Week 4 Session 5
There are different types of power converters used in ev vehicles.
1) AC-AC convertes
2)AC-DC converters
3)DC-DC converters
4) DC-AC converters
DC-DC converters
convert unregulated dc input to regulated dc output. That is it convert a source of direct current dc from one voltage level to another by storing or relesing the energy.The amount of current flow between the input and output can controlled by adjusting the duty cycle. the most common dc-dc converters are
NON isolated converters; some of non isolated converters are buck,boost,buck boost
buck converter used for voltage step down
boost converter for step up the voltage .
buck boost converter used in both step up and step down the voltage.
Isolagted converters; its used in application where the output need to be completely isolated from input. In this type a high frequency transformer is used. half bridge,full bridge,fly back,forward converter are coming under this.
RESONANT converters; different family of dc converter ,used for high power conversion.
dc- dc converters delivering power to auxilary loads for operating. That is the auxilary load like light,horns needs less voltages so here dc-dc covert dc voltage to required level.
battery to charger station combability. if we are doing a dc charging from charging staion before battery storage dc-dc covertion will happen for required voltage level.
DC- AC CONVERTER (INVERTERS)
An inverter is a device that converts dc power from battery to ac power in electric vehivcle motor.it can control both magnitude and frequency of output voltage.widely seen in control of AC motors.used for converting dc to ac for at which motor required to run.for an ideal inverter wave form is sinsoidal for practical application its non sinsoidal. semiconductor power switches are used in these inverter.
AC-DC CONVERTER
Its used to convert AC power from grid into dc power that can be used to charge battery. this is widely seen in battery charging. AC-DC converter of an offboard charger is a rectifier before dc-dc convertsion. aC-DC converter has major role in charging time.