Battery Charger For Plug-in Electric Vehicles Research Articles

Integrated onboard single‐stage battery charger for PEVs incorporating asymmetrical six‐phase induction machine

This study proposes an integrated battery charger for plug-in electric vehicles (PEVs) that involves an asymmetrical six-phase induction motor as propulsion drive. Proposed power electronic interface (PEI) uses a CuK-based bidirectional DC/DC converter, which is capable of performing buck/boost function during all modes of operation. It operates as a power factor correction converter during plug-in charging mode, and a single switch inverting buck/boost converter in propulsion and regenerative braking modes. Selection of a wide range of battery voltages and adequate control over regenerative braking can be achieved with the proposed multi-functional converter. In addition, size, weight and cost of the charger are also reduced, as it involves a minimum number of components compared to existing buck/boost converters used in chargers. By utilising a six-phase induction machine drive in the propulsion system, efficiency and power density of the PEI is improved. This drive even allows for further modifications to the proposed topology. An efficient indirect field-oriented control for the six-phase machine is also demonstrated in the study. The proposed PEI is highly suitable for onboard charger and propulsion system of PEVs. A laboratory prototype of the aforementioned converter and propulsion drive has been built to validate all modes of vehicle operation.

Analysis of the Impact of Different PEV Battery Chargers during Faults

With a high penetration of Plug-In Electric Vehicles (PEVs) in the electric grid, utilities will have to face the challenges related to them. Considerable research is being done to study and mitigate the impact of PEVs on the electric grid and devise methodologies to utilize them for energy storage and distributed generation. In this paper, the impact of PEVs in a smart car park, placed in an unbalanced distribution system, during a Single Line to Ground fault with auto-recloser operation is studied. Level-2, bidirectional battery chargers with Current Controlled and Voltage Controlled Voltage Source Converters are modeled for the battery charging systems of the PEVs. A smart car park, with 16 vehicles connected to each of the three phases is simulated at one of the buses in the IEEE 13 Bus Test Feeder. The impacts observed during the fault are analyzed and a method to mitigate them is suggested.

Advantages of efficiency-aware smart charging strategies for PEVs

Plug-in Electric Vehicles (PEVs) diffusion is expected to grow considerably over the next few years. Aiming to overcome severe grid overload problems caused by a large PEV penetration, utilities and vehicle manufactures are involved in the effort of developing ad hoc charging systems interacting in real-time with smart grids in order to implement smart energy dispatching strategies for PEVs. Strategies which take advantage of varying the charging rate during the charging process appear the most effective solution to guarantee both a full exploitation of the grid capacity and suitable degrees of user satisfaction. This work demonstrates that the actual effectiveness of variable-rate-based dispatching strategies significantly depends on the energy efficiency of the battery charging process, which is in turn strongly related to the charging rate used. Simulation results for a realistic situation show that smart efficiency-aware dispatching strategies, which take into account the actual dependence between the charging efficiency and the charging rate, allow significant improvements in both the user satisfaction and the utility profit compared with non-efficiency-aware strategies. The results of the analysis performed give useful guidelines for the development of smart-grid management policies and for the design of next-generation PEVs battery chargers and charging stations.