Method for using chemical thermodynamics to buffer the voltage of electric circuits and power systems

• US 10,411,463 B2
• Filed: 10/31/2017
• Issued: 09/10/2019
• Est. Priority Date: 11/19/2015
• Status: Active Grant

• Current Assignee: Shepherd Hydricity Inc.
• Original Assignee: Shepherd Hydricity Inc.
• Inventors: Shepherd, Stephen H.
• Primary Examiner(s): Amrany, Adi
• Application Number:
  US15/798,702
• Publication Number:
  US 20180054052A1
• Time in Patent Office: 679 Days
• Field of Search: 307152
• CPC Class Codes: H02H 9/005 avoiding undesired transient conditions
• CPC Class Codes: H02J 2300/30 The power source being a fuel cell
• CPC Class Codes: H02J 3/12 for adjusting voltage in ac networks by changing a characteristic of the network load
• CPC Class Codes: H02J 3/28 Arrangements for balancing of the load in a network by storage of energy
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

A method for buffering the voltage of an electric system that undergoes transient voltage changes includes the step of placing a new load upon the electric system by electrically connecting at least one electrochemical device to the electric system so that electrical current flows from the electric system to the electrochemical device. Also included are the steps of causing at least one electrochemical reaction to occur within the at least one electrochemical device; varying the new load placed upon the electric system as transient voltage changes in the electric system occur; and changing the electrical current from the electric system to the electrochemical device in a manner that retards transient voltage changes in the electric system that would occur in the absence of the steps of placing, causing, and varying.

Claims

1. A method for buffering the voltage of electric circuit (EC) system that undergoes transient voltage changes, above or below a nominal operating voltage of the EC system, during use as a result of variances in loads on, or power to, the EC system, comprising:

placing a new load upon the EC system and its normal operating voltage by electrically connecting an electrochemical device to the EC system by a direct current (DC) circuit via a voltage transformer;

selecting a step-up or step-down transformer rating for the voltage transformer for causing the new load to have a voltage that varies without regulation in proportion to the voltage of the EC system during transient voltage changes;

selecting a capacity, a chemical concentration and an electrode design for the electrochemical device, wherein the selecting steps cause the new load to be powered by the EC system at voltage levels that cause at least one electrochemical reaction exhibiting Nernstian behavior of the reaction rate to occur within the electrochemical device;

providing, during a first transient voltage change in the EC system, additional voltage from the EC system to the electrochemical device to exponentially increase the load on the EC system when the EC system voltage increases, to retard the first transient voltage change that would occur in the absence of the placing, selecting and providing steps; and

providing, during a second transient voltage change in the EC system, reduced voltage from the EC system to the electrochemical device to exponentially decrease the load on the EC system when the EC system voltage decreases, to retard the second transient voltage change that would occur in the absence of the placing, selecting and providing steps.

2. The method of claim 1, wherein the at least one-electrochemical reaction is an electrolysis reaction to produce a product that is a fuel.

3. The method of claim 1, wherein the at least one electrochemical reaction is an electrolysis reaction that produces a hydrogen fuel, and wherein the method further comprises:

delivering the hydrogen fuel to a hydrogen fuel cell;

producing, in the hydrogen fuel cell, a DC electric power;

inverting the DC electric power produced by the hydrogen fuel cell into AC electrical power; and

delivering the AC electrical power to the EC system.

4. The method of claim 3, wherein the EC system transmits direct current (DC) electric power, and further including transforming the DC produced by the hydrogen fuel cell into high voltage DC, and delivering it to the EC system.

5. The method of claim 1, wherein the at least one electrochemical reaction is an electrolysis reaction to produce a product that is a fuel;

and wherein the method further includes producing alternating current (“

AC”

) electric power from an AC-power generator powered by the fuel, and delivering the AC electric power to one of;

an AC EC system, and an AC distribution system normally coupled to the AC EC system.

6. The method of claim 5, wherein the EC system transmits direct current (DC) electric power, and further including transforming the AC electrical power produced by the AC-power generator into a DC electrical power at a voltage appropriate for delivery to the EC system, and delivering the DC electrical power to the EC system.

7. The method of claim 1, wherein the electrochemical device is sized to allow an amount of EC system voltage control by reducing the magnitude of transient voltage changes, and the amount of EC system voltage control enables adjustment to the EC system that results in a zero derivative of EC system current with respect to EC system voltage before the voltage transient exceeds the limits of a desired control range.

8. The method of claim 1, further including connecting one or more voltage support units to the EC system to provide electric power to the EC system, and wherein the electrochemical device applies chemical thermodynamics and the one or more voltage support units provides electric power to retard increasing and decreasing EC voltage transients to cause the transient EC voltage to remain within a pre-specified voltage range.

9. The method of claim 1, wherein the electrochemical device has a voltage buffer capacity that is higher than a buffer capacity required to buffer voltage rises from loss of all other loads in the EC system.

10. The method of claim 1, wherein the EC system includes DC circuitry that is connected to the electrochemical device at a nominal voltage, and wherein the electrochemical device is constructed with a buffer capacity to buffer the voltage of the EC system DC circuitry to protect the EC system from overvoltage conditions caused by geomagnetically-induced voltage transient events.

11. The method of claim 10, wherein the selecting steps cause the new load normally to be powered by the EC system at voltage levels below the Standard Reference Potential of the electrochemical device that causes no electrochemical reaction to occur until a voltage transient occurs on the EC system that raises the voltage supplied to the electrochemical device above the Standard Reference Potential to cause at least one electrochemical reaction exhibiting Nernstian behavior of the reaction rate to occur within the electrochemical device.

12. The method of claim 1, wherein the EC system is an electric power transmission distribution system.

13. A system for retarding transient voltage changes occurring on an electric circuit (EC) system, above or below a nominal operating voltage of the EC system, the system comprising:

an EC system, wherein the EC system comprises a high voltage transmission line;

a DC circuit;

a step down transformer connected to the EC system to step down a high voltage on the high voltage transmission line of the EC system to provide a lower voltage that varies without regulation in proportion to the high voltage of the EC system during transient voltage changes;

an electrochemical device electrically connected through the step down transformer to the EC system so that electrical current can flow from the EC system to the electrochemical device, wherein the step down transformer comprises a voltage transformer rating and the electrochemical device comprises a capacity, a chemical concentration and an electrode design that are selected to cause the electrochemical device to be powered by the EC system at voltage levels that cause at least one electrochemical reaction exhibiting Nernstian behavior of the reaction rate to occur within the electrochemical device so that the lower voltage flowing to the electrochemical device varies with changes in the voltage level on the high voltage transmission line causing the load provided by the electrochemical device to exponentially vary to retard transient voltage changes occurring on the EC system that occur as a result of variances in loads on or power to the EC system;

wherein the system provides, during a first transient voltage change in the EC system, additional power from the EC system to the electrochemical device to exponentially increase the load on the system when the EC system voltage increases, to retard the first transient voltage change; and

wherein the system provides, during a second transient voltage change in the EC system, reduced power from the EC system to exponentially decrease the load on the system when the EC system voltage decreases, to retard the second transient voltage change.

14. The system of claim 13, wherein the at least one electrochemical reaction is an electrolysis reaction to produce a product that is a fuel.

15. The system of claim 14, wherein the system further comprises an alternating current (AC)-power generator that is powered by the fuel to produce an AC electric power and to deliver the AC electric power to the EC system.