A multi-module current-limited dc circuit breaker
The multi-module current-limiting DC circuit breaker, which uses a magnetic coupling module to sense the current and charge the capacitor, solves the problem that existing DC circuit breakers cannot quickly cut off the arc, and achieves fast interruption and current-limiting functions, while reducing cost and size.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XI AN JIAOTONG UNIV
- Filing Date
- 2022-06-20
- Publication Date
- 2026-05-12
AI Technical Summary
Existing DC circuit breakers are unable to quickly interrupt the arc when faced with short-circuit faults, and mechanical or hybrid circuit breakers are expensive and bulky, making them difficult to apply on a large scale.
A DC circuit breaker with multi-module current limiting is used. When a fault occurs, the magnetic coupling module induces current to charge the capacitor. The energy stored in the charging capacitor is used to generate a transfer current, which enables the circuit breaker to quickly break after the current crosses zero. Combined with a surge arrester, energy dissipation is completed.
It achieves rapid interruption of DC short-circuit current without pre-charging, has a flexible topology, current limiting function, and reduces cost and size.
Smart Images
Figure CN115347527B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a multi-module current-limiting DC circuit breaker with DC current breaking capability. Background Technology
[0002] As the scale and capacity of DC power systems continue to grow, the challenges posed by short-circuit fault currents are also increasing. Circuit breakers are typically used as the primary protection device; however, due to the diverse forms of short-circuit faults in these systems, DC circuit breakers are required to operate rapidly and interrupt the arc during the rapid rise of the fault current, making direct use of DC circuit breakers for short-circuit protection difficult. Current technical solutions for DC circuit breakers include mechanical circuit breakers, solid-state circuit breakers, and hybrid circuit breakers. Traditional mechanical or hybrid circuit breakers require pre-charged capacitors or power electronics, resulting in high costs, large size, and difficulty in large-scale application. Summary of the Invention
[0003] To address the shortcomings of the existing technology, the present invention aims to provide a multi-module current-limiting DC circuit breaker that can be applied to breaking scenarios requiring current limiting. This invention couples the current-carrying branch and the transfer branch through a magnetic coupling module. When a fault occurs, utilizing the rapid rise rate of the short-circuit current, a current is induced in the inductor of the magnetic coupling module to charge the capacitor. The energy stored in the charging capacitor generates a transfer current, causing the breaking current to cross zero. After crossing zero, the system voltage charges the capacitor of the magnetic coupling module. When the voltage across the capacitor reaches the surge arrester's operating voltage, the surge arrester operates, dissipating energy and achieving rapid breaking.
[0004] The DC circuit breaker described has advantages such as not requiring pre-stored energy, flexible topology, and current limiting function, and can interrupt DC short-circuit current. Specifically, the present invention adopts the following technical solution:
[0005] A multi-module current-limiting DC circuit breaker consists of a main current branch, a transfer branch, an energy dissipation branch, and a magnetic coupling module. The main current branch comprises a high-speed mechanical switch HSS and a magnetic coupling module coil L. 21 L 11 The circuit consists of a transfer branch composed of transfer capacitors C2 and C1, a transfer inductor L, and a thyristor T; an energy dissipation branch composed of a metal oxide zinc arrester (MOV); and a magnetic coupling module connecting the main current branch and the transfer branch via inductive magnetic coupling. Multiple magnetic coupling modules can be connected in series as needed for the breaking conditions. Its key feature is:
[0006] (1) The main current branch is the high-speed mechanical switch HSS and the magnetic coupling module coil L. 21 L 11 composition.
[0007] (2) The transfer branch consists of transfer capacitors C2 and C1, transfer inductor L and thyristor T.
[0008] (3) The magnetic coupling module consists of a magnetic coupling coil, a diode D and an energy storage capacitor C.
[0009] (4) The energy dissipation branch consists of a surge arrester.
[0010] (5) The magnetic coupling module can be used in series with multiple modules.
[0011] Under normal system current-carrying conditions, the system current flows out after passing through the inductance of the magnetic coupling module and the closed high-speed mechanical switch. At this time, the high-speed switch on the main circuit is closed, and no current flows through the magnetic coupling module, the transfer branch, or the energy dissipation branch.
[0012] When a short-circuit fault occurs, the main branch current rises rapidly. The magnetic coupling module limits the rate of increase of the main branch current and simultaneously induces current to charge its capacitors. When the main branch current exceeds the circuit breaker's setting current, the circuit breaker begins to operate. The high-speed mechanical switch HSS receives the trip signal and actuates, pulling its contacts open. Simultaneously, an electric arc is generated. After the contact travels a certain distance, the thyristor T in the transfer branch turns on, and capacitors C2 and C1 in the magnetic coupling module discharge. The stored energy is converted into transfer branch current, causing the vacuum break current to cross zero. After crossing zero, insulation is established at the break point, and the system voltage reverse-charges the capacitors in the magnetic coupling module. When the voltage across the capacitors reaches the surge arrester's operating voltage, the surge arrester operates, dissipating energy, and the interruption ends.
[0013] The high-speed mechanical switch HSS is a vacuum high-speed mechanical switch based on electromagnetic repulsion, a vacuum mechanical switch driven by a high-speed motor, or a vacuum high-speed mechanical switch driven by explosion.
[0014] The thyristor T is characterized in that: the thyristor T is a unidirectional semi-controlled device, which can be a single device or a combination of the following devices: GTO, thyristor, IGBT.
[0015] The energy dissipation circuit is characterized in that: the energy dissipation circuit includes, but is not limited to, one or more combinations of the following devices: metal oxide surge arrester, line-type metal oxide surge arrester, gapless line-type metal oxide surge arrester, fully insulated composite jacket metal oxide surge arrester, and detachable surge arrester.
[0016] The transfer branch includes, but is not limited to, a commutation bridge circuit composed of a single capacitor and an inductor, or a capacitor and multiple diodes.
[0017] The magnetic coupling module capacitor can be a single capacitor, a series-parallel capacitor group, a single capacitor with series inductance, or a series-parallel capacitor group with series inductance.
[0018] The magnetic coupling module can be used individually or in combination with multiple modules connected in series. Attached Figure Description
[0019] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, 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.
[0020] Figures 1(a) to 1(b) This is a circuit breaker topology diagram;
[0021] Figures 2(a) to 2(e) This is a schematic diagram of the circuit breaker of the present invention during operation;
[0022] Figure 3 This is an embodiment of a series-connected diode with a break in the circuit according to the present invention;
[0023] Figure 4 This is an embodiment of a parallel freewheeling diode with a break in the circuit according to the present invention; Detailed Implementation Plan
[0024] The following will refer to the appendix. Figures 1(a) to 4 Specific embodiments of this disclosure will be described in more detail below. While specific embodiments of this disclosure are shown in the accompanying drawings, it should be understood that this disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.
[0025] 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 this disclosure; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of this disclosure. The scope of protection of this disclosure is determined by the appended claims.
[0026] To facilitate understanding of the embodiments of this disclosure, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. The accompanying drawings do not constitute a limitation on the embodiments of this disclosure.
[0027] In one embodiment of the circuit breaker, Figures 1(a) to 1(b) This invention provides a multi-module current-limiting DC circuit breaker, comprising a main current branch, a transfer branch, an energy dissipation branch, and a magnetic coupling module. The main current branch consists of a high-speed mechanical switch HSS and a magnetic coupling module coil L. 21 L 11 The circuit consists of a transfer branch composed of transfer capacitors C2 and C1, a transfer inductor L, and a thyristor T; an energy dissipation branch composed of a metal oxide zinc arrester (MOV); and a magnetic coupling module connecting the main current branch and the transfer branch via inductive magnetic coupling. Multiple magnetic coupling modules can be connected in series as needed for the breaking conditions. Its key feature is:
[0028] (1) The main current branch is the high-speed mechanical switch HSS and the magnetic coupling module coil L. 21 L 11 composition.
[0029] (2) The transfer branch consists of transfer capacitors C2 and C1, transfer inductor L and thyristor T.
[0030] (3) The magnetic coupling module consists of a magnetic coupling coil, a diode D and an energy storage capacitor C.
[0031] (4) The energy dissipation branch consists of a surge arrester.
[0032] (5) The magnetic coupling module can be used in series with multiple modules.
[0033] Under normal system current-carrying conditions, the system current flows out after passing through the inductance of the magnetic coupling module and the closed high-speed mechanical switch. At this time, the high-speed switch on the main circuit is closed, and no current flows through the magnetic coupling module, the transfer branch, or the energy dissipation branch.
[0034] When a short-circuit fault occurs, the main branch current rises rapidly. The magnetic coupling module limits the rate of increase of the main branch current and simultaneously induces current to charge its capacitors. When the main branch current exceeds the circuit breaker's setting current, the circuit breaker begins to operate. The high-speed mechanical switch HSS receives the trip signal and actuates, pulling its contacts open. Simultaneously, an electric arc is generated. After the contact travels a certain distance, the thyristor T in the transfer branch turns on, and capacitors C2 and C1 in the magnetic coupling module discharge. The stored energy is converted into transfer branch current, causing the vacuum break current to cross zero. After crossing zero, insulation is established at the break point, and the system voltage reverse-charges the capacitors in the magnetic coupling module. When the voltage across the capacitors reaches the surge arrester's operating voltage, the surge arrester operates, dissipating energy, and the interruption ends.
[0035] The circuit breaker described in this embodiment is shown in Figure 2 as a structural schematic diagram during its operation.
[0036] As shown in Figure 2(a), under normal system operation, current flows through the magnetic coupling module coil L in the main circuit. 21 L 11 A closed high-speed mechanical switch HSS.
[0037] As shown in Figure 2(b), when a short-circuit fault occurs or a tripping command is received from the upper level, the magnetic coupling module limits the rate of rise of the main branch current, and simultaneously L 22 and L 12 The induced current charges capacitors C2 and C1 of the magnetic coupling module.
[0038] As shown in Figure 2(c), when the contact travel reaches a certain distance, the thyristor T turns on, and C2 and C1 discharge through the discharge circuit formed by the transfer circuit inductor L and the thyristor T, thereby reducing the high-speed switch break current.
[0039] As shown in Figure 2(d), when the high-speed switch break current decreases to zero, the break insulation begins to recover, and the main circuit current is transferred to the transfer branch, charging capacitors C2 and C1.
[0040] As shown in Figure 2(e), when the voltage on capacitors C2 and C1 reaches the conduction voltage of the surge arrester on the energy dissipation branch, the remaining energy is discharged through the surge arrester, and the current is transferred to the energy dissipation branch.
[0041] In another embodiment of the magnetically controlled oscillating circuit breaker: the high-speed mechanical switch HSS is a vacuum high-speed mechanical switch based on electromagnetic repulsion, a vacuum mechanical switch driven by a high-speed motor, or a vacuum high-speed mechanical switch driven by explosion.
[0042] In another embodiment of the circuit breaker, the thyristor device T is a unidirectional semi-controlled device, which can be a single device or a combination of the following devices: GTO, thyristor, IGBT.
[0043] like Figure 3 As shown, in one embodiment of the circuit breaker, the high-speed switch series diode prevents the reverse transfer current from passing through after the break current crosses zero.
[0044] like Figure 4 As shown, in one embodiment of the circuit breaker, an anti-parallel diode is added to the circuit breaker break to help transfer the current to flow in the opposite direction instead of through the break, thus preventing the insulation from being restored.
[0045] Although the embodiments of this disclosure have been described above in conjunction with the accompanying drawings, this disclosure 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 this disclosure, and all of these are within the scope of protection of this disclosure.
Claims
1. A multi-module current-limiting DC circuit breaker, comprising a main current branch, a transfer branch, an energy dissipation branch, and a magnetic coupling module, wherein, The main current branch consists of the high-speed mechanical switch HSS and the magnetically coupled coil L. 21 L 11 The circuit consists of a transfer branch composed of transfer capacitors C2 and C1, a transfer inductor L, and a thyristor T; an energy dissipation branch composed of a metal oxide zinc arrester (MOV); and a magnetic coupling module connecting the main current branch and the transfer branch via inductive magnetic coupling. Multiple magnetic coupling modules can be connected in series as needed for the breaking conditions. Its key feature is: (1) The main current branch is the high-speed mechanical switch HSS and the magnetic coupling coil L. 21 L 11 composition; (2) The transfer branch consists of transfer capacitors C2 and C1, transfer inductor L and thyristor T; (3) The magnetic coupling module consists of a magnetic coupling coil L 11 L 12 It consists of diode D1 and transfer capacitor C1, or the magnetic coupling module consists of magnetic coupling coil L. 21 L 22 It consists of diode D2 and transfer capacitor C2; (4) The energy dissipation branch consists of a surge arrester; (5) Under normal system current conditions, the system current flows out after passing through the inductance of the magnetic coupling module and the high-speed mechanical switch in the closed state. At this time, the high-speed switch on the main current branch is closed, and no current flows through the magnetic coupling module, the transfer branch and the energy dissipation branch. Under normal operating conditions, current flows through the magnetic coupling coil L in the main current branch. 21 L 11 A closed high-speed mechanical switch HSS; When a short-circuit fault occurs or a tripping command is received from the upper level, the magnetic coupling module limits the rate of rise of the main current branch current, while L 22 and L 12 The induced current charges capacitors C2 and C1 of the magnetic coupling module through the diode; When the contact travel reaches a certain distance, the thyristor T turns on, and C2 and C1 discharge through the discharge circuit formed by the transfer inductor L and the thyristor T, thereby reducing the high-speed switch break current. When the high-speed switch break current decreases to zero, the break insulation begins to recover, and the main current branch current is transferred to the transfer branch. The main current branch current reverse charges capacitors C2 and C1. The circuit breaker couples the main current branch and the transfer branch through a magnetic coupling module. When a fault occurs, the fast rise rate of the short-circuit current is utilized to induce a current in the inductor of the magnetic coupling module to charge the capacitor. The energy stored in the charging capacitor generates a transfer current, causing the break current to cross zero. After crossing zero, the system voltage charges the capacitor of the magnetic coupling module. When the voltage across the capacitor reaches the operating voltage of the surge arrester, the surge arrester operates and dissipates energy, thereby achieving rapid breaking.
2. The circuit breaker according to claim 1, characterized in that: When a short-circuit fault occurs, the main current branch current rises rapidly. The magnetic coupling module limits the rate of rise of the main current branch current and induces current to charge the capacitor of the magnetic coupling module. When the main current branch current exceeds the circuit breaker setting current, the circuit breaker starts to operate. The high-speed mechanical switch HSS receives the trip signal and operates to pull the contacts open, generating an electric arc. After the contact travels a certain distance, the thyristor T of the transfer branch turns on, and the capacitors C2 and C1 of the magnetic coupling module discharge. The stored electrical energy is converted into the transfer branch current, causing the vacuum break current to cross zero. After crossing zero, the break establishes insulation, and the system voltage reverse charges the capacitor of the magnetic coupling module. When the voltage across the capacitor reaches the surge arrester operating voltage, the surge arrester completes its operation and dissipates energy, and the interruption ends.
3. The circuit breaker according to any one of claims 1-2, characterized in that: The high-speed mechanical switch HSS is a vacuum high-speed mechanical switch based on electromagnetic repulsion, a vacuum mechanical switch driven by a high-speed motor, or a vacuum high-speed mechanical switch driven by explosion.
4. The circuit breaker according to any one of claims 1-2, characterized in that: The thyristor T is a unidirectional semi-controlled device, or a single device or combination of GTO, IGBT.
5. The circuit breaker according to any one of claims 1-2, characterized in that: The energy dissipation branch includes a metal oxide surge arrester.
6. The circuit breaker according to any one of claims 1-2, characterized in that: The energy dissipation branch includes a line-type metal oxide surge arrester.
7. The circuit breaker according to any one of claims 1-2, characterized in that: The energy dissipation branch includes a gapless line type metal oxide surge arrester.
8. The circuit breaker according to any one of claims 1-2, characterized in that: The energy dissipation branch includes a fully insulated composite jacket metal oxide surge arrester.
9. The circuit breaker according to any one of claims 1-2, characterized in that: The energy dissipation branch includes a removable surge arrester.
10. The circuit breaker according to any one of claims 1-2, characterized in that: The transfer branch includes, but is not limited to, a commutation bridge circuit composed of a single capacitor and an inductor, or a capacitor and multiple diodes.
11. The circuit breaker according to any one of claims 1-2, characterized in that: The magnetic coupling module capacitor can be a single capacitor, a series-parallel capacitor group, a single capacitor in series with an inductor, or a series-parallel capacitor group in series with an inductor.