Design and implementation of dual-source (WPT + PV) charger for EV battery charging

摘要

Adaption of an on-board solar PV system in electric vehicles (EVs) can cut pollution by reducing the demand from the grid. It eliminates the need of human intervention for charging EVs as well. Similarly, introducing wireless power transfer (WPT) for EVs cuts attendant requirements and charger chord handling. Therefore, charging a EV battery with combined power from the on-board solar PV system and WPT using a dual-input DC-DC converter is introduced in this article. A small signal model of the dual-input boost (DIB), dual-input buck (DIBK) and dual-input buck-boost (DIBB) converters is derived. Transfer functions for all three converter operations are derived and used to design proportional integral (PI) controllers. The WPT source is considered a variable DC source, and a lead-acid battery rated 120 V/165 Ah at 55% state of charge (SoC) is used as load in the simulation. Controller design and stability analysis are discussed in detail. The hardware experimentation of a developed combined charging system test bench is performed with resistive load and 10 nos. of lead-acid battery stack, each rated 12 V/20 Ah. The performance of DIB and DIBB converter modes under continuous conduction is studied with a detailed loss analysis of the WPT system and dual-input converter (DIC). Also, the proposed integrated system is compared with various integrated DIC topologies.