李红萍,杨洪耕,曾巧燕.孤岛型微电网中逆变器并联运行控制策略[J].电测与仪表,2016,53(6):. LI Hong-ping,YANG Hong-geng,ZENG Qiao-yan.Control Strategy for Paralleled Inverters in Islanded Microgrid[J].Electrical Measurement & Instrumentation,2016,53(6):.
孤岛型微电网中逆变器并联运行控制策略
Control Strategy for Paralleled Inverters in Islanded Microgrid
In order to solve the problem that unreasonable reactive power sharing and output voltage and frequency deviations based on the conventional droop control of paralleled inverters, a parallel inverter control strategy which bases on virtual impedance, frequency/voltage and reactive power regulation is proposed. Virtual impedance is added in conventional droop control to make the output impedances of inverters present inductive and weaken the power coupled caused by resistive component. Voltage/frequency secondary regulation improves the quality of voltage and frequency, and inverters can still maintain voltage and frequency rating even if large load power changes. Secondary reactive power regulation directly controls the distribution of reactive power, and reactive power sharing can be obtained independently from inverter output voltage, and achieve high precision reactive power sharing. Small-signal dynamic model of microgrid is built to analyse stability and choose reasonable control parameters. Simulation results verify the effectiveness and feasibility of the proposed strategy.
