Novel Load Following Control of an Auxiliary Power Unit

A new power follower is presented to get APU power output effectively for the series hybrid electric drive system. Both engine and generator is matched to get an optimized efficiency - emission zone. Within this optimized zone, it decouples engine speed and generator torque. Speed is divided into different levels, on which APU power is completely covered. When power command is beyond this speed level power range, APU will run up or down to the nearest level. APU torque is regulated by generator excitation current. Experiments are built to validate it on the APU bench. Meanwhile, its control system is implemented on one dSPACEreg prototype controller. Results explain that this power follower allows APU, battery and hybrid supply to switch freely