Parallel structure of three-phase multilevel pwm converter

Abstract

The present invention relates to a parallel structure of three-phase multi-level PWM converters which are suitable for distributed power supplies, and systems for grid-connected power generation with renewable energies, charging and discharging and energy storage therefor and the like. Then present invention includes more than two three-phase multi-level PWM converters and control circuit units thereof, a digital signal processor and a three-phase alternating current power supply circuit; and further includes a common unified voltage regulator, the unified voltage regulator consisting of a voltage sampling circuit, a voltage sensor, a third adder and an external loop voltage PI regulator, the voltage sampling circuit being connected in parallel to a load RL. The advantages of the present invention are as follows: the energy flow direction consistency problem of each three-phase multi-level PWM converter when operating in parallel is solved, the generation of a loop current is avoided, and at the same time the problem of equal current when each three-phase multi-level PWM converter operates in parallel is solved. The present invention is suitable for scenarios in which high power and scaled power electronics conversion is applied.

Description

technical field [0001] The invention relates to a parallel structure of a three-phase multi-level PWM converter, which is suitable for systems such as distributed power supply, grid connection of renewable energy generation, charging and discharging, and energy storage. Background technique [0002] In recent years, power electronics technology has developed continuously and has been widely used in various fields that require electric energy conversion. In the field of low-voltage and low-power electricity consumption, power electronics technology is becoming mature, while in the field of high-voltage and high-power applications, multi-level power conversion technology has gradually become the core and hot issue of research. [0003] Multi-level conversion technology is a new type of converter that realizes high-voltage and high-power output by improving the converter's own topology. It does not require step-up transformers and voltage equalization and transformation circuit...

AI Technical Summary

Problems solved by technology

[0009] The technical problem to be solved by the present invention is to provide a three-phase multi-voltage converter that can solve the problem of consistency of energy flow in parallel multi-level PWM converters, avoid the generation of circulating current, and solve the problem of parallel current sharing of multi-level PWM converters. Parallel Structure of Flat PWM Converter

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