Systems and methods for switch-controlled VAR sources coupled to a power grid

• US 9,104,184 B2
• Filed: 12/06/2012
• Issued: 08/11/2015
• Est. Priority Date: 09/16/2011
• Status: Active Grant

• Current Assignee: Sentient Energy Technology LLC
• Original Assignee: Varentec Incorporated (KOCH Industries Incorporated)
• Inventors: Divan, Deepakraj M., Chen, Hao, Prasai, Anish
• Primary Examiner(s): Shechtman, Sean
• Application Number:
  US13/707,560
• Publication Number:
  US 20130138260A1
• Time in Patent Office: 978 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G05B 13/02 electric
• CPC Class Codes: H02J 3/16 by adjustment of reactive power
• CPC Class Codes: H02J 3/1842 wherein at least one reactive element is actively controlled by a bridge converter, e.g. active filters
• CPC Class Codes: H02J 3/1871 Methods for planning installation of shunt reactive power compensators
• CPC Class Codes: Y02E 40/20 Active power filtering [APF]
• CPC Class Codes: Y02E 40/30 Reactive power compensation

Abstract

Systems and methods for switch-controlled VAR sources coupled to a power grid are described. In some embodiments, a system comprises a distribution power network coupled to a first switch-controlled VAR source. The first switch-controlled VAR source may comprise a processor, a voltage compensation component, and a switch. The first switch-controlled VAR source may be configured to obtain a first delay value, monitor a first proximate voltage, initiate a first delay duration based on the comparison of the first proximate voltage to at least one set point, the first delay duration being based on the first delay value, determine, with the processor, after the first delay duration, whether to connect the voltage compensation component based on the monitored voltage, and control, based on the determination, the switch to connect the voltage compensation component to adjust a network voltage or a network voltage component.

Claims

1. A system comprising:

a distribution power network;

a first switch-controlled VAR source coupled to the distribution power network, the first switch-controlled VAR source comprising a processor, a voltage compensation component, and a switch, the first switch-controlled VAR source configured to

obtain a first delay value that is different from another delay value of another switch-controlled VAR source coupled to the distribution power network,

monitor a first proximate voltage of the distribution power network, the first proximate voltage being proximate to the first switch-controlled VAR source,

initiate a first delay duration based on the comparison of the first proximate voltage to at least one set point, the first delay duration being based on the first delay value,

determine, with the processor, after the first delay duration, whether to connect the voltage compensation component based on the monitored voltage, the monitored voltage being possibly changed by the other switch-controlled VAR source, and

control, based on the determination, the switch to connect the voltage compensation component to adjust a network voltage or a network voltage component associated with the distribution power network.

2. The system of claim 1, wherein the first switch-controlled VAR source configured to obtain the first delay value comprises the switch-controlled VAR source configured to generate the first delay value.

3. The system of claim 1, wherein the switch-controlled VAR source configured to generate the first delay value comprises the switch-controlled VAR source configured to generate the first delay value with a randomizer.

4. The system of claim 1, wherein the first switch-controlled VAR source configured to obtain the first delay value comprises the first switch-controlled VAR source receiving, via a communication interface of the switch-controlled VAR source, the first delay value.

5. The system of claim 1, wherein the first switch-controlled VAR source configured to obtain the first delay value comprises a memory of the first switch-controlled VAR source configured to store the first delay value, the memory being accessible by the processor.

6. The system of claim 1, wherein the first switch-controlled VAR source configured to control, based on the determination, the switch to connect the voltage compensation component to adjust the network voltage or the network voltage component associated with the distribution power network comprises the first switch-controlled VAR source configured to control, based on the determination, the switch to connect the voltage compensation component to adjust real power, reactive power, or both real and reactive power.

7. The system of claim 1, further comprising a second switch-controlled VAR source coupled to the distribution power network, the second switch-controlled VAR source configured to obtain a second delay value that is different from the first delay value, monitor a second proximate voltage of the distribution power network, the second proximate voltage being proximate to the second switch-controlled VAR source, initiate a second delay duration based on the comparison of the second proximate voltage to at least one set point, the second delay duration being based on the second delay value, determine, by a processor of the second switch-controlled VAR source, after the second delay duration, whether to connect a voltage compensation component of the second switch-controlled VAR source based on the monitored second proximate voltage, the monitored second proximate voltage being changed by the first switch-controlled VAR source before the end of the second delay duration, and control, based on the determination, a switch of the second switch-controlled VAR source to connect the voltage compensation component of the second switch-controlled VAR source to adjust a network voltage or a network voltage component associated with the distribution power network.

8. The system of claim 1, further comprising a second switch-controlled VAR source coupled to the distribution power network, the second switch-controlled VAR source configured to obtain a second delay value that is different from the first delay value, monitor a second proximate voltage of the distribution power network, the second proximate voltage being proximate to the second switch-controlled VAR source, initiate a second delay duration based on the comparison of the second proximate voltage to at least one set point, the second delay duration being based on the second delay value, and determine, by a processor of the second switch-controlled VAR source, after the second delay duration, to not connect a voltage compensation component of the second switch-controlled VAR source based on the monitored second proximate voltage, the monitored second proximate voltage being changed by the first switch-controlled VAR source before the end of the second delay duration.

9. The system of claim 1, wherein the first switch-controlled VAR source is further configured to obtain a different delay value that is longer than the first delay value after control of the switch.

10. The system of claim 1, wherein the switch comprises a semiconductor switch in series with an NTC or resistor, and wherein the semiconductor switch in series with the NTC or resistor is in parallel with a relay.

11. A method comprising:

obtaining, by a first switch-controlled VAR source coupled to a distribution power network, a first delay value that is different from another delay value of another switch-controlled VAR source coupled to the distribution power network;

monitoring a first proximate voltage of the distribution power network, the first proximate voltage being proximate to the first switch-controlled VAR source;

initiating a first delay duration based on the comparison of the first proximate voltage to at least one set point, the first delay duration being based on the first delay value;

determining, with a processor of the first switch-controlled VAR source, after the first delay duration, whether to connect a voltage compensation component of the first switch-controlled VAR source based on the monitored voltage, the monitored voltage being possibly changed by the other switch-controlled VAR source; and

controlling, based on the determination, a switch of the first switch-controlled VAR source to connect the voltage compensation component to adjust a network voltage or a network voltage component associated with the distribution power network.

12. The method of claim 11, wherein obtaining the first delay value comprises generating the first delay value.

13. The method of claim 11, wherein obtaining the first delay value comprises generating the first delay value with a randomizer.

14. The method of claim 11, wherein obtaining the first delay value comprises receiving, via a communication interface of the first switch-controlled VAR source, the first delay value.

15. The method of claim 11, wherein obtaining the first delay value comprises a memory of the first switch-controlled VAR source receiving the first delay value, the memory being accessible by the processor.

16. The method of claim 11, wherein controlling, based on the determination, the switch of the first switch-controlled VAR source to connect the voltage compensation component to adjust the network voltage or the network voltage component associated with the distribution power network comprises controlling, based on the determination, the switch of the first switch-controlled VAR source to connect the voltage compensation component to adjust real power, reactive power, or both real and reactive power.

17. The method of claim 11, further comprising, obtaining, by a second switch-controlled VAR source coupled to the distribution power network, a second delay value that is different from the first delay value, monitoring a second proximate voltage of the distribution power network, the second proximate voltage being proximate to the second switch-controlled VAR source, initiating a second delay duration based on the comparison of the second proximate voltage to at least one set point, the second delay duration being based on the second delay value, determining, by a processor of the second switch-controlled VAR source, after the second delay duration, whether to connect a voltage compensation component of the second switch-controlled VAR source based on the monitored second proximate voltage, the monitored second proximate voltage being changed by the first switch-controlled VAR source before the end of the second delay duration, and controlling, based on the determination, a switch of the second switch-controlled VAR source to connect the voltage compensation component of the second switch-controlled VAR source to adjust a network voltage or a network voltage component associated with the distribution power network.

18. The method of claim 11, further comprising obtaining, by a second switch-controlled VAR source coupled to the distribution power network, a second delay value that is different from the first delay value, monitoring a second proximate voltage of the distribution power network, the second proximate voltage being proximate to the second switch-controlled VAR source, initiating a second delay duration based on the comparison of the second proximate voltage to at least one set point, the second delay duration being based on the second delay value, and determining, by a processor of the second switch-controlled VAR source, after the second delay duration, to not connect a voltage compensation component of the second switch-controlled VAR source based on the monitored second proximate voltage, the monitored second proximate voltage being changed by the first switch-controlled VAR source before the end of the second delay duration.

19. The method of claim 11, further comprising obtaining a different delay value that is longer than the first delay value after controlling the switch.

20. The method of claim 11, wherein the switch comprises a semiconductor switch in series with an NTC or resistor, and wherein the semiconductor switch in series with the NTC or resistor is in parallel with a relay.

21. A non-transitory computer readable medium comprising instructions executable by a processor for performing a method, the method comprising:

obtaining, by a first switch-controlled VAR source coupled to a distribution power network, a first delay value that is different from another delay value of another switch-controlled VAR source coupled to the distribution power network;

monitoring a first proximate voltage of the distribution power network, the first proximate voltage being proximate to the first switch-controlled VAR source;

initiating a first delay duration based on the comparison of the first proximate voltage to at least one set point, the first delay duration being based on the first delay value;

determining, with a processor of the first switch-controlled VAR source, after the first delay duration, whether to connect a voltage compensation component of the first switch-controlled VAR source based on the monitored voltage, the monitored voltage being possibly changed by the other switch-controlled VAR source; and

controlling, based on the determination, a switch of the first switch-controlled VAR source to connect the voltage compensation component to adjust a network voltage or a network voltage component associated with the distribution power network.