航空发动机起动发电系统要求在热机与冷机情况不同负载转矩未知且突变明显时都能够可靠起动，且要求起动时间尽可能短。传统的永磁同步电机开环I/f控制方法存在转速调节时间长、电流利用率低、给定电流与负载转矩不匹配时易发生失步现象等问题，因此并不适用于航空发动机起动发电系统。针对此问题，提出了一种基于瞬时功率检测的改进闭环I/f控制策略，通过检测瞬时有功功率的扰动量对给定电流矢量的角速度进行补偿，增加系统阻尼转矩分量，加快转速收敛；通过检测瞬时无功功率调节电流矢量幅值，使电机工作在最大转矩/电流比状态，适应负载转矩的突变。同时建立了基于小信号的线性化模型，对传统开环I/f与改进闭环I/f控制方法的稳定性及鲁棒性进行了分析，选取了合适的阻尼补偿系数。最后通过仿真及试验验证了改进闭环I/f起动控制方法可以减小升速阶段转速波动约±60 r/min，减小转速达到稳定的收敛时间约0.3 s，提高电流利用率约20%，且能够适应航空发动机起动发电系统中未知且突变的负载转矩，及时对给定电流进行调整，不再会出现失步现象，实现可靠起动，可以有效地应用在航空发动机起动发电系统中。

It is required that the aero-engine starter/generator system can start reliably when the load torque is unknown and the mutation is obvious in case of heat engine and cold engine. The starting time is also required to be as short as possible too. The traditional open-loop I/f control method of permanent magnet synchronous motor has some problems， such as long speed adjustment time， low current utilization rate， and easy out-of-step phenomenon when the given current does not match the load torque， so it is not suitable for the aero-engine starter/generator system. In this paper， an improved closed-loop I/f control strategy is proposed based on instantaneous power disturbance detection. By detecting instantaneous active power， the frequency of the given current vector is compensated， the damping torque component of the system is increased， and the speed convergence is accelerated. By detecting instantaneous reactive power， the amplitude of current vector is adjusted to keep the motor working in the state of maximum torque/current ratio and adapt to the sudden change of load torque. At the same time， a linearized model is established based on small signals. The stability and robustness of the traditional and the improved I/f control methods are compared， and the appropriate damping compensation coefficient is selected. Finally， it is verified through simulation and experiment that the improved closed-loop I/f starting control method can reduce the speed fluctuation by ±60 r/min in the acceleration stage， reduce the speed convergence time by 0. 3 s， and improve the current utilization rate by about 20%. The improved method can also adapt to the unknown and sudden load torque change in the aero-engine starter/generator system. When the given current is adjusted in time， the out-of-step phenomenon will no longer occur and reliable starting can be realized. The results show that the improved method can be effectively applied in the aero-engine starter/generator system.