Surge Protection for Electric Vehicle Charging

With the increasing popularity of electric vehicles (EV) in many countries and regions, the availability and safety of electric vehicles and charging stations have become critical factors. Routine maintenance is essential, especially in protecting charging stations from lightning strikes. The recommended choice is power SPD.

Over 90% of charging stations are connected to the power grid, so it is necessary to carefully consider the risks posed to the charging station by surge voltages generated by lightning events or switching operations. Once transient voltages are coupled into the vehicle through the power grid connection, they can pose serious threats to the vehicle's electronic equipment.

Why you need power SPD to prevent transient overvoltage

Electric vehicles, due to their embedded electronic devices, typically have electrical systems rated at 2.5 kV (overvoltage category II). This rating is usually insufficient to protect the vehicle from damage in the event of high surge voltages. Incoming surge voltages often exceed these ratings, potentially causing uncertain damage to the connected vehicle's electronic equipment during charging.

This is where power SPD comes into play. It can detect voltage surges and divert transient voltages exceeding a preset threshold to the ground, thus protecting the EV charger from surge voltages.

When selecting the appropriate configuration and related ratings for surge protection devices (SPD) in electric vehicle infrastructure, it is essential to consider the types of surge protection devices and adhere to existing international technical standards. IEC 60364-7-722 Section 722.443 clearly mentions the need for surge protection to prevent transient overvoltages during atmospheric influence or switching operations. This is ensured by using Type 2 or Type 2.5 SPD with protection level Up ≤ 1 kV, in compliance with IEC 61643-11 standard. This is clearly required for charging points in public facilities.

Selecting the suitable EV charger power SPD

Selecting the right power SPD for your EV charger is critical. Choosing the correct SPD and designing based on the specific needs of the EV charging station is very important. Protection schemes need to be customized according to the location and nature of the threat.

Based on IEC 61851-1 standard, the charging methods for electric vehicles are generally divided into four types. These different charging methods explain different installation types. Based on these modes, power SPD configurations may vary.

• EV charges directly from an AC power source through a conventional single-phase household socket.

• EV charges through a conventional single-phase household socket, with the charging cable including control and protective devices, known as In-Cable Control and Protection Device (ICCPD).

• EV charges through a permanently installed charging station, designed for either wall-mounted or station type, with a rated power > 4.6 kVA  which must be connected to a three-phase AC system.

• Electric vehicles are charged directly with DC. Charging cables are permanently connected to the charging station. Charging power starts from 24 kW  but is often higher (up to 350 kW) and is connected to the three-phase AC power source.

Solutions

For the first three charging methods, AC power SPD can ensure a high level of transient overvoltage protection for power supply lines at the building entrance, including overvoltage generated by direct lightning discharges.

To prevent Type 2 transient overvoltage, we recommend using the Techwin 400KA lightning protection box. Techwin can provide all the protection needed for a comprehensive protection concept, ensuring your charging station operates normally at any time and under any weather conditions.