基于等效内部阻抗的单相电压控制型逆变器控制策略

Control Scheme of Single-Phase Voltage-Controlled Inverter Based on Equivalent Inner Impedance

对于大量分布式电源接入配电网引起的高渗透率问题,传统的电流控制型逆变器在电网电压及频率的调节、电网故障时无缝切换等方面存在困难,为此提出了一种单相电压控制型策略。通过控制环路的设计和控制参数的设定,使得等效阻抗精确可控,且从外特性上可模拟同步发电机的频率及电压控制特性,使逆变器具备调节电网电压和频率的功能,提升电网对分布式电源接纳能力。仿真及实验结果验证了控制策略的有效性。

In view of the fact that there are difficulties in the adjustment of network voltage and frequency and the seamless switching during fault occurred in distribution network it is hard for traditional current-controlled inverter to cope with the high penetration caused by connecting a lot of distributed generations to distribution network. For this reason, a control strategy based on single-phase voltage-controlled inverter is proposed. Through the design of control loop and setting of control parameters, the equivalent impedance is controllable accurately, besides, its external characteristics can simulate the frequency and voltage control characteristic of synchronous generator to make the inverter possessing the function of adjusting both network voltage and frequency, thus the ability of distribution network to accommodate distributed generation is enhanced. The effectiveness of the proposed control strategy is validated by results of both simulation and experiments.