NEW CONTROL STRATEGY FOR LLC RESONANT CONVERTER USED IN DISTRIBUTED POWER SYSTEM (DPS)

In the Power management of digital power systems, the advancements in VLSI technology have imposed major challenges such as power density and Hold up time requirement. So in this paper a better design and control Distributed Power System (DPS) is proposed. The DPS, a digital power system is tremandously used inserver applications. LLC resonant DC/DC converter was chosen as Front-end converter in DPS. In this paper, a new design technique of LLC resonant DC/DC converter using a proper selection of inductance ratio i.e. parallel to series resonant inductors (Lm/Lr), is proposed by carrying out simulation studies with MATLAB 10.0 and PSIM 6.0. A new control strategy called Pulse-Position Modulation (PPM) is introduced and proposed for LLC resonant DC/DC converter by carrying out simulation studies with PSIM 6.0 software tool. Finally, a prototype is developed for a design example of 12V, 5A output with an input voltage range of 300V to 400V was considered for the converter. A maximum output current of 5A DC with an efficiency of 94% was achieved