A High Voltage DC Circuit Breaker Topology

Abstract

High-voltage direct-current breaker topology is composed of a first current path (1) and a second current path (2). The first current path (1) is formed by connecting at least one electronic power switch module (3) and a mechanical switch (4) in series, and the second current path (2) is formed by a capacitance set (C) and a cascading type capacitance subunit switching module (5). The cascading type capacitance subunit switching module (5) is formed by connecting a plurality of subunits (6) in series. Multiple forming modes exist between the electronic power switch module (3) and the subunits (6) of the cascading type capacitance subunit switching module (5). A first leading-out terminal of the first current path (1) and a first leading-out terminal of the second current path (2) are connected to serve as a first leading-out terminal of a direct-current breaker to be connected with a direct-current transmission line, and a second leading-out terminal of the first current path (1) and a second leading-out terminal of the second current path (2) serve as a second leading-out terminal of the direct-current breaker to be connected with the other end of the direct-current transmission line.

Description

technical field [0001] The invention relates to a circuit breaker, in particular to a DC circuit breaker topology. Background technique [0002] Fast DC circuit breaker is one of the key equipment to ensure the stable, safe and reliable operation of DC power transmission and distribution system and DC grid system. Different from the AC system, the current of the DC system does not have a natural zero-crossing point, so the natural zero-crossing point of the current cannot be used in the DC system like the AC system. Therefore, the breaking of the DC current has always been a problem worth studying. topic. [0003] At present, there are usually two ways to break DC current. The first is a pure power electronic circuit breaker, such as patent CN102870181A, which can turn off power electronic devices with high power and directly break DC current. Although the solid-state circuit breaker manufactured by this principle can meet the requirements of the multi-terminal flexible DC...

AI Technical Summary

Problems solved by technology

Different from the AC system, the current of the DC system does not have a natural zero-crossing point, so the natural zero-crossing point of the current cannot be used in the DC system like the AC system. Therefore, the breaking of the DC current has always been a problem worth studying. Subject

However, when the capacitance value is large, the breaking speed will be affected

[0006] ABB's patent (WO2011141054A1) proposes a hybrid circuit breaker technology, in which a mechanical switch and a power electronic full-control device are connected in series on the main path, and the other bypass is composed of a surge arrester and a crimped IGBT connected in parallel. When a fault current is detected, the bypass All the crimping IGBTs on the road are turned on, and then the power electronic full control device on the main path is disconnected, and the mechanical switch also starts to turn off. After the mechanical switch is completely turned off, the crimping IGBT is turned off, and the arrester is connected to the circuit to suppress the short-circuit current , this kind of circuit breaker has a fast breaking speed, but the sum of the withstand voltage of the crimped IGBTs of the entire bypass must be greater than the initial voltage of the DC transmission line, which requires a large number of crimped IGBTs in series, resulting in a higher cost for the entire DC circuit breaker

[0007] Moreover, the main circuits of the above two patents must use full-control switching devices in series with mechanical switches, resulting in large conduction losses in normal conditions.

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