are not energized when there is no corresponding trip or closing command; the motor power supply live wire L and motor power supply neutral wire N are connected to the motor power supply and are always energized.

[0040] In this embodiment, the start time of the opening contactor TX and the closing contactor CX is t1, and the reset time is t2; the start time of the protection relay MX is t3, and the reset time is t4. Since the duration of the opening and closing pulse commands is generally 1 second, t1 + t3 < 1 second. To ensure that the isolating switch and grounding switch do not open or close incorrectly, t2 < t3. The state of the normally open and normally closed contacts corresponding to the coil will only change effectively when the energization time of the contactor or relay coil reaches the start time; the state of the normally open and normally closed contacts corresponding to the coil will only return to its original state when the de-energization time of the contactor or relay coil reaches the reset time.

[0041] After adopting this invention, the normal closing operation steps of the disconnecting switch are as follows:

[0042] ① The closing command input terminal X4 receives the closing pulse command, and the duration of the closing pulse command is generally 1 second;

[0043] ② Under the action of the closing pulse command, the coil CX (A1-A2) of the closing contactor is energized, the normally open contact CX (23-24) of the closing contactor in the closing holding branch is closed, and the normally open contacts CX (33-34), CX (43-44) and CX (13-14) of the closing contactor in the motor drive circuit are closed;

[0044] ③ When the coil MX (A1-A2) of the protection relay is energized, the normally open contact MX (13-14) of the protection relay closes;

[0045] ④ The closing contactor coil CX (A1-A2) forms a self-holding circuit through the normally open contact CX (23-24) of the closing contactor and the normally open contact MX (13-14) of the protection relay, and the control power supply continuously supplies power to the closing contactor coil CX (A1-A2).

[0046] ⑤ The stator winding M (D1-D2) and the rotor winding M (Z1-Z2) of the motor are energized, and the motor M continues to run;

[0047] ⑥ After the motor M runs for about 5 seconds, the isolating switch is closed. The normally closed contact LSB (3-4) of the closing limit switch opens, the coil CX (A1-A2) of the closing contactor is de-energized, and the normally open contacts CX (33-34), CX (43-44) and CX (13-14) of the closing contactor in the motor drive circuit turn to the open state. The motor M is de-energized and stops running, and the closing operation of the isolating switch is completed.

[0048] The operating procedures for normal opening of disconnecting switches and normal opening and closing of grounding switches are similar to those for closing disconnecting switches, and will not be repeated here.

[0049] The principle behind how a disconnecting switch can eliminate vibration interference and prevent accidental closing when in the open position is as follows:

[0050] ① The disconnecting switch did not receive a closing command, that is, no closing pulse command was input to the closing command input terminal X4, but the circuit breaker near the disconnecting switch mechanism box performed a tripping or closing operation;

[0051] ② Due to the vibration caused by the opening and closing operation of the circuit breaker, the closing contactor CX in the disconnector mechanism box malfunctioned, that is, the normally open contacts CX (23-24), CX (33-34), CX (43-44) and CX (13-14) of the closing contactor closed simultaneously.

[0052] ③ Because the reset time t2 of the closing contactor CX is less than the start time t3 of the protection relay MX, the protection relay MX cannot start normally. That is, when the closing contactor coil CX (A1-A2) is not energized, the normally open contact of the closing contactor CX will open automatically after time t2 after closing. However, the normally open contact MX (13-14) of the protection relay can only close after time t3. Therefore, the vibration caused by the circuit breaker opening and closing is insufficient to effectively connect the opening and closing control circuit and the motor drive circuit, thereby eliminating vibration interference.

[0053] ④ The closing contactor coil CX (A1-A2) cannot form a self-holding circuit through the normally open contact CX (23-24) of the closing contactor and the normally open contact MX (13-14) of the protection relay. The normally open contact CX (23-24), normally open contact CX (33-34), normally open contact CX (43-44) of the closing contactor and normally open contact CX (13-14) of the closing contactor reset after time t2.

[0054] ⑤ If the motor M does not receive enough power, it cannot start and run normally, and the disconnecting switch will not close accidentally.

[0055] The principle of eliminating vibration interference when the disconnecting switch is closed is similar to the principle of eliminating vibration interference when the grounding switch is open or closed, and the principle of eliminating vibration interference when the disconnecting switch is open to prevent accidental closing. It will not be elaborated here.

[0056] Equipment Example:

[0057] A GIS device of the present invention includes a circuit breaker, a disconnecting switch and a grounding switch. When designing and installing the disconnecting switch and the grounding switch, the opening and closing control circuit for the disconnecting switch or the grounding switch in the control circuit embodiment is adopted. The structure of the circuit has been clearly described in the control circuit embodiment and will not be repeated here.

[0058] In summary, the control circuit and GIS equipment designed in this invention for disconnecting switches or grounding switches can be widely used in gas-insulated metal-enclosed switchgear (GIS) for disconnecting switches, grounding switches and their operating mechanisms. It is especially suitable for disconnecting switches, grounding switches and their operating mechanisms at voltage levels of 550kV and above that are susceptible to mechanical vibrations during circuit breaker operation. It can ensure the normal opening and closing operation of disconnecting switches and grounding switches, and avoid maloperation of disconnecting switches and grounding switches caused by mechanical vibrations during circuit breaker operation, so that disconnecting switches and grounding switches are in a controlled and safe state.

Claims

1. A control circuit for a disconnector or grounding switch, comprising a tripping control branch and a closing control branch, wherein a tripping contactor coil is connected in series in the tripping control branch, and a closing contactor coil is connected in series in the closing control branch; one end of the tripping control branch is connected to a tripping signal input terminal and is also connected to a positive control power supply through a tripping holding branch; one end of the closing control branch is connected to a closing signal input terminal and is also connected to a positive control power supply through a closing holding branch; characterized in that... It also includes a protection relay and a switch module. The protection relay coil and the switch module are connected in series between the positive and negative poles of the motor power supply. Both the opening and closing holding branches are connected to the positive control power supply through the normally open contact of the protection relay. The switch module includes the first normally open contact of the opening contactor and the first normally open contact of the closing contactor connected in parallel. The start time of the protection relay is greater than the reset time of the opening contactor and the reset time of the closing contactor.

2. The control circuit for a disconnector or grounding switch according to claim 1, characterized in that, The tripping holding branch is connected in series with the second normally open contact of the tripping contactor, and the closing holding branch is connected in series with the second normally open contact of the closing contactor; one end of the tripping holding branch and one end of the closing holding branch are connected to the positive control power supply through the normally open contact of the protection relay.

3. The control circuit for a disconnector or grounding switch according to claim 1, characterized in that, It also includes a motor drive circuit connected in series with the switch module. The motor drive circuit includes a first rotary branch for opening the circuit and a second rotary branch for closing the circuit. The third normally open contact of the opening contactor, the stator winding of the motor, and the rotor winding of the motor are connected in series to form the first rotary branch. The third normally open contact of the closing contactor, the stator winding of the motor, and the rotor winding of the motor are connected in series to form the second rotary branch. The protective relay coil is connected in parallel with the motor drive circuit.

4. The control circuit for a disconnector or grounding switch according to claim 1, characterized in that, The tripping control branch is also connected in series with a normally closed contact of a closing contactor, and the closing control branch is also connected in series with a normally closed contact of a tripping contactor.

5. The control circuit for a disconnector or grounding switch according to claim 4, characterized in that, The tripping control branch is also connected in series with a tripping limit switch, and the closing control branch is also connected in series with a closing limit switch.

6. A GIS device, characterized in that, The system includes a control circuit for a disconnector or grounding switch. This control circuit comprises a tripping control branch and a closing control branch. A tripping contactor coil is connected in series in the tripping control branch, and a closing contactor coil is connected in series in the closing control branch. One end of the tripping control branch is connected to the tripping signal input terminal and is also connected to the positive control power supply via a tripping holding branch. One end of the closing control branch is connected to the closing signal input terminal and is also connected to the positive control power supply via a closing holding branch. The system also includes a protection relay and a switch module. The protection relay coil and the switch module are connected in series between the positive and negative terminals of the motor power supply. Both the tripping holding branch and the closing holding branch are connected to the positive control power supply via normally open contacts of the protection relay. The switch module includes first normally open contacts of the tripping contactor and the first normally open contact of the closing contactor connected in parallel. The start-up time of the protection relay is greater than the reset time of the tripping contactor and the reset time of the closing contactor.

7. The GIS equipment according to claim 6, characterized in that, The tripping holding branch is connected in series with the second normally open contact of the tripping contactor, and the closing holding branch is connected in series with the second normally open contact of the closing contactor; one end of the tripping holding branch and one end of the closing holding branch are connected to the positive control power supply through the normally open contact of the protection relay.

8. The GIS equipment according to claim 6, characterized in that, It also includes a motor drive circuit connected in series with the switch module. The motor drive circuit includes a first rotary branch for opening the circuit and a second rotary branch for closing the circuit. The third normally open contact of the opening contactor, the stator winding of the motor, and the rotor winding of the motor are connected in series to form the first rotary branch. The third normally open contact of the closing contactor, the stator winding of the motor, and the rotor winding of the motor are connected in series to form the second rotary branch. The protective relay coil is connected in parallel with the motor drive circuit.

9. The GIS equipment according to claim 6, characterized in that, The tripping control branch is also connected in series with a normally closed contact of a closing contactor, and the closing control branch is also connected in series with a normally closed contact of a tripping contactor.

10. The GIS equipment according to claim 9, characterized in that, The tripping control branch is also connected in series with a tripping limit switch, and the closing control branch is also connected in series with a closing limit switch.

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