Isolated microgrid multi-phase three-phase inverter parallel system and distributed control method thereof

Abstract

The invention relates to a parallel microgrid multi-phase three-phase inverter parallel system and a distributed control method thereof. The system comprises a plurality of three-phase inverter parallel units, a three-phase load and an AC bus, wherein each three-phase inverter parallel unit comprises a three-phase inverter circuit, a control circuit of the three-phase inverter circuit and equivalent transmission line impedance. The coordinated control of the multi-parallel inverters without a communication line or under very few communication lines can be achieved effectively, and good voltageregulation and current sharing characteristics can be achieved. The system is fast in dynamic response, does not require a multi-loop controller and is simple and effective. The system can serve as anetworking component in an isolated microgrid to provide voltage and frequency support for the system. In case of power fluctuation or load sudden change of the system, rapid accurate power distribution can be achieved, and the power supply reliability of the isolated microgrid is ensured.

Description

technical field [0001] The invention belongs to the technical field of isolated microgrids, and relates to the parallel operation control technology of multi-three-phase inverters of isolated microgrids, in particular to an isolated microgrid multi-three-phase inverter parallel system and a distributed control method thereof. Background technique [0002] As one of the key technologies of the smart grid, microgrid can effectively solve the impact of distributed power on the main network and users due to scattered locations, various forms, and different characteristics, and realize the effective integration and efficient utilization of distributed power. has received widespread attention. When the microgrid operates in island mode, multiple three-phase inverters are required to operate in parallel, and together serve as networking components to provide voltage and frequency support for the independent microgrid. [0003] However, in the parallel connection system of multiple...

AI Technical Summary

Problems solved by technology

However, traditional droop control has an inherent contradiction between voltage regulation performance and power distribution accuracy, which will cause disadvantages such as voltage and frequency deviation from the rated value or uneven power distribution.

Therefore, various improvement methods based on traditional droop control have been proposed one after another, such as adding virtual impedance and additional feedback loop, but it will cause complex control structure of the system and difficulty in parameter setting, which will affect the control effect; Affects the dynamic response speed of the entire system

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