Part 3: A Review Of Battery Charger Topologies and Infrastructure For Plug-In Electric and Hybrid Vehicles

摘要

An inductive charger transfers power magnetically. This type of charger has been explored for Levels 1 and 2 devices. A recommended practice for EV inductive charging was published by the SAE in 1995. The clear advantage of contactless charging is its convenience for the user. Instead of deep-cycling the battery, the vehicle battery can be topped off frequently while parked at home or at work, when shopping and even at traffic lights. Cables and cords are eliminated. Advantages include convenience and galvanic isolation. It is also possible to build charging strips into highways which enables charging while driving. Therefore, inductive charging could strongly reduce the need for a fast-charging infrastructure. Disadvantages include relatively low efficiency and power density, manufacturing complexity, size, and cost. Given that energy savings is an important motivator for EVs, the extra power loss is an important consideration. Basic principles of inductive power transfer (IPT) are similar to transformers, although most versions have poor magnetic coupling and high leakage flux. The secondary side may be stationary, or moving (roadbed charging). Typical stationary and roadbed IPT charging systems are represented in Figs. 16 and 17.