A study of DC48V power supply system utilizing 6-pulse rectified active DCL and resonant converter

This paper proposes a DC48V power supply system utilizing a new 6-pulse rectified active DCL and resonant DC/DC converter. The efficiency of the rectifier unit is estimated 98.4% with a load of 5 kW. The estimation of losses in a three-phase diode bridge rectifier and the active DCL is 1.02% and 0.54% respectively. The estimated efficiency of the DC/DC converter is 95%. Consequently the total estimated efficiency of the system is 93.5%. The total harmonic distortion ( THD ) of input current is 78.9% in use of the three-phase diode bridge rectifier only. Utilizing the active DCL, the THD is improved to 29.4 % by mitigating of 5th and 7th harmonic components up to one-fifth and one-half respectively. By the rectifier unit, this system satisfies the requirements for class A equipment of Japanese guideline for reduction of harmonic emission, which are applied during tentative period for three-phase 200 V equipment. The weight of the DC48V power supply system is one-half of that utilizing an 18-pulse transformer and the two three-phase diode bridge rectifiers which we proposed at INTELEC´02. The size of the system is improved by removing the 18-pulse transformer and the two three-phase diode bridges. This novel DC48V power supply system utilizing 6-pulse rectified active DCL realizes a low cost and high efficient power supply system for telecommunication and data communications.