Research On Series Resonant Technology Applied To Power Supplies For Telecommunication

Nowadays the technology of telecommunication power supply is gradually being perfect. However, there is no end to the demand for a smaller, more efficient power supply. Switching losses is prime factor limiting utilization of much higher switching frequency in PWM converter, so soft-switching technology has become the way forward for the telecommunication power supply.This thesis discusses some research focus of soft-switching technology and introduces three traditional resonant convert topologies. Based on this, it presents a novel soft switching LLC series resonant converter used for telecommunication rectifier. In resonant converter all switches are working on the ZVS and the secondary diodes are working on the ZCS, so we can achieve high efficiency .In order to realize soft-switching over the entire operating, magnetizing inductance is utilized to widen input range. Moreover, leakage inductance participate in resonance, we can effectively reduce EMI and secondary rectifier voltage stress.Based on the detailed analysis of the principle of LLC series resonant converter, a 50V/20A rectifier is manufactured. The result proves that efficiency can achieve 92.4%.