Main power supply and standby power supply switching circuit

Abstract

The invention discloses a main power supply and standby power supply switching circuit, which comprises a direct-current input main power supply U1 and a direct-current input standby power supply U2 for supplying power to a ship rectification generator, a first Boost chopper circuit for boosting the direct-current input main power supply U1, a second Boost chopper circuit for boosting the direct-current input standby power supply U2, counter-current protection diodes D1-D4, a filtering module and an inversion unit for converting direct-current input into three-phase alternating-current output,wherein the two Boost chopper circuits adopt closed-loop PID control, and the Boost branch output voltage U1' of the first Boost chopper circuit is controlled to be 2-10 V larger than the Boost branch output voltage U2' of the second Boost chopper circuit. According to the main power supply and standby power supply switching circuit, priority selection of main power supply branches and automaticswitching between main and standby power supplies can be realized; and compared with the traditional power supply switching circuit adopting a circuit breaker and a relay, the main power supply and standby power supply switching of the invention adopts a power electronic device to switch, has the extremely short switching time of only [mu]s, can ensure the uninterrupted output of the inverter sidein the power supply switching process, and achieves seamless switching.

Description

technical field [0001] The invention belongs to the field of power electronics, and in particular relates to a main and standby power switching circuit. Background technique [0002] With the development of power electronics technology, the reliability and stability of power supply for power electronics equipment are becoming more and more stringent. For example, power electronic equipment such as frequency converters and inverter power supplies are required to be powered by two main and backup power sources to ensure safe and reliable power supply. [0003] The traditional main and backup power switching circuit adopts circuit breakers and relays, which have many disadvantages: [0004] First, it is difficult to realize the priority selection of the main power supply and the automatic switching between the main and backup power supplies; the second is that the opening and closing time of the circuit breaker is relatively long, generally at the ms level, so that the output ...

AI Technical Summary

Problems solved by technology

[0004] First, it is difficult to realize the priority selection of the main power supply and the automatic switching of the main and backup power supplies; the second is that the opening and closing time of the circuit breaker is relatively long, generally at the ms level, so that the output cannot be maintained during the power supply switching process. Uninterrupted; thirdly, during the power switching process, due to the large voltage difference between the main power supply and the backup power supply, the impact current on the supporting capacitor is relatively large, so the supporting capacitor may be broken down; fourthly, the power consumption of the circuit breaker during the switching process Larger and sparks will be generated during reed switching, which is dangerous

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