电流型变流器在电网电压不平衡时的控制

Control Strategy for Current-source Converters Under Unbalanced Network Voltage Conditions

提出一种电网电压不对称情况下抑制三相脉宽调制(PWM)电流型变流器(CSC)直流输出电流二次谐波、减少网侧电流低次谐波的控制方法。该方法对传统的预测控制进行改进并应用到电网不平衡的三相CSC系统中,获得了良好的控制性能。应用电流空间矢量调制技术,使器件的利用率得到提高。所提出的方法无需电流传感器检测网侧电流,降低了实现成本。实验结果证明所提出的方法是正确、可行的。

This paper presents a new control strategy to eliminate second harmonic of dc output current in the 3-phase unbalanced network voltage PWM current-source converters （CSC）. This proposed method can effectively reduce low order harmonics of the network current. The proposed method improves the traditional predictive controller and achieves good control performance. With application of current space vector modulation, the utilization of the devices is enhanced greatly. Also with this proposed scheme, current sensors are avoided, which results in cost down. Experimental results confirm the feasibility of the proposed method.