Multiple output SMPS with improved input power quality

Personal Computers (PC) and embedded system based control applications require power supplies with multiple outputs delivering stiffly regulated and isolated DC voltages at different levels such as ±5 V, +3.3 V and ± 12 V. At present, most of the commercially available multiple output Switched Mode Power Supplies (SMPS) use multiple number of DC-DC converters that increase the cost and complexity of the system and reduce reliability. In this work, the use of a single DC-DC converter for a multiple output SMPS is proposed and the employability of various DC-DC converters is investigated for a 175 W SMPS. Such an SMPS is designed, modeled and simulated in PSIM with different DC-DC converters such as flyback converter, forward converter, SEPIC and Cuk converter. The performance comparison of these DC-DC converters for a multiple output SMPS is brought out in terms of the output voltage regulation it can offer, response time, Total Harmonic Distortion (THD) of the input current and power factor at the single phase ac mains. The results highlight the merits and demerits of one converter configuration over the others for the SMPS application.