Hybrid active high-voltage direct-current circuit breaker

Abstract

Provided in the invention is a hybrid active high-voltage direct-current circuit breaker comprising a main branch circuit, a converter branch circuit, an energy consumption branch circuit, a current-limiting inductor, a residual direct-current circuit breaker and a high-voltage ignition sphere gap for protection. The direct-current circuit breaker has advantage of simple circuit topological structure, simple and convenient control, high security and reliability, and fast motion; the used power electronic devices are mainly semi-controlled and uncontrolled ones, so that the number of control trigger circuits of the power electronic devices is reduced; the technology is mature and is easy to realize; the through-current capacity and the breaking current capability are great and the voltage-withstanding level is high; the expansion capability is excellent. Moreover, the high-voltage ignition sphere gap with the low cost and the mature technology is used as a discharging and protection switch, so that the cost is reduced substantially, the reliability is enhanced, and the equipment security is protected.

Description

【Technical field】 [0001] The invention relates to a DC circuit breaker of a high-voltage direct current transmission system, in particular to a hybrid active high-voltage direct current circuit breaker. 【Background technique】 [0002] With the rapid development of power electronics technology, flexible DC transmission based on fully-controlled power electronic devices and modular multilevel converter technology has completely solved the problem of commutation failure in the receiving end of traditional high-voltage DC transmission, and can independently Rapid control of the transmitted active and reactive power greatly improves the flexibility of power transmission. Especially in recent years, the multi-terminal DC transmission system that can realize multi-power supply and multi-drop power receiving has attracted more and more attention, and the high-voltage DC circuit breaker is one of the key technologies that can realize multi-terminal DC transmission system networking. ...

AI Technical Summary

Problems solved by technology

In the above-mentioned high-voltage DC circuit breaker scheme, on the one hand, it is necessary to configure a large number of fully-controlled power electronic devices IGBT, but limited by the current technical level of fully-controlled power devices, its price is very expensive, and the voltage and current parameters of IGBT are far less than Semi-controlled power device thyristor, so it is very unsuitable to be widely used in HVDC transmission system engineering

On the other hand, with the increase of the voltage level of the DC transmission system, the number of IGBTs connected in series in the ABB scheme for blocking higher voltages will also increase significantly. The synchronization problem of its series control is also prominent

[0004] In addition, patents CN104767170A and CN104767171A propose two similar hybrid DC circuit breaker solutions, the former requires the use of two sets of capacitor banks and two sets of charging devices, and the latter uses six sets of thyristor valves, which greatly increases the DC circuit breaker manufacturing cost

In particular, there are no anti-parallel diodes at both ends of the two series thyristors. Although the function of shutting off the DC current can also be realized, the thyristors will produce a large voltage during the shut-off process, especially in the process of shutting off the short-circuit current. Reverse recovery current, and there will be a high reverse recovery voltage across the thyristor, which is very easy to damage the thyristor

Likewise, the thyristor valves in the LC discharge circuits of both are also at risk of being damaged due to an excessively high rate of change of the discharge current

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