High efficiency power factor correction using interleaving techniques

A highly efficient 1.5 kW power factor correction converter for computer applications is presented. Eight boost-topology switching cells are interleaved to meet stringent EMI input ripple specifications while operating at a very low switching frequency (25 kHz per cell) to minimize switching losses. The result is a system with very high conversion efficiency (94%-97%, including input bridge, bias supply, and EMI filter losses) over the 93-264 VAC input range. Key implementation details, including discontinuous inductor current operation, a combination of linear and bang-bang control algorithms for fast dynamic load response, and extended (100 ms) power outage ride-through capability, are described.<
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