Converter direct current side capacitance minimization method based on high-frequency transformer

Abstract

The invention discloses a converter direct current side capacitance minimization method based on a high-frequency transformer, and the method comprises the steps: taking an input converter as a reference direction, adding the instantaneous power of all ports, obtaining the total fluctuation power Pf, distributing the power to each direct current side capacitor, and calculating the power PCi which needs to be buffered by each direct current side capacitor; the input power Poi of each port is detected, the power transmitted to the high-frequency transformer by each high-frequency converter is controlled, so that the average value Pi of the power in a high-frequency period is equal to the difference value between the input power Poi of the port and the buffer power PCi of the direct-current side capacitor, and the value is reduced without adding extra components; according to the rule that fluctuation power of an alternating current port is counteracted through a magnetic circuit, the fluctuation power buffered at the capacitor is reduced, the capacitance value of the direct current side capacitor is reduced to the maximum extent, and therefore the size and weight of the capacitor are reduced, and the technical requirement for power density is met.

Description

technical field [0001] The invention belongs to the technical field of power electronic energy conversion, and relates to a method for minimizing the DC side capacitance of a converter based on a high-frequency transformer. Background technique [0002] With the increasingly serious problems of global energy shortage and environmental pollution, the development and utilization of new energy has received more and more attention, and it has also brought new challenges to power equipment. In the process of power conversion, the traditional power frequency transformer has the disadvantage of large volume, and its high power density technology has become a hot and difficult research point. On the other hand, multi-port power electronic transformers have become more and more widely used due to the different requirements of distributed power sources and loads of different voltage levels and types of power sources. It can be seen that the research on power equipment with high power...

AI Technical Summary

Problems solved by technology

[0004] However, the converter still faces a technical challenge, that is, the capacitance value of the DC side capacitor needs to be further optimized to increase the power density

Traditional isolated converter units transfer power fluctuations to the DC side when processing AC power. Large electrolytic capacitors are required on the DC side to buffer power fluctuations. Large-capacity capacitors lead to huge equipment volume and weight, which increases equipment costs. At the same time It is also accompanied by serious defects such as short life

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