Study Of Parallel Hybrid Electric Vehicle Control Strategy

The research and development on Hybrid Electric Vehicle(HEV)is an important method to resolve the pollute of environment and the energy crisis. But at the present time, the research on HEV in our country is in the very beginning. The National Department of Science and Technology makes HEV a significant project of 863 Plan. The Hybrid Electric Vehicle (HEV) is a complicated great nonlinear system which combines mechanical, electric, chemicals and Thermodynamic. The aim of the research of HEV is to make the vehicles Oil Consumption economically and to concern the cost of the vehicles as well. In this paper, the main object of research is Parallel Hybrid Electric Vehicle (PHEV) and the main method of research is fuzzy logic control strategy. The ADVISOR and Matlab/Simulink is used to simulate the auto model which is established power unit distributing model on fuzzy logic controller.Firstly, this paper gives an analysis on the types and hybrid configurations of hybrid electric vehicle, and summarizes the characters of all the driving types and their working conditions. Secondly, expatiate the control idea and the control strategy of the parallel hybrid electric vehicle, compare the difference of these control strategy, conform the control strategy based on fuzzy logic control, then, introduce the basic theory of the fuzzy logic simply. Proposed a modified fuzzy control strategy, it is actually a multi-structure fuzzy controller, when the vehicle is under the different operation sets such as started,acceleration,deceleration,cruise or idle mode, the control rules are also different in order to adapt to different energy needs when the car under each mode.By embedding the improved fuzzy controller in the ADVISOR and making simulation, to contrast this improved fuzzy controller simulation results with the general fuzzy controller, it can be seen that the improved fuzzy control effect is in general better than general fuzzy control, in the improved fuzzy logic control, hybrid electric vehicle emissions and fuel consumption are reduced by 12.2% and 6.5% in the CYC_ECE_EUDC driving cycle and 1.8% and 4.6% in the CYC_UDDS driving cycle. And in the improved FLC, the operating point of the engine is more dense, it shows that the volatility of the engine is smaller when running, thus it can reduce vehicle exhaust emissions and save energy.