Week 4 Session 5
Applications of Power Converters in an Electric Vehicle
Power converters are used in EVs to manage and convert electrical power between different voltage and current levels for various components. Here are common EV components and the types of converters used:
1. Horn (Needs < 10V DC)
-
Type of Converter: DC-DC Buck Converter
-
Reason: Horn requires low-voltage DC (around 6V–10V), so a buck converter steps down from 12V/24V DC.
2. Headlights / Interior Lights
-
Type of Converter: DC-DC Buck Converter
-
Reason: These operate on 12V DC, while the main battery may be 300V–400V, so a converter is used to reduce voltage.
3. Electric Traction Motor
-
Type of Converter: DC-AC Inverter
-
Reason: Motor needs 3-phase AC supply from a DC battery (usually 300–400V), so inverter converts DC to AC.
4. Battery Charging (from AC supply)
-
Type of Converter: AC-DC Converter (Rectifier + Charger Circuit)
-
Reason: Converts grid AC power to DC for charging the battery.
5. Regenerative Braking System
-
Type of Converter: AC-DC Converter (Bi-directional)
-
Reason: Converts AC from motor (during braking) to DC to charge the battery.
6. Infotainment System / Sensors / ECU
-
Type of Converter: DC-DC Buck Converter
-
Reason: These systems need stable low voltage (5V, 3.3V), converted from 12V.
7. Cooling Fans / Pump Motors
-
Type of Converter: DC-DC Converter or Inverter
-
Reason: Depending on whether fans are DC or AC, converter type is chosen to run them from main battery.
8. Onboard Charger (OBC)
-
Type of Converter: AC-DC Converter + DC-DC Converter
-
Reason: First converts grid AC to DC, then steps it up or down to suitable charging voltage for the battery.
So, power converters are critical in EVs to ensure that every component gets the right voltage and current, improving safety, performance, and efficiency.