基于滑模变结构光伏并网逆变器控制研究

Grid-connected PV Inverter Control Strategy Based on Sliding Mode

针对光伏并网逆变器采用传统PI控制方式存在的缺点,提出了采用积分滑模变结构控制策略,对并网逆变器进行控制研究。详细介绍了并网逆变器直接电流控制方式中的滑模变结构控制策略,对滑模面的存在性和系统稳定性进行理论推导,并基于Matlab仿真平台对滑模变结构控制策略及传统的PI加电压补偿控制策略进行仿真比较,分析并网逆变器的输出电流谐波及功率因数,结果证明了所提出的控制策略降低了电流谐波畸变率,提高了并网系统的控制精度,改善了系统的鲁棒性及抗干扰能力,功率因数近似为1,具有一定的优越性和可行性。

In view of the disadvantages of the traditional PI control method for grid-connected photovoltaic inverters,the control strategy of variable structure with integral sliding mode to control grid-connected inverters was investigated in this paper.The control strategy of variable structure with sliding mode in the direct current control mode of grid-connected inverters is introduced in detail.The control strategy of variable structure with sliding mode and the control strategy of traditional PI voltage compensation are compared based on the Matlab simulation.And the output current harmonics and power factor of the grid-connected inverters are analyzed.The results proved the superiority and feasibility of the proposed control strategy,which reduces the current harmonic distortion rate,improves the control accuracy of the grid-connected system,improves the robustness and anti-interference ability of the system,and the power factor is close to 1.