Energy Management of Low Voltage Power Supply of Plug-in Hybrid Electric Vehicle

Under the pressure of energy crisis and environmental pollutions, regulations of automotive emission and energy consumption are becoming more and more stringent. Plug-in Hybrid Electric Vehicle (PHEV), which can solve environmental issues and mileage limitations, becomes the most popular development trend at present. Optimization control of power battery energy contributes greatly to improving vehicle fuel economy and dynamic performance, energy optimization control of vehicle low voltage power supply also has significant influence on vehicle fuel consumption and dynamic performance. In this paper, a Low-Voltage Power Supply Energy Management System (LVPSEMS) is proposed to optimize the energy of low voltage power supply of PHEV. Dynamic management voltage output of DC/DC is conducted and realized based on vehicle states, power battery SOC and low voltage battery status with the purpose of achieving fuel economy and dynamic performance of automobile. The tests in vehicle show that the proposed LVPSEMS and control strategy can effectively improve the pure electric mileage of 1.72% and reduce the electric energy consumption by 4%.