Systems and methods for harmonic resonance control

• US 9,134,746 B2
• Filed: 12/06/2012
• Issued: 09/15/2015
• 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., Prasai, Anish
• Primary Examiner(s): DEBERADINIS, ROBERT L
• Application Number:
  US13/707,583
• Publication Number:
  US 20130173078A1
• Time in Patent Office: 1,013 Days
• Field of Search: 307/20
• US Class Current: 1/1
• CPC Class Codes: G05F 5/00 Systems for regulating electric variables by detecting deviations in the electric input to the system and thereby controlling a device within the system to obtain a regulated output
• CPC Class Codes: H02J 3/1864 wherein the stepless control of reactive power is obtained by at least one reactive element connected in series with a semiconductor switch
• CPC Class Codes: H02J 3/1878 using tap changing or phase shifting transformers
• CPC Class Codes: Y02E 40/10 Flexible AC transmission systems [FACTS]
• CPC Class Codes: Y02E 40/30 Reactive power compensation

Abstract

Systems and methods for harmonic resonance control are described. In some embodiments, a system comprises a first switch-controlled VAR source and a harmonic management block which may each be configured to be coupled to a distribution power network. The first switch-controlled VAR source may comprise a first processor, a voltage compensation component, and a switch. The first processor may be configured to enable the voltage compensation component after a delay by controlling the switch based on first proximate voltage after a duration associated with the delay to adjust voltage volt-ampere reactive. The harmonic management block may be configured to compare a second proximate voltage to at least one resonant threshold to detect potential resonance caused by enablement of the voltage compensation component and to engage based on the comparison the resonance compensation component to manage the potential resonance.

Claims

1. A system comprising:

a distribution power network;

a plurality of loads at or near an edge of the distribution power network, each of the plurality of loads configured to receive power from the distribution power network;

a plurality of shunt-connected, switch-controlled VAR source at the edge or near the edge of the distribution power network, each of the plurality of shunt-connected, switch-controlled VAR sources configured to detect a first proximate voltage at the edge or near the edge of the distribution power network, each of the plurality of shunt-connected, switch-controlled VAR sources comprising a first processor and a voltage compensation component, the processor configured to enable the shunt-connected, switch-controlled VAR source to determine, after a delay, whether to enable the VAR compensation component based on the first proximate voltage to adjust voltage volt-ampere reactive by controlling the VAR compensation component based on the determination; and

a plurality of harmonic management blocks coupled to the distribution power network, each harmonic management block comprising a resonance detection module and a resonance compensation component, each harmonic management block configured to compare a second proximate voltage to at least one resonant threshold to detect potential resonance caused by enablement of the voltage compensation component of at least one of the plurality of shunt-connected, switch-controlled VAR sources, and to engage based on the comparison the resonance compensation component to manage the potential resonance.

2. The system of claim 1, wherein the resonance detection module comprises an inductor and a zener diode.

3. The system of claim 2, wherein the resonance threshold is the break down voltage of the zener diode.

4. The system of claim 2, wherein the resonance compensation component comprises a transistor and a resistor, the transistor closing based on a comparison of voltage across the inductor to the resonance threshold to engage the resistor and dampen the potential resonance.

5. The system of claim 1, wherein the resonance detection module comprises a transformer and an inverter.

6. The system of claim 5, wherein the resonance compensation component comprises at least one capacitor and wherein the inverter with the at least one capacitor is configured to synthesize harmonic voltages in anti-phase to cancel potential resonance.

7. The system of claim 1, wherein the resonance detection module comprises an inductor and an LED.

8. The system of claim 7, wherein the resonance compensation component comprises a processor configured to enable or disable the VAR compensation component of at least one of the shunt-connected, switch-controlled VAR sources based on light from the LED.

9. A system comprising:

a distribution power network;

a plurality of loads at or near an edge of the distribution power network, each of the plurality of loads configured to receive power from the distribution power network;

a plurality of shunt-connected, switch-controlled VAR source at the edge or near the edge of the distribution power network, each of the plurality of shunt-connected, switch-controlled VAR sources configured to detect a first proximate voltage at the edge or near the edge of the distribution power network, each of the plurality of shunt-connected, switch-controlled VAR sources comprising a first processor and a voltage compensation component, the processor configured to enable the shunt-connected, switch-controlled VAR source to determine, after a delay, whether to enable the VAR compensation component based on the first proximate voltage to adjust voltage volt-ampere reactive by controlling the VAR compensation component based on the determination; and

a plurality of means for managing potential resonance, the plurality of means coupled to the distribution power network, each of the plurality of means comprising a resonance detection module and a resonance compensation component, each of the plurality of means configured to compare a second proximate voltage to at least one resonant threshold to detect potential resonance caused by enablement of the voltage compensation component of at least one of the plurality of shunt-connected, switch-controlled VAR sources, and to engage based on the comparison the resonance compensation component to manage the potential resonance.

10. A system comprising:

a first switch-controlled VAR source configured to be coupled to a distribution power network, the first switch-controlled VAR source comprising a first processor, a voltage compensation component, and a switch, the first processor configured to enable the voltage compensation component after a delay by controlling the switch based on first proximate voltage after a duration associated with the delay to adjust voltage volt-ampere reactive; and

a harmonic management block configured to be coupled to the distribution power network, the harmonic management block comprising a resonance detection module and a resonance compensation component, the harmonic management block configured to compare a second proximate voltage to at least one resonant threshold to detect potential resonance caused by enablement of the voltage compensation component and to engage based on the comparison the resonance compensation component to manage the potential resonance.

11. The system of claim 10, wherein the resonance detection module comprises an inductor and a zener diode.

12. The system of claim 11, wherein the resonance threshold is the break down voltage of the zener diode.

13. The system of claim 11, wherein the resonance compensation component comprises a transistor and a resistor, the transistor closing based on a comparison of voltage across the inductor to the resonance threshold to engage the resistor and dampen the potential resonance.

14. The system of claim 10, wherein the resonance detection module comprises a transformer and an inverter.

15. The system of claim 14, wherein the resonance compensation component comprises at least one capacitor and wherein the inverter with the at least one capacitor is configured to synthesize harmonic voltages in anti-phase to cancel potential resonance.

16. The system of claim 10, wherein the resonance detection module comprises an inductor and an LED.

17. The system of claim 16, wherein the resonance compensation component comprises a processor configured to enable or disable the VAR compensation component of at least one of the shunt-connected, switch-controlled VAR sources based on light from the LED.

18. A system comprising:

a first switch-controlled VAR source configured to be coupled to a distribution power network, the first switch-controlled VAR source comprising a first processor, a voltage compensation component, and a switch, the first processor configured to enable the voltage compensation component after a delay by controlling the switch based on first proximate voltage after a duration associated with the delay to adjust voltage volt-ampere reactive; and

a harmonic management block configured to be coupled to the distribution power network, the harmonic management block comprising a means for detecting resonance and a means for compensation of resonance, the means for detecting resonance configured to compare a second proximate voltage to at least one resonant threshold to detect potential resonance caused by enablement of the voltage compensation component and the means for compensation of resonance configured to manage the potential resonance based on the comparison.

19. A method comprising:

installing a first switch-controlled VAR source configured to a distribution power network, the first switch-controlled VAR source comprising a first processor, a voltage compensation component, and a switch, the first processor configured to enable the voltage compensation component after a delay by controlling the switch based on first proximate voltage after a duration associated with the delay to adjust voltage volt-ampere reactive; and

installing a harmonic management block configured to the distribution power network, the harmonic management block comprising a resonance detection module and a resonance compensation component, the harmonic management block configured to compare a second proximate voltage to at least one resonant threshold to detect potential resonance caused by enablement of the voltage compensation component and to engage based on the comparison the resonance compensation component to manage the potential resonance.