High performance, high efficiency switch mode DC/DC converters are widely used in electric cars in the automotive industry. They can convert the main battery’s voltage of some hundreds of volts into 12V direct current.12V voltage is widespread due to the fact that most devices and integrated circuits used in cars are designed to handle this kind of voltage.
As a member of BME Paradicsom team I designed a DC/DC converter with a rated power of 600W to supply for the auxiliary subsystems of the electric car made for the Shell ECO-marathon. Designing was carried out as part of my thesis.
In my thesis I describe the characteristics and the structure of the most frequently used isolated output switch mode power converters. The architecture I implemented will be introduced in greater detail. The sizing of the transformer, inductor and magnetic batteries will also be discussed. Furthermore, I calculated the dissipated power on the converter on the basis of which the power supply was sized in a way, due to thermal issues, to be capable of delivering its rated power in high ambient temperature. The converter and the wiring diagram of the circuit communicating with the other ECUs (Electronic Control Unit) on the CAN (Controller Area Network) bus and controlling the converter are also displayed along with the design of the printed circuit.