Bypass module for power unit of high-voltage frequency converter

Abstract

The invention discloses a bypass module for a power unit of a high-voltage frequency converter. The bypass module comprises a bypass driving circuit used for driving a bypass contactor switch of the power unit; the bypass module further comprises a bypass state detection circuit, a bypass failure feedback circuit and a communication fault feedback circuit; the bypass state detection circuit is used for detecting whether a bypass contactor is successfully driven or not; the bypass failure feedback circuit is used for feeding back a bypass failure signal detected by the bypass state detection circuit to a main control system of the high-voltage frequency converter; and the communication fault feedback circuit is used for feeding back a signal of a bypass optical fiber communication fault tothe main control system of the frequency converter in time. A triode in the bypass driving circuit works in a saturation region; a collector and an emitter are conducted; a relay obtains electricity to be closed; and that a bypass signal is already sent out is displayed in time through a first signal loop, so that the bypass driving circuit has the advantages of being simple in structure, low in cost and high in reliability.

Description

technical field [0001] The invention relates to the technical field of frequency converters, in particular to a bypass module used for a power unit of a high-voltage frequency converter. Background technique [0002] With the development of power electronics technology, the application of high-voltage frequency converters composed of power unit cascade technology is becoming more and more extensive. In the application of cascaded high-voltage inverters, since high-voltage motors are generally used in more critical occasions, the failure of high-voltage inverters will seriously affect the normal production of the enterprise, and even cause major economic losses. For this reason, the power unit bypass device is usually used to improve the stability and reliability of the high-voltage inverter. When a part of the high-voltage inverter fails, it can ensure uninterrupted operation and avoid the shutdown of the high-voltage inverter. [0003] In cascaded high-voltage inverters, e...

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Problems solved by technology

[0004] The bypass module of the cascaded frequency converter in the prior art has several disadvantages during use: 1) the design is complicated, the cost is high and the volume is large; 2) the state of the bypass contactor cannot be automatically fed back; 3) it cannot be automatically Feedback whether the operation of the bypass contactor is successful; 4) Can not automatically feedback the failure of the optical fiber communication between the main control system of the inverter and the bypass module; resulting in low efficiency of the bypass device of the power unit, reducing the stability and reliability of the inverter

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