■Difference between normal charging and rapid charging for electric vehicles
We will explain the difference between normal charging and rapid charging for electric vehicles.
<Normal charging (AC charging)>
For normal charging, a 200V alternating current obtained from an electric wire is connected to the vehicle via a household power source.
Therefore, it is also called AC charging.
Outputs include 3kW and 6kW. The vehicle has a built-in AC-DC converter, which boosts the voltage to the battery's output voltage level and converts it to direct current to charge the lithium-ion battery.
The AC-DC converter built into the vehicle is called an OBC (On Board Charger).
<Quick Charging (DC Charging)>
For quick charging, the power source is the same as for normal charging, 200V AC current obtained from an electric wire, but large-scale equipment is required to obtain high output.
As a result, quick charging cannot be done on the vehicle, so the DC current boosted by external equipment is supplied directly to the battery. The contents of a quick charger are as follows: AC⇒DC⇒DC⇒AC⇒AC⇒DC conversion is performed to generate a DC voltage and supply it to the vehicle.
Since a DC current is supplied to the vehicle, it is also called DC charging. There are also equipment with an output of 50kW and 100kW or more.
■Differences in charging connectors
Charging methods are different in Japan, Europe, and the United States.
<Japanese charging connector>
The charging method in Japan is divided into normal charging and quick charging. This quick charging method is called CHAdeMo. The communication standard used is CAN.
<American charging connector>
In the United States, there is a type of charging connector that combines normal charging and quick charging, which is called COMBO1 (CCS:Combined Charging System).
The communication standard used is PLC.
In addition to the above methods, there is a charging method developed by Tesla called NACS (North American Charging Standard). Initially, it was a method exclusive to Tesla cars, but Tesla made the standard public.
As a result, Japanese manufacturers such as Nissan announced that they would adopt this method. The characteristic of this method is that the DC terminal and AC terminal are common, and it has a simpler structure than other methods.
<European charging connector>
In Europe, the charging connector shape also combines normal charging and quick charging, and is called COMBO2.
The difference from COMBO1 is that AC charging supports three-phase AC, so it is possible to charge at a high output.