Method and System for Regulating Power of an Electricity Grid System
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 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.
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 store is faster than that of the source;
a first switch connecting said store to said 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 energy stored in the store and energy available from said source and for selectively controlling the first switch to close to transfer energy from the source to the store;
a second controller configured to monitor 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, controlling the second switch to close to transfer energy from the store to the grid.
2 . The system of claim 1 wherein said first controller is configured to control the first switch to close to transfer energy from the source to the store if said energy stored in said store falls below a lower threshold and said source has available energy.
3 . The system of claim 1 or claim 2 wherein said second controller is also configured to control said second switch to close to transfer energy from said grid to said store, on receiving an indication that there is surplus of energy in said grid, if energy stored in said store is below an absorption threshold,
4 . The system of claim 3 wherein said store is a second store and said source is a first store and wherein said first controller is further configured to control said first switch to close to transfer energy from said second store to said first store, where energy stored in said second store rises above an upper threshold and energy stored in said first store is below a maximum threshold.
5 . The system of claim 4 wherein said second store is a capacitive store.
6 . The system of claim 4 wherein said electrical grid is an AC grid, said second store stores DC energy, and said second switch comprises a power inverter and rectifier.
7 . The system of any one of claim 4 to claim 6 wherein said first store stores AC energy and wherein said first switch comprises a power inverter and rectifier.
8 . The system of claim 5 further comprising a voltage sensor measuring voltage across said capacitive store and wherein said first controller is responsive to said voltage sensor for monitoring energy stored in said capacitive store by monitoring voltage of said capacitive store.
9 . The system of claim 5 further comprising a voltage sensor measuring voltage across said capacitive store and wherein said second controller is responsive to said voltage sensor for monitoring energy stored in said capacitive store by monitoring voltage of said capacitive store.
10 . The system of any one of claim 4 to claim 9 wherein said first store is a kinetic battery.
11 . The system of claim 10 wherein said kinetic battery is a flywheel.
12 . The system of claim 11 wherein said first controller is configured for monitoring energy available from said flywheel by monitoring the revolutions per minute of said flywheel.
13 . The system of any one of claim 1 to claim 12 wherein said first controller is configured to determine said source has available energy to transfer to said store if energy in said source exceeds a minimum threshold.
14 . The system of any one of claim 1 to claim 13 further comprising a supervisory controller for sending said indication that additional energy is needed in the grid to said second controller.
15 . 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 said 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, said first response time being faster than said second response time;
a second switch comprising a power inverter, said second switch connected at one side to said 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 energy available from said kinetic battery and configured to control said first switch to close to transfer energy from said kinetic battery to said capacitive store, when said voltage of said capacitive store falls below a lower threshold and said kinetic battery has available energy;
a second controller connected to monitor voltage of said capacitive store and intermittently receiving a request to supply additional energy to said grid, said second controller configured to control said second switch to close to transfer energy from said capacitive store through said power inverter to said AC grid on receiving a request to supply additional energy to said grid, when voltage of said capacitive store exceeds a supply threshold.
16 . The system of claim 15 wherein said second switch further comprises a rectifier, said second switch configured to have an open position, a first switch path through said power inverter, and a second switch path through said rectifier and wherein said second controller is also configured to control said second switch to close to transfer energy from said grid to said capacitive store through said rectifier, when said at least one characteristic of power in said grid indicates a surplus of energy in said grid and energy stored in said capacitive store is below an absorption threshold.
17 . 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 said 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, said first response time being faster than said second response time;
a second switch connected at one side to said store and for connection at an opposite side to said electrical grid;
a first controller for monitoring energy stored in said store and energy available from said source and for, where said indication of energy stored in said store falls below a lower threshold and said source has available energy, controlling said first switch to close to transfer energy from said source to said store;
a second controller for monitoring energy stored in said store and configured to receive an indication of at least one characteristic of power in said grid and control said second switch to close to transfer energy from said store to said grid when said at least one characteristic of power in said grid indicates a need for additional energy in said grid and energy stored in said store exceeds a supply threshold.
18 . The system of claim 17 wherein said second controller is also configured to control said second switch to close to transfer energy from said grid to said store when said at least one characteristic of power in said grid indicates a surplus of energy in said grid and energy stored in said store is below an absorption threshold.
19 . The system of claim 17 or claim 18 wherein said store is a second store and said source is a first store and wherein said first controller is further configured to control said first switch to close to transfer energy from said second store to said first store when said indication of energy stored in said second store rises above an upper threshold and energy stored in said first store is below a maximum threshold.
20 . A method for regulating power on a grid comprising:
(a) in a first process:
(i) monitoring energy stored in a store and energy available from a source;
(ii) where said indication of energy stored in said store falls below a lower threshold and said source has available energy, transferring energy from said source to said store;
(b) in a second process independent of said first process:
(i) monitoring energy stored in said store; and
(ii) on receiving an indication of a need for additional energy in said grid, if energy stored in said store exceeds a supply threshold, transferring energy from said store to said grid.
21 . The method of claim 20 wherein said second process further comprises, on receiving an indication of surplus of energy in said grid, if energy stored in said store is below an absorption threshold, transferring energy from said grid to said store.
22 . The method of claim 20 or claim 21 wherein said store is a second store and said source is a first store and wherein said first process further comprises:
(iii) where said indication of energy stored in said second store rises above an upper threshold and energy stored in said first store is below a maximum threshold, transferring energy from said second store to said first store.
23 . The method of claim 22 wherein said grid is an AC grid and second store is a capacitive store and wherein said second process, when transferring energy from said second store to said grid, undertakes a conversion from DC to AC.
24 . The method of claim 22 wherein said second process, when transferring energy from said grid to said second store, undertakes a conversion from AC to DC.