针对由H桥驱动的单绕组无轴承薄片电机因功率系统开关管发生故障导致电机无法正常运行的问题,以六相单绕组无轴承薄片电机为例,分析了开关管发生开路和短路故障时H桥的工作模态以及故障对系统造成的影响。在故障分析的基础上,对电机短路电流数学模型进行了推导,提出统一的故障容错控制方法。该方法通过非故障相电流重构,补偿功率模块故障对系统造成的影响,提供电机稳定运行所需悬浮力与转矩。通过有限元分析,验证了短路电流模型的正确性及故障容错方法的有效性。以1相和2相绕组功率开关管发生开路或短路故障为例,在一台原理样机上实验验证了理论分析与仿真结论。
Aiming at the problem that single winding bearingless slice motor driven by H-bridge cannot run normally due to fault of power switches in power inverter system. Taking a six-phase single winding slice motor for example, this paper analyses H-bridge work mode and the influence caused by fault of the power inverter when the switch tube is at open-circuit and short-circuit state. Based on the analysis, a mathematical model of short-circuit current was derived and a general fault-tolerant control strategy has been proposed. The method, using the reconstruction of healthy phases, compensates the impact to the system caused by the fault power module, and meets the stable operation of motor required levitation force and torque. The fault-tolerant control strategy was verified by finite element simulation. Finally, taking the experiments of the first and second phases' power switches working at open-circuit and short-circuit fault state for example, the validity of the theoretical analysis and simulation conclusions referred in the paper are fully proved.