Micro-grid multi-inverter parallel voltage control method for droop control of robust power

Abstract

The invention discloses a micro-grid multi-inverter parallel voltage control method for droop control of robust power. The method comprises the following steps of: specific to each inverter in a micro-grid, computing and synthesizing an inverter output reference voltage by adopting a robust power droop controller; and introducing virtual complex impedance containing a resistance component and an inductive impedance component, and keeping inverter output impedance in a pure resistance state under a power frequency condition by adopting a multi-loop voltage control method based on virtual impedance and quasi-resonance PR (Proportional-Resonant) control, thereby realizing micro-grid multi-inverter parallel running and power equation, wherein the robustness of a micro-grid parallel system on numeric value computing errors, parameter drift, noise interference and the like is enhanced. Due to the adoption of the method, the defects of larger loop current of a parallel system, non-uniform power distribution and the like caused by the inductivity of the impedance output by inverters in the conventional droop method are overcome; and the method is suitable for multi-grid parallel uniform current control in a low-voltage micro-grid.

Description

technical field [0001] The invention relates to the field of micro-grid multi-inverter control, in particular to a micro-grid multi-inverter parallel voltage control method for robust power droop control. Background technique [0002] In order to better tap the potential of distributed power generation and solve the adverse effects of distributed power generation on large power grids, the use of microgrids to organize distributed power access has become a hot spot in current power system research. In recent years, with the operation of many experimental micro-grids, certain achievements have been made in micro-grid energy management systems and power electronic interface control. Microgrid is increasingly becoming a research hotspot. [0003] A key issue in the operation of low-voltage microgrids is the parallel operation of multiple inverters. The control strategy of a single inverter determines its output impedance characteristics, and the output impedance characteristic...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a micro-grid multi-inverter parallel voltage control method with robust power droop control for the deficiencies of the existing technology, and to solve the problem of applying the existing method to multi-inverter in low-voltage micro-grid In the case of parallel current sharing control, the power sharing accuracy is not high and the circulation current is large

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