Patent ID: 7504806

Claim:
An apparatus for controlling operation of a voltage regulator via a tap position change, the voltage regulator operatively coupled to a single-phase of a three-phase power system to regulate a measured voltage of the single-phase to an in-band area for delivery to a load, the apparatus comprising: a means for deriving a digitized voltage stream representative of the measured voltage of the single-phase; and a microcontroller operatively coupled to the means for deriving the digitized voltage stream and configured to enable the tap position change, the microcontroller having a microprocessor and a memory operatively coupled to the microprocessor, the microcontroller being programmed to: start a countdown time period of a first timer upon detecting a first excursion of the measured voltage from the in-band area to an out-of-band area, upon detecting a first return of the measured voltage to the in-band area, record a first elapsed time of the first timer, reset the first timer to the countdown time period, and start a second timer, upon detecting a second excursion of the measured voltage from the in-band area to the out-of-band area, record a second elapsed time of the second timer, compare the second elapsed time to a predetermined dip time period, if the second elapsed time is less than the predetermined dip time period, start an adjusted countdown time period of the first timer, and if the second elapsed time is more than the predetermined dip time period, start the countdown time period of the first timer upon subsequent entry of the measured voltage into the out-of-bound area.