Optimal and stable electric power system for more electric aircraft: Parallel operation of generators and weight reduction

More electric aircraft has become an interesting topic in recent studies. In this paper, an optimal electric power generation mechanism is proposed for aircraft. Inverter-interfaced engine-driven induction generators are considered as distributed generators in the aircraft microgrid. Droop controller is applied to enable the parallel operation of generators and eliminate using of conventional constant speed drives. A new method is proposed to determine optimal droop gain for active power sharing. The method is applied to minimize the frequency deviation of the AC aircraft network. In the following, the reactive power sharing is considered as a challenge in case of asymmetrical load distribution. By proposing a new algorithm, optimal reactive power droop gain is determined with regard to the small signal stability of the system. Proposed power sharing methods are evaluated by simulation of a sample aircraft grid. The optimization results for assigned power and droop gain are given. Simulation results show that the frequency regulation of aircraft electric grid is properly achieved. Also it is shown that the reactive power sharing is enhanced and the system stability is maintained.