Design and control of a battery charger for electric vehicles

Identifier:  TDX:2315

Handle: https://hdl.handle.net/20.500.11797/TDX2315

Authors:  Marcos Pastor, Adrià

Abstract:
This thesis presents the design and control of a battery charger for plug-in electric vehicles. The implemented prototype is bidirectional, with a rated power of 3 kW and it has been designed for a battery voltage range of 200 V and 380 V. The digital control has been implemented on one Digital Signal Controller (DSC) type TMS320F28335. The proposed topology of the battery charger is based on a full bridge synchronous rectifier followed by two cascaded stages. The first stage consists of three boost converters connected in parallel, while the second stage is composed by three parallel buck converters connected to the battery. The first stage is meant to correct the power factor and to regulate the DC-link voltage at 400 V. The second stage delivers to the battery the current calculated by the battery state of charger controller. The inductor current controllers have been designed by means the applications of the discrete-time sliding-mode control theory, so that their operation at a constant switching frequency is possible. Hence, the application of interleaving operation mode is directly applicable. Besides, the reduction of the DC-link capacitors, generally present in single-phase applications based on two-cascaded stages, is also addressed in order to avoid the use of electrolytic capacitors owing to their reduced lifespan. Two different scenarios have been taken into account. The first one considers that the second stage is meant to operate as a constant power sink and the DC-link voltage regulation is carried out by the first stage. The second scenario proposes the DC-link voltage is regulated by the second stage while the first stage behaves as a constant power source.