POWER FACTOR CORRECTION SYSTEM FOR POLYPHASE DISTRIBUTION NETWORK

摘要

An electric power generator system includes a switched capacitor controlled induction generator adapted to provide power at a regulated voltage and frequency. The induction generator system includes an n-phase induction machine having a rotatable input shaft and at least n output lines. The input shaft is driven at a controlled frequency by a prime mover. An N-stage, switched capacitor array provides a controlled reactive current to the output lines of the induction machine. Each stage of the array includes a capacitor network associated with each of the permutations of pairs of the n output lines. The capacitor networks for each stage are characterized by substantially the same capacitance. Each stage further includes an associated switch network associated with each capacitor network for selectively coupling the capacitor network across its associated pair of output lines. A feedback network is coupled between the output lines and the capacitor array to adaptively control the switching of the various N-stages in and out of operation. In grid-connected operation, the feedback network includes a power factor detector for producing a signal representative of the power factor at the output lines of the induction machine. The feedback network uses this power factor signal to control the switched capacitor array to adaptively vary that net capacitance across the output lines of the induction generator so that the generator presents a unity power factor to the grid.