基于多台光伏逆变器的谐波补偿控制策略研究

Research on Harmonic Compensation Control Strategy Based on Multiple Photovoltaic Inverters

为消除电网背景谐波电压和指令信号中谐波成分对多台光伏逆变器并网电流的影响,提出一种基于基波准比例谐振环并联特定谐波补偿环的复合比例谐振控制策略。在多台逆变器并网闭环模型基础上,采用波特图分析法对比了前馈控制与复合比例谐振控制对多逆变器并网电流品质的影响。研究结果表明:复合比例谐振控制策略能更好地对基频处正弦指令信号实行无差跟踪,同时增强系统在3,5,7次谐波频率处对入网电流的抗干扰能力。仿真和实验结果验证了该策略的正确性与有效性。

In order to eliminate the influence of the harmonic voltage and the harmonic components in the command signal on the grid-connected current of multiple photovohaic inverters, a composite proportional resonance control strategy based on the quasi proportional resonant loop parallel to the specific harmonic compensation loop is present- ed.Based on the closed loop model of multiple inverters,the influence of feed-forward control and composite propor- tional resonance control on the multi-inverter grid-connected current quality is compared by using Bode diagram method.The results show that the composite proportional resonance control strategy can better track the sine command signal at the fundamental frequency, and enhance the anti-jamming ability of the system at the frequency of 3,5,7 harmonic.Simulation and experimental results verify the correctness and effectiveness of this strategy.