Influence of Weak Excitation Inductance on Full-bridge DC-DC Converter and Its Autonomous Soft-switching.

Switching power supply is now developing towards high-frequency soft-switching and high power density, the volume of magnetic components is greatly reduced, and the excitation inductance of transformer no longer meets the assumption of large excitation inductance in traditional analysis. Under this background, the influence of the weak excitation inductance on the full-bridge circuit was analyzed, and proposed that the full-bridge circuit can achieve autonomous soft-switching through the charging and discharging of the capacitor under the condition of the weak excitation inductance. The autonomous soft-switching of the full-bridge converter can be realized when the duty ratio is large. Through principle analysis and calculation, relationship between the charge and discharge of the switch body capacitance and the inductance current and the time constant was obtained, and the above principle through simulation were verified . Finally, an experimental platform with a working frequency of 200 kHz was built to verify the above analysis and simulation results. [ABSTRACT FROM AUTHOR]