DC-DC Converter Analog Device Design Of Urban Rail

To the unbalanced distribution of teaching equipments for urban railway in highervocational schools which is the status quo, we came up with a device, with both high similarityto the DC-DC convertor on real railways and good human-computer interface. Electriclocomotive companies had never touched on this field yet. And traditional makers of teachingequipments still lack the ability to get into this field. If successfully designed, it will surelybecome a commonly used teaching equipment in all institutes of railways, and will bring greatconvenience to the training of maintainers of urban rail vehicle in our country. It will be of greatreference value to developing the auxiliary power supply system of Urban rail of our own. So, itgoes without saying how big the market prospective is. The idea of DC-DC convertor analogdevice of Urban rail derives mainly from the fast improvement of Urban rail transit industry andpower electronic technology.The DC-DC converter analog device in the auxiliary power supply system of Urban raildesigned in this task uses IGBT as the Power Switching Device. As it has higher switchingfrequency, it greatly reduced the volume of the Magnetic Materials. Also, the adaption of phaseshift control full bridge soft switching technology significantly lowered the switching loss andimproved the utilization rate of electrical energy. This project aims to summarize the formerexperience of study on DC-DC converter device and design a DC-DC converter device withbetter human-computer interface for urban railways.It uses peak current control mode, gets inductance current changes, feeds back to a closedloop current, IGBT, fast controlled and effectively reducing the volume and price of the outputfilter the inductance. The current and voltage is passed to control circuit by various sensors andrealize the isolation between the control circuit and power circuit. This topic uses PIC formonolithic processor of the system, that the cost performance of processor is higher, can meetthe requirements of the system. It realizes the PC and a machine communication through a serialport, uses the touchscreen of MCGS for the man-machine interface, so users can make more easyto see charging the input voltage, current, and the output voltage, current, etc. Driving circuituses the EXB841for drive chip, establishes the bridge connecting control circuit and powercircuit. Control circuit can’t direct role in high power circuit, first, the output power of controlcircuit is limited, can’t drive high power circuit; second, the voltage between control circuit andpower circuit often can’t match; third, the control circuit and high power must realize theelectrical isolation. Based on EXB841, it designs the driving circuit to solve the problem of the above.In the selection of components, this paper uses the method of calculation and simulation,uses method of the AP for designing transformer, uses some specific calculation to completeselection of high power devices such as rectifier bridge, filter capacitance fusion, etc.