光伏并网逆变器电压跌落模型电流预测控制方法研究

针对传统光伏逆变器低电压穿越技术存在的不足,提出一种基于模型电流预测控制的低电压穿越控制方法,能够有效提高光伏逆变器的输出特性及响应速度。该策略通过逆变器预测模型得到预测电流,将有功、无功电流分量预测电流与给定电流误差之和作为价值函数进行最佳电压矢量的选取。针对系统不同运行状态自动平滑切换优先有功和优先无功两种控制模式,提出一种低压穿越输出电流控制方法,有效提高了光伏逆变器低压穿越能力。最后,通过Matlab/Simulink仿真及实验,验证了所提控制策略的正确性及有效性。

Study on Model Current Predictive Control Method of Grid-connected Inverters for Photovoltaic System with Voltage Sag

In order to overcome the lack of traditional photovoltaic inverter low voltage ride through (LVRT) technology, a LVRT control method based on model current predictive control(MCPC) is presented in this paper to effectively improve the photovoltaic inverter output characteristics and response speed. In this method, the predictive current is obtained from the inverter predictive model,and the sum of the predicted current and the given current error is selected as the optimal value of the voltage vector. Based on the automatic switch system of priority active or reactive power control mode according to the different operating states in photovoltaic inverter,a control method of LVRT output current is proposed to effectively improve the inverter capability of LVRT. Finally, The LVRT control method is carried out on the Matlab/Simulink,and the results verify that the proposed strategy is valid and effective.