开绕组电机控制系统的共模电压抑制方法研究

为解决单电源供电开绕组交流电机驱动系统存在的共模电压问题，分析了开绕组交流电机驱动系统与常规交流电机驱动系统共模电压的关系，给出了开绕组交流电机端的共模电压表达式，分别针对开绕组交流电机在常规直接转矩控制（DTC）和简化空间矢量调制直接转矩控制（SSVM—DTC）算法下的共模电压抑制问题，提出了电压空间矢量的选取方法，优化了两种控制策略。针对DTC，利用两个逆变器中4组不同空间电压矢量所产生的共模电压为零的特性，选取合适的组合以抑制共模电压；针对SSVM—DTC，将电机端给定电压空间电压矢量分解为两个幅值相等、相位与给定电压矢量互差30。的新电压空间矢量，以达到合成电压空间矢量共模电压为零的目的。仿真结果表明，共模电压的最大幅值会减小至接近于零，远小于原先的幅值，验证了该控制策略的有效性和可行性。

Research of common-mode voltage elimination for open-end winding AC motor drive system

In order to eliminate the common-mode voltage in a single power source open-end winding AC motor drive system, the common- mode voltage expression was detevmined by analyzing the open-end winding AC motor drive system and the conventional AC motor drive sys- tem. A voltage vector selection method was proposed in both direct torque control（DTC） and simplified space vector modulation based direct torque control（SSVM-DTC） strategy. In DTC, the method was fulfilled by selecting the corresponding voltage vectors; and in SSVM-DTC, the method was realized by proportioning the reference voltage vector properly into two vectors with the same amplitude and 30 degree angle a- part from the original vector. The simulation results show that the maximum amplitude of the common-mode voltage has been reduced to near zero and much smaller than the original value, which validates the correctness of the proposed control strategies.