System and method for operating a tap changer

1. A method of operating a tap changer of a transformer or a voltage regulator in a power grid comprising:

obtaining a load forecast for a time period;

determining an average voltage profile for the time period based on the load forecast;

estimating tap positions of the tap changer for leveling the average voltage profile during the time period; and

providing switching signal commands to the tap changer based on the estimated tap positions;

wherein determining the average voltage profile comprises determining an average of node voltages for a phase in a zone.

2. The method of claim 1 , wherein the load forecast comprises active and reactive power forecasts.

3. The method of claim 1 , wherein the time period comprises a time determined by an operator including an hour, a day or a week.

4. The method of claim 1 , wherein the zone comprises a network between two tap changers.

5. The method of claim 1 , wherein determining the average voltage profile comprises running a load flow algorithm on the load forecast.

6. The method of claim 1 , wherein leveling the average voltage profile comprises determining a flat voltage value for the time period.

7. The method of claim 6 , wherein tap positions are based on the average voltage profile, the flat voltage value and a voltage value per tap.

8. The method of claim 6 , wherein the flat voltage value comprises a predetermined voltage value.

9. The method of claim 8 , wherein the predetermined voltage value may be determined based on conservation voltage reduction factor.

10. The method of claim 6 , wherein the flat voltage value is determined to minimize tap position changes.

11. The method of claim 6 , wherein the flat voltage value comprises an average value or a median value of a minimum and a maximum voltages of the voltage profile.

12. A tap changer control system comprising:

a load forecasting module to determine a load forecast for a time period;

a load flow module to determine an average voltage profile for the time period of interest;

a tap position identification module to estimate tap positions of a tap changer of a transformer or a voltage regulator for leveling the average voltage profile; and

a switching circuitry to adjust taps of the tap changer based on the estimated tap positions;

wherein the average voltage profile comprises an average of node voltages for a phase in a zone.

13. The system of claim 12 , wherein the load forecast comprises active and reactive power forecasts.

14. The system of claim 12 , wherein the zone comprises a network between two tap changers.

15. The system of claim 12 , wherein the load flow module comprises a numerical method to obtain average voltages over the time period.

16. The system of claim 12 , wherein leveling the average voltage profile comprises determining a flat voltage value for the time period.

17. The method of claim 16 , wherein tap positions are based on the average voltage profile, the flat voltage value and a voltage value per tap.

18. A computer-readable medium comprising non-transitory computer-readable instructions that, when executed by a processor, cause the processor to perform a method of operating a tap changer of a transformer or a voltage regulator in a power grid, the method comprising:

obtaining a load forecast for a time period;

determining an average voltage profile for the time period based on the load forecast;

estimating tap positions of the tap changer for leveling the average voltage profile during the time period; and

providing switching signal commands to tap changer based on the estimated tap positions;

wherein determining the average voltage profile comprises determining an average of node voltages for a phase in a zone.