System and method for controlling frequency

• US 9,780,565 B2
• Filed: 03/05/2013
• Issued: 10/03/2017
• Est. Priority Date: 03/08/2012
• Status: Active Grant

• Current Assignee: SK On Company Limited (SK Innovation Company Limited)
• Original Assignee: SK Innovation Company Limited
• Inventors: Choi, Jin Young, Park, Eun Sung
• Primary Examiner(s): Fleming, Fritz M
• Assistant Examiner(s): Dhillon, Jagdeep
• Application Number:
  US14/383,339
• Publication Number:
  US 20150015069A1
• Time in Patent Office: 1,673 Days
• Field of Search: 307 23, 307 64, 307 66, 307 68, 307 84, 307 72- 76, 363 37, 363 34, 363 35, 320128, 320132, 320130, 290 1 R, 290 7
• CPC Class Codes: H02H 7/06 for dynamo-electric generators; for synchronous capacitors
• CPC Class Codes: H02J 3/322 the battery being on-board an electric or hybrid vehicle, e.g. vehicle to grid arrangements [V2G], power aggregation, use of the battery for network load balancing, coordinated or cooperative battery charging
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence

Abstract

Provided are a system and a method for controlling a frequency. The system for controlling the frequency includes: at least one power supplying unit generating power; at least one systematic unit consuming the power generated from the power supplying unit; at least one standby power unit storing the power generated from the power supplying unit and including at least one storage device; and at least one grid unit connecting the power supplying unit, the systematic unit, and the standby power unit to one another and controlling a frequency of the systematic unit.

Claims

1. A system for controlling a frequency, the system comprising:

at least one power supplying unit generating power;

at least one systematic unit consuming the power generated from the power supplying unit;

at least one standby power unit storing the power generated from the power supplying unit and including a plurality of storage devices, wherein the at least one standby power unit includes a controlling unit, wherein the controlling unit is configured to determine whether an absolute value obtained by subtracting a first reference value of the state of charge (SOC) from the respective SOC of the storage devices is a predetermined first reference value or less, and cause the storage device having the SOC of the storage device of the first reference value or less to participate in the system for controlling the frequency; and

at least one grid unit connecting the power supplying unit, the systematic unit, and the standby power unit to one another and controlling a frequency of power flowing to the systematic unit.

2. The system of claim 1, wherein the plurality of storage devices being discharged when a frequency supplied to the systematic unit is decreased below a predetermined value and being charged when the frequency supplied to the systematic unit is increased above the predetermined value.

3. The system of claim 1, wherein the controlling unit determining a use priority of the storage device using the state of charge (SOC) of the storage device.

4. A method for controlling a frequency by the system for controlling the frequency of claim 1, the method comprising:

an operation of calculating a first SOC calculating the respective state of charge (SOC) of the storage devices constituting the standby power unit;

an operation of determining a first SOC reference determining whether an absolute value obtained by subtracting a first reference value of the SOC from the SOC of the storage device calculated in the operation of calculating the first SOC is a predetermined first reference or less;

an operation of participating a storage device participating the storage device having the SOC of the storage device of the first reference value or less in the operation of determining the first SOC reference in the system for controlling the frequency;

an operation of determining a priority determining priorities of the storage devices participated in the operation of participating the storage device;

an operation of requesting a frequency increase adjustment requesting the frequency increase adjustment by the systematic unit consuming the power generated from the power supplying unit;

an operation of calculating the number of participated storage devices calculating, by the standby power unit storing the power generated from the power supplying unit and including one or more storage devices, the number of storage devices necessary to perform the frequency increase requested in the operation of requesting the frequency increase adjustment;

an operation of adjusting a frequency increase increasing the frequency by applying the power stored in the storage device to the systematic unit in the case in which the storage devices as many as the necessary number calculated in the operation of calculating the storage device need to increase the frequency depending on the priority determined in the operation of determining the priority;

an operation of calculating a second SOC calculating the respective SOC of the storage devices constituting the standby power unit;

an operation of determining a second SOC reference determining whether an absolute value obtained by subtracting a second reference value of the SOC from the SOC of the storage device calculated in the operation of calculating the second SOC exceeds a predetermined second reference; and

an operation of detaching a storage device detaching the storage device having the SOC of the storage device exceeding the second reference in the operation of determining the second SOC reference from the system for controlling the frequency.

5. A method for controlling a frequency by the system for controlling the frequency of claim 1, the method comprising:

an operation of calculating a first SOC calculating the respective state of charge (SOC) of the storage devices constituting the standby power unit;

an operation of determining a first SOC reference determining whether the SOC of the storage device calculated in the operation of calculating the first SOC is a predetermined first reference value or less;

an operation of participating a storage device participating the storage device having the SOC of the storage device of the first reference value or less in the operation of determining the first SOC reference in the system for controlling the frequency;

an operation of determining a priority determining priorities of the storage devices participated in the operation of participating the storage device;

an operation of requesting a frequency decrease adjustment requesting the frequency decrease adjustment by the systematic unit consuming the power generated from the power supplying unit;

an operation of calculating the number of participated storage devices calculating, by the standby power unit storing the power generated from the power supplying unit and including one or more storage devices, the number of storage devices necessary to perform the frequency decrease requested in the operation of requesting the frequency decrease adjustment;

an operation of adjusting a frequency decrease decreasing the frequency by charging the storage device with the power generated from the power supplying unit in the case in which the storage devices as many as the necessary number calculated in the operation of calculating the storage device need to decrease the frequency depending on the priority determined in the operation of determining the priority;

an operation of calculating a second SOC calculating the respective SOC of the storage devices constituting the standby power unit;

an operation of determining a second SOC reference determining whether the SOC of the storage device calculated in the operation of calculating the second SOC exceeds a predetermined second reference value; and

an operation of detaching a storage device detaching the storage device having the SOC of the storage device exceeding the second reference value in the operation of determining the second SOC reference from the system for controlling the frequency.

6. The method of claim 4, wherein the first reference value is an absolute value (|SOC−

first reference value|) obtained by subtracting the first reference value from the SOC of the storage device and is between 10% and 30%.

7. The method of claim 6, wherein the first reference value is between 40% and 80%.

8. The method of claim 4, wherein the second reference value is an absolute value (|SOC−

second reference value|) obtained by subtracting the second reference value from the SOC of the storage device and is between 20% and 40%.

9. The method of claim 8, wherein the second reference value is between 40% and 80%.

10. The method of claim 4, wherein in the case in which the storage device is added to the standby power unit, the added storage device is performed from the operation of calculating the SOC after a predetermined reference time lapses.

11. The method of claim 10, wherein the reference time is between four seconds and thirty minutes after the storage device is added.