Research On Electrical Power Management Of Hybrid Electric Vehicle

Hybrid Electric Vehicle (HEV) is a model which can solve energy shortage and limited drive range of electric vehicle. But none of devices as vehicle power supply can satisfy the drive requirements perfectly. In result there are many problems now such as short lifetime of battery, high price of HEV and so on.This drew attention from scientists. If there is only one kind of power supply in HEV, it can not manage the state of power supply all the time, so power supply always works in overload statement. Then lifetime of power supply will be shorted, and scientists drew a conclusion that hybrid power supply (HPS) is a good idea. HPS comprises two or more complementary energy storage devices.This paper chooses battery and ultracapacitor as the hybrid power supply and analysis HPS's configuration and operating principle. Then select ultracapacitor parallel with battery through DC-DC converter mode. According to equivalent circuits of battery and ultracapacitor, introduce operating principle, energy storage capacity of battery and ultracapacitor, buck and boost mode and efficiency of DC-DC converter.This paper added ultracapacitor and DC-DC converter model into Prius vehicle model based on advisor software. The simulation results of developed vehicle model indicate that acceleration performance is enhanced and the current in battery is slumped. At the same time, the fuel consumption is reduced.Because control strategy has big effect on performance of hybrid power supply, two types of control strategies are analyzed-logic threshold control and fuzzy logic control. Simulink models of two control strategies are built in chapter 4 and combined with models built in chapter 3. Compare simulation results of 4 types of drive cycles, J1015, NYCC, UDDS, INDIA URBAN SAMPLE. The results of two control strategies manifest that fuzzy logic control is more stable and effective than logic threshold control.