Hierarchical switching control design for single-axle parallel hybrid electric vehicles
FU Zhu-mu
LI Dong-wei
SONG Shu-zhong
WANG Xiao-hong
Abstract：In order to improve the fuel economy and reduce the exhaust emissions, a hierarchical switching control method for single-axle parallel hybrid electric vehicles (PHEVs) is proposed in this paper. Firstly, based on analyzing the steady-state efficiency of the engine and the change laws of batteries charge/discharge internal resistance, the switching rules between operation modes of PHEV are formulated by a hierarchical switching idea. Then, the energy allocation strategies under different target operating modes are researched. For single driving modes and three braking modes, a torque distribution strategy based on rules is devised. For the hybrid modes, a power allocation strategy on the basis of the Lyapunov optimal algorithm is designed in driving charge or hybrid driving mode, and a Willans line model extreme-value method of power allocation strategy is developed to split the power in the parking charge mode, respectively. Finally, simulation results show that the proposed strategy can ensure the engine and batteries work in high-efficiency area. Under UDDS+HWFET cycle conditions, the fuel consumption per hundred kilometers is reduced by 40.82％, CH, CO and NOx emissions by 2.86％, 4.41％and 8.02％respectively compared with that of the electric assist control strategy. The fuel consumption per hundred kilometers decreases by 9.37％compared with that of the global optimization strategy based on Pontryagin's minimum principle (PMP).
Keywords：hybrid electric vehicle (HEV)hierarchical controlswitching controlLyapunov optimal algorithm
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 1339-1348 )