Bandwidth Based Methodology for Designing a Hybrid Energy Storage System for a Series Hybrid Electric Vehicle with Limited All Electric Mode

The cost and fuel economy of hybrid electrical vehicles (HEVs) are significantly dependent on the power-train energy storage system (ESS). A series HEV with a minimal all-electric mode (AEM) permits minimizing the size and cost of the ESS. This manuscript, pursuing the minimal size tactic, introduces a bandwidth based methodology for designing an efficient ESS. First, for a mid-size reference vehicle, a parametric study is carried out over various minimal-size ESSs, both hybrid (HESS) and non-hybrid (ESS), for finding the highest fuel economy. The results show that a specific type of high power battery with 4.5 kWh capacity can be selected as the winning candidate to study for further minimization. In a second study, following the twin goals of maximizing Fuel Economy (FE) and improving consumer acceptance, a sports car class Series-HEV (SHEV) was considered as a potential application which requires even more ESS minimization. The challenge with this vehicle is to reduce the ESS size compared to 4.5 kWh, because the available space allocation is only one fourth of the allowed battery size in the mid-size study by volume. Therefore, an advanced bandwidth-based controller is developed that allows a hybridized Subaru BRZ model to be realized with a light ESS. The result allows a SHEV to be realized with 1.13 kWh ESS capacity. In a third study, the objective is to find optimum SHEV designs with minimal AEM assumption which cover the design space between the fuel economies in the mid-size car study and the sports car study. Maximizing FE while minimizing ESS cost is more aligned with customer acceptance in the current state of market. The techniques applied to manage the power flow between energy sources of the power-train significantly affect the results of this optimization. A Pareto Frontier, including ESS cost and FE, for a SHEV with limited AEM, is introduced using an advanced bandwidth-based control strategy teamed up with duty ratio control. This controller allows the series hybrid’s advantage of tightly managing engine efficiency to be extended to lighter ESS, as compared to the size of the ESS in available products in the market

Planning of Electric Vehicle Charging Facilities on Highways Based on Chaos Cat Swarm Simulated Annealing Algorithm

Aiming at the layout planning of electric vehicle (EV) charging facilities on highways, this study builds a multi-objective optimization model with the minimum construction cost of charging facilities, minimum access cost to the grid, minimum operation and maintenance cost, and maximum carbon emission reduction benefit by combining the state of charge (SOC) variation characteristics and charging demand characteristics of EVs. A chaos cat swarm simulated annealing (CCSSA) algorithm is proposed. In this algorithm, chaotic logistic mapping is introduced into the cat swarm optimization (CSO) algorithm to satisfy the planning demand of EV charging facilities. The location information of the cat swarm is changed during iteration, the search mode and tracking mode are improved accordingly. The simulated annealing method is adopted for global optimization search to balance the whole swarm in terms of local and global search ability, thus obtaining the optimal distribution strategy of charging facilities. The case of the Xi’an highway network in Shanxi Province, China, shows that the optimization model considering carbon emission reduction benefits can minimize the comprehensive cost and balance economic and environmental benefits. The facility spacing of the obtained layout scheme can meet the daily charging demand of the target road network area

Design optimisation and real-time energy management control of the electrified off-highway vehicle with artificial intelligence

Targeting zeros-emissions in transportation, future vehicles will be more energy-efficient via powertrain electrification. This PhD research aims to optimise an electrified off-highway vehicle to achieve the maximum energy efficiency by exploring new artificial intelligence algorithms. The modelling study of the vehicle system is firstly performed. Offline design optimisation and online optimum energy management control methodologies have been researched. New optimisation methods are proposed and compared with the benchmark methods. Hardware-in-the-Loop testing of the energy management controller has been carried out for validation of the control methods. This research delivers three original contributions: 1) Chaos-enhance accelerated particle swarm optimisation algorithm for offline design optimisation is proposed for the first time. This can achieve 200% higher reputation-index value compared to the particle swarm optimisation method. 2) Online swarm intelligent programming is developed as a new online optimisation method for model-based predictive control of the vehicle energy-flow. This method can save up to 17% energy over the rule-based strategy. 3) Multi-step reinforcement learning is researched for a new concept of ‘model-free’ predictive energy management with the capability of continuously online optimisation in real-world driving. It can further save at least 9% energy