Systems and methods for improving cell balancing and cell failure detection

Patent metadata

Field	Value
Publication number	US-10574076-B2
Application number	US-201615384972-A
Country	US
Kind code	B2
Filing date	Dec 20, 2016
Priority date	Dec 20, 2016
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

In one aspect, an embodiment of this invention comprises an energy storage device balancing apparatus. The energy storage device balancing apparatus comprises a balancing circuit and an alarm circuit. Both the balancing circuit and the alarm circuit are coupled to the energy storage device. The balancing circuit is configured to monitor a voltage of the energy storage cell and dissipate energy from the energy storage cell if the voltage is at or above a first reference voltage. The alarm circuit is configured to generate an alarm when the voltage of the energy storage cell is at or above a second reference voltage and dissipate energy from the energy storage cell when the voltage is at or above the second reference voltage.

First claim

What is claimed is:

1. An energy storage device balancing apparatus comprising:
a balancing circuit coupled to an energy storage cell and configured to:
monitor a voltage of the energy storage cell; and
dissipate a first energy from the energy storage cell if the voltage is at or above a first reference voltage; and

an alarm circuit coupled to the energy storage cell and configured to:
generate an alarm when the voltage of the energy storage cell is at or above a second reference voltage, wherein the second reference voltage is greater than the first reference voltage, and
dissipate a second energy from the energy storage cell when the voltage is at or above the second reference voltage.

2. The apparatus of claim 1 , wherein the balancing circuit dissipates the first energy from the energy storage cell by conducting a discharging current through at least one of a passive dissipative component and an active dissipative component.

3. The apparatus of claim 1 , wherein the alarm circuit dissipates the second energy from the energy storage cell by conducting a discharging current through at least one of a passive dissipative component and an active dissipative component.

4. The apparatus of claim 1 , wherein the alarm circuit dissipates the second energy from the energy storage cell by conducting a discharging current through a resistor.

5. The apparatus of claim 1 , wherein the balancing circuit comprises a shunt regulator configured to operate in a comparator mode.

6. An overvoltage alarm conveying apparatus comprising:
an overvoltage alarm circuit configured to generate an overvoltage alarm signal based on a received overvoltage signal;
a Zener diode;
an isolating device configured to provide an isolated output signal; and
a current limiting circuit configured to provide a current flow through the Zener diode to the isolating device when exposed to a voltage exceeding a rating of the Zener diode,
wherein the Zener diode, the isolating device, and the current limiting circuit are configured to maintain the overvoltage alarm signal generated by the overvoltage alarm circuit if the overvoltage alarm circuit is unable to maintain the overvoltage alarm signal itself.

7. The apparatus of claim 6 , where the overvoltage alarm circuit comprises:
a balancing circuit coupled to an energy storage cell and configured to:
monitor a voltage of the energy storage cell; and
dissipate energy from the energy storage cell if the voltage is at or above a first reference voltage; and

an alarm circuit coupled to the energy storage cell and configured to:
generate an alarm when the voltage of the energy storage cell is at or above a second reference voltage, and
dissipate energy from the energy storage cell when the voltage is at or above the second reference voltage.

8. The apparatus of claim 1 , further comprising a controller configured to:
prevent dissipation of energy from the energy storage cell by the balancing circuit and the alarm circuit when the voltage is below the first reference voltage,
operate the balancing circuit to dissipate the first energy from the energy storage cell when the voltage is at or above the first reference voltage, and
operate the balancing circuit and the alarm circuit to dissipate the first and second energies from the energy storage cell when the voltage is at or above the second reference voltage.

9. The apparatus of claim 1 , wherein each of the balancing circuit and the alarm circuit comprises (1) a resistive voltage divider comprising a first resistor and a second resistor and (2) a dissipative leg comprising a passive dissipative component and an active dissipative component, wherein each of the active dissipative components is configured to permit a discharging current to flow through the respective passive and active dissipative components based on a voltage output by the respective resistive voltage divider.

Assignees

• Maxwell Lab

Inventors

• Kaminsky Ilya

Classifications

• G05F1/569

  for protection · CPC title

• H02H9/04 Primary

  responsive to excess voltage (lightning arrestors H01C7/12, H01C8/04, H01G9/18, H01T) · CPC title

• G01R31/3835

  involving only voltage measurements · CPC title

• H02J7/54

  Passive balancing, e.g. using resistors or parallel MOSFETs · CPC title

• H02J7/82 Primary

  Control of state of charge [SOC] · CPC title