Jordan Francis Morris
Design and Testing of a Bidirectional Smart Charger Prototype
Mehrdad Kazerani and Claudio Canizares
Rising greenhouse gas emissions, sky-rocketing fuel costs and recent technological advances are causing a paradigm shift in the auto-industry away from traditional internal combustion engine vehicles to Electric Vehicles (EVs). Although great for the environment, mass deployment of electric and hybrid electric vehicles has the possibility to cause devastating effects to the power grid, such as phase imbalances, voltage deviations and distribution transformer overloading since an EV can potentially draw 19.2 kW in a residential neighbourhood from a single-phase outlet. However, if charging is properly controlled and coordinated, EVs have the potential to improve the power grid, acting as distributed generation or storage unit.
This thesis aims to address this issue by developing a fully-functional smart bidirectional EV charger prototype. The term ‘smart’ refers to the charger’s ability to control the charging and discharging of the battery pack based on the preferences of the car owner, the electricity price at the time of use, battery’s operational constraints and the distribution system’s requirements at the command of the utility or Local Distribution Operator (LDO). ‘Bidirectional’ refers to power flow; the charger will employ a design that allows the power to flow from the grid to the battery and vise-versa.
First, this thesis will review existing bidirectional charger topologies and smart grid communication technologies. Then, a review of relevant standards, battery technologies and controller options will be presented. This will be followed by the charger design process and simulation results to validate the design. The thesis will conclude with the presentation of the smart bidirectional charger prototype to prove its validity as a solution to the aforementioned problem.