AC: What does it mean?

An electric current that reverses direction at regular intervals.

AC: The long answer

Alternating Current (AC) in electric cars refers to the type of electrical current that reverses direction periodically. Unlike Direct Current (DC), where the electric charge flows in one order, the electric charge in an AC circuit changes direction periodically.

Here's how AC is utilised in electric cars:

AC Motors: Electric cars often use AC induction or synchronous motors. These motors are more efficient and can provide more torque over a wider range of speeds than DC motors.

Charging: Electric cars can be charged using both AC and DC charging methods.

AC Charging: This is the common method of charging at home or at public charging stations. The car's onboard charger converts the AC from the grid to the DC required to charge the battery.

DC Fast Charging: This method bypasses the car's onboard charger and provides DC directly to the battery, allowing for much faster charging. It's typically found at specialised fast-charging stations.

Inverter: Electric cars with AC motors require an inverter. The inverter converts the DC power from the battery into AC power to drive the electric motor. This conversion is necessary because the battery stores energy as DC, but the motor operates on AC. The inverter can also control the frequency of the AC, allowing precise control of the motor's speed and torque.

Regenerative Braking: Many electric cars also use regenerative braking, where the electric motor is used as a generator to convert the kinetic energy lost when braking into electricity. This electricity is then fed back into the battery. AC motors are particularly well-suited for regenerative braking, as they can efficiently convert mechanical energy back into electrical energy.