CN-115347527-B - Multi-module current-limiting direct current breaker

CN115347527BCN 115347527 BCN115347527 BCN 115347527BCN-115347527-B

Abstract

A multi-module current-limiting direct current circuit breaker is composed of 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 transfer branch consists of transfer capacitors C 2 and C 1 , a transfer inductor L and a thyristor T, the energy dissipation branch consists of a metal zinc oxide arrester MOV, the magnetic coupling module is connected with the main current branch and the transfer branch through inductive magnetic coupling, and a plurality of magnetic coupling modules can be connected in series according to the requirement of the switching-on working condition. The direct current breaker has the advantages of no need of advanced energy storage, flexible topology, current limiting function and the like, and can break direct current short-circuit current.

Inventors

WU YI
XIAO YU
GUO JIAHAO
SHI MINGMING
XIAO XIAOLONG
LIU AIQIANG
RONG MINGZHE
WU YIFEI

Assignees

西安交通大学
国网江苏省电力有限公司电力科学研究院

Dates

Publication Date: 20260512
Application Date: 20220620

Claims (11)

1. The utility model provides a direct current breaker of multi-module current-limiting, by main current branch road, transfer branch road, energy dissipation branch road and magnetic coupling module are constituteed, wherein, main current branch road comprises high-speed mechanical switch HSS and magnetic coupling coil L 21 、L 11 , transfer branch road comprises transfer electric capacity C 2 and C 1 , transfer inductance L and thyristor T, energy dissipation branch road comprises metallic zinc oxide arrester MOV, magnetic coupling module passes through inductance magnetic coupling hookup main current branch road and transfer branch road, can use a plurality of magnetic coupling module series connection according to the operating mode needs of cutting off, its characterized in that: (1) The main current branch consists of a high-speed mechanical switch HSS and a magnetic coupling coil L 21 、L 11 ; (2) The transfer branch consists of transfer capacitors C 2 and C 1 , a transfer inductor L and a thyristor T; (3) The magnetic coupling module consists of a magnetic coupling coil L 11 、L 12 , a diode D 1 and a transfer capacitor C 1 , or consists of a magnetic coupling coil L 21 、L 22 , a diode D 2 and a transfer capacitor C 2 ; (4) The energy dissipation branch circuit consists of a lightning arrester; (5) Under the condition of normal through flow of the system, the system current flows out after passing through the inductance of the magnetic coupling module and the high-speed mechanical switch in a closed state, at the moment, the high-speed switch-off opening on the main current branch is closed, and no current flows through the magnetic coupling module, the transfer branch and the energy dissipation branch; In the normal circulation state of the system, current flows through a magnetic coupling coil L 21 、L 11 in a main current branch, and a closed high-speed mechanical switch HSS; when a short circuit fault occurs or an upper switching-off instruction is received, the magnetic coupling module limits the current rising rate of the main current branch, and meanwhile, L 22 and L 12 induce currents to charge the capacitors C 2 and C 1 of the magnetic coupling module through the diodes; When the contact stroke reaches a certain distance, the thyristors T are turned on, and the C 2 and the C 1 discharge through a discharge loop formed by the transfer inductor L and the thyristors T, so that the current of a high-speed opening and closing opening is reduced; When the current of the high-speed switch opening is reduced to zero, the fracture insulation begins to recover, the current of the main current branch is completely transferred to the transfer branch, and the current of the main current branch reversely charges the capacitors C 2 and C 1 ; The circuit breaker couples the main current branch and the transfer branch through the magnetic coupling module, when the fault occurs, the characteristics of high rising speed of short-circuit current are utilized, current is induced on the inductance of the magnetic coupling module to charge the capacitor, the transfer current is generated by utilizing the energy stored by the charging capacitor, so that the fracture current crosses zero, the system voltage charges the capacitor of the magnetic coupling module after crossing zero, and when the voltage at two ends of the capacitor reaches the action voltage of the lightning arrester, the lightning arrester action is used for completing energy dissipation, and then quick switching-off is realized.
2. The circuit breaker according to claim 1, characterized in that: When short circuit fault occurs, the current of the main current branch is quickly increased, the magnetic coupling module limits the current rising rate of the main current branch, on the one hand, current is induced to charge the capacitor of the magnetic coupling module, when the current of the main current branch exceeds the setting current of the circuit breaker, the circuit breaker starts to act, the high-speed mechanical switch HSS receives a brake-separating signal, the high-speed mechanical switch acts to pull a contact open and simultaneously generate an electric arc, after the contact stroke reaches a certain distance, the thyristor T of the transfer branch is started, the capacitors C 2 and C 1 of the magnetic coupling module discharge, stored electric energy is converted into the current of the transfer branch to enable the vacuum break current to cross zero, the break is insulated after the zero crossing, the system voltage reversely charges the capacitor of the magnetic coupling module, and when the voltage of the two ends of the capacitor reaches the action voltage of the lightning arrester, the lightning arrester acts to complete energy dissipation and simultaneously the break is ended.
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 based on high-speed motor drive or a vacuum high-speed mechanical switch based on explosion drive.
4. The circuit breaker according to any one of claims 1-2, characterized in that the thyristor T is a half-controlled device conducting unidirectionally, or a single device or a combination of GTO and IGBT.
5. The circuit breaker according to any one of claims 1-2, wherein the energy dissipation branch comprises a metal oxide arrester.
6. The circuit breaker according to any one of claims 1-2, wherein the energy dissipating branch comprises a wire-type metal oxide arrester.
7. The circuit breaker according to any one of claims 1-2, wherein the energy dissipating branch comprises a gapless circuit type metal oxide arrester.
8. The circuit breaker according to any one of claims 1-2, wherein the energy dissipating branch comprises a fully insulated composite housed metal oxide arrester.
9. The circuit breaker according to any one of claims 1-2, wherein the energy dissipation branch comprises a detachable arrester.
10. The circuit breaker of any of claims 1-2 wherein the transfer leg comprises, but is not limited to, a single capacitor and inductor combination, a capacitor and multiple diode combination commutating bridge circuit.
11. The circuit breaker of any of claims 1-2, wherein the magnetic coupling module capacitor is a single capacitor, a series-parallel capacitor set, a single capacitor series inductor, or a series inductor of a series-parallel capacitor set.

Description

Multi-module current-limiting direct current breaker Technical Field The invention relates to a multi-module current-limiting direct current breaker which has direct current breaking capacity. Background As the scale and capacity of dc power systems continue to grow, so does the challenges presented by short-circuit fault currents. Circuit breakers are generally used as main protection devices, but because of various short-circuit fault modes of the system, the direct current circuit breakers are required to be capable of operating rapidly and cutting off the arc in the rapid rising stage of fault current, so that the direct use of the direct current circuit breakers for short-circuit protection has a certain difficulty. The technical scheme of the current direct current circuit breaker comprises a mechanical circuit breaker, a solid circuit breaker and a hybrid circuit breaker. The original mechanical or hybrid type needs to precharge a capacitor or power electronics, and has high cost, large volume and difficult large-scale application. Disclosure of Invention In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a multi-module current-limiting dc circuit breaker, which can be applied to an open-circuit scenario requiring current limiting. According to the invention, the through-flow branch and the transfer branch are coupled through the magnetic coupling module, when a fault occurs, the current is induced on the inductance of the magnetic coupling module to charge the capacitor by utilizing the characteristic of high rising speed of short-circuit current, the transfer current is generated by utilizing the energy stored by the charging capacitor, so that the fracture current crosses zero, the system voltage charges the capacitor of the magnetic coupling module after the zero crossing, and when the voltage at two ends of the capacitor reaches the action voltage of the lightning arrester, the action of the lightning arrester is completed to dissipate the energy, thereby realizing rapid switching. The direct current breaker has the advantages of no need of advanced energy storage, flexible topology, current limiting function and the like, and can break direct current short-circuit current. Specifically, the invention adopts the following technical scheme: A multi-module current-limiting direct current circuit breaker is composed of 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、L11, the transfer branch consists of transfer capacitors C 2 and C 1, a transfer inductor L and a thyristor T, the energy dissipation branch consists of a metal zinc oxide arrester MOV, the magnetic coupling module is connected with the main current branch and the transfer branch through inductive magnetic coupling, and a plurality of magnetic coupling modules can be connected in series according to the requirement of the switching-on working condition. The method is characterized in that: (1) The main current branch route consists of a high-speed mechanical switch HSS and a magnetic coupling module coil L 21、L11. (2) The transfer branch consists of transfer capacitors C 2 and C 1, a transfer inductor L and a thyristor T. (3) The magnetic coupling module consists of a magnetic coupling coil, a diode D and an energy storage capacitor C. (4) The energy dissipation branch consists of a lightning arrester. (5) The magnetic coupling modules can be used in series with multiple modules. Under the condition of normal through flow of the system, the system current flows out after passing through the inductor of the magnetic coupling module and the high-speed mechanical switch in a closed state. At the moment, a high-speed switch opening on the main loop is closed, and the magnetic coupling module is arranged. No current flows through both the transfer branch and the energy dissipation branch. When short circuit fault occurs, the current of the main branch rises rapidly, the magnetic coupling module limits the rising rate of the current of the main branch on one hand, and on the other hand, the induced current charges the capacitor of the magnetic coupling module. When the current of the main circuit branch exceeds the setting current of the circuit breaker, the circuit breaker starts to act. The high-speed mechanical switch HSS receives the brake-separating signal, and the contact is pulled open by the action of the high-speed mechanical switch. And simultaneously generating an electric arc, after the contact stroke reaches a certain distance, starting a thyristor T of the transfer branch, discharging the capacitors C 2 and C 1 of the magnetic coupling module, and converting the stored electric energy into the current of the transfer branch to enable the current of the vacuum fracture to cross zero. And after zero crossing, the fract