Week 4 Session 5

Power Converters inside Electric Vehicle:

     There has been 3 Types of Power converts used since years inside an electric vehicle.

1) DC - DC Converter : 

   DC-DC converters are mainly classified as shown below..

               Here, the Linear DC-DC converter uses sophisticated method of dissipating power across resistor in either series faishon & parallel. Definitely this kind of converters are not preferred inside an EV.

               The switching kind of converters are used 99.99% in all of the electric power conversion application along with EV.

                Buck Converter : 

               Buck converter is used inside the EV Power conversion module where the main traction battery gives supply to the Auxilaray or low voltage battery.In this converter the output voltage of the converter would be lesser than input voltage. Every part of EV which works on lesser voltage than traction voltage needed to be supplied by the buck converter. More the number of different voltage ( lesser than traction battery voltage ) will need the buck power converter.

                Boost Converter : 

               During the regenerative braking if the voltage induced in the braking operation is very less than it will be boosted up by mean of this converter & This boostd voltage will be supplied back to the main traction Battery.

                Buck boost converter : It will be used in the application where we are saving the space occuoied by the electronic circuitory & we want to have both buck & boost operation in the same circuit.

2) DC - AC Converter :

                DC to AC power converter also known as Inverter. It uses semiconductor switches to achieve its function. When the Electric vehicle uses Induction Motor or any other AC motor as a traction motor than we need AC power to feed in. This is achieved by mean of this converter. Here in the figure below they have first converted the Battery voltage into motor required voltage of DC level. Six switches shown forms an inverter which is also connected with load too.

AC to DC Converter :

     In the braking mode of an electric vehicle voltage induces across the terminals of the motor. If the motor is an AC motor than the voltage will be supplied back to the traction battery. but to do this essential conversion We need AC to DC conversion known as a rectifier.

     These are the main power converters inside an Electric vehicle.