We have come to the end of this module on EV charging technology. In the first lecture, we saw various charging methods for EVs. The three common ways are conductive charging, inductive charging and battery swap. Conductive charging is the most common charging method right now and it has two categories: AC and DC charging. The second method is inductive charging and consists of two types: static and dynamic charging. The final method is battery swap. These charging methods have their own advantages and disadvantages. While battery swap provides the quickest “charging” time, it faces a big challenge in requiring standardisation across EV manufacturers for the battery and car design. Inductive charging provides maximum convenience to the user but has a higher cost and relatively lower efficiency than conductive charging.

The second lecture was on AC charging of electric vehicles. In its simplest form, AC charging uses an onboard charger to convert AC power from the conventional AC grid to direct current or DC power to charge the traction battery. Then we saw the essential components needed in an AC charging station for a safe and reliable charging process. There are four main types of AC charging connectors: Type 1, Type 2, Type 3 and proprietary connector used by Tesla. The proximity and control pilot of the TYpe 1 and Type 2 chargers provide the control of the charging process. Finally, we understood how a simple formula could be used to estimate the charging power and charging time for AC charging.

The third lecture was on DC charging of electric vehicles. We looked at the power flow for DC charging from the DC charger to the EV battery. There are five types of DC charging connectors used globally: CCS-combo 1, CCS-combo 2, Chademo, Tesla DC connectors and the Chinese GB/T connector.. Even though DC charging is quite attractive in the sense of high power charging with short charging times, fast charging limited due to the maximum power that the charging cable and EV battery can handle and its impact on the battery lifetime.

The fourth part was on smart charging of electric vehicles, vehicle-to-grid technology and the necessary ICT protocols. Smart charging is a series of intelligent functionalities to control the EV charging power in order to create a flexible, sustainable, low cost and efficient charging environment. There are several benefits of smart charging and it has huge potential: EV charging can be controlled based on renewable generation, energy prices, grid loading and how the EV can be used as a storage and as an emergency power supply. Vehicle-to-grid is a special case of smart charging where the energy from the EV battery can be used to feed power to homes, buildings and to the grid.

The next lecture looked at charging electric cars as an evolving ecosystem with many different machines and stakeholders that must be able to exchange information using various protocols. Open protocols will be crucial for the development of the charging infrastructure market. Finally, we learnt about current and future trends in EV charging technology through the case study of ABB charging infrastructure.