10kV switch closing locking loop capable of preventing voltage relay from refusing operation
By integrating low-voltage relays in the 10kV switch closing locking circuit, the protection logic is optimized, and the problem of switching closing locking circuit failure caused by the refusal of overvoltage relay is solved, and the stability and safety of the switch closing locking circuit are achieved.
Patent Information
- Application Number
- CN202422139646.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-09-02
AI Technical Summary
In the prior art, when the DC power supply of the overvoltage relay fails or the function is damaged, the relay refuses to move, causing the switch closing locking circuit to fail, and there is a risk of the switch closing at different times, resulting in equipment damage or voltage fluctuations.
A 10kV switch closing locking circuit with anti-voltage relay is designed. By integrating a low-voltage relay in the locking circuit and rationally using its normally open/normal closed contact characteristics, the traditional protection logic is optimized to ensure that the switch closing locking circuit is still valid when the relay cannot operate.
It effectively prevents the failure of the closing locking function caused by the refusal of the voltage relay, enhances the safety and stability of the power system operation, and avoids the risks of closing the switch, equipment damage and voltage fluctuations during different periods.
Smart Images
Figure CN222995309U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of relays. Specifically, it relates to a 10kV switch closing interlock circuit for preventing voltage relay refusal to operate. Background Art
[0002] When there are multiple power sources in a power system line or bus, to prevent multiple power sources from simultaneously supplying power to the bus, causing non-synchronous closing of the switch and resulting in power system fluctuations, an interlock circuit is usually designed in the closing circuit of the bus incoming power switch. An overvoltage relay is used to monitor the bus or incoming power source for no voltage, and the normally closed contact is output for the closing interlock circuit of the incoming power switch. However, there is a safety hazard in the existing system. If the DC power supply of the overvoltage relay is powered off, the function is damaged, etc., resulting in the relay refusing to operate, the normally closed contact cannot be opened, the switch closing interlock circuit fails, and there is a risk of non-synchronous closing of the switch, causing equipment damage or voltage fluctuations, etc. Summary of the Utility Model
[0003] The purpose of this application is to provide a 10kV switch closing interlock circuit for preventing voltage relay refusal to operate, which can achieve that when the relay cannot operate due to power loss of the voltage relay power supply, function damage, etc., the switch closing interlock circuit is still effective, so as to solve the technical problem that when the voltage relay refuses to operate in the existing technology, it may cause non-synchronous closing of the switch, resulting in equipment damage and voltage fluctuations.
[0004] The purpose of this application is achieved through the following technical solutions:
[0005] In a first aspect, this application proposes a 10kV switch closing interlock circuit for preventing voltage relay refusal to operate. The interlock circuit includes a detection circuit, and the detection circuit includes a three-phase bus, a bus voltage transformer, a bus low-voltage relay, an incoming switch, incoming three-phase lines, an incoming power source, an incoming line voltage transformer, and an incoming line low-voltage relay;
[0006] The three-phase bus is respectively connected to the bus voltage transformer and the incoming switch. The bus voltage transformer is connected to the bus low-voltage relay. The incoming switch is connected to the incoming three-phase lines. The incoming three-phase lines are respectively connected to the incoming power source and the incoming line voltage transformer. The incoming line voltage transformer is connected to the incoming line low-voltage relay.
[0007] In a possible implementation manner, the interlock circuit further includes an interlock sub-circuit connected to the detection circuit. The interlock sub-circuit includes an incoming switch closing interlock coil, a bus low-voltage relay k1 contact, a line low-voltage relay k2 contact, and a DC power supply;
[0008] The contacts of the bus low-voltage relay K1 and the line low-voltage relay K2 are connected in parallel and are respectively connected to the DC power supply and the closing locking coil of the incoming line switch, and the DC power supply is connected to the closing locking coil of the incoming line switch.
[0009] In a possible implementation manner, the models of the bus low-voltage relay and the incoming line low-voltage relay are RYII-D2.
[0010] In a possible implementation manner, the three-phase bus is made of copper or aluminum.
[0011] In a possible implementation manner, the models of the bus voltage transformer and the incoming line voltage transformer are JDZ-10 or JDZW-10.
[0012] In a possible implementation manner, the model of the incoming line switch is selected as LW36-12.
[0013] In a possible implementation manner, the incoming line three-phase line adopts a YJV-10kV cable.
[0014] In a possible implementation manner, the closing locking coil of the incoming line switch is a special coil matching the VS1-12 or LW36-12 circuit breaker.
[0015] The main solution of the present application and its various further selection solutions can be freely combined to form multiple solutions, all of which are solutions that can be adopted and claimed by the present application; and in the present application, (each non-conflicting selection) selections can also be freely combined with each other and with other selections. Those skilled in the art can understand that there are various combinations according to the prior art and common general knowledge after understanding the solution of the present application, all of which are the technical solutions to be protected by the present application, and are not enumerated herein.
[0016] The present application discloses a 10kV switch closing locking circuit for preventing voltage relay refusal to operate. The three-phase bus is respectively connected to the bus voltage transformer and the incoming line switch. The bus voltage transformer is connected to the bus low-voltage relay. The incoming line switch is connected to the incoming line three-phase line. The incoming line three-phase line is respectively connected to the incoming line power supply and the incoming line voltage transformer. The incoming line voltage transformer is connected to the incoming line low-voltage relay. This circuit can achieve that when the voltage relay power supply loses power, the function is damaged, etc., resulting in the relay being unable to operate, the switch closing locking circuit is still effective, so as to solve the technical problems that in the prior art, when the voltage relay refuses to operate, it may cause the switch to be closed out of phase, resulting in equipment damage and voltage fluctuation. Description of the Drawings
[0017] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.
[0018] Figure 1 It shows a schematic diagram of the detection circuit proposed in the embodiments of the present application.
[0019] Figure 2 It shows a schematic diagram of the latching sub-circuit proposed in the embodiments of the present application.
[0020] Icon: 1 - Three-phase busbar; 2 - Bus voltage transformer; 3 - Bus low-voltage relay; 4 - Incoming line switch; 5 - Incoming three-phase line; 6 - Incoming power supply; 7 - Incoming line voltage transformer; 8 - Incoming line low-voltage relay; 9 - Incoming line switch closing latching coil; 10 - Bus low-voltage relay k1 contact; 11 - Line low-voltage relay k2 contact; 12 - DC power supply. Detailed implementation manners
[0021] The following uses specific specific examples to illustrate the implementation manners of the present application. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific implementation manners. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.
[0022] Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present application.
[0023] In the prior art, when there are multiple power source points in the power system line or busbar, to prevent multiple power source points from simultaneously supplying power to the busbar, causing non-synchronous closing of the switch and resulting in power system fluctuations, a latching circuit is usually designed in the closing circuit of the busbar incoming power supply 6 switch. An overvoltage relay is used to monitor the busbar or the incoming power supply 6 without voltage, and the normally closed contact is output for the incoming power supply 6 switch closing latching circuit. However, there is a safety hazard in the existing system. If the DC power supply of the overvoltage relay loses power, the function is damaged, etc., resulting in the relay failing to operate, the normally closed contact cannot be opened, and the switch closing latching circuit fails, there is a risk of non-synchronous closing of the switch, causing equipment damage or voltage fluctuations, etc.
[0024] Therefore, to solve the above technical problems, the embodiments of the present application propose a closing locking circuit for a 10 kV switch to prevent the voltage relay from failing to operate. This circuit can ensure that the switch closing locking circuit remains effective when the voltage relay power supply loses power, the function is damaged, or other situations cause the relay to fail to operate, so as to solve the technical problems in the prior art that when the voltage relay fails to operate, it may cause the switch to close out of synchronization, resulting in equipment damage and voltage fluctuations. Next, a detailed description of the closing locking circuit for a 10 kV switch to prevent the voltage relay from failing to operate will be given.
[0025] Please refer to Figure 1 , Figure 1 , which shows a schematic diagram of the detection circuit proposed by the embodiments of the present application. The locking circuit includes a detection circuit, and the detection circuit includes a three-phase bus 1, a bus voltage transformer 2, a bus low-voltage relay 3, an incoming line switch 4, an incoming three-phase line 5, an incoming power supply 6, an incoming line voltage transformer 7, and an incoming line low-voltage relay 8;
[0026] The three-phase bus 1 is respectively connected to the bus voltage transformer 2 and the incoming line switch 4. The bus voltage transformer 2 is connected to the bus low-voltage relay 3. The incoming line switch 4 is connected to the incoming three-phase line 5. The incoming three-phase line 5 is respectively connected to the incoming power supply 6 and the incoming line voltage transformer 7. The incoming line voltage transformer 7 is connected to the incoming line low-voltage relay 8.
[0027] The three-phase bus 1 is the main trunk of the entire circuit, connecting the power supply and the load. The bus voltage transformer 2 is used to monitor the voltage condition on the bus and convert it into a low-voltage signal that can be processed. The bus low-voltage relay 3 receives the signal from the bus voltage transformer 2 and is used to detect whether the bus voltage is lower than the threshold. The incoming line switch 4 controls the current to flow into or disconnect from the incoming three-phase line 5. The incoming three-phase line 5 connects the external power supply and the internal system and is the channel for power transmission. The incoming power supply 6 provides the necessary electrical energy for the system. The incoming line voltage transformer 7 monitors the voltage level of the incoming line. The incoming line low-voltage relay 8 analyzes the output of the incoming line voltage transformer 7 and judges the incoming line voltage state.
[0028] By directly integrating the low-voltage relay into the locking circuit and reasonably utilizing the normally open / normally closed contact characteristics, the traditional protection logic is optimized, effectively preventing the failure of the closing locking function caused by the potential failure of the voltage relay, thereby enhancing the safety and stability of the power system operation.
[0029] Figure 2 , which shows a schematic diagram of the locking sub-circuit proposed by the embodiments of the present application. The locking circuit further includes a locking sub-circuit connected to the detection circuit. The locking sub-circuit includes an incoming line switch closing locking coil 9, a bus low-voltage relay k1 contact 10, a line low-voltage relay k2 contact 11, and a DC power supply 12;
[0030] The contacts 10 of the bus low-voltage relay k1 are connected in parallel and are respectively connected to the DC power supply 12 and the closing interlock coil 9 of the incoming line switch. The DC power supply 12 is connected to the closing interlock coil 9 of the incoming line switch.
[0031] The closing interlock coil 9 of the incoming line switch is a key actuating element that can ensure that the switch avoids closing under inappropriate conditions. The contacts 10 of the bus low-voltage relay k1, as the output interface of the bus low-voltage relay, directly participate in the interlock logic. The contacts 11 of the line low-voltage relay k2 correspond to the output of the line low-voltage relay and are connected in parallel with the contacts 10. The DC power supply 12 provides the necessary energy support for the closing interlock coil. This design forms a more rigorous control strategy by connecting the contacts 10 of the bus low-voltage relay k1 and the contacts 11 of the line low-voltage relay k2 in parallel and then connecting them to the DC power supply 12 and the closing interlock coil 9 of the incoming line switch. Such an arrangement means that only when the contacts of both the k1 and k2 relays are in the expected open state (i.e., normal voltage), the interlock coil will not be energized, allowing the switch to close.
[0032] The three-phase bus 1 is a transmission line with 10 kV high voltage. The three-phase bus 1 is connected to the incoming power supply 6. The three-phase bus 1 is equipped with a bus voltage transformer 2. The incoming power supply 6 is connected to the incoming line voltage transformer 7. The bus voltage transformer 2 is connected to the bus low-voltage relay to control the contacts 10 of the bus low-voltage relay k1. The incoming line voltage transformer 7 is connected to the incoming line low-voltage relay 8 to control the contacts 10 of the bus low-voltage relay k1. When both the bus and the line are energized, neither the bus low-voltage relay nor the line low-voltage relay operates, and the contacts are all in the open state. When the closing interlock circuit of the switch is not conducting, the switch will not close by mistake. That is, the closing path of the switch will remain open, effectively preventing misclosing events, thereby improving the safety and stability of the power grid operation.
[0033] The models of the bus low-voltage relay and the incoming line low-voltage relay 8 are RYII-D2.
[0034] Using low-voltage relays to monitor the voltages of the bus and the incoming power supply 6, compared with the traditional scheme, the low-voltage relays (model RYII-D2) selected in this application can more accurately detect the no-voltage state of the bus or the incoming power supply 6, which improves the sensitivity and response speed of the system to voltage abnormalities.
[0035] The three-phase bus 1 is made of copper or aluminum, and the specific model is determined according to the current-carrying capacity and installation standards, such as series like TMY, TMJ, etc.
[0036] The models of the bus voltage transformer 2 and the incoming line voltage transformer 7 are JDZ-10 or JDZW-10. These models can adapt to the 10kV voltage level, and specific selection also needs to be based on requirements such as accuracy and capacity.
[0037] The model of the incoming line switch is selected as LW36-12.
[0038] The incoming line three-phase line 5 uses YJV-10kV cables, and its specifications are selected according to the current and voltage levels.
[0039] The closing lockout coil 9 of the incoming line switch is a special coil matching with the VS1-12 or LW36-12 circuit breaker. Usually, it is an internal component of the circuit breaker, and the model depends on the circuit breaker model.
[0040] Compared with the prior art, the embodiments of the present application have the following beneficial effects:
[0041] By using a low-voltage relay to monitor the voltage-free of the bus or the bus incoming line power supply 6 in the 10kV switch closing lockout circuit, and replacing the normally closed contact of the relay contact connected to the switch closing lockout circuit with a normally open contact, the switch closing lockout circuit can be conducted only after the low-voltage relay operates correctly, solving the problems in the prior art that the overvoltage relay refuses to operate, the switch closing lockout circuit is always conducted, the function fails, and it may cause the switch to close out of sync due to misoperation of closing the power switch, resulting in equipment damage and voltage fluctuation.
[0042] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.
Claims
1. A 10kV switch closing lockout circuit to prevent voltage relay refusal to operate, characterized in that: The locking loop includes a detection circuit, and the detection circuit includes a three-phase bus, a bus voltage transformer, a bus low-voltage relay, an incoming switch, an incoming three-phase line, an incoming power supply, an incoming line voltage transformer, and an incoming line low-voltage relay; The three-phase bus is connected to the bus voltage transformer and the incoming switch respectively, the bus voltage transformer is connected to the bus low-voltage relay, the incoming switch is connected to the incoming three-phase line, the incoming three-phase line is connected to the incoming power supply and the incoming line voltage transformer respectively, and the incoming line voltage transformer is connected to the incoming line low-voltage relay.
2. The 10kV switch closing lockout circuit according to claim 1, characterized in that: The locking circuit also includes a locking sub-circuit connected to the detection circuit, and the locking sub-circuit includes an incoming switch closing locking coil, a busbar low-voltage relay k1 contact, a line low-voltage relay k2 contact, and a DC power supply; The busbar low voltage relay k1 contact and the line low voltage relay k2 contact are connected in parallel and are respectively connected to the DC power supply and the incoming switch closing lock coil, and the DC power supply is connected to the incoming switch closing lock coil.
3. The 10kV switch closing lockout circuit according to claim 1, characterized in that: The model of busbar low voltage relay and incoming line low voltage relay is RYII-D2.
4. The 10kV switch closing lockout circuit according to claim 1, characterized in that: The three-phase busbars are made of copper or aluminum.
5. The 10kV switch closing lockout circuit according to claim 1, characterized in that: The models of busbar voltage transformer and incoming line voltage transformer are JDZ-10 or JDZW-10.
6. The 10kV switch closing lockout circuit according to claim 1, characterized in that: The model of incoming line switch is LW36-12.
7. The 10kV switch closing lockout circuit according to claim 1, characterized in that: The incoming three-phase line adopts YJV-10kV cable.
8. The 10kV switch closing lockout circuit according to claim 2, characterized in that: The incoming switch closing lockout coil is a special coil matching the VS1-12 or LW36-12 circuit breaker.