Battery Balance Circuit, Control Method for Battery Balance and Battery System

• US 20180090950A1
• Filed: 09/28/2017
• Published: 03/29/2018
• Est. Priority Date: 09/29/2016
• Status: Active Grant

• Current Assignee: Joulwatt Technology (Hangzhou) Co. Ltd.
• Original Assignee: Joulwatt Technology (Hangzhou) Co. Ltd.
• Inventors: Huang, Libin, Wong, Pitleong, Ren, Yuancheng, Zhou, Xunwei
• Granted Patent: US 10,644,517 B2
• Time in Patent Office: Days
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• 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 10/486 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: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits
• CPC Class Codes: H03K 19/20 characterised by logic function, e.g. AND, OR, NOR, NOT circuits H03K19/003 - H03K19/01 take precedence
• CPC Class Codes: H03K 5/24 the characteristic being amplitude
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Disclosed a battery balance circuit, a control method for battery balance and a battery system. The battery balance circuit is implemented on basis of a circuit structure having a plurality of cascaded balance modules, in which a judgement of abnormal states of batteries or balance modules is realized together with synchronizations of the detection of battery states and battery balance. When the judgement of abnormal states of batteries (including the abnormal states of battery voltages, battery temperatures and battery currents) is made, the balance modules stop balancing by transferring signals, meanwhile, when the balance modules restore from the abnormal state, they restore balance. The disclosure increases the judgement of abnormal states, and implements detection and alarm at abnormal states.

Claims

1. A battery balance circuit, comprising:

a plurality of balance modules configured to balance a plurality of batteries being coupled in series; and

a control module configured to provide a control signal to a logic input terminal of a first-processing balance module of said plurality of balance modules,

wherein, among said plurality of balance modules, a logic output terminal of a pre-processing balance module is coupled to a logic input terminal of a post-processing balance module, a logic output terminal of a last-processing balance module is connected with said control module,

when one of said plurality of balance modules detects an abnormal state on itself or on a corresponding battery of said plurality of batteries, it stops balancing and provides an abnormal signal representing the abnormal state and transfers said abnormal signal to its post-processing balance modules through corresponding logic output terminals stage by stage, so that all its post-processing balance modules stop balancing, and then said abnormal signal is transferred from said logic output terminal of said last-processing balance module to said control module;

when said control module receives said abnormal signal, it determines that a state of a battery is abnormal and outputs said control signal representing an ending of balancing which is transferred from said first-processing balance module stage by stage, so that all the pre-processing balance modules of said one of said plurality of balance modules stop balancing.

2. The battery balance circuit according to claim 1, wherein said one of said plurality of balance modules comprises:

a first control circuit, a second control circuit and a logic circuit,

said first control circuit is connected with said logic input terminal of said one of said plurality of balance modules, said second control circuit is connected with said logic output terminal of said one of said plurality of balance modules, and said logic circuit is connected between said first control circuit and said second control circuit.

3. The battery balance circuit according to claim 2, wherein said one of said plurality of balance modules further comprises:

a battery detection module configured to detect voltages and/or currents and/or temperatures of a first battery and a second battery corresponding to said one of said plurality of balance modules.

4. The battery balance module according to claim 3, wherein said battery detection module determines whether the voltages and/or currents and/or temperatures of said first battery and said second battery are within a range defined by upper and lower limit values, if the voltages and/or currents and/or temperatures of said first battery and said second battery are beyond said range, said battery detection module determines that the states of corresponding batteries are abnormal and then transfers its determination to said logic circuit of said one of said plurality of balance modules.

5. The battery balance module according to claim 4, wherein, when said battery detection module detects that the voltages and/or currents and/or temperatures of said first battery and said second battery recovers to be within a normal range, said one of said plurality of balance modules starts to balance and provides a normal signal representing a normal state which is transferred to the post-processing balance modules of said one of said plurality of balance modules stage by stage, so that all the post-processing balance modules of said one of said plurality of balance modules begin to balance, said last-processing balance module outputs said normal signal to said control module, said control module receives said normal signal and then provides said control signal representing the normal state to said first-processing balance module which is transferred stage by stage, so that all the pre-processing balance modules of said one of said plurality of balance modules start to balance.

6. The battery balance circuit according to claim 1, further comprising:

an optocoupler, which is connected between said logic output terminal of said last-processing balance module and said control module.

7. The battery balance circuit according to claim 3, wherein, said battery detection module comprises:

a first comparator which has an input terminal for receiving a signal representing a voltage of said first battery and a reference value representing an upper limit value of the voltage of said first battery, and an output terminal being connected with a first input terminal of a NOR gate;

a second comparator which has an input terminal for receiving a signal representing a voltage of said first battery and a reference value representing a lower limit value of the voltage of said first battery, and an output terminal being connected with a second input terminal of said NOR gate;

a third comparator which has an input terminal for receiving a signal representing a voltage of said second battery and a reference value representing an upper limit value of the voltage of said second battery, and an output terminal being connected with a third input terminal of said NOR gate;

a fourth comparator which has an input terminal for receiving a signal representing a voltage of said second battery and a reference value representing a lower limit value of the voltage of said second battery, and an output terminal being connected with a fourth input terminal of said NOR gate,

the output terminal of said NOR gate is connected with said logic circuit.

8. The battery balance circuit according to claim 2, wherein, said control module provides said control signal representing detecting battery states,

when said first-processing balance module receives said control signal representing detecting battery states, it performs detecting battery states and controls said second control circuit by said logic circuit, so that all the post-processing balance modules of said first-processing balance module perform detecting battery states stage by stage and at the same time, the logic circuit in each balance module measures time for detection of battery states,

when a state of a logic input terminal of a balance module has been changed but the duration time of detection of battery states does not reach a first time threshold, the detection of battery states is ineffective and the balance module does not perform balancing;

when the state of the logic input terminal of the balance module has been changed and the duration time of detection of battery states reaches said first time threshold, the balance module performs balancing.

9. The battery balance circuit according to claim 2, wherein, while said plurality of balance modules perform balancing, the logic circuits measure time, when the duration time of battery balance reaches a second time threshold, said plurality of balance modules stop balancing.

10. The battery balance circuit according to claim 2, wherein said first control circuit is a pull-up circuit, said second control circuit is a pull-down circuit, the logic input terminal of each balance module is connected with a control terminal of the pull-down circuit through said logic circuit;

or, said first control circuit is a pull-down circuit, said second control circuit is a pull-up circuit, the logic input terminal of each balance module is connected with a control terminal of the pull-up circuit through said logic circuit.

11. The battery balance circuit according to claim 2, wherein, when said one of said plurality of balance modules detects that a voltage of a battery is abnormal, said one of said plurality of balance modules stops balancing and detecting battery states, and maintains its logic output terminal to be in high level or low level,

said one of said plurality of balance modules provides a signal in high level or low level to the logic input terminals of the post-processing balance modules, so that the logic input terminals of the post-processing balance modules are set to be in high level or low level, and the signal in high level or low level is transferred stage by stage until the logic input terminal of said last-processing balance module is correspondingly set to be in high level or low level,

said last-processing balance module transfers the signal in high level or low level to the control module through its logic output terminal,

said control module determines a state of a battery is abnormal in accordance with the received signal in high level or low level.

16. The battery system, comprising:

a battery balance circuit according to claim 1.

12. A control method for battery balance, comprising:

receiving an abnormal signal from a plurality of balance modules which is configured to balance a plurality of batteries connected in series;

generating a control signal in according to the abnormal signal;

transferring said control signal to said plurality of balance modules; and

stopping balancing when said plurality of balance modules receives said control signal,

wherein, among said plurality of balance modules, a logic output terminal of a pre-processing balance module is connected with a logic input terminal of a post-processing balance module, a logic output terminal of a last-processing balance module is connected with a control module,

when one of said plurality of balance modules detects an abnormal state on itself or on a corresponding battery of said plurality of batteries, it stops balancing and provides an abnormal signal representing the abnormal state which is transferred to its post-processing balance modules through its logic output terminals stage by stage so that all its post-processing balance modules stop balancing, and then said abnormal signal is transferred from said logic output terminal of said last-processing balance module to said control module;

when said control module receives said abnormal signal, it determines that a state of a battery is abnormal and outputs said control signal representing an ending on balancing, said control signal is transferred from said first-processing balance module stage by stage, so that all the pre-processing balance modules of said one of said plurality of balance modules stop balancing.

13. The control method for battery balance according to claim 12, wherein, said one of said plurality of balance modules detects voltages and/or currents and/or temperatures of a first battery and a second battery corresponding to said one of said plurality of balance modules.

14. The control method for battery balance according to claim 13, that said one of said plurality of balance modules detects voltages and/or currents and/or temperatures of a first battery and a second battery corresponding to said one of said plurality of balance modules means:

said one of said plurality of balance modules determines whether the voltages and/or currents and/or temperatures of said first battery and said second battery are within in a range defined by upper and lower limit values, if the voltages and/or currents and/or temperatures of said first battery and said second battery are beyond said range, said one of said plurality of balance modules determines a state of a battery is abnormal.

15. The control method for battery balance according to claim 13, wherein, when said one of said plurality of balance modules detects that the voltages and/or currents and/or temperatures of said first battery and said second battery recover to be within a normal range, it starts to balance and provides a normal signal representing a normal state which is transferred to the post-processing balance modules of said one of said plurality of balance modules stage by stage, so that all the post-processing balance modules of said one of said plurality of balance modules begin to balance, said last-processing balance module outputs the normal signal to said control module, said control module receives the normal signal and then provides said control signal representing a normal state to said first-processing balance module, said control signal is transferred stage by stage, so that all the pre-processing balance modules of said one of said plurality of balance modules start to balance.