Fast switching back-up power supply system employing rechargeable electrochemical cells

• US 10,644,537 B2
• Filed: 04/09/2018
• Issued: 05/05/2020
• Est. Priority Date: 04/09/2017
• Status: Active Grant

• Current Assignee: Form Energy, Inc.
• Original Assignee: NantEnergy, Inc.
• Inventors: Krishnan, Ramkumar, Banuelos Solis, Javier Eduardo
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Barnett, Joel
• Application Number:
  US15/948,005
• Publication Number:
  US 20180301929A1
• Time in Patent Office: 757 Days
• Field of Search: None
• CPC Class Codes: H01M 10/4214 Arrangements for moving electrodes or electrolyte
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 12/06 with one metallic and one gaseous electrode
• CPC Class Codes: H01M 12/08 composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type
• CPC Class Codes: H01M 4/42 Alloys based on zinc
• CPC Class Codes: H01M 8/0656 by electrochemical means H01M8/065 takes precedence
• CPC Class Codes: H01M 8/08 Fuel cells with aqueous electrolytes
• CPC Class Codes: H01M 8/186 by electrolytic decomposition of the electrolytic solution or the formed water product
• CPC Class Codes: H01M 8/225 Fuel cells in which the fuel is based on materials comprising particulate active material in the form of a suspension, a dispersion, a fluidised bed or a paste
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems
• CPC Class Codes: H02J 9/061 for DC powered loads
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A back-up rechargeable battery supply system comprises communication linkages and a configuration of switches to allow battery back-up power to be provided by cells within a battery unit that are in a ready mode and to by-pass batteries that are in a non-ready mode, or maintenance mode. The unique configuration of switches and communication methods enables the back-up power to be provided very quickly to avoid disruptions in power to a load. Each battery cell has a charge and discharge switch and a power switch. Both the power switch and one of the charge or discharge switches must be closed to allow the battery cell to charge or discharge respectively. The by-pass switch may be controlled by the battery system control or by the cell controller and when closed, the cell may be bypassed from discharging or charging. The battery cells may be electrochemical cells such as metal air batteries.

Claims

1. A back-up power supply system for use in conjunction with a primary electrical power source, the system comprising:

a primary power sensor configured to detect a characteristic of primary electrical power provided by the primary electrical power source to a load, the primary power sensor being configured to output a threshold signal, the threshold signal indicating a discharge mode or a charge mode based on the characteristic detected;

a system controller;

a battery system comprising a plurality of rechargeable battery cells arranged in series, each cell comprising;

(i) a cell controller;

(ii) at least one ready state sensor coupled to the cell controller for sensing one or more conditions of the cell for determining if the rechargeable battery cell is in a ready charge mode for charging, and if the rechargeable battery cell is in a ready discharge mode for discharging;

(iii) a cell bypass switch coupled to the cell controller, the cell bypass switch being switchable between a normal state for enabling said cell to be electrically coupled in said series and a bypass state bypassing the cell within the series; and

(iv) a power switch switchable between a closed state electrically coupling the battery within the series to communicate power between the battery and the load and an open state electrically decoupling the battery cell from the series;

wherein the system controller is coupled to each cell controller and each cell controller is configured to receive communication signals from the system controller;

wherein the primary power sensor is electrically coupled in parallel to the system controller and to each cell for bypassing the system controller and transmitting the threshold signal directly thereto;

wherein each cell is configured to switch its respective power switch to said closed state in response to receiving the threshold signal;

wherein each cell controller is configured to switch said bypass switch between said bypass state and said normal state in response to said at least one ready state sensor.

2. The backup power supply system of claim 1, wherein said cell controller is configured to switch said bypass switch between the normal state and the bypass state independently of the threshold signal.

3. The backup power supply system of claim 1, wherein each cell comprises a fuel electrode, a cathode, and a charging electrode, each cell further comprising:

a discharge switch switchable between a closed position for coupling the cell to the series by the cathode for discharging the cell and an open position for decoupling the cathode from the series, and

a charge switch switchable between a closed position for coupling the cell to the series by the charging electrode for charging and an open position for decoupling the charging electrode from the series,

wherein each cell is also configured to switch the discharge switch to the closed position thereof in response to the threshold signal indicating the discharge mode and to switch the charge switch to the closed position in response to the threshold signal indicating the charge mode.

4. The backup power supply system of claim 3, wherein the cell controller is configured to switch said bypass switch between said normal state and said bypass state independently of said threshold signal.

5. The backup power supply system of claim 3, wherein the primary power sensor is coupled in parallel to the cell controller of each cell for transmitting the threshold signal directly thereto, each cell controller being configured to (a) switch the power switch and the discharge switch to the closed states thereof in response to the threshold signal indicating the discharge mode and (b) switch the power switch and the charge switch to the closed states thereof in response to the threshold signal indicating the charge mode.

6. The backup power supply system of claim 5, wherein each cell controller has an interrupt input and the primary power sensor is coupled in parallel to the interrupt input of the cell controller of each cell.

7. The backup power supply system of claim 3, wherein each cell has a discharge control circuit coupled to the cell controller thereof and a charge control circuit coupled to the cell controller thereof,

wherein the primary power sensor is coupled in parallel to the discharge control circuit and the charge control circuit of each cell for transmitting the threshold signal directly thereto;

wherein each discharge control circuit is configured to switch the discharge switch to the closed state thereof in response to receiving the threshold signal indicating the discharge mode and a ready discharge signal from the cell controller indicating the cell is in a ready discharge state;

wherein each charge control circuit is configured to switch the charge switch to the closed state thereof in response to receiving the threshold signal indicating the charge mode and a ready charge signal from the cell controller indicating the cell is in a ready charge state.

8. The backup power supply system of claim 7, wherein each cell further comprises an inverter between the discharge and charge control circuits for preventing simultaneous closure of the charge and discharge switches.

9. The backup power supply system of claim 7, further comprising a power switch control circuit coupled to the cell controller thereof,

wherein the primary power sensor is coupled in parallel to the power switch control circuit for transmitting the threshold signal directly thereto;

wherein the power switch control circuit is configured to switch the power switch to the closed state thereof in response to receiving the threshold signal indicating the discharge mode and a ready discharge signal from the cell controller indicating the cell is in a ready discharge state; and

wherein the power switch control circuit is configured to switch the power switch to the closed state thereof in response to receiving the threshold signal indicating the charge mode and a ready charge signal from the cell controller indicating the cell is in a ready charge state.

10. The backup power supply system of claim 3, wherein each of the battery cells is a metal-air battery with the fuel electrode comprising a metal fuel electrode comprising a metal fuel and the cathode comprising an air cathode.

11. The backup power supply system of claim 10, wherein the charging electrode of each metal-air battery is an oxygen evolving electrode.

12. The backup power supply sys of claim 10, wherein the metal fuel comprises zinc.

13. The backup power supply system of claim 1, wherein the primary power sensor is a voltage sensor.

14. The backup power supply system of claim 1, wherein the primary power sensor is a current sensor.