H∞ synthesis design of electric vehicle powertrain systems

Aiming at the oscillation problem in the electric vehicle powertrain systems, an H_∞ synthesis robust control strategy is proposed from the angle of acceleration control. The desired frequency characteristics of the system are obtained through H_∞ loop-shaping, which ensures the high-frequency and low-frequency performance of the system, and the μ-synthesis ensures the robustness under the uncertainty of system parameters. By adding the coprime factor perturbation and the stability margin of the system into the H_∞ loop-shaping, the oscillation existing in the system is suppressed. In the simulation analysis, the μ-analysis is used to verify the robustness and stability of the system, and the performance of the model uncertainty is intuitively displayed. The system has better closed-loop performance and robustness in the presence of parameter uncertainty and transmission shaft clearance. The designed acceleration controller also has a good control effect on the speed.