基于虚拟方波注入的五相永磁同步电机开路故障下直接转矩控制  

Virtual Square Wave Injection Based Direct Torque Control for Five-Phase PMSM with Open-Circuit Fault

作　　者：周华伟[1] 周振伍 朱流川 Zhou Huawei;Zhou Zhenwu;Zhu Liuchuan(School of Electrical and Information Engineering Jiangsu University,Zhenjiang,212013,China)

机构地区：[1]江苏大学电气信息工程学院,镇江212013

出　　处：《电工技术学报》2024年第22期7073-7083,共11页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(52277052)。

摘　　要：在传统直接转矩控制(DTC)中,参考磁链往往是一个固定值,这将导致五相永磁同步电机(PMSM)在正常及容错情况下运行时效率不高。为解决该问题,该文提出一种基于虚拟方波注入的DTC(VSWI-DTC)策略。首先,建立五相PMSM在正常和开路故障情况下的数学模型,在同步旋转坐标系中推导出恒定转矩下电流幅值与定子磁链幅值的关系。其次,设计最优定子磁链探测器。通过向定子磁链幅值中注入虚拟方波信号,根据电流幅值的变化情况补偿定子磁链幅值,在线探寻最优定子磁链幅值。最后,与无差拍DTC相结合,实现电机高效率DTC运行。实验结果表明,所提策略不但能保持DTC良好的动态性能,抑制开路故障引起的转矩脉动,而且提高了电机在正常和开路故障情况下的效率。The five-phase permanent magnet synchronous motor(PMSM)has received attention in electric vehicles and marine transportation due to its more control degrees of freedom,fast response,and high torque density.The most popular control strategies are field-oriented control(FOC)and direct torque control(DTC)strategies.Compared with FOC,a switching table and two hysteresis controllers are applied in DTC to control torque and stator flux linkage.Thus,DTC has the advantages of simple structure,high torque dynamic performance,and fast dynamic response.It also has disadvantages,such as large torque and flux linkage fluctuations.Deadbeat-based DTC(DB-DTC)can solve this problem by discretizing the mathematical model to obtain the voltage vector,which can reduce the fluctuations of torque and stator flux linkage within one sampling period.However,the amplitude of reference flux linkage is usually constant in traditional DTC strategy,resulting in inefficient operation of five-phase PMSM under both healthy and open-circuit fault conditions.This paper proposes a novel DTC based on virtual square wave injection(VSWI-DTC)strategy,which can detect the optimal stator flux linkage amplitude online under healthy and open-circuit fault conditions,achieve the minimum copper loss,improve the operational efficiency,and maintain good dynamic performance.Firstly,the model of five-phase PMSM is derived in the rotor-flux reference frame under healthy and open-circuit fault conditions,and the relationship between stator current and stator flux linkage under constant torque is deduced.Secondly,the optimal stator flux linkage detector is designed.The virtual square wave signal is injected into the stator flux linkage amplitude,which is compensated according to current amplitude variations under constant torque.Thus,online detection of the optimal stator flux linkage amplitude can be realized.Finally,combined with DB-DTC,the torque and stator flux linkage fluctuations can be reduced.The experimental results demonstrate that VSWI-DTC has good stead

关 键 词：直接转矩控制 五相永磁同步电机 单相开路故障 最优定子磁链 虚拟方波注入 

分 类 号：TM351[电气工程—电机]