交流微电网中考虑电压质量的DG之间谐波功率均分控制策略

在多节点微电网系统中，并联分布式电源(DG)在传统的对等控制下难以精确均分谐波功率且会对母线电压质量带来不利的影响。为此，基于两级式分层控制，提出了一种考虑电压质量的DG之间谐波功率均分控制策略。通过各DG之间的低带宽通信实现输出谐波功率信息的共享，根据获得的谐波功率信息动态重塑系统在谐波域的等效阻抗，能在提高谐波功率均分精度的同时兼顾母线电压质量。从谐波环流偏差、电压质量方面，将所提控制策略与已有的自适应虚拟谐波阻抗法进行对比分析。仿真和实验结果表明所提控制策略能够在均分谐波功率的同时，减小母线电压幅值跌落和总谐波畸变率，提高母线电压质量。

Harmonic power equalization control strategy among DGs in AC microgrid considering voltage quality

In the multi-bus microgrid system, it is difficult for the parallel DGs(Distributed Generations) to equalize harmonic power accurately under the traditional peer-to-peer control, and the bus voltage quality is adversely affected. Therefore, based on two-stage hierarchical control, a harmonic power equalization control strategy among DGs considering voltage quality is proposed. Through the low-bandwidth communication among DGs, the output harmonic power information is shared. Based on the obtained harmonic power information, the equivalent impedance of the system in the harmonic domain is dynamically reconstructed, which can improve the equalization precision of harmonic power and take into account the bus voltage quality. In terms of harmonic circulating current deviation and voltage quality, the proposed control strategy is compared with the adaptive virtual harmonic impedance method. The simulative and experimental results show that the proposed control strategy can reduce amplitude sag and total harmonic distortion of bus voltage and improve bus voltage quality while equalizing harmonic power.