Novel parallel high-voltage circuit breaker device for generator outlet fault protection

Abstract

The invention belongs to the technical field of high-voltage circuit breakers, and particularly discloses a novel parallel high-voltage circuit breaker device for generator outlet fault protection, which comprises a first branch circuit, a second branch circuit and a third branch circuit which are connected in parallel, when a short-circuit fault occurs, the first branch circuit is conducted and forms a closed LC oscillation circuit with the second branch circuit. The LC oscillating circuit generates oscillating current, and the oscillating current is injected into the main circuit breaker to neutralize and counteract fault current of a short-circuit fault, so that the main circuit breaker can be quickly disconnected at a zero current point; after the main circuit breaker is disconnected, the current is transferred to the first branch, the thyristor assembly is stopped from being triggered and conducted by closing the circuit breaker assembly of the third branch, the thyristor assembly is disconnected when the oscillating current crosses zero, and the third branch bears the fault current transferred through the first branch. And the current sharing of the circuit breaker assembly is realized through the anti-coupling inductance of the high-coupling reactor. According to the invention, the circuit breaker can be quickly disconnected, and the safety and reliability of a power system are improved.

Description

Technical Field

[0001] The present application belongs to the technical field of high-voltage circuit breakers, and more specifically, relates to a novel parallel-type high-voltage circuit breaker device for generator outlet fault protection. Background Art

[0002] Driven by power grid construction and smart grid technology, high-voltage circuit breaker technology and market have achieved remarkable development. It has been widely used in power grids. By cutting off and connecting load circuits and cutting off fault circuits, accidents are prevented from expanding, ensuring the safe operation of the power grid system. When a short circuit occurs at the generator outlet, the fault current can be divided into an AC component and a DC component. At the moment of the fault, in order to maintain the conservation of the winding flux, a DC component is induced in the winding to offset the flux change caused by the AC component. At this time, the initial amplitudes of the DC component and the AC component are equal. However, in the subtransient stage, the AC component decays faster than the DC component, and the difference in attenuation between the two causes the fault current to have a delayed zero crossing phenomenon.

[0003] The conventional high-voltage circuit breakers widely used today rely on the current zero-crossing point to break, so they cannot achieve fast disconnection operations, which may cause further impact and damage to the power grid system. This design is difficult to meet the demand for higher breaking capacity and fast response time in complex power grid operating environments.

[0004] Therefore, it is necessary to optimize and improve the high-voltage circuit breaker device at the existing generator outlet to eliminate the delayed zero-crossing phenomenon and improve the overall breaking capacity and response speed of the circuit breaker to meet the needs of modern power grid operation. Summary of the invention

[0005] In view of the defects of the prior art, the purpose of this application is to provide a new parallel high-voltage circuit breaker device for generator outlet fault protection, aiming to solve the problem in the prior art that the circuit breaker cannot be disconnected quickly, causing damage to the power grid system.

[0006] To achieve the above object, the present application provides a novel parallel high-voltage circuit breaker device for generator outlet fault protection, comprising: The first branch includes a thyristor assembly, an inductor and a capacitor connected in series in sequence; one end of the thyristor assembly is connected to the circuit input end, and the other end is connected to the inductor; one end of the capacitor is connected to the inductor, and the other end is connected to the circuit output end; the second branch includes a main circuit breaker; When a short circuit fault occurs, the first branch is turned on and forms a closed LC oscillation circuit with the second branch; The LC oscillation circuit generates an oscillating current, which is injected into the second branch main circuit breaker. The oscillating current is neutralized and offset by the fault current of the short-circuit fault, and the main circuit breaker realizes current zero crossing to achieve rapid disconnection, and the fault current is transferred to the first branch; The third branch includes a high-coupling reactor and a circuit breaker assembly. After the main circuit breaker is disconnected, the third branch circuit breaker assembly is closed to stop triggering and turning on the thyristor assembly. The thyristor assembly is disconnected when the oscillating current passes through zero. The third branch carries the fault current transferred via the first branch, and the current of the circuit breaker assembly is evenly distributed through the reverse coupling inductance of the high-coupling reactor.

[0007] Optionally, the high-coupling reactor includes a first coupling inductor and a second coupling inductor, the circuit breaker assembly includes a first branch circuit breaker and a second branch circuit breaker connected in parallel to each other, and the first coupling inductor and the second coupling inductor are reversely coupled to achieve current equalization in the first branch circuit breaker and the second branch circuit breaker.

[0008] Optionally, the high-coupling reactor is used to accelerate the gradual attenuation of the DC component of the system short-circuit current based on its own high resistance.

[0009] Optionally, the thyristor assembly consists of two thyristors connected in reverse parallel.

[0010] Optionally, the thyristor assembly is composed of a diode and a thyristor connected in parallel.

[0011] The present application also provides a circuit system, comprising the novel parallel high-voltage circuit breaker device for generator outlet fault protection as described in any one of the above items.

[0012] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art: (1) By constructing a closed LC oscillation circuit, the present application can quickly generate an oscillating current when a short-circuit fault occurs, neutralize and offset the fault current, and ensure that the main circuit breaker can be quickly disconnected at the zero current point, thereby significantly improving the response speed of fault handling, reducing the risk of equipment damage, and ensuring the safety and reliability of the power system.

[0013] (2) The reverse coupled inductor circuit introduced in the embodiment of the present application effectively improves the breaking capacity of the high-voltage circuit breaker at the same voltage level, so that the system can better cope with and ensure the normal operation of the circuit breaker when facing high fault current, reduce equipment damage or failure caused by overload, and improve the overall stability of the power system.

[0014] (3) The introduction of the coupled inductor of the present application accelerates the attenuation of the large-amplitude oscillating current generated by the LC oscillation circuit, effectively avoiding further damage that the oscillating current may cause to the power grid system. The coupled inductor not only increases the attenuation speed of the current, but also optimizes the current distribution, reduces the impact on the power grid, and ensures the safety and stability of the power system under fault conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a novel parallel high-voltage circuit breaker device for generator outlet fault protection provided in an embodiment of the present application; Figure 2 It is an overall circuit diagram of a novel parallel high-voltage circuit breaker device for generator outlet fault protection provided in an embodiment of the present application; Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein: S1 is the first branch; S2 is the second branch; S3 is the third branch; 11 is a thyristor assembly; 12 is an inductor; 13 is a capacitor; 21 is the main circuit breaker; 31 is a high coupling reactor; 32 is a circuit breaker assembly. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0017] The term "and / or" in this article is a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The symbol " / " in this article indicates that the associated objects are in an or relationship, for example, A / B means A or B.

[0018] The terms "first" and "second" in the specification and claims herein are used to distinguish different objects rather than to describe a specific order of the objects. For example, a first response message and a second response message are used to distinguish different response messages rather than to describe a specific order of the response messages.

[0019] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0020] In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more than two. For example, multiple processing units refer to two or more processing units, etc.; multiple elements refer to two or more elements, etc.

[0021] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0022] Reference Figure 1 , the present application provides a novel parallel type high voltage circuit breaker device for generator outlet fault protection, comprising: a first branch S1, a second branch S2 and a third branch S3 connected in parallel with each other; The first branch S1 includes a thyristor assembly 11, an inductor 12 and a capacitor 13 connected in series in sequence; one end of the thyristor assembly 11 is connected to the circuit input end, and the other end is connected to the inductor 12; one end of the capacitor 12 is connected to the inductor 13, and the other end is connected to the circuit output end; the second branch S2 includes a main circuit breaker 21; When a short circuit fault occurs, the first branch S1 is turned on and forms a closed LC oscillation circuit with the second branch S2; The LC oscillation circuit is used to generate an oscillating current, which is injected into the second branch main circuit breaker. The oscillating current is neutralized and offset by the fault current of the short-circuit fault. The main circuit breaker 21 realizes current zero crossing to achieve rapid disconnection, and the fault current is transferred to the first branch S1; The third branch S3 includes a high-coupling reactor 31 and a circuit breaker assembly 32. After the main circuit breaker is disconnected, the third branch circuit breaker assembly is closed to stop triggering the thyristor assembly to turn on. The thyristor assembly is disconnected when the oscillating current passes through zero. The third branch carries the fault current transferred via the first branch, and the current of the circuit breaker assembly is evenly distributed through the reverse coupling inductance of the high-coupling reactor.

[0023] The high-coupling reactor includes a first coupling inductor and a second coupling inductor, and the circuit breaker assembly includes a first branch circuit breaker and a second branch circuit breaker connected in parallel with each other. The first coupling inductor and the second coupling inductor are reversely coupled to achieve current equalization in the first branch circuit breaker and the second branch circuit breaker.

[0024] Specifically, the novel parallel high-voltage circuit breaker device for generator outlet fault protection provided in the embodiment of the present application includes a first branch S1, a second branch S2 and a third branch S3. The first branch S1 is composed of a thyristor assembly, an inductor and a capacitor connected in series in sequence, and is responsible for forming a closed LC oscillation circuit when a short-circuit fault occurs. The second branch S2 includes a main circuit breaker, which is mainly used to cut off the fault current. The third branch S3 is a reverse-coupled inductor circuit, which is intended to multiply the breaking capacity of the high-voltage circuit breaker and realize the average current distribution after the main circuit breaker is shut down at zero crossing.

[0025] The core components of the first branch S1 include a thyristor component 11, an inductor 12 and a capacitor 13. One end of the thyristor component 11 is connected to the input end of the circuit, and the other end is connected to the inductor 12. The inductor 12 is connected in series with the capacitor 13, and the other end of the capacitor is connected to the output end of the circuit. When a short-circuit fault occurs, the first branch S1 is turned on and forms a closed LC oscillation circuit with the second branch S2. The LC oscillation circuit can generate an oscillating current, which is neutralized and offset by the short-circuit fault current, thereby realizing the rapid disconnection of the main circuit breaker at the zero current point.

[0026] Under normal circumstances, the capacitor 12 of the first branch S1 has a certain initial voltage and energy; when a short circuit fault occurs, the current increases sharply, and the thyristor assembly 11 is triggered to turn on. The conduction of the thyristor assembly 11 increases the voltage difference of the first branch S1. As the voltage difference increases, the fault current can flow into the first branch; that is, the fault current will cause the LC oscillation circuit to generate an oscillating current, which is injected into the second branch S2. The second branch S2 has multiple zero crossings through the oscillating current and the fault current, and the main circuit breaker will quickly disconnect to protect the circuit.

[0027] The LC oscillator circuit can not only generate an oscillating current, but also generate multiple zero crossings according to the oscillating current and the fault current. These zero crossings provide multiple time points for the main circuit breaker, ensuring that it smoothly crosses zero at the right time, thereby improving the reliability and safety of the circuit breaker. Through the design of the present application, the system can respond quickly when a fault occurs, reducing the risk of damage to the equipment. The present application constructs a closed LC oscillator circuit, which can quickly generate an oscillating current when a short-circuit fault occurs, neutralize and offset the fault current, and ensure that the main circuit breaker can be quickly disconnected at the zero current point, thereby significantly improving the response speed of fault processing, reducing the risk of equipment damage, and ensuring the safety and reliability of the power system. The introduced reverse coupling inductor circuit effectively improves the breaking capacity of the high-voltage circuit breaker at the same voltage level, so that the system can better cope with and ensure the normal operation of the circuit breaker when facing a high fault current, reducing equipment damage or failure caused by overload, and improving the overall stability of the power system. The introduction of coupled inductors accelerates the attenuation of the large-value oscillating current generated by the LC oscillation circuit, effectively avoiding further damage to the power grid system caused by the oscillating current. The coupled inductors not only increase the current attenuation speed, but also optimize the current distribution, reduce the impact on the power grid, and ensure the safety and stability of the power system under fault conditions.

[0028] Further, refer to Figure 2 , the third branch S3 of the embodiment of the present application is designed as a reverse coupled inductor circuit, the main purpose of which is to multiply the breaking capacity of the high-voltage circuit breaker at the same voltage level. The high-coupling reactor includes a first coupled inductor and a second coupled inductor, and the circuit breaker assembly includes a first branch circuit breaker and a second branch circuit breaker connected in parallel with each other, and the first coupled inductor and the second coupled inductor are reversely coupled to achieve current equalization in the first branch circuit breaker and the second branch circuit breaker. The first coupled inductor and the second coupled inductor of this embodiment can effectively improve the current distribution capability of the system in the event of a fault, and ensure that the average current is divided after the main circuit breaker is shut down through zero, thereby enhancing the stability and safety of the system. Among them, the number of turns of the coils of the first coupled inductor and the second coupled inductor is the same to ensure that the voltage ratio of the first coupled inductor and the second coupled inductor is 1:1. Furthermore, the high-coupling reactor is used to accelerate the gradual attenuation of the DC component of the system short-circuit current based on its own high resistance.

[0029] Furthermore, the current directions of the two coils of the third branch S3 in this embodiment are consistent, and the currents passing through the two coils are the same. Since the first coupled inductor and the second coupled inductor are reversely coupled, the inductance values ​​cancel each other out, which can reduce the mutual inductance. Therefore, the remaining current will be evenly divided into two parts of equal size when passing through the third branch S3, passing through the two coils and the first branch circuit breaker and the second branch circuit breaker, that is, circuit breakers 1 and 2.

[0030] Since the current that circuit breakers 1 and 2 need to break is reduced by half, the current distribution is optimized. In addition, since the resistance of the coupled inductor is large, the current decays faster, thereby increasing the current decay rate, optimizing the current distribution, enhancing the current breaking capacity, reducing the impact on the power grid, and ensuring the safety and stability of the power system under fault conditions.

[0031] Optionally, the thyristor assembly consists of two thyristors connected in reverse parallel.

[0032] Optionally, the thyristor assembly is composed of a diode and a thyristor connected in parallel.

[0033] The embodiment of the present application can optionally be configured with a thyristor assembly, which is composed of two thyristors connected in reverse parallel, which can achieve more efficient current control and enhance the response speed and operation stability of the switch. In addition, the thyristor assembly of the embodiment of the present application can also be composed of a diode and a thyristor connected in parallel to further improve the flexibility and anti-interference ability of the system.

[0034] The present application also provides a circuit system, comprising a novel parallel high-voltage circuit breaker device for generator outlet fault protection as described in any one of the above items.

[0035] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A novel parallel high voltage circuit breaker device for generator outlet fault protection, characterized in that: include: A first branch, a second branch and a third branch connected in parallel; The first branch includes a thyristor assembly, an inductor and a capacitor connected in series in sequence; One end of the thyristor assembly is connected to the circuit input end, and the other end is connected to the inductor; one end of the capacitor is connected to the inductor, and the other end is connected to the circuit output end; the second branch includes a main circuit breaker; When a short circuit fault occurs, the first branch is turned on and forms a closed LC oscillation circuit with the second branch; The LC oscillation circuit generates an oscillating current, which is injected into the second branch main circuit breaker. The oscillating current is neutralized and offset by the fault current of the short-circuit fault, and the main circuit breaker realizes current zero crossing to achieve rapid disconnection, and the fault current is transferred to the first branch; The third branch includes a high-coupling reactor and a circuit breaker assembly. After the main circuit breaker is disconnected, the third branch circuit breaker assembly is closed to stop triggering and turning on the thyristor assembly. The thyristor assembly is disconnected when the oscillating current passes through zero. The third branch carries the fault current transferred via the first branch, and the current of the circuit breaker assembly is evenly distributed through the reverse coupling inductance of the high-coupling reactor.

2. The novel parallel high voltage circuit breaker device for generator outlet fault protection according to claim 1 is characterized in that: The high-coupling reactor includes a first coupling inductor and a second coupling inductor, and the circuit breaker assembly includes a first branch circuit breaker and a second branch circuit breaker connected in parallel with each other. The first coupling inductor and the second coupling inductor are reversely coupled to achieve current equalization in the first branch circuit breaker and the second branch circuit breaker.

3. The novel parallel high-voltage circuit breaker device for generator outlet fault protection according to claim 2 is characterized in that: The high-coupling reactor is used to accelerate the gradual attenuation of the DC component of the system short-circuit current based on its own high resistance.

4. The novel parallel high voltage circuit breaker device for generator outlet fault protection according to claim 1 is characterized in that: The thyristor assembly consists of two thyristors connected in reverse parallel.

5. The novel parallel high voltage circuit breaker device for generator outlet fault protection according to claim 1 is characterized in that: The thyristor assembly is composed of a diode and a thyristor connected in parallel.

6. A circuit system, characterized in that: It comprises a novel parallel high-voltage circuit breaker device for generator outlet fault protection as described in any one of claims 1-5.

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