Research On Bridgeless Power Factor Correction Base On Direct Current Algorithm

With continuous innovation and advancement of power electronics and advancedcontrol technology, the electrical equipments with better performance are expected.Most traditional converters consist of rectifier-bridge for AC/DC function, and PFCaspects to limit the harmonics and improve the power factor and power utilization.However, the power consumption of the rectifier-bridge along with increased powerlevel will occupy a large proportion of total loss, and hinder the development ofhigh-power applications. Therefore under the circumstance of advocating clean use ofenergy, the application requirement of new PFC technology becomes very urgent. Asone kind of AC/DC conversion innovative technology, the bridgeless PFC can obtainbetter performance in the case of a bridgeless rectifier. It becomes an important symbolfor the implementation of "green power" and has profound significance for powerproducts.This paper expands the work around the bridgeless PFC technology, gives ahigh-performance improved bridgeless PFC structure, uses the direct current algorithmfor its theoretical discussion, and builds a bridgeless PFC prototype to realize thefront-level AC/DC function for communication power. At the same time, based on asingle-phase parallel style and the improved PFC, we propose a novel three-phasebridgeless PFC program applied in the three-phase high-power smart grid, and build asimulation platform for its theory research. The main work of this paper is:(1) We review the existing PFC topology and analyse the advantages anddisadvantages of each structure, as well as the PFC control technology.(2) We give a high-performance improved bridgeless PFC circuit, and utilize thedirect current algorithms to build theoretical platforms for their performance verification.According to the performance evaluation of test data, we select one-cycle controlmethod for a prototype based on the advantages and disadvantages of each algorithm.(3) Based on the above theory platform, we give the specific circuit design stepsand parameter selection in detail. We use the improved bridgeless PFC in the frontcircuit of communication power, and builds prototype hardware for experimental demonstration.(4) Adopted a single-phase parallel style and the improved bridgeless PFC, wepropose a novel three-phase bridgeless PFC program applied in the three-phasehigh-power smart grid, then analyse its working process and build a simulation model inorder to prove the program theoretically and research its performance.Through the comprehensive analysis and discussion of the theory and practice ofthe bridgeless PFC topology and control technology, the results fully demonstrates thatthe bridgeless PFC with good performance, which is of great significance, provides theapplication of the bridgeless PFC topology and control strategy with a reliabletheoretical and realistic foundation.