PWM逆变器相电流重构研究与误差分析  

Phase Current Reconstruction Method for PWM Inverter and Error Analysis

作　　者：马鸿雁[1,2] 孙凯[1] 魏庆[1] 黄立培[1] 

机构地区：[1]清华大学电力系统及大型发电设备安全控制与仿真国家重点实验室,北京100084 [2]北京建筑工程学院电信学院,北京100044

出　　处：《电工技术学报》2011年第1期108-114,161,共8页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金(50607012);北京市教委科技发展计划(KM200710016008)资助项目

摘　　要：为了降低系统成本和体积,研究了脉宽调制(PWM)逆变器供电的电动机变频调速系统仅采用一个直流电流传感器获得交流相电流时存在的问题,通过修改逆变器开关状态的相电流重构方法满足了直流电流的采样要求,根据逆变器的开关状态实现了交流侧电动机相电流的重构。针对在该方法作用下重构相电流与实际相电流之间的误差,详细分析其产生的原因,并提出了一些解决措施。在PWM逆变器供电的永磁同步电动机矢量控制系统上进行了仿真和实验验证。结果表明,采用本文方法不仅实现了PWM逆变器-交流电动机调速系统的单电流传感器运行,而且由直流母线电流重构出的交流电流值具有很高的精度,与实际交流电流值之间的误差很小,为改善交流电动机变频调速系统的性能提供了一种重要的解决方案。In order to lower the cost and volume,the operation of getting alternating current（AC） link phase current in pulse width modulation（PWM） inverter fed AC machine variable frequency drive system with only a direct current（DC） link current sensor was investigated.The proposed method was to fulfill the requirements of DC-link current detection by adjusting inverter switching state and realize the reconstruction of AC phase currents according to the switching states of the inverter.The errors between the reconstructed phase currents and the real phase currents are discussed.The causes of reconstructed current errors are analyzed in detail and some solutions are proposed.Experiments and simulations have been conducted on a PWM inverter fed permanent magnet synchronous machine（PMSM） vector control system.Experimental and simulation results show that,by using the proposed method under current error elimination,the operation of PWM inverter fed AC drive system by single DC-link current sensor is implemented,the precision of AC phase reconstructed currents that are calculated by DC-link current is increased,the reconstructed current errors are reduced.These works are beneficial for the performance improvement of the AC machine variable frequency drive system.

关 键 词：PWM逆变器 相电流重构 永磁同步电动机 重构电流误差 直流电流传感器 

分 类 号：TM464[电气工程—电器]