An Engine Speed Stability-enhanced Energy Management Strategy Under Power Transients for Heavy-duty Hybrid Electric Vehicles

TY - JOUR

T1 - An Engine Speed Stability-enhanced Energy Management Strategy Under Power Transients for Heavy-duty Hybrid Electric Vehicles

AU - Xin, Yuntong

AU - Yang, Chao

AU - Yang, Liuquan

AU - Yan, Qingdong

AU - Wang, Muyao

AU - Wang, Weida

N1 - Publisher Copyright: © 2015 IEEE.

PY - 2026

Y1 - 2026

N2 - In heavy-duty hybrid electric vehicles (HEVs), the engine-generator system (EGS) serves as the dominant power source for propulsion, paired with a small-capacity battery. During vehicle climbing or acceleration, the demand power varies significantly. Sudden changes in demanded power cannot be buffered by the battery alone, and part of the transient power must be supplied by EGS. However, the mismatch between the fast response of generator and the sluggish dynamic of engine leads to engine-speed fluctuation or even flameout, affecting normal operation of vehicle. Thus, ensuring vehicle stable operation and economy is a challenge. This paper proposes an energy management strategy considering EGS speed stability under power transients for heavy-duty HEVs. First, the Lyapunov theory and the sums-of-squares optimization is employed to derive the mathematical expression of the EGS speed stability boundary. Then, according to the characteristics of hybrid powertrains, the dynamic boundary constraints of generalized stability regions are derived. And a real-time iteration method for the equivalence factor is proposed, integrating the shooting method to achieve precise control within the feasible range. Finally, the proposed strategy is validated through simulations and hardware-in-the-loop experiments. The results indicate rotational-speed stability is improved by 64.7% compared to the base strategy.

AB - In heavy-duty hybrid electric vehicles (HEVs), the engine-generator system (EGS) serves as the dominant power source for propulsion, paired with a small-capacity battery. During vehicle climbing or acceleration, the demand power varies significantly. Sudden changes in demanded power cannot be buffered by the battery alone, and part of the transient power must be supplied by EGS. However, the mismatch between the fast response of generator and the sluggish dynamic of engine leads to engine-speed fluctuation or even flameout, affecting normal operation of vehicle. Thus, ensuring vehicle stable operation and economy is a challenge. This paper proposes an energy management strategy considering EGS speed stability under power transients for heavy-duty HEVs. First, the Lyapunov theory and the sums-of-squares optimization is employed to derive the mathematical expression of the EGS speed stability boundary. Then, according to the characteristics of hybrid powertrains, the dynamic boundary constraints of generalized stability regions are derived. And a real-time iteration method for the equivalence factor is proposed, integrating the shooting method to achieve precise control within the feasible range. Finally, the proposed strategy is validated through simulations and hardware-in-the-loop experiments. The results indicate rotational-speed stability is improved by 64.7% compared to the base strategy.

KW - Energy management strategy (EMS)

KW - Engine speed stability

KW - Heavy-duty hybrid electric vehicle

UR - https://www.scopus.com/pages/publications/105033260475

U2 - 10.1109/TTE.2026.3674947

DO - 10.1109/TTE.2026.3674947

M3 - Article

AN - SCOPUS:105033260475

SN - 2332-7782

JO - IEEE Transactions on Transportation Electrification

JF - IEEE Transactions on Transportation Electrification

ER -