Thermal Design & Multi-Objective Optimization of On-Board Chargers in Electric Vehicles

For the foreseeable future, On-Board Charging will be a critical feature for all EVs, as it allows greater flexibility when charging vehicles from common power points and dedicated EVSEs. The OBC (On-Board Charger) has no function while the vehicle is moving; at the same time, heavy or large OBC reduces range. So, designers must design OBCs that are both energy efficient and lightweight. In addition to surviving the rigors of the automotive environment, such as heat and vibrations, they must also be cost-competitive. Designing OBCs encapsulating multiple objectives thus becomes a necessity. However, current methods often use the “most important” objective and transform other objectives into constraints that do not truly reflect the tradeoffs among all possible designs. Simulating Multi-Objective Optimization methods allow for an in-depth exploration of the solution and tradeoffs. In this paper, a comprehensive thermal design approach based on modeling, simulation, and testing is proposed to build an optimal OBC. According to the concerns regarding the Thermal Optimization study of in-house 3.3 kW OBC using this framework, the formulation is implemented at the Design Phase to select the right EE and ME architectures.