Control method, system and storage medium of multi-module direct parallel converter

Abstract

The invention discloses a control method of a multi-module direct parallel converter, comprising: determining the product of the number of converter modules connected in parallel on the AC winding of the transformer and the current phase number of a single converter module; combining 360° with the product The quotient of is determined as the target angle; the carrier waves of each phase loaded on each converter module are staggered so that the phases of the carrier waves of each phase are sequentially different from the target angle. Applying the control method of the multi-module directly parallel-connected converter provided by the present invention can reduce the high-frequency harmonics near the switching frequency in the multi-module direct-parallel converter, and greatly increase the active power output by the system. The invention also provides a control system and a computer-readable storage medium of a multi-module direct parallel converter, which have corresponding technical effects.

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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