Design and Development of 50w Multi-Output PWM Dc-Dc Converter Employing Magnetic Amplifier and Soft Switching Techniques

Abstract

The aim of this project is to design and develop multi-output DC-DC converter having 50 W output power for high speed digital sub-system to be used in various microwave remote sensing satellite missions. The major electronic circuits require different output voltages with current ratings associated with stringent output ripple and regulation requirements. Push-pull topology for SMPS design, an isolated PWM DC-DC converter topology is employed for this application. Since the main output is highly regulated due to the inherent circuit characteris- tics, the auxiliary output voltage regulation is the focus. For better output voltage regulation on auxiliary outputs, magnetic amplifier post regulators are incorporated as the conventional series pass regulators and other post regulators are inefficient for low voltage high current outputs. In conventional hard switching PWM DC-DC converters, switching losses in power switches are major concern for overall efficiency. By employing soft switching tech- niques these losses can be minimized, which results in an efficient converter particu- larly for the space borne subsystems where input power is limited. This report describes all design steps, detailed derivations of design equations, observed waveforms and efficiency results for 50W multi output push pull converter. This high efficiency converter can be used in different payloads for space applications.