DEVICES AND METHODS FOR DECENTRALIZED VOLT/VAR CONTROL

• US 20130030598A1
• Filed: 07/26/2011
• Published: 01/31/2013
• Est. Priority Date: 07/26/2011
• Status: Active Grant

• Current Assignee: GE Digital Holdings LLC (GE Aerospace)
• Original Assignee: General Electric Company
• Inventors: Milosevic, Borka, Toit, Willem Hendrik Du, Vukojevic, Aleksandar
• Granted Patent: US 8,838,284 B2
• Time in Patent Office: Days
• US Class Current: 700/298
• CPC Class Codes: H02J 13/00002 characterised by monitoring
• CPC Class Codes: H02J 13/00034 the elements or equipment being or involving an electric power substation
• CPC Class Codes: H02J 3/16 by adjustment of reactive power
• CPC Class Codes: H02J 3/1821 using shunt compensators H02J3/1807, H02J3/1878 take precedence
• CPC Class Codes: H02J 3/1878 using tap changing or phase shifting transformers
• CPC Class Codes: Y02E 40/30 Reactive power compensation
• CPC Class Codes: Y02E 40/70 Smart grids as climate change mitigation technology in the energy generation sector
• CPC Class Codes: Y04S 10/22 Flexible AC transmission systems [FACTS] or power factor or reactive power compensating or correcting units
• CPC Class Codes: Y04S 10/30 State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge
• CPC Class Codes: Y04S 10/50 Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications

Abstract

Devices and methods for the decentralized, coordinated control of the voltage and active power losses of an electrical distribution system in light of one another are provided. For example, a controller may include a network interface and data processing circuitry. The network interface may receive first measurements associated with a segment of an electrical distribution system and transmit a control signal configured to control equipment of the segment of the electrical distribution system. The data processing circuitry may run simulations of the segment of the electrical distribution system in various equipment configurations, selecting from among the various configurations one that is expected to cause the voltage deviation and the active power losses of the segment to approach desired values while keeping power factor within a desired range. The data processing circuitry then may generate the control signal, which may cause the equipment of the segment of the electrical distribution system to conform to the equipment configuration.

Claims

1. A controller comprising:

a network interface configured to receive first measurements associated with a segment of an electrical distribution system and transmit a control signal configured to control equipment of the segment of the electrical distribution system; and

data processing circuitry configured to run first simulation of the segment of the electrical distribution system simulating various equipment configurations based at least in part on the first measurements, to select from among the various equipment configurations an equipment configuration that is expected to cause a voltage deviation of the segment of the electrical distribution system to approach a first desired value and active power losses of the segment of the electrical distribution system to approach a second desired value, and generate the control signal, wherein the control signal is configured to cause the equipment of the segment of the electrical distribution system to conform to the equipment configuration.

2. The controller of claim 1, wherein the control signal is configured to control the equipment of the segment of the electrical distribution system, wherein the equipment comprises at least one capacitor, and wherein the data processing circuitry is configured to run simulations of the segment of the electrical distribution system simulating various equipment configurations, wherein the various equipment configurations comprise various capacitor switching configurations, and wherein the data processing circuitry is configured to select from among the various capacitor switching configurations a capacitor switching configuration that is expected to cause the voltage deviation of the segment of the electrical distribution system to most closely approach the first desired value while the active power losses of the segment of the electrical distribution system most closely approach the second desired value.

3. The controller of claim 2, wherein the capacitor switching configuration indicates that a single one of a plurality of capacitors of the segment of the electrical distribution system is to be switched on or off.

4. The controller of claim 2, wherein the capacitor switching configuration indicates that a combination of a plurality of capacitors of the segment of the electrical distribution system are to be switched on or off.

5. The controller of claim 4, wherein the data processing circuitry is configured to determine a switching order of the combination of the plurality of capacitors.

6. The controller of claim 1, wherein the network interface is configured to obtain the first measurements from a plurality of remote terminal units, wherein the first measurements comprise:

a voltage magnitude at a low side bus of a substation of the segment of the electrical distribution system;

a voltage magnitude at capacitors of the segment of the electrical distribution system;

a voltage magnitude at low side of voltage regulators of the segment of the electrical distribution system;

tap positions of the voltage regulators;

real and reactive power flows at capacitors and at all junction points between the capacitors and the voltage regulators and the substation;

real and reactive power flows at a high side bus of the substation or real and reactive power flows from each feeder of the segment of the electrical distribution system, or both;

real and reactive demand from each industrial or commercial load, or industrial and commercial load between the substation and any of the capacitors; and

end of line voltages of the segment of the electrical distribution system or a voltage drop between a last measurement point and an end of a feeder.

7. The controller of claim 1, wherein the data processing circuitry is configured to determine a plurality of operational parameters of the segment of the electrical distribution that are expected to vary depending on the various equipment configurations, wherein the plurality of operational parameters comprises the voltage deviation over the segment of the electrical distribution system, the active power losses of the segment of the electrical distribution system, and a power factor on the segment of the electrical distribution system.

8. The controller of claim 7, wherein the data processing circuitry is configured to determine, after determining the equipment configuration that is expected to cause the voltage deviation of the segment of the electrical distribution system to approach the first desired value and expected to cause the active power losses of the segment of the electrical distribution system to approach the second desired value, a reduced supply voltage that is lower than a normal supply voltage to the segment of the electrical distribution system and that is not expected to result in a voltage violation when the equipment of the segment of the electrical distribution system conforms to the equipment configuration.

9. The controller of claim 7, wherein the data processing circuitry is configured to select the equipment configuration from among the various equipment configurations by:

selecting one or more first equipment configurations that are expected to cause the voltage deviation to most closely approach the first desired value while the active power losses most closely approaches the second desired value from among the various equipment configurations; and

selecting a final equipment configuration that is expected to cause a power factor to most closely approach a desired value from among the one or more first equipment configurations.

10. The controller of claim 1, wherein the data processing circuitry is configured to run second digital simulations of the segment of the electrical distribution system based at least in part on the selected equipment configuration before generating the control signal to determine whether the selected equipment configuration is expected to cause a voltage violation on the segment of the electrical distribution system and, when the selected equipment configuration is expected to cause the voltage violation, to determine a tap position for a voltage regulator of the segment of the electrical distribution system that is expected to prevent the voltage violation from occurring.

11. The controller of claim 1, wherein the network interface is configured to receive second measurements associated with the segment of the electrical distribution system a period of time after transmitting the control signal, wherein the second measurements reflect an actual effect of the equipment configuration on the segment of the electrical distribution system, and wherein the data processing circuitry is configured to determine whether the second measurements indicate a voltage violation and, when the second measurements indicate the voltage violation, to vary the equipment configuration to prevent the voltage violation.

12. The controller of claim 11, wherein the data processing circuitry is configured, when the second measurements indicate the voltage violation, to identify a voltage regulator of the segment of the electrical distribution system that is situated closest to a substation of the electrical distribution system, to calculate a lower or higher tap position associated with the voltage regulator that is expected to prevent the voltage violation and, when the tap position is not higher than a maximum tap position or lower than a minimum tap position, to cause the to cause the voltage regulator to assume the tap position and, when the tap position is higher than the maximum tap position or lower than the minimum tap position, to cause a switchable capacitor of the segment of the electrical distribution system that is located furthest from the substation of the electrical distribution system or that is the largest capacitor of the segment of the electrical distribution system to be switched on or off.

13. The controller of claim 1, wherein the data processing circuitry is configured, after transmitting the control signal, to cause one or more voltage regulators of the segment of the electrical distribution system to cause a high side voltage of the one or more voltage regulators to be approximately equal to a low side voltage of a substation that supplies voltage to the segment of the electrical distribution system.

14. A method for controlling first and second segments of an electrical distribution system while the first segment is providing power to a recovered portion of the second segment, using respective first and second application platforms, comprising:

running a Volt/VAR control function on the second segment using the second application platform, wherein the Volt/VAR control function is configured to cause a voltage deviation over the second segment to approach a first desired value and to cause active power losses of the second segment to approach a second desired value;

while the second application platform is running the Volt/VAR control function on the second segment, running a violation check function on the first segment using the first application platform, wherein the violation check function is configured to prevent or mitigate a voltage violation on the first segment; and

after running the Volt/VAR control function on the second segment using the second application platform, running the Volt/VAR control function on the first segment using the first application platform, wherein the Volt/VAR control function is configured to cause a voltage deviation of the first segment to approach the first desired value and to cause the active power losses of the first segment to approach the second desired value.

15. The method of claim 14, comprising communicating a minimum voltage of the second segment from the second application platform to the first application platform while the first application platform is running the violation check function on the first segment or while the first application platform is running the voltage control function on the first segment, or both.

16. The method of claim 14, comprising communicating from the second application platform to the first application platform an indication that the second application platform has finished running the voltage control function when the second application platform has finished running the voltage control function and communicating from the first application platform to the second application platform an indication that the first application platform has finished running the voltage control function when the first application platform has finished running the voltage control function.

17. The method of claim 14, comprising, while the first application platform is running the voltage control function on the first segment, running a violation check function on the second segment using the second application platform, wherein the violation check function is configured to prevent or mitigate a voltage violation on the second segment.

18. An article of manufacture comprising:

one or more tangible, machine-readable storage media having instructions encoded thereon for execution by a processor of an electronic device, the instructions comprising;

instructions to receive measurements associated with a feeder of an electrical distribution system;

instructions to simulate a distribution power flow of the feeder according to various capacitor switching configurations of at least one capacitor of the feeder using the measurements;

instructions to determine an expected voltage deviation, reduction in power loss, and power factor associated with the various capacitor switching configurations based at least in part on the simulated distribution power flow of the feeder;

instructions to select a non-dominated capacitor switching configuration from among the various capacitor switching configurations in which the voltage deviation most closely approaches a first desired value and the reduction in power loss most closely approaches a second desired value; and

instructions to control capacitors of the feeder according to the non-dominated capacitor switching configuration.

19. The article of manufacture of claim 18, wherein the instructions to simulate a distribution power flow of the feeder comprise instructions to simulate an effect of distributed generation on the feeder.

20. The article of manufacture of claim 18, comprising instructions to transmit at least one of the measurements to another electronic device associated with another feeder of the electrical distribution system.