基于αβ坐标下离网逆变器控制策略研究

摘要

三相离网逆变器的数学模型在dq坐标系下存在耦合项,并且当负载突变或不平衡时,输出电流波形易产生畸变,对负载造成一定的损坏并减少其使用寿命.针对上述存在的问题,提出基于αβ坐标系下的电流重复控制策略,该控制策略不需要进行Park变换和解耦计算,且能有效地抑制波形的畸变.仿真结果表明:采用LC型滤波器三相逆变器在αβ坐标系下电流重复控制方法是正确的,且能够减少逆变器输出电流波形的谐波含量,满足谐波畸变率要求,为负载提供优质的电能.%The mathematical model of the three-phase off-grid inverter has a coupling term in the dq coordinate system,and the output current waveform is prone to distortion when the load is abrupt or unbalanced,which causes certainly damage to the load and reduces its service life.In order to solve the above problems,the current repetitive control strategy based on αβ coordinate system is proposed.The control strategy can effectively suppress the harmonic distortion without using Park transformation and decoupling calculation.The simulation results show that the current repetitive control strategy on LC type filter for three-phase inverter in the αβcoordinate system is correct,the total harmonic distortion rate of the output current of the inverter can be reduced,the requirement of harmonic distortion rate is met.It provides high quality electric energy for the loads.