三相光伏并网逆变器电流控制器优化设计(英文)

Current Controller Optimum Design for Three-Phase Photovoltaic Grid-Connected Inverter

在光伏发电系统中,并网逆变器通常用来将高质量的电能馈入电网。但是由于死区控制、电网扰动等因素的影响,逆变器馈入电网的电流中含有大量谐波成分。由于带宽的限制,单纯的比例积分控制器不能有效地抑制谐波。因此本文提出了一种由比例积分控制器(PI)和重复控制器(RC)并联构成的复合控制器以提高系统的谐波电流抑制能力。本文建立了同步旋转坐标系下的逆变器动态模型并给出了控制器设计方法。理论分析以及一台20kW逆变器样机的实验结果证明了所提控制策略的可行性。

Three-phase grid-connected voltage source inverter（VSI） is often used to feed high quality current into grid in photovoltaic（PV） power generation system. But many factors,such as switching dead-time effects and disturbance of grids etc,will deteriorate the current waveform,and a large number of harmonic will be fed into grid too. Owing to the conflict between stability and fast response,proportional-integral （PI） controller has limited capabilities to restrain harmonic disturbances and can not guarantee the output performance of grid-connected inverter,so a new control algorithm using compound controller constituted by repetitive controller（RC） and PI controller is proposed in this paper to overcome the shortcomings of PI controller in harmonic control. A dynamic model of grid-connected inverter in synchronous rotating frame（SRF） is derived and the compound current controller design is presented too. Theoretic analysis and experimental results on a 20kW prototype verify that the proposed current controller offers a high performance of current control.