基于加权控制的三相四线储能逆变器输出电压不平衡抑制

Unbalance suppression for output voltage of three-phase four-wire energy-storage inverter based on weighting control

三相四线储能逆变器的优点是在孤岛模式下运行时可以输出相电压,但也存在因为不平衡负载而导致逆变器输出电压不平衡的问题。传统采用双dq变换、PI+R(准谐振控制器)混合控制的不平衡抑制方法存在控制系统复杂、参数设计困难及控制器之间耦合等缺陷。因此,本文提出一种基于电压加权控制的输出电压不平衡抑制策略,通过对公共连接点负序和零序电压进行加权控制从而实现对输出电压的不平衡抑制。相比于现有的抗不平衡控制策略,该方法属于对不平衡电压的直接控制,更加简单、直接且有效。最后,通过仿真和实验验证了该方法的有效性。

The advantage of the three-phase four-wire energy storage inverter is that it can output phase voltage while operating in island mode.However,the output voltage of the inverter is often unbalanced due to the unbalanced load.The traditional unbalance suppression methods with double-dq transformations and PI+R(quasi-resonant)control have disadvantages such as complicated control,difficult parameter design,and coupling between controllers.Therefore,this paper proposes an output voltage unbalance suppression strategy based on voltage weighting control,which suppresses unbalanced output voltage by weighting control of the negative-sequence and zero-sequence voltages at the point of common coupling.Compared with the existing anti-imbalance control strategies,the proposed method belongs to direct control for unbalanced voltage,which is simpler,more direct,and effective.Finally,the effectiveness of the method is verified by simulation and experimental results.