电压扰动情况光伏并网逆变器控制策略研究

针对三电平光伏并网逆变器,提出一种修正的比例谐振控制策略,实现电网电压扰动情况下并网电流谐波抑制。首先在电网扰动情况下,通过比例谐振控制器实现低次电流谐波抑制,该方法能够在电网扰动情况下实现并网电流准确控制。并针对三电平逆变器存在的中点平衡问题,提出采用PI控制器实现三电平逆变器中点电位平衡控制。该方法采用载波调制方法,避免了空间矢量调制复杂的计算。仿真和实验结果表明:电网扰动情况下,三电平逆变器能够快速准确地跟踪给定电流。

Control Strategy Research on Photovoltaic Grid Inverter Under Voltage Disturbance Condition

In view of the three-level photovoltaic grid inverter,a fixed proportional resonance control strategy was put forward,the grid current harmonic suppression was implemented under power grid voltage disturbance situation. First of all,in the case of grid disturbances,proportional resonant controller was adopted to realize low current harmonic suppression,grid current control could be achieved accurately. Aiming at the midpoint balance problems of the three-level inverter,PI controller was put forward to realize neutral voltage balance control of the three-level inverter. The carrier modulation method was adopted to avoid the space vector modulation complex calculations. Simulation and experimental results show that three-level inverter track the given current fast under the disturbance situation.