Control of a novel dual stator doubly salient aircraft engine starter-generator

A novel dual stator doubly salient Aircraft Engine Starter-Generator System has been designed and built for an aircraft engine application. The system bases on a dual stator doubly salient Electromagnetic machine, which was chosen for its simplicity, ruggedness, high speed capability, low torque ripple in motoring and low output voltage ripple in generating. This paper describes the motor control system algorithms and hardware which are used to control the motor over its operating speed range from standstill to 11425rpm in both motoring and generating modes. There are some novel features in this starter-generator control system: the particular motor structure, angle advanced control strategy is adopted in aircraft engine starting process, which controls the value of advanced angle to maintain optimum torque at medium and high speed automatically; the transition between starting and generating process is fulfilled by a hardware-based digital commutation controller which generates phase firing pulses for the inverter based on the machine rotor angle, pulse width, and pulse advance. The results of aircraft engine coldstart show that the brushless starter-generator system has good starting character and smooth starting torque.