Development Of Digital DC Power Supply Based On DSP

In this paper, a DC digital Power for laboratory is studied. which usesAPFC as the input stage, full-bridge converter as the main power conversiontopology,TMS320F28027which belongs to the C2000family ofmicrocontrollers as the master chip, and phase-shifted control based on peakcurrent mode as control strategy.In the paper, the input voltage of the power supply is220VAC, outputvoltage is adjust in1~300VDC. High power density, high efficiency andhigh power factor have always been the goal for what this paper selected thetopology and determined the control strategy, then designed and made theexperimental prototype of the converter by theoretical analyzing andcalculating.The paper selected power factor correction circuit based on BOOST asthe input stage (AC/DC). BOOST circuit is widely applied in the PFC.Given the favorable effect to power factor correction of it, the power factor ofthe experiment would be improved effectively and the harmonics would bereduced significantly to use it as the input stage. The full-bridge converter isselected as the main power (DC/DC) conversion topology because of lowvoltage stress. And the application of phase-shifted control strategy makes thetopology able to perform soft-switching, thus eliminating the limitation of the switching frequency and thereby increasing the power density of thepower supply. Peak current mode gives itself a priority while selecting thecontrol mechanism due to its inherent voltage feedforward, auto-by-cyclecurrent limiting flux balancing and other advantages. Therefore, thisexperiment adopted phase-shifted full-bridge based on peak current mode.The dynamic performance and steady performance of the converter areimproved by digital controller providing digital compensation.Based on the theoretical analysis, the paper manufactured aexperimental prototype. At last, the prototype is tested in detail and thetest waveforms is produced.