Battery pack and connecting circuits of battery modules

• US 9,716,392 B2
• Filed: 12/14/2015
• Issued: 07/25/2017
• Est. Priority Date: 03/16/2015
• Status: Active Grant

• Current Assignee: Thunder Power New Energy Vehicle Development Company Limited
• Original Assignee: Thunder Power New Energy Vehicle Development Company Limited
• Inventors: Lian, Po-Han
• Primary Examiner(s): Isla Rodas, Richard
• Assistant Examiner(s): TORRES RUIZ, JOHALI ALEJANDRA
• Application Number:
  US14/967,359
• Publication Number:
  US 20160276855A1
• Time in Patent Office: 589 Days
• Field of Search: 320121, 320122
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/54 related to batteries
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 58/10 for monitoring or controlling batteries
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/19 Switching between serial connection and parallel connection of battery modules
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60L 58/25 by controlling the electric load
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2220/20 : Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 50/204 : Racks, modules or packs for multiple batteries or multiple cells
• CPC Class Codes: H01M 50/249 : specially adapted for aircraft or vehicles, e.g. cars or trains constructional details of batteries specially adapted for electric vehicles B60L50/64
• CPC Class Codes: H01M 50/574 : Devices or arrangements for the interruption of current
• CPC Class Codes: H02J 7/0013 : acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0024 : Parallel/serial switching of connection of batteries to charge or load circuit
• CPC Class Codes: H02J 7/0029 : with safety or protection devices or circuits
• CPC Class Codes: H02J 7/0031 : using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0048 : Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/005 : Detection of state of health [SOH]
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries

Abstract

A battery pack and connecting circuits of battery modules. The battery pack includes a plurality of battery modules connected in series, wherein each battery module is provided with a connecting circuit. When the battery module operates normally, the connecting circuit serially connects the current battery module to the previous battery module and the succeeding battery module. When the battery module operates abnormally, the connecting circuit selectively disconnects the current battery module, and if it disconnects the current battery module, it directly connects the previous battery module and the succeeding battery module in series. When a battery module is damaged or abnormal, the current damaged battery module can be disconnected from the series battery pack and bypassed. As such, the previous battery module may be directly connected with the succeeding battery module, ensuring the normal connection of the series circuit.

Claims

1. A battery pack in a vehicle, the battery pack comprising:

a plurality of battery modules connected in series through connecting circuits, the plurality of battery modules including a first battery module; and

a control device comprising a processor and a battery monitoring unit, the control device being configured to selectively disconnect any one of the plurality of battery modules from the connecting circuits, wherein;

the battery monitoring unit is configured to monitor multiple working parameters of the battery modules, the working parameters including a first parameter and a second parameter; and

the processor is configured to;

receive the first parameter for the first battery module from the battery monitoring unit;

receive the second parameter for the first battery module from the battery monitoring unit;

determine whether the first battery module is in a first state based on the first parameter and second parameter for the first battery module, wherein the first state indicates the first battery module is in a normal operational state;

determine whether the first battery module is in a second state based on the first parameter and second parameter for the first battery module, wherein the second state indicates the first battery module indicates an abnormal state with a potential danger;

determine whether the first battery is in a third state based on the first parameter and second parameter for the first battery module, wherein the third state indicates the first battery module indicates an abnormal state with an immediate danger;

when the first battery module is determined to be in the second state, generate instructions for removing the first battery module from the connecting circuits, and a first warning to inform the vehicle requires maintenance;

when the first battery module is determined to be in the third state, generate instructions for removing the first battery module from the connecting circuits, and a second warning informing a user of the vehicle to leave the vehicle immediately.

2. The battery pack of claim 1, wherein:

each battery module comprises one or more battery units.

3. The battery pack of claim 1, wherein each battery module is provided with a positive terminal and a negative terminal, and each connecting circuit comprises:

a first switch;

a second switch; and

a bridge, comprising a first end point and a second end point, which are electrically connected with each other;

wherein in the connecting circuit of the first battery module the first switch selectively connects or disconnects the negative terminal of a second battery module in the plurality of battery modules with or from the positive terminal of the first battery module, and correspondingly disconnects or connects the negative terminal of the second battery module from or with the first end point of the bridge;

the second switch selectively connects or disconnects the positive terminal of a third battery module in the plurality of battery modules with or from the negative terminal of the first battery module, and correspondingly disconnects or connects the positive terminal of the third battery module from or with the second end point of the bridge.

4. The battery pack of claim 3, further comprising,

a driving circuit configured to control connection states of the first switch and the second switch according to control signals transmitted by the control device.

5. The battery pack of claim 4, further comprising:

monitoring circuits, which are respectively connected with the plurality of battery modules, and configured to monitor working states of the plurality of battery modules and transmit monitoring signals to the control device; and

a battery monitoring unit provided within the control device and configured to receive the monitoring signals of the monitoring circuits and analyze the monitoring signals,

wherein the control device controls the plurality of driving circuits according to a determination result of the battery monitoring system with respect to the working states of the battery modules.

6. The battery pack of claim 1, wherein the first parameter measures a working voltage for each of the battery modules and the second parameter measures a working temperature for each of the battery modules.

7. The battery pack of claim 6, wherein,

when the working voltage V of the first battery module is less than a lower limit Vbot1 or the working temperature T is greater than an upper limit Ttop1, the battery monitoring unit determines that the first battery module is operating in the abnormal state, and transmits a signal indicating the abnormal state to the processor;

the processor analyzes a working voltage state and a working temperature state of the first battery module to determine whether to disconnect the first battery module operating in the abnormal state and transmit one or more fault signals to a vehicle control unit (VCU);

wherein, when the processor analyzes the working voltage state of the current battery module, the working voltage V of the current battery module is compared with a safety lower limit Vbot2,

the first battery module is determined to be in a state A if Vbot1>

V>

Vbot2, and the first battery module is determined to be in a state B if V<

Vbot2;

when the control device analyzes the working temperature state of the first battery module, the working temperature T of the battery module is compared with a safety upper limit Ttop2, the first battery module is determined to be in a state C if Ttop2>

T>

Ttop1, and the first battery module is determined to be in a state D if T>

Ttop2;

wherein, if the processor determines that the first battery module is in the state A or C, the processor determines that the first battery module is operating in the abnormal state without an immediate danger, and determines not to disconnect the first battery module, maintains the connection of the first battery module, and transmits a fault signal of warning a driver to drive to a maintenance station as early as possible to the VCU;

if the processor determines that the first battery module is in the state B, B and C, A and C, A and D, or D, the processor determines that the current battery module is operating in the abnormal state with a potential danger, and disconnects the current battery module, and transmits a fault signal of warning the driver to drive to the maintenance station immediately to the VCU; and

if the processor determines that the first battery module is in the state B and D, the processor determines that the current battery module is operating in the abnormal state with an immediate danger, and disconnects the abnormal battery module, and transmits a fault signal of warning the driver to leave the vehicle immediately to the VCU.

8. A method of controlling a vehicle battery pack having a plurality of battery modules connected in series through connecting circuits, the plurality of battery modules including a first battery module, each battery module connected to a connecting circuit, said method comprising:

monitoring multiple working parameters of the battery modules, the working parameters including a first parameter and a second parameter;

receive the first parameter for the first battery module from the battery monitoring unit;

receive the second parameter for the first battery module from the battery monitoring unit;

determine whether the first battery module is in a first state based on the first parameter and second parameter for the first battery module, wherein the first state indicates the first battery module is in a normal operational state;

determine whether the first battery module is in a second state based on the first parameter and second parameter for the first battery module, wherein the second state indicates the first battery module indicates an abnormal state with a potential danger;

determine whether the first battery is in a third state based on the first parameter and second parameter for the first battery module, wherein the third state indicates the first battery module indicates an abnormal state with an immediate danger;

when the first battery module is determined to be in the second state, generate instructions for removing the first battery module from the connecting circuits, and a first warning to inform the vehicle requires maintenance;

when the first battery module is determined to be in the third state, generate instructions for removing the first battery module from the connecting circuits, and a second warning informing a user of the vehicle to leave the vehicle immediately.

9. The method of claim 8, wherein each battery module is provided with a positive terminal and a negative terminal, and each connecting circuit comprises:

a first switch;

a second switch;

a bridge, comprising a first end point and a second end point, which are electrically connected with each other;

wherein said disconnecting includes;

in the connecting circuit of the first battery module

the first switch selectively disconnecting the negative terminal of a second battery module in the plurality of battery modules from the positive terminal of the first battery module, and connecting the negative terminal of the second battery module with the first end point of the bridge, and

the second switch selectively disconnecting the positive terminal of a third battery module in the plurality of battery modules from the negative terminal of the first battery module, and connecting the positive terminal of the third battery module with the second end point of the bridge.

10. The method of claim 9, wherein said disconnecting includes transmitting control signals via a control device to control the first switch and the second switch.

11. The method of claim 10, wherein, a driving circuit of the plurality of driving circuits controls connection states of the first switch and the second switch according to the control signals transmitted by the control device.

12. The method of claim 11, further comprising:

monitoring working states of the plurality of battery modules via monitoring circuits respectively connected with the plurality of battery modules;

transmitting monitoring signals from the monitoring circuits to the control device;

receiving the monitoring signals at a battery monitoring unit provided within the control device;

analyzing the monitoring signals via the battery monitoring unit; and

controlling the plurality of driving circuits via the control device according to a determination result of the battery monitoring unit with respect to the working states of the battery modules.

13. The method of claim 12, wherein,

the first parameter measures a working voltage V and the second parameter measures a working temperature T of the plurality of battery modules, and wherein

when the working voltage V of the first battery module is less than a lower limit Vbot1 or the working temperature T is greater than an upper limit Ttop1, the method comprises determining that the first battery module is operating in the abnormal state, and transmitting a signal indicating the abnormal state to a processor of the control device.

14. The method of claim 13, further comprising:

analyzing the working voltage state and the working temperature state of the first battery module to determine whether to disconnect the current battery module operating in the abnormal state and transmit one or more fault signals to a vehicle control unit (VCU);

wherein, when analyzing the working voltage state of the first battery module, the working voltage V of the first battery module is compared with a safety lower limit Vbot2,

the first battery module is determined to be in a state A if Vbot1>

V>

Vbot2, and the first battery module is determined to be in a state B if V<

Vbot2;

when analyzing the working temperature state of the first battery module, the working temperature T of the battery module is compared with a safety upper limit Ttop2, the first battery module is determined to be in a state C if Ttop2>

T>

Ttop1, and the first battery module is determined to be in a state D if T>

Ttop2.