What Is an Electric Vehicle Charger?

An electric vehicle chargers is a charging device that charges electric vehicles (EVs) and plug-in hybrid EVs.

As electric vehicle chargers become more popular, they are installed in homes, hotels, hospitals, commercial facilities, highways, gas stations, etc. There are two types of electric vehicle chargers: wired (using cables) and wireless (non-contact).

Currently, the wired charging method, which requires less charging time than the non-contact charging method, is the mainstream, but it is expected that in the future the highly convenient non-contact charging method will be used in combination with the wired charging method. Wired charging systems can be further classified into normal chargers and quick chargers.

Uses of Electric Vehicle Chargers

Electric vehicle chargers are used to charge electric and hybrid vehicles. The wired power supply methods that are currently in widespread use include normal chargers and quick chargers.

1. Standard Charger

Regular chargers are installed mainly at homes, business parking lots, hotels, hospitals, and commercial facilities. Since the standard charging time for regular chargers is as long as 8 to 10 hours, they are used to fully charge the battery at home or in hotels at night when the car is not in use, and then recharge the battery at hospitals, commercial facilities, and other destinations depending on the time spent there.

2. Rapid Charger

Rapid chargers are installed on highways, gas stations, and other locations where there are many users for short periods of time and where there are few restrictions on installation space. Rapid chargers can charge a vehicle in about 30 minutes, so they are used to charge a vehicle in addition to the time spent on the route between the home and the destination.

Principle of Electric Vehicle Chargers

There are two types of normal chargers with a wired power supply system: 100V and 200V voltage. The single-phase alternating current (AC) for household use is supplied directly to the car, and the rectifier circuit installed in the car converts it to direct current (DC) to charge the EV battery.

In a wired power supply quick charger, three-phase 200 V AC current is converted into high-voltage, high-output DC current by the AC/DC converter inside the quick charger, and DC is supplied to the car.

There are three main types of quick charger protocols: CHAdeMO (Chademo), which was developed mainly in Japan; CCS (Combined Charging System), which is being developed mainly by European and American automakers; and Tesla Supercharger, which was developed independently by Tesla vehicles. There are three types of charging protocols.

Other Information on Electric Vehicle Chargers

1. Contactless Charging System

Contactless charging is another method that is currently being developed and standardized. The non-contact power transfer method is a system in which power is wirelessly supplied from a power transmission coil installed on the ground to a power receiving coil on the EV side.

The advantages include the convenience of being able to charge automatically without getting out of the car, and the safety of not having to touch the charger, eliminating the risk of electric shock.

There are two main types of non-contact power supply systems: electromagnetic induction and magnetic field resonance. The magnetic resonance method is superior to the electromagnetic induction method in its ability to transmit power over long distances and in its power transmission efficiency.

2. Chademo

The CHAdeMO protocol uses the CAN communication standard to control data communication between vehicles and chargers so that electric vehicle chargers and quick chargers from various manufacturers can be matched. In addition, to ensure the safety of quick chargers that handle large currents, it is essential to have an independent control power supply to protect the entire charger from abnormalities that occur in the main power supply, as well as an isolation transformer between the main power supply side and the secondary side (DC side).

In addition, to ensure that the life of the EV battery is not adversely affected, the on-board ECU sends instructions to the fast charger for the optimal charging current value according to conditions such as the remaining capacity of the EV battery, and the fast charger sends current according to the ECU's instructions.

3. CCS (Combined Charging System)

The CCS vehicle inlet is designed to allow both AC and DC charging with only one vehicle charging inlet. The inlet refers to the plug at the end of the power cord located in the vehicle and is also called a receptacle.

The CCS connection type is standardized in North America by SAE J1772 (connector type 1) and in Europe by IEC 62196 (connector type 2). Communication is not via power lines, but is superimposed on PWM signals. In the charging sequence, the EV side sends a request and the charging spot responds to the request.