基于并联电流源光伏逆变器的特定谐波消除法

Selective Harmonic Elimination for Parallel Current Source PV Inverters

提出了一种适用于低开关频率并联电流源光伏逆变器的改进谐波控制策略。建立了并联电流源光伏逆变器模型,分析了影响并网点电流谐波的几个关键因素。针对传统指定谐波消除法(SHE)不能直接控制并网点谐波的局限性,对传统指定谐波消除法的波形约束条件和并联电流源协同控制条件进行修改,提出了极低开关频率下利用逆变桥输出特定电流谐波主动补偿并网点电流波形质量的改进控制方法。测试结果验证了所提方案可以有效改善并网电流谐波性能。

An optimizing harmonic control scheme applied to parallel current-source photovoltaic inverters worked in low switching frequency was proposed.The model of parallel current-source photovoltaic inverters was built and some core factors affecting current harmonic performance of point of common coupling(PCC)were analyzed.With respect to the limitation of traditional selective harmonic elimination(SHE)which cannot directly control the harmonic current of PCC,the control conditions of SHE and parallel current-source inverter were modified.The optimizing control method of active improving PCC current waveform quality within extremely low switching frequency was proposed,which taking advantage of outputting selective harmonic current by invertor bridge to compensate the current of PCC.The results of examination illustrate the ability of proposed scheme optimizing the harmonic current performance of PCC.