A hybrid supply system consisting of supercapacitors and lithium batteries can effectively reduce the fuel consumption of hybrid electric vehicles (HEV) and the life decay of lithium battery. To further improve the above performance

a hierarchical energy management strategy by identifying driving conditions recognition and driver styles recognition is proposed by this paper. The overall strategy is divided into upper engine and lower composite power energy management strategy. The working condition recognition technology is introduced into the engine energy management strategy

and the engine operation strategy is selected according to the identified working conditions

and the engine power Pe {P_{\text{e}}} and composite power Pm {P_{\text{m}}} are reasonably allocated to make the engine run at the best working point. The driver style and composite power information are introduced into the energy management strategy of the composite power supply to adjust the filter coefficient of the low-pass filter online. The low-pass filter decomposes the power of the composite power supply into the low-frequency power of the lithium battery and the high-frequency power of the supercapacitor

so as to reduce the impact on the lithium battery and the life decay. The control strategy model is embedded in the ADVISOR software for simulation

and the results show that compared with the traditional composite power supply strategy using fuzzy control

the hierarchical energy management strategy proposed in this paper can reduce fuel consumption by 5.82% and increase the life mileage of lithium battery by 9.65% under comprehensive cycle conditions

and effectively improve the comprehensive performance of HEV.