Third Harmonic Compensation in a Single-Phase H-bridge PFC

This paper presents a harmonic compensation method, which can be used to significantly reduce lowe-rorder harmonics in the grid-side current of single phase power factor correction (PFC) circuits. Often there are limitations on the percentage of lower-order harmonics in the grid currents to maintain conducted EMI standard, which may be violated, especially during light load conditions. The proposed harmonic compensation technique can reduce the amount of these lower-order harmonics, thus leading to an improvement in the line current total harmonic distortion (THD). H-Bridge based boost topology is a popular choice for single-phase PFCs because of its simple control and high performance. An experimental prototype of 600W is developed to validate the proposed harmonic compensation technique. THD improvement from 7% to 5% at lighter load with 97% full-load efficiency are observed from the experimental results.