Circulating current battery heater

• US 6,259,229 B1
• Filed: 09/22/1999
• Issued: 07/10/2001
• Est. Priority Date: 04/30/1998
• Status: Expired due to Term

• Current Assignee: FCA US LLC (Stellantis NV)
• Original Assignee: Daimler Chrysler Corporation (Mercedes-Benz Group AG), University of Toledo
• Inventors: Stuart, Thomas A., Ashtiani, Cyrus N.
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US09/400,779
• Time in Patent Office: 657 Days
• Field of Search: 320/118, 320/121, 320/127, 320/128, 320/139, 320/145, 320/153
• US Class Current: 320/128
• CPC Class Codes: H01M 10/615 Heating or keeping warm
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 10/633 characterised by algorithms, flow charts, software details or the like
• CPC Class Codes: H01M 10/637 characterised by the use of reversible temperature-sensitive devices, e.g. NTC, PTC or bimetal devices; characterised by control of the internal current flowing through the cells, e.g. by switching means for preventing undesired use or discharge H01M50/572
• CPC Class Codes: H05B 1/0236 for vehicles
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A circuit for heating energy storage devices such as batteries is provided. The circuit includes a pair of switches connected in a half-bridge configuration. Unidirectional current conduction devices are connected in parallel with each switch. A series resonant element for storing energy is connected from the energy storage device to the pair of switches. An energy storage device for intermediate storage of energy is connected in a loop with the series resonant element and one of the switches. The energy storage device which is being heated is connected in a loop with the series resonant element and the other switch. Energy from the heated energy storage device is transferred to the switched network and then recirculated back to the battery. The flow of energy through the battery causes internal power dissipation due to electrical to chemical conversion inefficiencies. The dissipated power causes the internal temperature of the battery to increase. Higher internal temperatures expand the cold temperature operating range and energy capacity utilization of the battery. As disclosed, either fixed frequency or variable frequency modulation schemes may be used to control the network.

Claims

1. A circuit for heating an energy storage device comprising:

a first switching device connected to the energy storage device;

a second switching device connected to the energy storage device; and

an inductor disposed between the first and second switching devices;

wherein the first and second switching devices each include a transistor connected to the energy storage device and connected to the inductor and the first and second switching devices each include a diode connected in parallel with the transistor.

2. A device for circulating energy for performing a heating function comprising:

an energy storage device comprising a plurality of energy storage cells;

a first switching circuit connected to the energy storage device;

a second switching circuit connected to the energy storage device; and

an inductor connected between the first and second switching circuits;

wherein the first and second switching circuits are alternately switched between a current conducting state and a non-conducting state for transferring energy back and forth between the energy device and the inductor;

wherein the first and second switching circuits each include a transistor connected to the energy storage device and connected to the inductor and the first and second switching circuits each include a diode connected in parallel with the transistor.

3. A device for equalizing the energy potential within the cells of an energy storage device comprising:

at least a first storage cell and a second storage cell contained within the energy storage device;

a first switching circuit connected across the first storage cell;

a second switching circuit connected across the second storage cell; and

an inductor connected between the first and second switching circuits;

the first and second switching circuits being alternately switched between a current conducting state and a non-conducting state for transferring energy between the first storage cell, the inductor, and the second storage cell, wherein the first and second switching circuits are alternately switched until a net energy transferred between the first storage cell and the second storage cell approaches zero;

wherein the first and second switching circuits each include a transistor connected to the energy storage device and connected to the inductor and the first and second switching circuits each include a diode connected in parallel with the transistor.

4. A circuit for heating an energy storage device comprising:

a first switching device connected to the energy storage device;

a second switching device connected to the energy storage device;

an inductor disposed between the first and second switching devices; and

a frequency modulation circuit for alternately switching the first and second switching devices between a conducting state and a non-conducting state.

5. A device for circulating energy for performing a heating function comprising:

an energy storage device comprising a plurality of energy storage cells;

a first switching circuit connected to the energy storage device;

a second switching circuit connected to the energy storage device; and

an inductor connected between the first and second switching circuits;

wherein the first and second switching circuits are alternately switched between a current conducting state and a non-conducting state for transferring energy back and forth between the energy device and the inductor; and

a frequency modulation circuit for alternately switching the first and second switching circuits between a conducting state and a non-conducting state.

6. A device for equalizing the energy potential within the cells of an energy storage device comprising:

at least a first storage cell and a second storage cell contained within the energy storage device;

a first switching circuit connected across the first storage cell;

a second switching circuit connected across the second storage cell; and

an inductor connected between the first and second switching circuits;

the first and second switching circuits being alternately switched between a current conducting state and a non-conducting state for transferring energy between the first storage cell, the inductor, and the second storage cell, wherein the first and second switching circuits are alternately switched until a net energy transferred between the first storage cell and the second storage cell approaches zero;

a frequency modulation circuit for alternately switching the first and second switching circuits between a conducting state and a non-conducting state.