常振东,陶彩霞.并联微网逆变器输出功率精确分配研究[J].电测与仪表,2019,56(11):75-80,107. CHANG Zhendong,TAO Caixia.Research on accurate output power distributed of parallel microgrid inverter[J].Electrical Measurement & Instrumentation,2019,56(11):75-80,107.
并联微网逆变器输出功率精确分配研究
Research on accurate output power distributed of parallel microgrid inverter
In order to solve the problem of unreasonable output power distribution of parallel microgrid inverters under traditional droop control, this paper takes parallel operation model of two inverters as the research object, Detailed analysis of the output power distribution mechanism of parallel inverters in droop control, and the essential reason for inaccurate output power distribution of parallel inverters is the mismatch between the total output impedance of the inverter and the rated capacity. Therefore, an improved droop control strategy is proposed to solve this problem. The quasi-proportional resonance (PR) control is applied to the outer voltage loop, and the virtual impedance is introduced into the current feedback loop, so that the total output impedance of the inverter is similar to the virtual impedance, thus achieving accurate distribution of output power of parallel inverters by setting virtual impedance according to capacity ratio. In addition, introducing the inverter output voltage amplitude feedback loop into the power control loop and properly selecting of the predetermined voltage can effectively improve the output voltage reduction caused by the virtual impedance. the validity and feasibility of the theoretical analysis are verified by simulation software.
