三相LCL光伏并网逆变器的准比例谐振重复控制研究

Research on Repetitive Control Parallel with Quasi-PR of the Three-phase Photovoltaic Grid-connected Inverter with LCL Filter

针对LCL型光伏并网逆变器控制系统,提出了一种重复控制并联准比例谐振控制的复合控制策略,以改善并网逆变器的输出电流质量。该控制策略结合了两者的优点,其中准比例谐振控制能够保证系统的动态性能,并提高系统抗电网频率波动的能力,而重复控制在并网系统稳定以后可以抑制电网的周期性扰动,提高电流波形跟踪精度,从而获得更高质量的并网电流波形。通过Matlab/Simulink进行仿真实验,证明了这种复合控制策略的有效性和可行性,使系统具有良好的动、稳态性能和抗干扰能力,降低了并网电流的谐波含量。

Considering the photovoltaic grid-connected inverter system with LCL filter, a compound strategy basedon repetitive control parallel with quasi proportional resonant（Quasi-PR） control is proposed, with the purpose toimprove the quality of output current. The compound strategy combines the advantages of the two Quasi-PR controlcan ensure the dynamic performance of the system. And it can also improve the ability against power grid frequencyfluctuation. While repetitive control can suppress the periodic disturbance of the power grid after the grid-connectedsystem has been stabilized. It can also improve the tracking accuracy of the current waveform. As a result a higherquality of the grid-connected current waveform can be obtained. Simulation by Matlab/ Simulink can verify the ef-fectiveness and feasibility of the proposed compound strategy, which ensures the high quality performance of thesystem in both dynamic and steady-state accuracy, improvies the disturbance rejection and reduces the harmoniccontent of the grid-connected current.