Patent ID: 8134346

Claim:
A power factor correction system, comprising: a power factor correction controller, the power factor correction controller comprising: a capacitor bank, comprising a plurality of capacitors; and a power factor correction circuit coupled to the capacitor bank for determining an existing power factor of a load and for selectively coupling one or more of the plurality of capacitors in parallel with the load to adjust the power factor towards unity, the power factor correction circuit comprising: a signal conditioning circuit coupled across a first and second alternating current incoming power lines, the signal monitoring circuit to sense a voltage signal supplied to a load by the first and second alternating current power lines and to sense a load current signal drawn by the load; an analog to digital conversion circuit coupled to the signal monitoring circuit, the analog to digital conversion circuit to receive the sensed voltage signal and the sensed current signal and to generate a digital pulse representative of the zero-crossing of the voltage signal and the current signal; a digital signal processing and communications circuit coupled to the analog to digital conversion circuit, the digital signal processing and communications circuit to receive the digital pulse representative of the zero-crossing of the voltage signal and the current signal, to determine a phase angle representative of an existing power factor of the load and to compare the existing power factor of the load to a preset threshold phase angle to determine if the existing power factor is leading or lagging; and a capacitor switching circuit coupled to the digital signal processing and communications circuit and to the capacitor bank, the capacitor switching circuit to selectively couple one or more of the plurality of capacitors in the capacitor bank to be in parallel with the load to adjust the power factor of the load towards unity; and a watt-hour meter adapter electrically coupled to the power factor correction controller.