Parallel connection structure for single-phase multi-level PWM (Pulse-Width Modulation) convertors

Abstract

The invention relates to a parallel connection structure for single-phase multi-level PWM (Pulse-Width Modulation) convertors, which is suitable for a distributed power supply, a renewable energy source generating combined grid, charging / discharging and energy storing systems and the like. The parallel connection structure comprises more than two single-phase multi-level PWM convertors and control circuit units thereof, a digital signal processor, a single-phase alternated power circuit and a shared uniform voltage regulator, wherein the shared uniform voltage regulator is composed of a voltage sampling circuit, a voltage sensor, a third summing unit and an outer ring voltage PI (Proportional Integral) regulator. The voltage sampling circuit is in parallel connection with an RL (Resistance Load). The parallel connection structure for single-phase multi-level PWM convertors has the advantages that the problem of the energy flow direction consistency of the single-phase multi-level PWM convertors in a parallel running process is solved, the circulation current is avoided, the equalized flow problem of the single-phase multi-level PWM convertors in the parallel running process is solved, and the parallel connection structure for the single-phase multi-level PWM convertors is suitable for an application situation of a high-power large-scale power electronic convertor.

Description

technical field [0001] The invention relates to a parallel structure of a single-phase multi-level PWM converter, which is suitable for systems such as distributed power supply, renewable energy generation grid connection, 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 circuits....

AI Technical Summary

Problems solved by technology

[0009] The technical problem to be solved by the present invention is to provide a single-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 currents, and solve the problem of parallel current sharing of multi-level PWM converters. Parallel Structure of Flat PWM Converter

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