AC DC Energy Meters in EV Charger Piles Project in Spain

Electric vehicle charging current: What is the difference between AC and DC?

Electric cars can run on two types of "fuel." They are called alternating current (AC) and direct current (DC).

Electricity from the grid is always alternating current. However, batteries, such as those in your electric car, can only store electrical energy as direct current. This is why most electronic devices have built-in converters in their plugs. You may not realize that every time you charge a device like your smartphone, the plug actually converts alternating current to direct current.

There are two types of AC plugs:
Type 1 is a single-phase plug that is standard for electric vehicles in the United States and Asia. It allows you to charge your car at speeds of up to 7.4kW, depending on your car's charging power and grid capacity.
Type 2 is a three-phase plug, which is standard in Europe because they have three additional wires to let the current through. So naturally, they can charge your car faster. At home, the maximum charging power is 22 kW, while public charging stations can charge up to 43 kW, again depending on the charging power of your car and the capacity of the grid.

There are two types of DC plugs:
CHAdeMO: This fast charging system was developed in Japan and enables very high charging capacity and two-way charging. Currently, Asian automakers are leading the way in offering electric vehicles that are compatible with CHAdeMO plugs. It allows charging up to 100 kW.
CCS: The CCS plug is an enhanced version of the Type 2 plug with two additional power contacts for fast charging. It supports AC and DC charging. It allows charging at speeds of up to 350 kW.

There are four types plugs, two for AC (Type 1 and 2) and two for DC (CHAdeMo and CCS).

Type 1 is a single-phase plug commonly found in American vehicles. The charging speed can reach up to 7.4 kW.

Type 2 is a standard configuration for European and Asian vehicles since 2018, with a three-phase plug and maximum charging power can reach up to 43 kW.

CCS is a type 2 version with two additional power contacts. It allows for faster charging.

CHAdeMO can be found in Asian cars and allows for high charging capacity and bidirectional charging.

1. Power quality analyzer is configured in the total incoming circuit: the power quality of the entire charging pile power supply circuit is monitored, and the leakage current monitoring device is set.

2. The three-phase main circuit is configured with residual current relay: provides shock protection for indirect contact.

3. The three-phase AC circuit is configured with guideway energy meter: Since such charging pile consumes large power, it is used to measure total electric energy, and monitors the operating efficiency of the entire charging station with DC energy meter.

4. DC electric energy meter installed inside the DC charging pile: used to measure the energy used for charging electric vehicles.

5. Charge management controller: responsible for external man-machine interface, charge control, 485 reading DC energy meter power data, control DC charging output circuit breaker opening and closing.

6. DC charging pile insulation detection module.