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In view of the requirements of the special structural features of a series-parallel hybrid electric bus on its control strategy, an optimization simulation on its energy management strategy, which determines the power distribution between engine and battery, is conducted by using Pontryagin's minimum principle and based on the solution flow chart designed and the simulation model built, with battery power as control variable and minimizing fuel consumption as objective. The results demonstrate the marked effects of optimization on energy management strategy based on Pontryagin's minimum principle with the fuel consumption per 100km 18. 33% lower than that with rule-based control strategy. [ABSTRACT FROM AUTHOR]

Aiming at the effects of many factors such as uncertain driving environment and different driver's styles on the fuel economy of novel series-parallel hybrid electric bus (SPHEB) in real world driving conditions, a Markov model for driver's required power is built based on statistical data of several city driving cycles, and an energy management strategy based on stochastic dynamic programming (SDP) algorithm is proposed and the control rules for power distribution between engine and battery are obtained. Both the results of simulation on the forward model for novel SPHEB and hardware-in-the-loop test demonstrate that the proposed strategy enables the battery SOC to keep balance within its preset range and makes the engine operate in high efficiency region. In addition the fuel consumption per 100km of novel SPHEB reduces by 30.17% and 11. 29% respectively compared with original bus and that with rule-based strategy. [ABSTRACT FROM AUTHOR]

A three-dimensional heat dissipation model is built for the lithium-ion battery pack in an electric vehicle. Both simulation and test are conducted on the temperature field of lithium-ion battery pack in a condition of cruise driving and natural air cooling with a result showing their consistency in temperature variation trend, meaning the rationality of the model built. On this basis an optimization scheme for the heat dissipation structure of lithium-ion battery pack is proposed and a simulation is performed. The results indicate that after optimization, lithium-ion battery pack has a good cooling effects: the highest temperature of battery pack lowers from 46°C to 33°C and the temperature difference among the batteries is less than 6°C. [ABSTRACT FROM AUTHOR]