Power compensation apparatus and method of controlling the same

Patent metadata

Field	Value
Publication number	US-9979194-B2
Application number	US-201715684808-A
Country	US
Kind code	B2
Filing date	Aug 23, 2017
Priority date	Sep 22, 2016
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A power compensation apparatus compensates for power of a power system to be allowed to transmit from at least one or more power sources to a load. The power compensation apparatus includes a first system connected to the power system to compensate for active power and reactive power of the power system, a second system connected to the first system to store power necessary for compensating for active power and reactive power, and a third system connected to the second system to generate the power to be stored in the second system.

First claim

What is claimed is:

1. A power compensation apparatus for compensating for power of a power system to be allowed to transmit from at least one or more power sources to a load, the power compensation apparatus comprising:
a first system connected to the power system to compensate for active power and reactive power of the power system;
a second system connected to the first system to store power necessary for compensating for active power and reactive power; and
a third system connected to the second system to generate power to be stored in the second system,
wherein the first system includes:
a converter connected to the power system to convert power;
a capacitor connected to the converter and charged with active power of the power system or the power of the second system; and
a first controller configured to control the converter and the capacitor.

2. The power compensation apparatus according to claim 1 , wherein the first system further includes:
a first switch element between the converter and the capacitor;
a second switch element between the capacitor and the second system; and
a third switch element between the converter and the second system.

3. The power compensation apparatus according to claim 1 , wherein the second system includes:
a power storage apparatus configured to store active power of the power system or the power generated by the third system; and
a second controller configured to perform data communication with the first system and to control the power storage apparatus.

4. The power compensation apparatus according to claim 3 , wherein the third system includes a renewable energy source configured to generate power to be transmitted to the second system.

5. The power compensation apparatus according to claim 4 , wherein the first controller:
determines whether reactive power is compensated for based on a voltage of the power system, and
controls the converter to supply reactive power to the power system or to absorb reactive power from the power system.

6. The power compensation apparatus according to claim 4 , wherein the first controller checks a charge amount of the capacitor and charges the capacitor with power stored in the power storage apparatus if the charge amount of the capacitor is insufficient.

7. The power compensation apparatus according to claim 4 , wherein the first controller:
determines whether active power and reactive power are compensated for based on a frequency of the power system, and
controls the converter to supply active power and reactive power to the power system or to absorb active power and reactive power from the power system.

8. The power compensation apparatus according to claim 7 , wherein the first controller controls the converter to supply power stored in the capacitor as active power to the power system when active power is supplied.

9. The power compensation apparatus according to claim 8 , wherein the first controller controls the second system to supply power stored in the power storage apparatus as active power to the power system, if the charge amount of the capacitor is insufficient.

10. The power compensation apparatus according to claim 9 , wherein the second controller controls the third system to receive power generated by the renewable energy source and to store the received power in the power storage apparatus, if the amount of power stored in the power storage apparatus is insufficient.

11. The power compensation apparatus according to claim 7 , wherein the first controller controls the converter to charge the capacitor with active power of the power system, when active power is absorbed.

12. The power compensation apparatus according to claim 11 , wherein the first controller controls the second system to store active power of the power system in the power storage apparatus, if the capacitor is fully charged.

13. The power compensation apparatus according to claim 12 , wherein the second controller controls the third system such that the third system does not transmit power, if the third system transmits power.

14. The power compensation apparatus according to claim 12 , wherein the first controller performs control to stop absorption of active power of the power system if the frequency of the power system is within a stable range.

15. A power compensation apparatus for compensating for power of a power system to be allowed to transmit from at least one or more power sources to a load, the power compensation apparatus comprising:
a first system connected to the power system to compensate for active power and reactive power of the power system and to store power necessary for compensating for active power and reactive power; and
a second system connected to the first system to generate power to be stored in the first system,
wherein the first system includes:
a converter connected to the power system to convert power;
a power storage apparatus connected to the converter to store active power of the power system or the power generated by the second system; and
a controller configured to control the converter and the power storage apparatus.

16. A method of controlling a power compensation apparatus including a first system including a converter and a capacitor, a second system including a power storage apparatus and a third system including at least one or more renewable energy sources, in order to compensate for power of a power system to be allowed to transmit from at least one or more power sources to a load, the method comprising:
measuring, by the first system, a voltage and frequency of the power system;
determining, by the first system, one of a reactive power supply mode, a reactive power absorption mode, an active power supply mode and an active power absorption mode based on the voltage and frequency;
compensating for, by the first system, power according to the determined mode; and
storing, by the second system, power generated by the at least one or more renewable energy sources in the power storage apparatus.

17. The method according to claim 16 , further comprising controlling, by the first system, the second system to receive the power from the power storage apparatus and to charge the received power on the capacitor of the first system if the capacitor of the first system is not charged upon initial operation of the first system.

18. The method according to claim 16 , further comprising controlling, by the first system, the converter of the first system to supply active power to the power system or to absorb reactive power of the power system in the reactive power supply mode or the reactive power absorption mode.

19. The method according to claim 16 , further comprising:
supplying, by the first system, the power stored in the capacitor of the first system to the power system as active power in the active power supply mode; and
controlling, by the first system, the second system to supply the power stored in the power storage apparatus to the power system as active power if a charge amount of the capacitor of the first system is insufficient.

20. The method according to claim 19 , further comprising controlling, by the second system, the third system to receive power generated by the renewable energy sources and to store the received power in the power storage apparatus if the amount of power stored in the power storage apparatus of the second system is insufficient.

21. The method according to claim 16 , further comprising:
charging, by the first system, the capacitor of

Assignees

• Lsis Co Ltd

Inventors

• Lee Eun Jae

Classifications

• H02J3/18 Primary

  Arrangements for adjusting, eliminating or compensating reactive power in networks · CPC title

• H02J3/1892

  the arrangements being an integral part of the loads or of their control circuits · CPC title

• G05F1/70

  Regulating power factor; Regulating reactive current or power · CPC title

• H02M1/4208

  Arrangements for improving power factor of AC input · CPC title

• H02J3/1814

  having reactive elements actively controlled by bridge converters, e.g. unified power flow controllers [UPFC] or controlled series voltage compensators · CPC title