A range-extender engine speed control strategy with generator torque as an auxiliary input

For the engine speed control in a range extender, responsiveness and anti-disturbance ability of the engine speed system are limited due to the inherent delay and slow response of the engine torque. In order to improve the system performance, a speed control strategy is proposed with the generator torque as an auxiliary input besides the engine torque. Firstly, an engine load compensation is presented to decouple the response from the required generator torque to the engine speed. In addition, a parameterization controller with an anti-windup strategy is provided to control the engine speed; the robustness and stability of the system are also analyzed. Then the undesired open-loop pole of the system is reconfigured using the generator torque as a secondary input to improve the anti-disturbance performance of the system. And the actual generator torque is designed to converge to the required torque when the engine is stable at the required speed to satisfy the power requirement of the vehicle. The effectiveness and practicability of the proposed strategy are evaluated by simulations on Matlab/Simulink and experiments on a range extender.