| Since the traditional rectifier produces large amount of harmonic current and reactivepower and has bad effect on the input current, it has become hot study in power electronicsthat how to eliminate harmonic pollution and improve power factor. The conventional rectifieris made up of diodes or SCRs, whose power factor is low, and current harmonic is large,energy utilization is low and it pollutes the power grid heavily. Therefore, it is very importantto improve the power factor. With the rapid development of power electronics, thesingle-phase Power Factor Correction(PFC) technology becomes more and more mature, butthe three-phase PFC technology which is suitable for high-power applications is still beingstudied. It is a hot research task during the recent decades.In this Dissertation, the theory of three-phase six-switch boost-PFC is introduced, themathematic model of the three-phase PFC in two-phase(dq coordinates) synchronizationCoordinates is reason out based on coordinates transform, active and reactive power can bedecoupled. Then the control system is designed with the theory, the model of the system isbuilt in MATLAB. In the end, a kind of three-phase 5kw rectifier with the function of powerfactor correction is designed based on TMS320F2812, as well as the detecting circuit andcontrol circuit are designed. The result of the experiment showed that the input currentwaveform is close to sine wave and followes the voltage’s. The power factor is close to 1.The research showed that the control strategy can realize the function of PFC, the circuitstructure is simple and convenient to control, and it is suitable for high-power applications. |
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