  The development of electric and connected vehicles as well as automated
driving technologies are key towards the smart city, with convenient urban
mobility and high energy economy performance. However, the global rise in
electricity price provokes renewed interest on CAVs with hybrid electric
powertrains rather than considering battery electric powertrains. This paper
provides a decentralized coordination strategy for a group of connected and
autonomous vehicles (CAVs) with a series hybrid electric (sHEV) powertrain at
signal-free intersections. The problem is formulated as a convex form with
suitable relaxation and approximation of the powertrain model and solved by
decentralized model predictive control, which is able to ensure a rapid search
and unique solution in real time. Numerical examples validate the effectiveness
of the proposed methods concerning physical and safety constraints. By
utilizing the petrol fuel and battery charging prices over the last year, the
performance of the proposed approach is evaluated against the optimal results
produced by two benchmark solutions, conventional vehicles (CVs) and battery
electric vehicles (BEVs). The comparison results show that the traveling cost
of sHEVs approaches and even under some circumstances reaches the same level as
for BEVs, which indicates the importance of hybridization, particularly under
the current rising electricity price situation.
