采用统一虚拟阻抗控制的逆变器并联系统

多逆变器并联控制常在各逆变单元中添加虚拟阻抗提高功率均分精度,为简化各种工况下并联系统中各逆变单元的虚拟阻抗控制逻辑,提出一种统一虚拟阻抗控制方案.首先,对各逆变器所需的虚拟阻抗值统一进行自适应调节,提高并联系统的功率分配性能,增强供电可靠性;然后,在PLECS软件中搭建由两台逆变器组成的并联系统仿真模型,验证文中方案的有效性.研究结果表明:文中方案能够适应线路阻抗差异,有效提高并联系统稳态功率的均分精度,实现输出功率的灵活分配控制.

Inverter Parallel System Using Unified Virtual Impedance Control

Parallel control of multiple inverters often adds virtual impedance on each inverter to improve power sharing accuracy. In order to simplify the virtual impedance control logic of each inverter in a parallel system under various working conditions, a unified virtual impedance control scheme is proposed. Firstly, the virtual impedance value required by each inverter is uniformly adjusted adaptively to improve the power distribution performance of the parallel system and enhance the reliability of power supply. Then a parallel system simulation model composed of two inverters is built with PLECS software to verify the effectiveness of the proposed scheme. The research results show that the proposed scheme can adapt to different line impedances, effectively improve the steady-state power sharing accuracy of the parallel system, and realize flexible distribution control of output power.