Abstract:The matching and optimizing of the parameters of the vacuum assisted brake system of electric vehicle were studied with an aim. The matching and calculation process was designed. A mathematical model for brake system was established. The matching optimization method of the parameters of vacuum assisted brake system was proposed for the start and stop vacuum degree, volume of vacuum tank and pumping speed, and etc. Taking an electric minibus for example, the minimum vacuum degree and the pumping speed that the electric vacuum pump must offer were calculated and matched. The relationship between the volume of vacuum tank and the pumping speed was analyzed. A model of simulation for vacuum assist brake system was set up to analyze the interplay of the start and stop vacuum degree, the pumping speed, working hours and energy consumption, and etc. The result shows that when the volume of vacuum tank is 5 L, the pumping speed is 18 L/min and the start and stop vacuum degree is 45~65 kPa, the vacuum assist brake system is in the best overall performance.