Research On Digital APFC Based On DSP

In recent years, power electronic devices have been widely used in all kinds of fields. However, it also causes negative problems, such as harmonic pollution in the grid and low power factor. Therefore, the power factor correction (PFC) technology has become an important research area. Compared with traditional analog PFC technology, digital control scheme needs fewer components and implements complex algorithms in a more flexible way and attracts wide attention of researchers. The development of digital control technology makes it possible to achieve the digital PFC.First, the background and development status of power factor correction are presented, and the prospect and necessity of developing digital PFC technology are pointed out. Moreover, deep analysis of topology structure, work mode and control strategy is performed, which provides a necessary theoretical foundation for feasible design of the system. Based on the theory, an average current mode control for power factor correction using Freescale’s digital signal controller MC56F8013is adopted in the dissertation.Secondly, the designs of both the system’s hardware and software are fulfilled. In the hardware design, device selection and parameters calculation and control loop design of MC56F8013are performed. In the hardware design, design concepts on functional blocks including soft start, voltage feed-forward and PI regulator are described in detail.Finally, the system simulation is performed by Matlab and the correctness of the principle and parameters design is verified. Furthermore, the arithmetic has been tested in a PFC prototype. The experiment result shows the prototype has good performance with high PF, low THD and high efficiency. All the indexes can meet the design requirements.