Research on Starting Optimizing Control and Active Load Fluctuation Control of More Electric Auxiliary Power Unit

The more electric auxiliary power unit (MEAPU) can provide electric power for more electric aircraft. Since the starter generator (SG) is used in MEAPU, the optimization of starting process control can be realized through fuel flow and SG torque control. Compared with the auxiliary power unit (APU), the electric load of SG in MEAPU can change abruptly during power generation, resulting in excessive speed fluctuation of MEAPU, which needs to be suppressed. In order to solve the above problems, a model consists of an APU and a SG is established. In the starting process, a variable substitution optimal control (VSOC) method is proposed, and the starting time is shortened by 10 s without over-temperature and surge. An active load fluctuation suppression control (ALFSC) method is used, suppressing the speed fluctuation caused by a sudden load of more than 80%.