Method and system for regulating power of an electricity grid system

• US 8,803,363 B2
• Filed: 04/16/2013
• Issued: 08/12/2014
• Est. Priority Date: 04/16/2012
• Status: Active Grant

• Current Assignee: Bc New Energy (Tianjin) Co., Ltd.
• Original Assignee: Temporal Power, Ltd.
• Inventors: Veltri, Jeffrey Allan
• Primary Examiner(s): Amrany, Adi
• Application Number:
  US13/863,727
• Publication Number:
  US 20130270914A1
• Time in Patent Office: 483 Days
• Field of Search: 307 47- 48, 307/82, 307 85- 87
• US Class Current: 307/87
• CPC Class Codes: H02J 3/28 Arrangements for balancing of the load in a network by storage of energy
• CPC Class Codes: H02J 3/30 using dynamo-electric machines coupled to flywheels
• CPC Class Codes: H02J 3/32 using batteries with converting means
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y02E 60/16 Mechanical energy storage, e.g. flywheels or pressurised fluids
• CPC Class Codes: Y04S 10/12 Monitoring or controlling equipment for energy generation units, e.g. distributed energy generation [DER] or load-side generation
• CPC Class Codes: Y04S 20/12 Energy storage units, uninterruptible power supply [UPS] systems or standby or emergency generators, e.g. in the last power distribution stages

Abstract

A power regulation system for an electrical grid has a store of electrical energy connected through a first switch to a source of electrical energy. The response time of the store is faster than that of the source. A second switch is connected to the store at one side with the opposite side for connection to the grid. A first controller monitors energy stored in the store and energy available from said source and selectively controls the first switch to close to transfer energy from the source to the store. A second controller monitors energy stored in said store and, on receiving an indication that additional energy is needed in the grid, if the energy stored in the store exceeds a supply threshold, controls the second switch to close to transfer energy from the store to the grid.

Claims

1. A power regulation system for an electrical grid comprising:

a store of electrical energy;

a source of electrical energy, wherein an energy supply response time of the stole is faster than that of the source;

a first switch connecting the store to the source;

a second switch connected to the store at one side and having an opposite side for connection to the grid;

a first controller configured to monitor an amount of energy stored in the store and an amount of energy stored in the source and to selectively control the first switch to close to transfer energy from the source to the store provided that the amount of energy stored in the source is above a minimum source amount or to transfer energy from the store to the source provided that the amount of energy stored in the source is below a maximum source amount;

a second controller configured to monitor the amount of energy stored in the store and to control the second switch to close to transfer energy to the grid provided that the amount of energy in the store is above a minimum store threshold or to absorb energy from the grid provided that the amount of energy in the store is below a maximum store threshold,

wherein the power regulation system operates in accordance with a regulation signal to transfer energy to the grid or to absorb energy from the grid.

2. The system of claim 1 wherein the second controller is also configured to control the second switch to open to cease transfer of energy from the store to the grid, if the amount of energy stored in the store falls below the minimum store threshold.

3. The system of claim 2 wherein the first controller is further configured to control the first switch to close to transfer energy from the store to the source when the amount of energy stored in the store exceeds an upper store threshold and when the amount of energy stored in the source is below the maximum source amount.

4. The system of claim 3 wherein the store is a capacitive store.

5. The system of claim 4 further comprising a voltage sensor measuring voltage across the capacitive store and wherein the first controller is responsive to the voltage sensor for monitoring the amount of energy stored in the capacitive store by monitoring a voltage of the capacitive store.

6. The system of claim 4 further comprising a voltage sensor measuring voltage across the capacitive store and wherein the second controller is responsive to the voltage sensor for monitoring the amount of energy stored in the capacitive store by monitoring voltage of the capacitive store.

7. The system of claim 3 wherein the electrical grid is an AC grid, the store stores DC energy, and the second switch comprises a power inverter and rectifier.

8. The system of claim 3 wherein the source stores AC energy and wherein the first switch comprises a power inverter and rectifier.

9. The system of claim 3 wherein the source is a kinetic battery.

10. The system of claim 9 wherein the kinetic battery is a flywheel.

11. The system of claim 10 wherein the first controller monitors the amount of energy stored in the source by monitoring the revolutions per minute of the flywheel.

12. A power regulation system for an AC grid, comprising:

a capacitive store able to supply energy on command within a first response time;

a first switch connected at one side to the capacitive store and for connection, at an opposite side, to a kinetic battery able, at least intermittently, to supply energy on command within a second response time, the first response time being faster than the second response time;

a second switch comprising a power inverter, the second switch connected at one side to the capacitive store and for connection at an opposite side to said AC grid;

a first controller connected to monitor voltage of said capacitive store and an amount of energy stored in the kinetic battery, the first controller being configured to control the first switch to close to transfer energy from the kinetic battery to the capacitive store, when the voltage of the capacitive store falls below a lower store threshold and the amount of energy stored in the kinetic battery is above a minimum battery amount in order to increase the voltage of the capacitive store above the lower store threshold;

a second controller to monitor the voltage of the capacitive store and intermittently receive a request to supply energy to the grid from the capacitive store, the second controller being configured to control the second switch to close to transfer energy from the capacitive store through the power inverter to the AC grid on receiving the request to supply the energy to the grid, and provided that the voltage of the capacitive store is above a minimum store threshold.

13. The system of claim 12 wherein the second switch further comprises a rectifier, the second switch being configured to have an open position, a first switch path through the power inverter, and a second switch path through the rectifier and wherein the second controller is also configured to control the second switch to close to transfer energy from the grid to the capacitive store through the rectifier, when a characteristic of power in the grid indicates a surplus of energy in the grid and the amount of energy stored in the capacitive store is below a maximum store threshold.

14. A power regulation system for an electrical grid, comprising:

a store of electrical energy able to supply energy on command within a first response time;

a first switch connected at one side to the store of electrical energy and for connection, at an opposite side, to a source of electrical energy able, at least intermittently, to supply energy on command within a second response time, the first response time being faster than the second response time;

a second switch connected at one side to the store and for connection at an opposite side to the electrical grid;

a first controller for monitoring an amount of energy stored in the store and an amount of energy stored in the source and for, controlling the first switch to close to transfer energy from the source to the store when the amount of energy stored in the store falls below a lower store threshold and the amount of energy stored in the source is above a minimum source amount in order to increase the amount of energy stored in the store to an amount above the lower store threshold;

a second controller for monitoring the amount of energy stored in the store and being configured to receive an indication of a characteristic of power in the grid and to control the second switch to close to transfer energy from the store to the grid provided that the characteristic of power in the grid indicates a need for additional energy in the grid and the amount of energy stored in the store is above a minimum store threshold.

15. The system of claim 14 wherein the second controller is also configured to control the second switch to close to transfer energy from the grid to the store provided that the characteristic of power in the grid indicates a surplus of energy in the grid and the amount of energy stored in the store is below a maximum store threshold.

16. The system of claim 15 wherein the first controller is further configured to control the first switch to close to transfer energy from the store to the source when the amount of energy in the store exceeds the maximum store threshold and when the amount of energy stored in the source is below a maximum source amount.

17. A method for regulating power on a grid comprising:

(a) in a first process;

(i) monitoring an amount of energy stored in a store and an amount of energy stored in a source;

(ii) transferring energy from the source to the store when the amount of energy stored in the store falls below a lower store threshold and the amount of energy in the source exceeds a minimum source amount in order to increase the amount of energy stored in the store to an amount at or above the lower store threshold;

(b) in a second process independent of the first process;

(i) monitoring energy stored in the store; and

(ii) transferring energy from the store to the grid on receiving an indication of a need for additional energy in the grid, provided that the amount of energy stored in the store exceeds a minimum store threshold.

18. The method of claim 17 wherein the second process further comprises, transferring energy from the grid to the store on receiving an indication of surplus of energy in the grid, if the amount of energy stored in the store is below a maximum store threshold.

19. The method of claim 18 wherein the first process further comprises:

(iii) transferring energy from the store to the source when the amount of energy stored in the store exceeds the maximum store threshold and the amount of energy stored in the source is below a maximum source amount.

20. The method of claim 19, wherein the grid is an AC grid and the store is a capacitive store, and

wherein transferring energy from the store to the grid involves a conversion of the energy from DC to AC.

21. The method of claim 19 wherein transferring energy from the grid to the store involves a conversion of the energy from AC to DC.