Design And Simulation Of Soft Switching Power Supply

The technology of soft switching power supply is a hot issue in power supply research field in recent years. Firstly in this thesis, the reason of turn-on loss and turn-off loss are analysed, then it is pointed out that soft switching mode is an effective method to reduce the loss. In another hand, present author makes analysis of the soft switching topology and choosed the full-bridge converter to use. Furthermore, the author studied the control strategy for the full-bridge converter. As a result, zero-voltage and zero-current switching strategy is chosen. In detail, the author analysed how to realize the soft-switch in theory and study the problem of loss of pulse width, reset of the current and so on.There is complicated relation between power and electronics in device of switching power supply. As we do research on it in the traditional experimental way, much manpower, finance source and time are consumed, but there are many hard problems left to be resolved. Espically for the soft-switching power supply, there are several modes in one work cycle and working state of switching device is influenced by so many terms and conditions. So it requires more advanced research means. If we research the switching power supply by computer simulation, different method and performance of the system can be compared rapidly, problems can be found soon and improved in time. All of these advantages raise the quality of design and reduce the cost of design.Present author use PSPICE software to simulate and analyse the soft switching converter and certify the workability of it. MATLAB software is used to simulate the control system. Open loop model was simulated in the first step, then based on the result, taking the require of system stability and dynamic performance into account, low frequency section is adjusted by PI unit and middle frequency section is adjusted by advanced unit. After that, the performance of system agreed with the requirement.