航空发动机内置式永磁容错发电系统的研究

Fault-tolerant internal permanent magnet generation system used in aviation engines

针对内置式航空发电系统高功率密度、高可靠性和高输出性能的要求,提出了基于三相四桥臂的航空用永磁容错发电系统。利用永磁容错电机大电感的特点,改进了传统弱磁控制算法,提出了简单高效的直轴电流Id解析法弱磁控制,通过实时计算弱磁电流给定实现了宽速范围(3倍额定转速)内的恒压发电控制。同时,根据容错电机磁隔离的特点,以保证故障前后电机定子磁场为圆形旋转磁场为前提,结合电压空间矢量脉宽调制(SVPWM)算法实现了单相断路或短路故障的容错发电控制。通过MATLAB仿真验证了控制算法的正确性。最后,对一套7.5kW永磁容错发电系统进行了算法验证实验,验证了I_d解析法弱磁控制和容错控制的可行性,为后续的系统性能测试打下基础。

High power density,high reliability and high output performance are required by internal power generation system in aviation.Thus,fault-tolerant permanent magnet generation system based on three-phase four-leg circuit topology was proposed.The permanent magnet fault-tolerant motor has the characteristics of large inductance.Id analysis flux-weakening control method is put forward by improving traditional flux-weakening control algorithm.It is a simple and efficient method.Idcurrent is calculated in real time.The algorithm can realize the constant voltage generation control in a wide speed range（three times of rated speed）by calculating the given flux-weakening current at real-time.Based on the characteristics of magnet isolation,the fault tolerant control of one-phase fault including open-circuit and short-circuit is proposed.Combining with space vector pulse width modulation（SVPWM）algorithm,it means to keep the magnetic fields generated by stator current as circular rotating fields.MATLAB simulation results verify the correctness of the Idanalysis method for the flux-weakening control and fault tolerant control.Finally,a 7.5kW fault-tolerant permanent magnet motor and its control system were tested.The experimental results also validate the Id analysis method for flux-weakening and the fault tolerant control method,which lays the foundation for the follow-up system performance test.