# US 10,374,417 B2 · Arc-free DC circuit breaker

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- Number: US 10,374,417 B2
- Document ID: US10374417B2
- Status: Granted
- Kind: B2
- Application number: 15/493,635
- Filed: 2017-04-21
- Published: 2018-05-17
- Granted: 2019-08-06
- Earliest claimed: 2016-11-11
- Assignees: Xi'an Jiaotong University
- Applicants: Xi'an Jiaotong University
- Inventors: Yi Wu; Mingzhe Rong; Yifei Wu; Fei Yang; Chunping Niu
- Web page: https://patentgrep.com/patent/US10374417B2

## CPC

- H02H 9/026: {Current limitation using PTC resistors, i.e. resistors with a large positive temperature coefficient}
- H01H 9/542: {Contacts shunted by static switch means}
- H01H 9/548: {Electromechanical and static switch connected in series}
- H01H 33/596: {for interrupting DC}
- H02H 3/087: for DC applications
- H01H 33/14: Multiple main contacts for the purpose of dividing the current through, or potential drop along, the arc
- H02H 3/025: {Disconnection after limiting, e.g. when limiting is not sufficient or for facilitating disconnection}
- H02H 7/268: {for DC systems}
- H02H: EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS (indicating or signalling undesired working conditions G01R, e.g. G01R31/00, G08B; locating faults along lines G01R31/08; emergency protective devices H01H)
- H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00)

## Abstract

The present disclosure provides an arc-free DC circuit breaker that combines magnetic induction transfer and resistive current limiting. The circuit breaker comprises a main current circuit and a transfer current circuit. The transfer current circuit has a bridge structure; with a group of unidirectional components having a breaking function, bidirectional current breaking is implemented, such that compared with the prior art, usage of the turn-off devices may be reduced to half. By controlling action sequences of the trigger gap, high-speed switch, and power semiconductor, fast switching arc-free opening of the main current circuit is implemented; meanwhile, the breaking capability of the circuit breaker is significantly improved. By virtue of the current limiting module circuit inside the transfer current circuit, the present disclosure quickly limits short-circuit fault current, and then reduces the number of parallel groups of full-controlled devices of the breaking module circuit. Compared with the existing circuit breaker structures, usage of turn-off devices and cost of the circuit breaker may be significantly reduced.

## Claims

### Claim 1

An arc-free DC circuit breaker, characterized in that the circuit breaker comprises a main current circuit and a transfer current circuit; wherein
the main current circuit is for current in a normal working state to pass through;
the transfer current circuit is for when a short-circuit fault current occurs, implementing transfer of the short-circuit fault current to the main current circuit, and limiting and breaking the short-circuit fault current;
the transfer current circuit includes a bridge circuit, the bridge circuit comprising a first circuit (1), a second circuit (2); a third circuit (3), a fourth circuit (4), an induction module (5), an over-voltage protection module (6), a capacitor (C) and resistor (R);
the first circuit (1) and second circuit (2) are connected in series and then connected in parallel with a circuit formed by the third circuit (3) and the fourth circuit (4) which are connected in series;
a first endpoint is provided between the first circuit (1) and second circuit (2);
a second endpoint is provided between the third circuit (3) and the fourth circuit (4);
a serial-connection circuit formed by a secondary side inductor (L1) in the induction module (5), a circuit formed by the resistor (R) and the capacitor (C) connected in parallel, and the over-voltage protection module (6) is connected between the first endpoint and the second endpoint to form the bridge circuit.

### Claim 2 (depends on 1)

The DC circuit breaker according to claim 1, characterized in that the main current circuit includes a high-speed mechanical switch (S) and a controllable device (A0) connected in series with the high-speed mechanical switch.

### Claim 3 (depends on 1)

The DC circuit breaker according to claim 1, characterized in that the first circuit (1), the second circuit (2), the third circuit (3) and the fourth circuit (4) are any one of a vacuum trigger gap, a gas trigger gap or the high-speed mechanical switch, or a combination of them connected in series/parallel.

### Claim 4 (depends on 1)

The DC circuit breaker according to claim 1, characterized in that the induction module (5) comprises:
a secondary side inductor (L1), a primary side inductor (L0), a first mutual inductance module (B1), and a second mutual inductance module (B2);
the secondary side inductor (L1) and the primary side inductor (L0) form a transformer; the primary side inductor (L0) is serially connected to the first mutual inductance module (B1) and the second mutual inductance module (B2) to form a closed loop; the first mutual inductance module (B1) comprises a pre-chargeable capacitor or a superconducting inductor, and the second mutual inductance module (B2) includes one or more of a half-controlled power semiconductor device, a gas trigger gap or a vacuum trigger gap.

### Claim 5 (depends on 4)

The DC circuit breaker according to claim 4, characterized in that the secondary side inductor (L1) and the primary side inductor (L0) are hollow inductors or magnetic core-contained inductors.

### Claim 6 (depends on 1)

The DC circuit breaker according to claim 1, characterized in that the over-voltage protection module (6) comprises a power semiconductor device (A6) and an arrestor (MOV) which are connected in parallel, wherein the power semiconductor device (A6) has a function of turning off the current; the arrester (MOV) is an arrestor formed by a varistor or a zinc oxide valve plate.

### Claim 7 (depends on 1)

The DC circuit breaker according to claim 1, characterized in that the resistor (R) is selected from a group consisting of a carbon film resistor, a metal film resistor, a metal oxide film resistor, a wire-wound resistor, a high-power wire-wound resistor, an organic solid resistor, a fuse resistor, a cement resistor, a superconducting current-limiting resistor, a liquid metal resistor, and a PTC resistor.

### Claim 8 (depends on 3)

The DC circuit breaker according to claim 3, characterized in that a fast switch (S) in the main current circuit, and the high-speed mechanical switch in the first circuit (1), the second circuit (2), the third circuit (3), the fourth circuit (4) are selected from the group consisting of an electromagnetic repulsion-based high-speed mechanical switch, a high-speed motor-driven mechanical switch or an explosion-driven high-speed mechanical switch.