Power compensation apparatus and method of controlling the same

• US 9,979,194 B2
• Filed: 08/23/2017
• Issued: 05/22/2018
• Est. Priority Date: 09/22/2016
• Status: Expired due to Fees

• Current Assignee: LSIS Co. Ltd. (LS Corporation)
• Original Assignee: LSIS Co. Ltd. (LS Corporation)
• Inventors: Lee, Eun Jae
• Primary Examiner(s): Sterrett, Jeffrey
• Application Number:
  US15/684,808
• Publication Number:
  US 20180083447A1
• Time in Patent Office: 272 Days
• Field of Search: 323207, 363 89, 363 98
• CPC Class Codes: G05F 1/70 Regulating power factor; Regulating reactive current or power
• CPC Class Codes: H02J 2310/12 The local stationary network supplying a household or a building
• CPC Class Codes: H02J 3/14 by switching loads on to, or off from, network, e.g. progressively balanced loading
• CPC Class Codes: H02J 3/16 by adjustment of reactive power
• CPC Class Codes: H02J 3/18 Arrangements for adjusting, eliminating or compensating reactive power in networks for adjustment of voltage H02J3/16
• CPC Class Codes: H02J 3/1814 wherein al least one reactive element is actively controlled by a bridge converter, e.g. unified power flow controllers [UPFC]
• 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: H02J 3/1892 the arrangements being an integral part of the load, e.g. a motor, or of its control circuit
• CPC Class Codes: H02J 3/20 in long overhead lines
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02M 1/4208 Arrangements for improving power factor of AC input
• CPC Class Codes: Y02B 70/3225 Demand response systems, e.g. load shedding, peak shaving
• CPC Class Codes: Y02E 40/10 Flexible AC transmission systems [FACTS]
• CPC Class Codes: Y02E 40/20 Active power filtering [APF]
• CPC Class Codes: Y02E 40/30 Reactive power compensation
• CPC Class Codes: Y04S 20/222 Demand response systems, e.g. load shedding, peak shaving

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.

Claims

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 the first system with the active power of the power system in the active power absorption mode; and

controlling, by the first system, the second system to store the active power of the power system in the power storage apparatus if the capacitor of the first system is fully charged.

22. The method according to claim 21, further comprising the second system controlling, by the second system, the third system to stop transmission of power from the third system if the third system transmits power.