Modeling and Decoupling Control of ICE APU with Uncontrolled Rectifier in Series Hybrid Vehicle

In series hybrid vehicle ICE (internal combustion engine), generator with rectifier and exciter are connected together as APU (Auxiliary Power Unit) to provide electricity for vehicle power system. The use of uncontrolled diode rectifier after AC synchronous generator can reduce system cost, but also makes the system difficult to control due to lacking of control variables. In order to achieve better control results, this paper constructs a simplified average model for the generator with exciter and diode rectifier. Internal relations in this MIMO (Multiple Input and Multiple Output) control system are analyzed. Decoupled control algorithms for controlling APU speed and output power independently are given. By road test experiments the model is validated. The result shows the model has very high accuracy.