A control method and system of a converter with multiple modules directly connected in parallel and a storage medium

Abstract

The invention discloses a control method of a converter with multiple modules directly connected in parallel. The control method comprises the steps: determining the product of the number of convertermodules connected to an alternating current winding of a transformer in parallel and the current phase number of a single converter module; determining the quotient of 360 degrees and the product asa target angle; and staggering carrier waves loaded on the converter modules to make the phases of the carrier waves sequentially differ by the target angle. According to the control method of the converter with the multiple modules directly connected in parallel, high-frequency harmonics near the switching frequency can be reduced in the converter with the multiple modules directly connected in parallel, and active power output by the system is greatly improved. The invention further provides a control system of the converter with the multiple modules directly connected in parallel and a computer readable storage medium; and corresponding technical effects are achieved.

Description

technical field [0001] The invention relates to the field of electric power technology, in particular to a control method, a system and a storage medium of a multi-module directly paralleled converter. Background technique [0002] With the continuous development of society and technology, in many occasions such as electric vehicle drive system, distributed power generation, electric drive system, etc., the demand for the quality and capacity of electric automation equipment is increasing day by day. Improving the output performance of the converter is the key One of the important research directions. [0003] Limited by the capacity of power devices, the converter usually includes multiple converter modules, and these converter modules are connected in parallel to the transformer. Multiple converter modules have the advantages of increasing the output power level of the system, improving the reliability of the system, and increasing the flexibility of the system. [0004]...

AI Technical Summary

Problems solved by technology

Due to certain differences in the impedance between the various converter modules, etc., there will be a voltage difference between the modules, which will cause a circulating current between the modules

The existence of circulating current will increase the power loss, which needs to be eliminated. Usually, it is closed-loop controlled by a control algorithm, but this kind of method only has a certain effect on low-frequency harmonics, and cannot eliminate high-frequency harmonics near the switching frequency in circulating current. , and there is a certain coupling between the suppression effect and the system parameters, when the system parameters change and reach a certain critical value, it may also cause oscillation between the low frequency and high frequency of the system

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