HARMONIC REDUCTION OF INPUT CURRENT OF BOOST-TYPE RECTIFIER USING SIGMA-DELTA MODULATION SCHEMES

초록

This paper presents Sigma-Delta Modulation (SDM) schemes as the powerful approach to achieve sinusoidal input current of a Boost-Type Rectifier (BTR). The dominant low-frequency harmonics of the input current in the BTR are eliminated by virtue of the switching pulse patterns of the SDM schemes which are configured by a long switching on-state duration of boost switcher at the starting of each half-cycle. The difference between the sinusoidal reference and real input current of the BTR is estimated at the starting of each half-cycle. The switching pulse patterns of the SDM schemes near input current zero crossing are compared with that of a fixed switching frequency PWM. The performances of the SDM schemes were validated on a 1.6kW BTR using computer simulations. The current THD values confirm that the BTR with the SDM schemes yield more sinusoidal input current than that with the fixed switching frequency PWM scheme