Multiple output SMPS with improved input power quality
ABSTRACT 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.
Conference Proceeding: Input current shaping and regulation of multiple outputs in a single isolated converter[show abstract] [hide abstract]
ABSTRACT: Input current shaping and wide bandwidth regulation of multiple outputs is demonstrated in a single power stage. These isolated capacitive idling converters, when operated in discontinuous inductor current mode (DICM) on the primary side, perform the input current shaping automatically, i.e. without the input current feedback loop. Consequently, the high power factor performance is obtained without any penalty in complexity, cost and efficiency of the converter. Moreover, due to the internal energy storage and presence of one secondary-side active switch for each output, the capacitive idling converters provide full regulation and short-circuit protection of all outputs, and eliminate the need to cross isolation barrier in the feedback pathTelecommunications Energy Conference, INTELEC '93. 15th International; 10/1993
Conference Proceeding: Design of a simple high-power-factor rectifier based on the flyback converter[show abstract] [hide abstract]
ABSTRACT: An equivalent circuit model for the discontinuous conduction mode flyback converter based on the loss-free resistor concept is presented. This simple model correctly describes the basic power processing properties of the converter, including input port resistor emulation, output port power source characteristics, and control characteristics. Based on this model, steady-state design equations are described and are used in a design example. Design of the slow output voltage feedback loop is also considered. A small-signal AC model is developed for both the resistive load and the DC-DC converter-voltage regulator load cases. In addition, a simple first-order approximation for the line current distortion and phase shift caused by 120 Hz duty cycle variations is derivedApplied Power Electronics Conference and Exposition, 1990. APEC '90, Conference Proceedings 1990., Fifth Annual; 04/1990
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ABSTRACT: The recently introduced new optimum topology dc-to-dc converter is extended in a simple and elegant manner to provide dc isolation and multiple outputs. In comparison with the single-transistor isolated forward and flyback converters operated under the same conditions, the single-transistor isolated new converter is shown to have equal or lower stress levels on the transistor, diode, and capacitor ripple current, and can utilize an isolation transformer with lower core and copper losses. Measurements of cross- and self-regulation properties of a two-output 45 W test converter are presented.01/1978; -1:256-264.