Automated voltage and VAR control in power transmission and distribution networks
First Claim
1. A method for controlling voltage in a power distribution network including power lines for distributing power at a lower voltage and at a higher voltage, power being distributed at the lower voltage to multiple lower-voltage locations, the network including, at the higher voltage, capacitor means and switch means for selectively switching the capacitor means into or out of the network, the method comprising the steps of:
- (a) measuring the voltage at one or more lower-voltage location,(b) ascertaining the deviation, if any, of the measured voltage from a predetermined voltage range intended to be present at the lower-voltage location,(c) determining whether switching the capacitor means into or out of the network changes the voltage deviation to bring the voltage at the measured lower-voltage location within the predetermined voltage range, and(d) selectively transmitting a signal to the switch means for switching the capacitor means into or out of operation in the network to effect a change in the voltage at the measured lower-voltage location.
2 Assignments
0 Petitions
Accused Products
Abstract
Controlling a customer voltage and VAR flow in a power transmission and distribution system includes measuring first voltages in a power line directed to a first location related to customers. Both the customer voltage and the VAR flow for the network is determined in relation to the number of capacitors associated with the first location which are switched in or out of the network. The measured voltages are communicated to a voltage control. Voltage deviations of the measured first voltage are determined relative to a predetermined voltage range intended to be present at the first locations. Switching the capacitor means into or out of the network is determined by the voltage control in accordance with a voltage rise table. A VAR flow controller is responsive to the voltage at the first locations, the effect of the VAR generation by the capacitors and the change of VAR generation by the capacitor. A decrease in voltage at the customers saves energy use. A decrease in the VAR generated upstream of the customer results in greater efficiency of energy generation.
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Citations
76 Claims
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1. A method for controlling voltage in a power distribution network including power lines for distributing power at a lower voltage and at a higher voltage, power being distributed at the lower voltage to multiple lower-voltage locations, the network including, at the higher voltage, capacitor means and switch means for selectively switching the capacitor means into or out of the network, the method comprising the steps of:
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(a) measuring the voltage at one or more lower-voltage location, (b) ascertaining the deviation, if any, of the measured voltage from a predetermined voltage range intended to be present at the lower-voltage location, (c) determining whether switching the capacitor means into or out of the network changes the voltage deviation to bring the voltage at the measured lower-voltage location within the predetermined voltage range, and (d) selectively transmitting a signal to the switch means for switching the capacitor means into or out of operation in the network to effect a change in the voltage at the measured lower-voltage location. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 64, 65)
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11. A method for controlling reactive power flow in a power transmission and distribution network including power lines and transformer means for distributing power at a lower voltage and at a higher voltage, power being distributed at the lower voltage to multiple lower-voltage locations, the network including, at the higher voltage, capacitor means and switch means for selectively lowering or raising the higher voltage, the method comprising the steps of:
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(a) measuring the voltage at one or more lower-voltage location (b) measuring the reactive power flow at the higher voltage, and upstream of the higher voltage (c) determining; (1) whether a change of the measured voltage, within a predetermined voltage range, at said lower-voltage location causes the capacitor means to switch into or out of the network, (2) the changes in reactive power flow resulting from a change of voltage, within the predetermined range, at said lower-voltage location, (3) with the proviso that the measured voltage is maintained within the predetermined voltage range, at least one of the following;
(i) the available reactive power from available capacitor means not presently in the network, or (ii) the removable reactive power at the higher voltage by switching capacitor means presently in the network out of the network, and(d) depending on the reactive power availability or removability, and the measured reactive power flows, selectively transmitting a signal to the switch means for lowering or raising the higher voltage to effect a change in the reactive power generated at the higher voltage with the proviso that the lower voltage remains within the predetermined voltage range. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A method for controlling voltage and reactive power flow in a power transmission and distribution network including power lines and transformer means for distributing power at a lower voltage, at an intermediate voltage, and at a higher voltage, power being distributed at the lower voltage to multiple lower-voltage locations, the network including, at the intermediate voltage, capacitor means and capacitor switch means for selectively switching the capacitor means into or out of the network, the network further comprising voltage switch means for selectively lowering or raising the higher voltage, the method comprising the steps of:
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(a) measuring the voltage at one or more lower-voltage location, (b) ascertaining the deviation, if any, of the measured voltage from a predetermined voltage range intended to be present at the lower-voltage location, (c) determining whether switching the capacitor means into or out of the network changes the voltage deviation to bring the voltage at the measured lower-voltage location within the predetermined voltage range, (d) selectively transmitting a signal to the capacitor switch means for switching the capacitor means into or out of operation in the network to effect a change in the voltage at the measured lower-voltage location, (e) measuring the reactive power flow at the higher voltage, (f) determining; (1) whether a change of the measured voltage, within the predetermined voltage range, at said lower-voltage location causes the capacitor means to switch into or out of the network, (2) the changes in reactive power flow resulting from a change of voltage, within the predetermined range, at said lower-voltage location, (3) with the proviso that the measured voltage is maintained within the predetermined voltage range, at least one of the following;
(i) the available reactive power from available capacitor means not presently in the network, or (ii) the removable reactive power at the intermediate voltage by switching capacitor means presently in the network out of the network, and(g) depending on the reactive power availability or removability, and the measured reactive power flow, selectively transmitting a signal to the voltage switch means for lowering or raising the higher voltage to effect a change in the reactive power generated at the higher voltage, with the proviso that the lower voltage remains within the predetermined voltage range. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 66)
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34. A system for controlling voltage in a power distribution network including power lines for distributing power at a lower voltage and at a higher voltage, power being distributed at the lower voltage to multiple lower-voltage locations, the network including, at the higher voltage, capacitor means and switch means for selectively switching the capacitor means into or out of the network, the system comprising:
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(a) means for measuring the voltage at one or more lower-voltage location, (b) means for ascertaining the deviation, if any, of the measured voltage from a predetermined voltage range intended to be present at the lower-voltage location, (c) means for determining whether switching the capacitor means into or out of the network changes the voltage deviation to bring the voltage at the measured lower-voltage location within the predetermined voltage range, and (d) means for selectively transmitting a signal to the switch means for switching the capacitor means into or out of operation in the network to effect a change in the voltage at the measured lower-voltage location. - View Dependent Claims (35, 36, 37, 38, 39, 40, 41, 42, 43, 67, 68, 69)
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44. A system for controlling reactive power flow in a power transmission and distribution network including power lines and transformer means for distributing power at a lower voltage and at a higher voltage, power being distributed to multiple lower-voltage locations at the lower voltage, the network including, at the higher voltage, capacitor means and switch means for selectively lowering or raising the higher voltage, the system comprising:
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(a) means for measuring the voltage at one or more lower-voltage location, (b) means for measuring the reactive power flow at the higher voltage and upstream of the higher voltage, (c) means for determining whether a voltage change at the lower-voltage location causes the capacitor means to switch into or out of the network while maintaining the lower voltage within a predetermined voltage range, (d) means for ascertaining, with the proviso that the measured voltage is maintained within the predetermined voltage range, at least one of the following;
(i) the available reactive power from available capacitor means not presently in the network or (ii) the removable reactive power at the higher voltage by switching the capacitor means presently in the network out of the network,(e) means for determining the changes in reactive power resulting from the change of voltage, within the predetermined range, at said lower-voltage location, and (f) means for selectively transmitting a signal to the switch means, depending on reactive power availability or removability, and the measured reactive power flows, for lowering or raising the higher voltage to effect a change in the reactive power generated at the higher voltage, with the proviso that the lower voltage remains within the predetermined voltage range. - View Dependent Claims (45, 46, 47, 48, 49, 50)
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51. A system of controlling voltage and reactive power flow in a power transmission distribution network including power lines and transformer means for distributing power at a lower voltage, a intermediate voltage, and a higher voltage, power being distributed at the lower voltage to multiple lower-voltage locations, the network including, at the intermediate voltage, capacitor means and capacitor switch means for switching the capacitor means into or out of the network, the network further comprising voltage switch means for selectively lowering or raising the higher voltage, the system comprising:
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(a) means for measuring the voltage at one or more lower-voltage location, (b) first determining means for determining deviation, if any, of the measured voltage from a predetermined voltage range intended to be present at the lower-voltage location, (c) second determining means for determining whether switching the capacitor means into or out of the network changes the voltage deviation to bring the voltage at the measured lower-voltage location within the predetermined voltage range, (d) first means for selectively transmitting a signal to the capacitor switch means for switching the capacitor means into or out of operation in the network to effect a change in the voltage at the measured lower-voltage location, (e) means for measuring the reactive power flow at the higher voltage, (f) third determining means for determining whether a voltage change, within the predetermined voltage range, at said lower-voltage location causes capacitor means to switch into or out of the network, (g) means for ascertaining, with the proviso that the measured voltage is maintained within the predetermined voltage range, at least one of the following;
(i) the available reactive power from available capacitor means not presently in the network or (ii) the removable reactive power at the higher voltage by switching the capacitor means presently in the network out of the network,(h) fourth determining means for determining the changes in reactive power resulting from the change of voltage, within the predetermined range, at said lower-voltage location, and (i) second means for selectively transmitting a signal to the voltage switch means, depending on reactive power availability or removability, and the measured reactive power flow, for lowering or raising the higher voltage to effect a change in the reactive power generated at the higher voltage, with the proviso that the lower voltage remains within the predetermined voltage range. - View Dependent Claims (52, 53, 54, 55, 56, 57)
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58. A voltage controller for controlling voltage in a power distribution network including power lines for distributing power at a lower voltage and at a higher voltage, power being distributed at the lower voltage to multiple lower-voltage locations, the network including, at the higher voltage, capacitor means and switch means for selectively switching the capacitor means into or out of the network, the voltage controller comprising:
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(a) means for receiving a voltage measured at one or more lower-voltage location, (b) means for determining the deviation, if any, of the measured voltage from a predetermined voltage range intended to be present at the measured lower-voltage location, (c) means for determining whether switching the capacitor means into or out of the network changes the voltage deviation to bring the voltage at the measured lower-voltage location within the predetermined voltage range, and (d) means for selectively transmitting a signal to the switch means for switching the capacitor means into or out of operation in the network to effect a change in the voltage at the measured lower-voltage location. - View Dependent Claims (59, 60, 61)
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62. A reactive power controller for controlling reactive power flow in a power transmission and distribution network including power lines and transformer means for distributing power at a lower voltage and at a higher voltage, power being distributed to multiple lower-voltage locations at the lower voltage, the network including capacitor means at the higher voltage and switch means for selectively switching the capacitor means into or out of the network, the system comprising:
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(a) means for receiving a voltage measured at one or more lower-voltage location, (b) means for receiving a reactive power flow measured at the higher voltage, (c) means for determining whether a change of the measured voltage, within a predetermined voltage range, at said lower-voltage location causes the capacitor means to switch into or out of the network, (d) means for ascertaining, with the proviso that the measured voltage is maintained within the predetermined voltage range, at least one of the following;
(i) the available reactive power from available capacitor means not presently in the network or (ii) the removable reactive power at the higher voltage by switching the capacitor means presently in the network out of the network,(e) means for determining the changes in reactive power resulting from the change of voltage, within the predetermined range, at said lower-voltage location, and (f) means for selectively transmitting a signal to the switch means, depending on reactive power availability or removability, and the measured reactive power flow, for lowering or raising the higher voltage to effect a change in the reactive power generated at the higher voltage with the proviso that the lower voltage remains within the predetermined voltage range.
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63. An apparatus for controlling voltage and reactive power flow in a power transmission distribution network including power lines and transformer means for distributing power at a lower voltage, an intermediate voltage, and a higher voltage, power being distributed at the lower voltage to multiple lower-voltage locations, the network including capacitor means at the intermediate voltage and capacitor switch means for switching the capacitor means into or out of the network, the network further comprising voltage switch means for selectively lowering or raising the higher voltage, the apparatus comprising:
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(a) means for receiving a voltage measured at one or more lower-voltage location, (b) means for determining the deviation, if any, of the measured voltage from a predetermined voltage range intended to be present at the measured lower-voltage location, (c) means for determining whether switching the capacitor means into or out of the network changes the voltage deviation to bring the first voltage at the measured lower-voltage location within the predetermined voltage range, and (d) means for selectively transmitting a signal to the capacitor switch means for switching the capacitor means into or out of operation in the network to effect a change in the lower voltage at the measured lower-voltage location, (e) means for receiving a reactive power flow measured at the higher voltage, (f) means for determining whether a change of the measured voltage, within the predetermined voltage range, at said lower-voltage location causes the capacitor means to switch into or out of the network, (g) means for ascertaining, with the proviso that the measured voltage is maintained within the predetermined voltage range, at least one of the following;
(i) the available reactive power from available capacitor means not presently in the network or (ii) the removable reactive power at the higher voltage by switching the capacitor means presently in the network out of the network,(h) means for determining the changes in reactive power resulting from the change of voltage, within the predetermined range, at said lower-voltage location, and (i) means for selectively transmitting a signal to the voltage switch means, depending on reactive power availability or removability, and the measured reactive power flow, for lowering or raising the higher voltage to effect a change in the reactive power generated at the higher voltage, with the proviso that the first lower voltage remains within the predetermined voltage range.
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70. A method for controlled reactive power flow in a power transmission and distribution network including power lines and transformer means for distributing power at a lower voltage and at a higher voltage, power being distributed at the lower voltage to multiple lower-voltage locations, the network including, at the higher voltage, capacitor means and switch means for selectively switching the capacitor means into or out of the network, the method comprising the steps of:
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(a) measuring the voltage at one or more lower-voltage location, (b) measuring the reactive power flow at the higher voltage, and upstream of the higher voltage, (c) determining; (1) whether a change of the measured voltage, within a predetermined voltage range, at said lower-voltage location causes the capacitor means to switch into or out of the network, (2) the change in reactive power resulting from a change of voltage, within the predetermined range, at said lower-voltage location, (3) with the proviso that the measured voltage is maintained within the predetermined voltage range, at least one of the following;
(i) the available reactive power from available capacitor means not presently in the network, or (ii) the removable reactive power at the higher voltage by switching capacitor means presently in the network out of the network, and(d) depending on the reactive power availability or removability, and the measured reactive power flows, selectively transmitting a signal to the switch means for switching the capacitor means in or out of the network to effect a change in the reactive power generated at the higher voltage, with the proviso that the lower voltage remains within the predetermined voltage range. - View Dependent Claims (71, 72, 73)
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74. A system for controlling reactive power flow in a power transmission and distribution network including power lines and transformer means for distributing power at a lower voltage and at a higher voltage, power being distributed to multiple lower-voltage locations at the lower voltage, the network including, at the higher voltage, capacitor means and switch means for selectively switching the capacitor means into or out of the network, the system comprising:
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(a) means for measuring the voltage at one or more lower-voltage location, (b) means for measuring the reactive power flow at the higher voltage, and upstream of the higher voltage, (c) means for determining whether a voltage change at the lower-voltage location causes the capacitor means to switch into or out of the network while maintaining the measured voltage within a predetermined voltage range, (d) ascertaining, with the proviso that the measured voltage is maintained within the predetermined voltage range, at least one of the following;
(i) the available reactive power from available capacitor means not presently in the network or (ii) the removable reactive power at the higher voltage by switching the capacitor means presently in the network out of the network,(e) means for determining the changes in reactive power resulting from the change of voltage, within the predetermined range, at said lower-voltage location, and (f) means for selectively transmitting a signal to the switch means, depending on reactive power availability or removability, and the measured reactive power flows, for lowering or raising the higher voltage to effect a change in the reactive power generated at the higher voltage, with the proviso that the measured voltage remains within the predetermined voltage range. - View Dependent Claims (75, 76)
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Specification