Power Decoupling Control Strategy of Variable Impedance Ratio Based on Virtual Impedance for Microgrid

doi:10.11985/2018.05.003

Abstract

Abstract:

In low-voltage microgrids, coupling of traditional droop control, and mismatched feeder impedances can lead the inverter to control the output power imprecise, could cause the circulation between inverters. This paper analyzed the output power characteristics of the inverter, and concluded the coupling relationship between the line resistance ratio and the droop control by introducing the virtual power. A power decoupling control strategy based on the virtual impedance is proposed. The virtual impedance control loop which is added to this control strategy, can not only changed the output impedance ratio of the inverter to realize the decoupling of the power control, but solved the problem that actual output power could not be equally divided during normal operation and load change. Using Matlab/Simulink platform to build a basic structure of low-voltage microgrid model, and comparison the effectiveness of this strategy is verified by comparison with traditional droop control.

Key words: Low-voltage microgrid, virtual impedance ratio, power decoupling, power sharing

CLC Number:

TM464

Xing Zuoxia,Lu Yandong,Dong Huanbao. Power Decoupling Control Strategy of Variable Impedance Ratio Based on Virtual Impedance for Microgrid[J]. Journal of Electrical Engineering, 2018, 13(5): 14-20.

Figures/Tables 8

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系统名称	参数数值
380V线路	R₁= 1.284Ω,R₂= 0.812Ω, L₁= j0.1930Ω,L₂= j0.0981Ω Line1 = 0.2km,Line2 = 0.192km
负荷	load1 = 30kW、10kvar load2 = 10kW、10kvar load3 = 10kW、10kvar