Novel PI Control Algorithm for Dynamic Emulation of Mechanical Loads during Transmission Shift of Electric Vehicles

Abstract

Considering the high dynamic characteristics of the vehicle motor during transmission shift of electric vehicles (EVs), bench tests of shift control laws on the Electric Motor-Dynamometer Set (EMDS) require higher demands than the steady tests. A traditional proportional-integral (PI) controller is the most frequently used for regulating the dynamometer speed to emulate the mechanical loads during the slowly changing process. However, the transient performances, under that, are highly dependent on the machine parameters, the external disturbances, and the control input constraints. Therefore, a novel proportional-integral (PI) speed regulator is designed. Firstly, Simulink models of the test bench and the vehicle considering shift dynamics are built. Then, a typical shift control strategy is adopted as the test object. A novel PI control algorithm which is capable of realizing the required transient load emulation performances under machine parameter variations, external disturbances and control input saturation is designed. Simulations and experiments are carried out to verify the validity of the newly proposed method, and results reveal that the developed novel PI control law can improve the transient performances and reduce the emulation error significantly compared with the traditional PI controller.