Development and field testing of a closed-loop adaptive power factor controller

A continuing effort to develop an effective, reliable, and inexpensive adaptive power factor controller (APFC) is reported. The APFC can adaptively compensate the reactive power of rapidly varying loads without adding harmonics or transients to the power system. Previously, an open-loop APFC, sized at 50 kVAr, has been built and installed at a field site in Southern California Edison territory. Based on thousands of hours of field operation, the APFC has been substantially modified to improve its reliability and effectiveness. The new design is called CL-APFC. It has a number of features that makes it more suitable for harsh environment, such as voltage fluctuations, voltage harmonics, and component failures. The latest design of a closed-loop APFC, sized at 300 kVAr, is reported, and the results of the field tests are demonstrated.<
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