A high voltage direct current circuit breaker

Abstract

A high-voltage direct-current breaker is composed of an initial current path (1) and a fail current interdicting path (2). The initial current path (1) comprises at least one electric electronic switch module (3) and a mechanical switch (4), and the fail current interdicting path (2) comprises an initial capacitor (C) and a modular switching subunit series connection component (5). The modular switching subunit series connection component (5) is formed by connecting a plurality of sub units (6) in series. When a high-voltage direct-current electric transmission line fails, the opening and closing of a fail electric transmission line can be rapidly achieved.

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 voltage limiting device and a crimping IGBT connected in parallel, when a fault current is detected , the crimping IGBTs on the bypass are all turned on, and then the power electronic full-control device on the main path is disconnected, and the mechanical switch is also turned off. After the mechanical switch is completely turned off, the crimping IGBT is turned off, and the voltage limiting device is connected. The circuit suppresses 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. This requires a large number of crimped IGBTs in series, resulting in the entire DC circuit breaker. higher cost

[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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