Study On A DSP-Based Control Strategy For Single-Phase Half-Bridge PFC Circuit

Reducing harmonic pollution especially conventional AC/DC rectifiergenerated and improving the power factor are hotspot in power electronicsfields. With the development of digital technique, more and more PFC controlalgorithms can be implemented in power electronics by the digital signalprocessors(DSP).Nowadays it is popular to use digital control in power supplydesign.Based on active power factor correction(APFC)of average current modecontrol, the paper introduce the design and implementation of a fully digitalcontrolled single-phase novel half-bridge power factor corrector. The controlmethod is realized using digital signal processor(DSP). At first, the basicworking principle of novel single-phase half-bridge is studied. The paperresearch small signal model of PFC circuit and build the simplified averagesmall signal model of the system. The double closeloop framework is appliedin the PFC control circuit and the PI algorithm is adopted. Based on simplifiedaverage small signal model, the paper develop design method of PI regulatorswhich are applied in double closeloop system. The hardware design andsoftware design are presented. Furthermore, the main program flow chart aregiven. At last, A power factor correction test system is introduced based onTMS320LF2407A. The whole system can achieve close to unity power factor,lower current harmonics and constant output voltage. Experimental resultsindicate the feasibility of control scheme and the validity of theory analysis.Anticipation is realized.