Electric vehicle (EV) charging stations fed by photovoltaic (PV) panels allow integration of various low-carbon technologies, and are gaining increasing attention as a mean to locally manage power generation and demand. This paper presents novel control schemes to improve coordination of an islanded PV-fed DC bus EV charging system during various disturbances, including rapid changes of irradiance, EV connection and disconnection, or energy storage unit (ESU) charging and discharging. A new hybrid control scheme combining the advantages of both master–slave control and droop control is proposed for a charging station supplying 20 EVs for a total power of 890 kW. In addition, a three-level (3L) boost converter with capacitor voltage balance control is designed for PV generation, with the aim to provide high voltage gain while employing a small inductor. The control techniques are implemented in a simulation environment. Various case studies are presented and analysed, confirming the effectiveness and stability of the control strategies proposed for the islanded charging system. For all tested conditions, the operating voltage is maintained within 5% of the rated value.
Bibliographical noteFunding Information:
Acknowledgments: The authors would like to acknowledge funding by the European Regional Development Fund, through the Welsh Government, for the 2nd Solar Photovoltaic Academic Research Consortium (SPARC II) which supported this research.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- Charging stations
- Droop control
- Electric vehicles
- Islanded microgrid
- Photovoltaic systems
ASJC Scopus subject areas
- Control and Systems Engineering
- Signal Processing
- Hardware and Architecture
- Computer Networks and Communications
- Electrical and Electronic Engineering