Research And Implementation Of Vehicle-Borne Digital Switching Mode Power Supply

Energy saving, environmental protection and safety are main concern of modern automobiles. Because of more and more electrical equipment and load, using a new 42V vehicle-borne power supply system to replace the existing 14V power supply system will be inevitable. Vehicle-borne switching mode power supplies often use analog control way which has much shortcoming. It is very necessary to consider digital control way in order to improve the conversion performance. So theory and design of vehicle-borne switching mode power supply are researched.Boost DC/DC converter which uses analog controller L4981B is realized. Based on theoretical analysis of Boost DC/DC converter, a 24VDC-42VDC converter with maximum output power 1kW is made by using active PFC circuit board.Push-pull DC/DC converter and Boost DC/DC converter which use analog controller TL494 are realized. Based on theoretical analysis of push-pull converter, power circuit, control circuit, protection circuit and PCB are designed. Then it is made into a 24VDC-42VDC vehicle-borne switching mode power supply with maximum output power 500W and system efficiency 87%. This circuit board can also used to make a 24VDC-42VDC converter with maximum output power 1kW.Boost DC/DC converter and single-phase inverter which use digital controller TMS320F2808 and digital PI control are realized. Based on theoretical analysis of Boost DC/DC converter and single-phase inverter, power circuit, output voltage closed-loop control circuit, detection circuit, driving circuit, PCB and software are designed. Then it is made into a 24VDC-42VDC vehicle-borne digital switching mode power supply with rated output power 500W and system efficiency 86%. It also contains 24VDC-97VDC-330VDC and 42VDC-24VAC converter.