Self-responding current-limited open-break dc circuit breaker

Abstract

Disclosed is a self-response current-limiting open-break DC circuit breaker, which comprises a current-limiting part and an open-break part connected in series for limiting rapid rise of current; the current-limiting part comprises IGCT components, RC blocking capacitor absorption circuit and repulsion coil connected in parallel, one end of the current-limiting part is connected to an inlet end A1, the other end is connected to the open-break part, the other end of the open-break part is connected to an outlet end A2 for leading out, the open-break part comprises a main current loop, a current transfer branch and an energy dissipation branch connected in parallel, the main current loop comprises a high-speed mechanical switch, the current transfer branch comprises a pre-charge capacitor C1, a thyristor component Trl and a transfer inductor L1 connected in series, and the repulsion coil drives the high-speed mechanical switch through a linkage of a repulsion disc.

Description

Technical Field

[0001] This invention relates to the field of circuit breakers, and in particular to a self-response current-limiting DC circuit breaker. Background Technology

[0002] With the rapid development of new energy power generation technologies, grid connection of new energy power generation has become a problem that must be solved in the development of power systems. DC power systems, due to their large capacity and low grid connection difficulty, have become a current research hotspot. Short-circuit fault current is a problem that must be solved in DC power systems. Because DC short-circuit fault current has characteristics such as rapid rise and lack of a natural zero-crossing point, interrupting DC fault current has become one of the difficulties in developing DC power systems.

[0003] The information disclosed in the background section is only intended to enhance the understanding of the background of the present invention, and therefore may contain information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] To address the shortcomings or defects of the existing technology, a self-response current-limiting DC circuit breaker is provided. This circuit breaker utilizes the surge current when the fault current is transferred to the repulsion coil. On one hand, it limits the rapid rise of the fault current; on the other hand, the surge current entering the repulsion coil can quickly drive the repulsion plate to complete the tripping action. The limited-rise short-circuit fault current is then transferred through the transfer branch, creating an artificial zero-crossing point on the mechanical break, thus completing the current interruption and insulation establishment.

[0005] The objective of this invention is achieved through the following technical solutions.

[0006] A self-response current-limiting and breaking DC circuit breaker includes a current-limiting section and a breaking section connected in series to limit the rapid rise of current. The current-limiting section includes an IGCT component, an RC snubber circuit, and a repulsion coil connected in parallel. One end of the current-limiting section is connected to the input terminal A1, and the other end is connected to the breaking section. The other end of the breaking section is connected to the output terminal A2. The breaking section includes a main current loop, a current transfer branch, and an energy dissipation branch connected in parallel. The main current loop includes a high-speed mechanical switch. The current transfer branch includes a pre-charge capacitor C1, a thyristor component Tr1, and a transfer inductor L1 connected in series. The repulsion coil drives the high-speed mechanical switch through a repulsion disk.

[0007] In the self-response current-limiting DC circuit breaker, when the system is working normally, the system current flows in from the input terminal A1, passes through the IGCT component and the main current circuit, and then flows out from the output terminal A2. At this time, the high-speed mechanical switch on the main current circuit is closed, and no current flows through the repulsion coil, the current transfer branch and the energy dissipation branch.

[0008] When a fault current occurs, the IGCT component receives an action signal and shuts down. The fault current is forced to transfer to the repulsion coil. The repulsion coil limits the rapid rise of the fault current and drives the repulsion disk to operate, causing the high-speed mechanical switch of the main current circuit to open. Subsequently, the thyristor component Tr1 in the transfer current branch turns on, and the pre-charge capacitor C1 discharges through the thyristor component Tr1 and the transfer inductor L1. The resulting transfer current and fault current are superimposed on the high-speed mechanical switch to generate a zero-crossing point. The main current circuit current is cut off at zero, and the fault current is transferred to the pre-charge capacitor C1. The mechanical break begins insulation recovery, and a system voltage is established across the main current circuit. Excess energy is released through the energy dissipation branch, completing the removal of the fault current.

[0009] In the self-response current-limiting DC circuit breaker, the high-speed mechanical switch HSS includes a break consisting of one or more breaks connected in series and parallel.

[0010] In the self-response current-limiting DC circuit breaker, the break point includes a vacuum break point or a gas break point.

[0011] In the self-response current-limiting DC circuit breaker, the gas break includes N2, air, and H2 breaks.

[0012] In the self-response current-limiting DC circuit breaker, the pre-charge capacitor C includes any one or a combination of multiple of the following: film capacitor, organic dielectric capacitor, inorganic dielectric capacitor, electrolytic capacitor, electrothermal capacitor, and air dielectric capacitor.

[0013] In the self-response current-limiting DC circuit breaker, the IGCT component is replaced by a fully controlled power device and its components, including an IGBT component, an IEGT component, or a GTO component.

[0014] In the self-response current-limiting DC circuit breaker, the energy dissipation circuit includes one or more of the following devices: metal oxide surge arrester and removable surge arrester.

[0015] In the self-response current-limiting DC circuit breaker, the metal oxide surge arrester includes a line-type metal oxide surge arrester, a gapless line-type metal oxide surge arrester, or a fully insulated composite jacket metal oxide surge arrester.

[0016] In the self-response current-limiting DC circuit breaker, the high-speed mechanical switch includes a vacuum high-speed mechanical switch based on electromagnetic repulsion, an air high-speed mechanical switch, and a gas-filled high-speed mechanical switch with arc-extinguishing capability.

[0017] Beneficial effects

[0018] This invention solves the problem of rapid short-circuit current rise, which is beneficial for circuit breakers to complete current interruption and reduces the parameter requirements of circuit breakers. Current is limited by a current-limiting section, and surge current is used to achieve rapid opening of the high-speed mechanical contact. Subsequently, the fault current is cleared using the breaking section. The DC circuit breaker has the functions of limiting the rapid rise of fault current and interrupting fault current. It achieves rapid opening of the contact by utilizing surge current, and its advantages in cost and size make it suitable for DC power systems.

[0019] The above description is merely an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and more understandable, so that those skilled in the art can implement it according to the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more obvious and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0020] Various other advantages and benefits of the present invention will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0021] In the attached diagram:

[0022] Figure 1 This is a schematic diagram of the structure of a self-response current-limiting DC circuit breaker according to an embodiment of the present invention;

[0023] Figures 2(a) to 2(d) This is a schematic diagram of the breaking principle of a self-response current-limiting DC circuit breaker according to an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of the structure of a self-response current-limiting DC circuit breaker according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the structure of a self-response current-limiting DC circuit breaker with bidirectional breaking capability according to an embodiment of the present invention.

[0026] The present invention will be further explained below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0027] The following will refer to the appendix. Figures 1 to 4Specific embodiments of the invention will be described in more detail below. While specific embodiments of the invention are shown in the accompanying drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0028] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0029] To facilitate understanding of the embodiments of the present invention, the following will provide further explanation and description with reference to the accompanying drawings and several specific embodiments, and the accompanying drawings do not constitute a limitation on the embodiments of the present invention.

[0030] like Figures 1 to 3 As shown, a self-response current-limiting and breaking DC circuit breaker includes a current-limiting section and a breaking section connected in series to limit the rapid rise of current. The current-limiting section includes an IGCT component, an RC snubber circuit, and a repulsion coil connected in parallel. One end of the current-limiting section is connected to the input terminal A1, and the other end is connected to the breaking section. The other end of the breaking section is connected to the output terminal A2. The breaking section includes a main current loop, a current transfer branch, and an energy dissipation branch connected in parallel. The main current loop includes a high-speed mechanical switch. The current transfer branch includes a pre-charge capacitor C1, a thyristor component Tr1, and a transfer inductor L1 connected in series. The repulsion coil drives the high-speed mechanical switch through a repulsion disk.

[0031] In a preferred embodiment of the self-response current-limiting DC circuit breaker, when the system is working normally, the system current flows in from the input terminal A1, passes through the IGCT component and the main current circuit, and then flows out from the output terminal A2. At this time, the high-speed mechanical switch on the main current circuit is closed, while no current flows through the repulsion coil, the current transfer branch and the energy dissipation branch.

[0032] When a fault current occurs, the IGCT component receives an action signal and shuts down. The fault current is forced to transfer to the repulsion coil. The repulsion coil limits the rapid rise of the fault current and drives the repulsion disk to operate, causing the high-speed mechanical switch of the main current circuit to open. Subsequently, the thyristor component Tr1 in the transfer current branch turns on, and the pre-charge capacitor C1 discharges through the thyristor component Tr1 and the transfer inductor L1. The resulting transfer current and fault current are superimposed on the high-speed mechanical switch to generate a zero-crossing point. The main current circuit current is cut off at zero, and the fault current is transferred to the pre-charge capacitor C1. The mechanical break begins insulation recovery, and a system voltage is established across the main current circuit. Excess energy is released through the energy dissipation branch, completing the removal of the fault current.

[0033] In a preferred embodiment of the self-response current-limiting DC circuit breaker, the high-speed mechanical switch HSS includes a break consisting of one or more breaks connected in series and parallel.

[0034] In a preferred embodiment of the self-response current-limiting DC circuit breaker, the break point includes a vacuum break point or a gas break point.

[0035] In a preferred embodiment of the self-response current-limiting DC circuit breaker, the gas break includes N2, air, and H2 breaks.

[0036] In a preferred embodiment of the self-response current-limiting DC circuit breaker, the pre-charge capacitor C includes any one or a combination of multiple of the following: film capacitor, organic dielectric capacitor, inorganic dielectric capacitor, electrolytic capacitor, electrothermal capacitor, and air dielectric capacitor.

[0037] In a preferred embodiment of the self-response current-limiting DC circuit breaker, the IGCT component is replaced with a fully controlled power device and its components, including an IGBT component, an IEGT component, or a GTO component.

[0038] In a preferred embodiment of the self-response current-limiting DC circuit breaker, the energy dissipation circuit includes one or more of the following devices: metal oxide surge arrester and removable surge arrester.

[0039] In a preferred embodiment of the self-response current-limiting DC circuit breaker, the metal oxide surge arrester includes a line-type metal oxide surge arrester, a gapless line-type metal oxide surge arrester, or a fully insulated composite jacket metal oxide surge arrester.

[0040] In a preferred embodiment of the self-response current-limiting DC circuit breaker, the high-speed mechanical switch includes a vacuum high-speed mechanical switch based on electromagnetic repulsion, an air high-speed mechanical switch, and a gas-filled high-speed mechanical switch with arc-extinguishing capability.

[0041] In one embodiment, Figure 1 This invention provides a self-response current-limiting and breaking DC circuit breaker, consisting of a current-limiting section and a breaking section connected in series. The current-limiting section comprises an IGCT assembly, an RC snubber circuit, and a repulsion coil connected in parallel. The breaking section comprises a main current loop, a current transfer branch, and an energy dissipation branch connected in parallel. One end of the current-limiting section is connected to the input terminal A1, and the other end is connected to the breaking section. The other end of the breaking section is connected to the output terminal A2. The current-limiting section limits the rapid rise of current, and the parallel repulsion coil drives a high-speed mechanical switch in the breaking section via a repulsion disk. The main current loop is a high-speed mechanical switch. The current transfer branch comprises a pre-charge capacitor, a thyristor assembly, and a transfer inductor connected in series.

[0042] Figures 2(a) to 2(d) Figure 2(a) shows the circuit breaker's breaking principle flowchart. When the system is operating normally, the system current flows in from the input terminal A1, passes through the IGCT component in the current-limiting section and the main current circuit in the breaking section, and then flows out from the output terminal A2. At this time, the high-speed mechanical switch on the main current circuit is closed, while no current flows through the repulsion coil, the current transfer branch, or the energy dissipation branch. As shown in Figure 2(b), when a fault current occurs, the circuit breaker receives an action command from the host computer control system. The IGCT component receives an action signal and closes, forcing the fault current to transfer to the repulsion coil. The repulsion coil limits the rapid rise of the fault current and drives the repulsion disk to operate, causing the high-speed mechanical switch in the main current circuit to open.

[0043] Subsequently, as shown in Figure 2(c), the thyristor assembly in the transfer current branch of the interrupted section turns on, and the pre-charge capacitor discharges through the thyristor assembly and the transfer inductor. The resulting transfer current and fault current are superimposed on the high-speed mechanical switch to produce a zero-crossing point. The main current loop current is cut off at zero crossing, the fault current is transferred to the pre-charge capacitor, and the mechanical break begins insulation recovery.

[0044] Finally, as shown in Figure 2(d), a system voltage is established across the main current loop, and excess energy is released through the energy dissipation branch, thus completing the removal of the fault current.

[0045] In another embodiment of the circuit breaker, the high-speed mechanical switch is a vacuum high-speed mechanical switch, an air high-speed mechanical switch, or a high-speed mechanical switch filled with SF6 or other gases with arc-extinguishing capabilities, based on electromagnetic repulsion.

[0046] In another embodiment of the circuit breaker, the IGCT component used in the current limiting section can be replaced with an IGBT component, an IEGT component, a GTO component, or other fully controllable power devices and their components.

[0047] like Figure 4As shown, the self-response current-limiting interrupting DC circuit breaker includes a current-limiting section and an interrupting section connected in series to limit the rapid rise of current. The current-limiting section includes a parallel IGCT assembly, an RC snubber circuit, and a repulsion coil. One end of the current-limiting section is connected to the input terminal A1, and the other end is connected to the interrupting section. The IGCT assembly includes parallel IGCT assemblies arranged in opposite directions. The other end of the interrupting section is connected to the output terminal A2. The interrupting section includes a parallel main current loop, a current transfer branch, and an energy dissipation branch. The main current loop includes a high-speed mechanical switch. The current transfer branch includes a pre-charge capacitor C1, a thyristor bridge H, and a transfer inductor L1 connected in series. One end of the first thyristor assembly is connected to the high-speed mechanical switch, and the other end is connected between the pre-charge capacitor C1 and the thyristor bridge H. One end of the second thyristor assembly is connected to the high-speed mechanical switch, and the other end is connected to the pre-charge capacitor C1. One end of the third thyristor assembly is connected between the second thyristor assembly and the pre-charge capacitor C1, and the other end is connected between the thyristor bridge H and the inductor L1. The repulsion coil drives the repulsion disk to link with the mechanical break of the high-speed mechanical switch. This circuit breaker can interrupt bidirectionally.

[0048] Although embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments and application fields described above. The specific embodiments described above are merely illustrative and instructive, and not restrictive. Those skilled in the art can make many other forms based on the guidance of this specification and without departing from the scope of protection of the claims of the present invention, and all of these are within the scope of protection of the present invention.

Claims

1. A self-response current-limiting interrupting DC circuit breaker, characterized in that, It includes a current-limiting section and a switching section connected in series to limit the rapid rise of current; the current-limiting section includes an IGCT component, an RC snubber circuit and a repulsion coil connected in parallel. One end of the current-limiting section is connected to the input terminal A1 and the other end is connected to the switching section. The other end of the switching section is connected to the output terminal A2. The switching section includes a main current loop, a current transfer branch and an energy dissipation branch connected in parallel. The main current loop includes a high-speed mechanical switch. The current transfer branch includes a pre-charge capacitor C1, a thyristor component Tr1 and a transfer inductor L1 connected in series. The repulsion coil drives the high-speed mechanical switch by driving the repulsion disk.

2. The self-response current-limiting DC circuit breaker according to claim 1, characterized in that, When the system is working normally, the system current flows in from the input terminal A1, passes through the IGCT component and the main current circuit, and then flows out from the output terminal A2. At this time, the high-speed mechanical switch on the main current circuit is closed, and no current flows through the repulsion coil, the current transfer branch and the energy dissipation branch. When a fault current occurs, the IGCT component receives an action signal and shuts down. The fault current is forced to transfer to the repulsion coil. The repulsion coil limits the rapid rise of the fault current and drives the repulsion disk to operate, causing the high-speed mechanical switch of the main current circuit to open. Subsequently, the thyristor component Tr1 in the current transfer branch turns on, and the pre-charge capacitor C1 discharges through the thyristor component Tr1 and the transfer inductor L1. The resulting transfer current and fault current are superimposed on the high-speed mechanical switch to generate a zero-crossing point. The current in the main current circuit is cut off at zero, and the fault current is transferred to the pre-charge capacitor C1. The mechanical break begins insulation recovery, and a system voltage is established across the main current circuit. Excess energy is released through the energy dissipation branch, completing the removal of the fault current.

3. The self-response current-limiting DC circuit breaker according to claim 1, characterized in that: The high-speed mechanical switch HSS includes a break consisting of one or more breaks connected in series and parallel.

4. The self-response current-limiting DC circuit breaker according to claim 3, characterized in that: The fracture surface includes a vacuum fracture surface or a gas fracture surface.

5. The self-response current-limiting DC circuit breaker according to claim 4, characterized in that: Gas breaks include N2, air, and H2 breaks.

6. The self-response current-limiting DC circuit breaker according to claim 1, characterized in that: The pre-charged capacitor C includes any one or a combination of multiple types of film capacitors, organic dielectric capacitors, inorganic dielectric capacitors, electrolytic capacitors, electrothermal capacitors, and air dielectric capacitors.

7. The self-response current-limiting DC circuit breaker according to claim 1, characterized in that: The IGCT component is replaced with a fully power-controlled device and its components, including IGBT components, IEGT components, or GTO components.

8. The self-response current-limiting DC circuit breaker according to claim 1, characterized in that: The energy dissipation branch includes one or more of the following devices: metal oxide surge arresters and removable surge arresters.

9. The self-response current-limiting DC circuit breaker according to claim 8, characterized in that: Metal oxide surge arresters include line-type metal oxide surge arresters, gapless line-type metal oxide surge arresters, or fully insulated composite-jacketed metal oxide surge arresters.

10. The self-response current-limiting DC circuit breaker according to claim 1, characterized in that: High-speed mechanical switches include vacuum high-speed mechanical switches based on electromagnetic repulsion, air high-speed mechanical switches, and gas-filled high-speed mechanical switches with arc-extinguishing capabilities.

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