The Research On Hybrid Electric Vehicle Power Control Method

The electric vehicles take battery as its drive unit, have the advantages of zero emissions, energy saving, low noise, high efficiency, able to save energy, and environmental protection. But there has not been a substantive battery technology breakthrough.Low specific power, difficulty high-current charge-discharge,limited cycle life makes the dynamic performance of the vehicle and driving range severely affected, which limited the development of electric vehicles.Super capacitor is an emerging power, with the advantages of fast charging, high specific power, long cycle life, short-term release of energy. A number of foreign car companies used super capacitor in hybrid vehicles as energy storage device.In this paper, a composite power electric vehicles for the study, the operating characteristics of batteries, super capacitors and DC/DC converters were firstly analyzed. Fully grasp the power characteristics of each element and based on the characteristics to establish batteries, super capacitors and DC/DC simulation models.Then study the control strategy to achieve control objectives,completing the design work with two control strategies:limited logic gates and the fuzzy control.Selecting the appropriate parameter simulation data and through ADVISOR2002 software, take simulation and analysis of control strategies in Beijing driving conditions. The results show that super capacitor can inhibit the battery high charge/discharge current, and it is capable of recovering braking energy effectively, compared with a single power supply, its power resistance, fuel economy and charge /discharge performance are able to get much more improvement, and verify the validity and correctness of the control strategy.