CN114062951A - Battery fault detection device and method - Google Patents

Battery fault detection device and method Download PDF

Info

Publication number
CN114062951A
CN114062951A CN202010751258.0A CN202010751258A CN114062951A CN 114062951 A CN114062951 A CN 114062951A CN 202010751258 A CN202010751258 A CN 202010751258A CN 114062951 A CN114062951 A CN 114062951A
Authority
CN
China
Prior art keywords
battery
batteries
voltage
time
nth
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010751258.0A
Other languages
Chinese (zh)
Inventor
林子闵
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Team Young Technology Co Ltd
Original Assignee
Team Young Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Team Young Technology Co Ltd filed Critical Team Young Technology Co Ltd
Priority to CN202010751258.0A priority Critical patent/CN114062951A/en
Publication of CN114062951A publication Critical patent/CN114062951A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/389—Measuring internal impedance, internal conductance or related variables
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/385—Arrangements for measuring battery or accumulator variables
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/396—Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Secondary Cells (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

The invention provides a battery fault detection device and a method, comprising the following steps: the control unit is used for detecting the open-circuit voltage, the conduction voltage and the conduction current of the battery, the conduction voltage and the conduction current are output for a preset number of N times, and N is greater than 1; the control unit calculates the nth turn-on voltage of the battery, the open-circuit voltage which is closest to the nth turn-on voltage at the detection time and the nth turn-on current of the battery to obtain the nth internal resistance value of the battery, wherein N is a positive integer and N is 1 to N; when n is greater than or equal to 2, calculating the absolute difference between the internal resistance value of the battery at the n-1 th time and the internal resistance value of the battery at the n-1 th time, and dividing the absolute difference by the internal resistance value of the battery at the n-1 th time to obtain the resistance variation of the battery at the n-1 th time; and judging whether the battery is in fault according to the resistance variation of the battery at the nth time.

Description

Battery fault detection device and method
Technical Field
The invention relates to the technical field of batteries, in particular to a battery fault detection device and method.
Background
The prior art has the problem that if one battery fails when a plurality of battery packs are used, the whole plurality of battery packs must stop working, otherwise the explosion or the service life of the battery can be seriously considered. Although different battery fault detection methods are possible at present, the problems are two, firstly, even if a plurality of battery packs on the market know that the battery fault exists, the battery packs can only choose to stop supplying power, and the stable power supply of a back-end system cannot be maintained while the fault is eliminated effectively, and secondly, an accurate and effective battery fault detection method is not available on the market in fact, because the batteries on the market cannot obtain accurate open-circuit voltage (OCV or offline voltage), the open-circuit voltage can be measured after the batteries are offline or before the batteries are started, so that accurate internal resistance of the batteries cannot be effectively obtained during the use period of the batteries, and the general batteries are modeled by resistance and voltage (open-circuit or conducting voltage) to analyze the battery fault behavior; therefore, how to more effectively detect the battery failure needs to be solved.
Disclosure of Invention
To achieve the above object, the present invention discloses a battery fault detection device for use in a charging/discharging system having M batteries, where M is a positive integer, comprising: m switching circuits, wherein the M switching circuits are connected with the M batteries in a one-to-one manner, so that M-X batteries in the M batteries form a charging/discharging loop, X is a positive integer, and the rest X batteries are offline in the charging/discharging loop to serve as X offline batteries; and at least one control unit connected to the M switching circuits and controlling the M switching circuits to form the charge/discharge loop, the control unit being configured to detect an open-circuit voltage, a turn-on voltage, and a turn-on current of each battery, the turn-on voltage and the turn-on current being output a predetermined number N of times, N > 1; wherein the control unit calculates the turn-on voltage of the nth time of each cell and the open-circuit voltage closest to the turn-on voltage of the nth time at a detection time, and the turn-on current of the nth time of each cell to obtain an internal resistance value of the nth time of each cell, N being a positive integer and N being 1 to N; when n is greater than or equal to 2, calculating an absolute difference value between the internal resistance value of the nth-1 th time and the internal resistance value of the nth time of each battery, and taking a result of dividing the absolute difference value by the internal resistance value of the nth-1 th time as a resistance variation of the nth time of each battery, wherein the control unit can simultaneously detect faults and maintain the operation of the charge/discharge system in the process of obtaining the resistance variation of each battery; judging whether each battery has a fault according to the resistance variation of the nth time of each battery; and comparing the M-X batteries with the X offline batteries respectively, taking the X batteries which are judged to be in fault or meet a switching condition offline from the charging/discharging loop to become new offline batteries, and adding the X offline batteries into the charging/discharging loop so as to maintain the M-X batteries in the charging/discharging loop when the M batteries are in system operation.
In order to achieve the above object, the battery failure detection apparatus according to the present invention is configured such that the switching condition satisfies that the resistance variation amount of the battery at the nth time is greater than a resistance difference preset value, and the battery failure is determined.
In order to achieve the above object, the present invention provides a battery failure detection device, wherein the preset resistance difference value ranges from 1% to 5%.
In order to achieve the above object, the battery failure detection device of the present invention is configured such that each of the M switching circuits includes a series switch and a bypass switch, the series switch is connected in series with the battery, the bypass switch is connected with the series switch and the battery and is connected in parallel with the series switch and the battery, and the control unit is configured to drive the series switch and the bypass switch of the switching circuit coupled to each battery to be turned off or on.
In order to achieve the above object, the battery failure detection apparatus of the present invention further includes a voltage measurement unit and a current measurement unit, wherein the voltage measurement unit and the current measurement unit are electrically connected to the M batteries, respectively, for measuring the open-circuit voltage, the on-state voltage, and the on-state current of each battery, and the control unit is electrically connected to the voltage measurement unit and the current measurement unit, respectively, for detecting the open-circuit voltage, the on-state voltage, and the on-state current of each battery.
In order to achieve the above object, the battery failure detection apparatus of the present invention further includes an alarm unit for generating an alarm signal when the control unit determines that the battery has failed.
Another primary object of the present invention is to provide a battery fault detection method for use in a charge/discharge system having M batteries, M being a positive integer, comprising: the control unit is connected with the M switching circuits and controls the M switching circuits to enable M-X batteries in the M batteries to form a charging/discharging loop, X is a positive integer, and the rest X batteries are offline in the charging/discharging loop to serve as X offline batteries; the control unit is used for detecting an open-circuit voltage, a conducting voltage and a conducting current of each battery, the conducting voltage and the conducting current are output for a preset number of N times, and N is greater than 1; the control unit calculates the turn-on voltage of the nth time of each cell and the open-circuit voltage closest to the turn-on voltage of the nth time at a detection time, and the turn-on current of the nth time of each cell to obtain an internal resistance value of the nth time of each cell, N being a positive integer and N being 1 to N, and when N is greater than or equal to 2, calculates an absolute difference between the internal resistance value of the nth-1 time and the internal resistance value of the nth time of each cell, and divides a result of the absolute difference and the internal resistance value of the nth-1 time as a resistance variation of the nth time of each cell, the control unit being capable of simultaneously performing fault detection and maintaining operation of the charge/discharge system during the process of obtaining the resistance variation of each cell; judging whether each battery has a fault according to the resistance variation of the nth time of each battery; and comparing the M-X batteries with the X offline batteries respectively, taking the X batteries which are judged to be in fault or meet a switching condition offline from the charging/discharging loop to become new offline batteries, and adding the X offline batteries into the charging/discharging loop so as to maintain the M-X batteries in the charging/discharging loop when the M batteries are in system operation.
In order to achieve the above object, the present invention provides a battery failure detection method, wherein the switching condition is that the n-th resistance variation of the battery is greater than a preset resistance difference value, and the battery failure is determined.
In order to achieve the above object, the present invention discloses a battery failure detection method, wherein the preset resistance difference value ranges from 1% to 5%.
In order to achieve the above object, a battery failure detection method according to the present invention is characterized in that the switching condition is that, during discharging, the storage capacity of X batteries having the smallest storage capacity among the M-X batteries is smaller than the storage capacity of the X offline batteries.
In order to achieve the above object, the battery failure detection method according to the present invention is configured such that, during discharging, the switching condition is that the on-voltage of X batteries with the lowest on-voltage among the M-X batteries is smaller than the open-circuit voltage of the X offline batteries.
In order to achieve the above object, according to the present invention, the control unit calculates the on-voltage of the nth time of each cell, the open-circuit voltage closest to the on-voltage of the nth time at the detection time, and the on-current of the nth time of each cell to obtain the internal resistance value of the nth time of each cell, where N is a positive integer and N is 1 to N, and specifically: satisfies the following formula (1): r (n) ═ VBC(n)–VOC) (n), wherein R (n) represents the n-th calculated internal resistance value of each cell, VBC(n) denotes the on-voltage, V, of the nth detection of each cellOCRepresents the open circuit voltage of each cell closest to the turn-on voltage at the nth time in the detection time, and i (n) represents the turn-on current of the nth detection of each cell.
Still another primary object of the present invention is to provide a method for detecting a battery failure of a single battery, comprising: the control unit is used for detecting an open-circuit voltage, a conducting voltage and a conducting current of a battery, wherein the conducting voltage and the conducting current are output for a preset number of N times, and N is greater than 1; the control unit calculates the turn-on voltage of the nth time of the battery, the open-circuit voltage closest to the turn-on voltage of the nth time at a detection time, and the turn-on current of the nth time of the battery to obtain an internal resistance value of the nth time of the battery, wherein N is a positive integer and N is 1 to N; when n is greater than or equal to 2, calculating an absolute difference value between the internal resistance value of the battery at the n-1 th time and the internal resistance value of the battery at the n-1 th time, and taking a result of dividing the absolute difference value by the internal resistance value of the battery at the n-1 th time as a resistance variation of the battery at the n-1 th time; and judging whether the battery is in fault according to the resistance variation of the battery at the nth time.
In order to achieve the above object, the battery failure detecting method according to the present invention is characterized in that the switching condition is that the n-th resistance variation of the battery is larger than a preset resistance difference value, the preset resistance difference value is set to be in a range of 1% to 5%, and the battery failure is determined.
The detailed structure, characteristics, assembly or use of the battery failure detection device and method provided by the present invention will be described in the following detailed description of the embodiments. However, it will be understood by those skilled in the art that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
Drawings
Fig. 1 is a block diagram of a charging/discharging system having M cells according to an embodiment of the present invention, in which M is 6;
FIG. 2 is a graph of voltage variation data for a battery failure during charging of a battery in accordance with one embodiment of the present invention;
fig. 3 is a data diagram illustrating the variation of internal resistance of a battery during a charging failure according to an embodiment of the present invention.
Detailed Description
The constituent elements, steps and effects of the battery failure detection apparatus and method according to the present invention will be described with reference to the accompanying drawings, which illustrate the preferred embodiments of the present invention, but the elements, dimensions and appearance of the battery failure detection apparatus and method are merely used to illustrate the technical features of the present invention, and the present invention is not limited thereto.
Referring to fig. 1 showing an embodiment of a charging/discharging system 10 having M batteries according to the present invention, where M is 6, the charging/discharging system 10 having M batteries according to the present invention is applied to an electric power system, and the electric power system may be a portable computer, a mobile phone, an electric vehicle, an electric locomotive, a portable small appliance, and other various devices that need to be operated by supplying power through the batteries.
As shown in fig. 1, a charging/discharging system 10 having M batteries is connected to the power system through two ends 11, 13, where M is 6, and includes six batteries 31-36 and a battery failure detection device 50, the battery failure detection device 50 includes six switching circuits 51-56 and a control unit 57, the number of the switching circuits 51-56 is equal to the number of the batteries, the six switching circuits 51-56 are connected to the six batteries 31-36 one-to-one, the control unit 57 is connected to the six switching circuits 51-56, and controls the six switching circuits 51-56 to form a charging/discharging loop. In other words, the control unit 57 has a plurality of connection ports for connecting the six switching circuits 51-56, and the control unit 57 has a plurality of connection ports as can be understood in the art, which is not described herein.
For example, the control unit 57 selects five batteries 31-35 from the six batteries 31-36 to form a charging/discharging loop, and detects the respective electrical properties of the six batteries 31-36, wherein the battery 36 not allocated in the charging/discharging loop is defined as an off-line battery.
It should be noted that, the total voltage of the total number of battery configurations of the conventional power system is equal to the voltage required by the power system, i.e. there is no extra off-line (idle) battery, but the present invention additionally adds one battery in addition to configuring the corresponding battery according to the amount of power required by the power system, therefore, in this embodiment, M is 6, the charging/discharging loop formed by M-1 (equal to 5) batteries is the amount of power required by the power system, and the off-line battery can be left to be allocated.
Although the number of the off-line batteries is one in the embodiment, in practice, the number of the off-line batteries may be two or more. When the off-line batteries are designed to be two or more, the number of the batteries of the charging/discharging loop is M-2 or M-X, and X represents that more than two off-line batteries exist.
When the battery 35 meets a switching condition as a result of comparing the respective electrical properties of the five batteries 31-35 with the electrical properties of the offline battery 36, the control unit 57 selects the battery 35 to be disconnected from the charging/discharging circuit, and adds the offline battery 36 to the charging/discharging circuit, so that the disconnected battery 35 becomes a new offline battery.
Since the control unit 57 includes a charging application and a discharging application, the switching condition also varies with the charging application and the discharging application, and the difference will be described in detail later.
The offline battery can effectively use the Lexate's principle to make the internal chemical composition of the battery obtain better balance at rest. In addition, the battery is disconnected from the charging/discharging loop (i.e. the off-line battery) for measurement, so as to avoid the voltage measurement error and further improve the electrical property estimation accuracy of the off-line battery.
In addition, when any one of the six batteries is in an abnormal state, such as an abnormal change in overvoltage, low voltage or internal resistance, during the charging or discharging process, the control unit 57 can detect the abnormal battery state and turn the battery off-line, thereby improving the safety of the plurality of batteries.
Each switching circuit 51-56 includes a series switch 511, 521, 531, 541, 551, 561 and a bypass switch 513, 523, 533, 543, 553, 563, the series switch 511, 521, 531, 541, 551, 561 connecting the batteries 31-36 in series, the bypass switch 513, 523, 533, 543, 553, 563 connecting the series switch 511, 521, 531, 541, 551, 561 and the batteries 31-36, and forming a parallel connection with the series switch 511, 521, 531, 541, 551, 561 and the batteries 31-36.
The charge/discharge loop is formed by controlling the plurality of switching circuits 51 to 56 by the control unit 57. For example, when the battery 35 in the charging/discharging circuit is switched to a new offline battery and the original offline battery 36 is added to the charging/discharging circuit, the control unit 57 may turn off the series switch 551 of the switching circuit 55 connected to the new offline battery 35 and turn on the bypass switch 553, so that the new offline battery 35 is not charged or discharged, and turn on the series switch 561 of the switching circuit 56 connected to the original offline battery 36 and turn off the bypass switch 563, so that the original offline battery 36 is added to the charging/discharging circuit for charging or discharging.
The above description shows the composition of the charging/discharging system 10 with M batteries according to the present invention, and the discharging application and the charging application, and the control operation of the battery failure detection apparatus 50 and the method will be described in detail later. In other words, the charging/discharging circuit is used for charging or discharging, rather than for both charging and discharging.
An embodiment of the present invention is implemented by equating the battery to a voltage source and a resistor that, when the battery fails, the generation of leakage or short circuit is simulated by connecting a resistor element in parallel, the voltage measured by the prior art through a voltage method after the battery fails is reduced, whether the battery fails or not is judged by comparing the voltage difference between the normal mode and the failure mode, fig. 2 is a voltage variation data graph of the battery failure during the charging of the battery according to an embodiment of the present invention, for example, the full-charge voltage of the lithium ion battery is 4.2 volts (V), the voltage of the battery rises linearly during the charging of the battery, the leakage of the battery occurs during the charging, the measured voltage drops from 4V to 3.96V instantly, the voltage drop difference value is 0.04V, namely, the voltage drop percentage is 1%, which easily falls within a reasonable measurement error range of the voltage measurement device, and it is impossible to accurately judge whether the battery leaks electricity.
In the same experiment as that shown in fig. 2, when the internal resistance of the battery suddenly decreases if the battery fails, such as abnormal leakage, the present invention calculates the internal resistance of the battery by using the open-circuit voltage, the on-state voltage and the on-state current of the battery, calculates an absolute difference between the previous internal resistance and the current internal resistance of each battery, and divides the absolute difference by the previous internal resistance, and determines the battery failure as a current resistance variation of each battery, where the current resistance variation of the battery is greater than a preset resistance difference value, fig. 3 is a data diagram of internal resistance variation of the battery during charging failure, such as a full-charge voltage of the lithium ion battery of 4.2V, and the internal resistance of the battery during charging linearly increases, and leakage occurs during charging of the battery, the internal resistance value of the battery is instantly reduced from 0.30Ohm (Ohm) of the previous time to 0.26Ohm of the current time, the absolute difference value of the internal resistance value of the battery is calculated to be 0.04Ohm, the result of dividing the absolute difference value of 0.04Ohm by the internal resistance value of 0.30Ohm of the previous time is used as the current resistance variation of 13.33% of the battery, the current resistance variation of 13.33% of the battery is larger than a resistance difference preset value, the set range of the resistance difference preset value is between 1% and 5%, the detection sensitivity of the invention in the abnormal state of the battery is found to be superior to the battery fault detection of the traditional voltage method of the figure 2, the battery fault leakage can be accurately and effectively judged, the expected effect is achieved, and the resistance difference change range of the battery can be determined according to the measurement resolution preset value.
Similarly, the present invention is also applicable to open circuit fault detection, when a battery is open-circuited, the internal resistance value of the battery will suddenly increase, the present invention calculates the internal resistance value of the battery by using the open circuit voltage, the on-state voltage and the on-state current of the battery, calculates an absolute difference between the previous internal resistance value and the current internal resistance value of each battery, and divides the absolute difference and the previous internal resistance value to obtain a result as a current resistance variation of each battery, the current resistance variation of the battery is greater than a resistance difference preset value, and the set range of the resistance difference preset value is between 1% and 5% or a larger preset value, and then the battery fault is determined, i.e. the battery fault is open-circuited.
Referring to fig. 1 and 3, a battery failure detection apparatus 50 is provided for use in a six-cell charge/discharge system 10, packComprises the following steps: six switching circuits 51-56, each of the switching circuits 51-56 comprises a series switch 511, 521, 531, 541, 551, 561 and a bypass switch 513, 523, 533, 543, 553, 563, the series switches 511, 521, 531, 541, 551, 561 are connected in series with the batteries 31-36, the bypass switches 513, 523, 533, 543, 553, 563 are connected with the series switches 511, 521, 531, 541, 551, 561 and the batteries 31-36, and are connected in parallel with the series switches 511, 521, 531, 541, 551, 561 and the batteries 31-36, the control unit 57 is configured to drive the series switches 511, 521, 531, 541, 551, 561 and the bypass switches 513, 523, 533, 543, 553, 563 of the switching circuits 51-56 coupled correspondingly to each of the batteries 31-36 to be turned on or off, the six switching circuits 51-56 are connected one-to one by one, for example, five batteries 31-35 of the six batteries 31-36 form a charging/discharging loop, and the other battery 36 is taken off-line in the charging/discharging loop as an off-line battery; and a control unit 57 connected to the six switching circuits 51 to 56 and controlling the six switching circuits 51 to 56 to form the charge/discharge circuit, the control unit 57 being configured to detect an open-circuit voltage, a turn-on voltage and a turn-on current of each of the batteries 31 to 36, the turn-on voltage and the turn-on current being output for a predetermined number of N times, N>1; the control unit 57 calculates the on-voltage of the nth time of each of the batteries 31 to 36, the open-circuit voltage closest to the on-voltage of the nth time at the detection time, and the on-current of the nth time of each of the batteries 31 to 36 to obtain an internal resistance value of the nth time of each of the batteries 31 to 36, where N is a positive integer and N is 1 to N, and specifically: satisfies the following formula (1): r (n) ═ VBC(n)–VOC) (n), wherein R (n) represents the n-th calculated internal resistance value, V, of each cell 31-36BC(n) represents the on-voltage, V, detected for the nth time for each cell 31-36OCRepresents the open circuit voltage of each cell 31-36 closest to the turn-on voltage at the nth detection time, I (n) represents the turn-on current of each cell 31-36 detected at the nth detection time, and calculates the turn-on current of each cell 31-36 when n is greater than or equal to 2An absolute difference value between the internal resistance value at the n-1 th time and the internal resistance value at the n-1 th time, and a result of dividing the absolute difference value by the internal resistance value at the n-1 st time is used as a resistance change amount at the n-th time of each of the batteries 31 to 36, and the control unit can simultaneously perform fault detection and maintain the operation of the charge/discharge system during the process of obtaining the resistance change amount of each of the batteries; and comparing the five batteries 31-35 with the one offline battery 36, respectively, and taking the battery 35 determined as a faulty battery or meeting a switching condition offline from the charging/discharging loop to a new offline battery, and adding the offline battery 36 into the charging/discharging loop, so that the six batteries maintain the five batteries in the charging/discharging loop during system operation, for example, the fault or the switching condition is that the resistance variation quantity of the nth time of the battery 35 is greater than a resistance difference preset value, and determining that the battery 35 is faulty, wherein the resistance difference preset value is within a set range of 1% to 5%.
Referring to fig. 1 and 3, the battery failure detection apparatus 50 of the present invention further includes a voltage measurement unit (not shown) and a current measurement unit (not shown), wherein the voltage measurement unit (not shown) and the current measurement unit (not shown) are electrically connected to the six batteries 31-36 respectively for measuring the open-circuit voltage, the on-state voltage and the on-state current of each battery 31-36 respectively, and the control unit 57 is electrically connected to the voltage measurement unit (not shown) and the current measurement unit (not shown) for detecting the open-circuit voltage, the on-state voltage and the on-state current of each battery 31-36 respectively.
With continuing reference to fig. 1 and 3, the battery failure detection apparatus 50 of the present invention further includes an alarm unit (not shown) for sending an alarm signal (not shown) when the control unit 57 determines that the batteries 31-36 are failed.
Another embodiment of the present invention (not shown) is similar to the aforementioned embodiment of the battery failure detection apparatus 50, and the difference is only that a plurality of control units, i.e. a battery failure detection apparatus, are provided for use in a charging/discharging system having M batteries, where M is a positive integer, including: m switching circuits, wherein the M switching circuits are connected with the M batteries in a one-to-one manner, so that M-X batteries in the M batteries form a charging/discharging loop, X is a positive integer, and the rest X batteries are offline in the charging/discharging loop to serve as offline batteries; and a plurality of control units, the control units are electrically connected with each other, are distributed and connected with the M switching circuits, and control the M switching circuits to form the charging/discharging loop, so as to detect an open-circuit voltage, a conduction voltage and a conduction current of each distributed battery, the conduction voltage and the conduction current are output for a preset number of N times, and N is greater than 1; wherein the control units calculate the turn-on voltage of the nth time of each cell allocated and the open-circuit voltage closest to the turn-on voltage of the nth time at a detection time, and the turn-on current of the nth time of each cell allocated to obtain an internal resistance value of the nth time of each cell allocated, N being a positive integer and N being 1 to N; when n is greater than or equal to 2, calculating an absolute difference value between the internal resistance value of each cell distributed at the n-1 th time and the internal resistance value of each cell distributed at the n-1 th time, and dividing a result of the absolute difference value by the internal resistance value of each cell distributed at the n-1 th time to obtain a resistance variation of each cell distributed at the n-th time, wherein the cells can be simultaneously detected by faults and the operation of the charge/discharge system can be maintained in the process of obtaining the resistance variation of each cell distributed by the control unit; the control unit judges whether each battery has a fault according to the resistance variation of the nth time of each battery; and comparing the M-X batteries with the X offline batteries respectively, taking the X batteries which are judged to be in fault or meet a switching condition offline from the charging/discharging loop to become new offline batteries, and adding the X offline batteries into the charging/discharging loop so as to maintain the M-X batteries in the charging/discharging loop when the M batteries are in system operation.
With continuing reference to FIGS. 1 and 3 and the foregoing description of the battery failure detection apparatus 50, an embodiment of the present invention is describedThe steps of the battery failure detection method for use in a charging/discharging system 10 having M batteries shown in fig. 1, M being a positive integer, M being 6 in the present embodiment, but the battery failure detection method of the present invention is not limited thereto; first, step S1: a control unit 57 connected to the six switching circuits 51-56 and controlling the six switching circuits 51-56 to make five of the six batteries 31-36 form a charging/discharging loop, for example, initially selecting five batteries 31-35 of the batteries 31-36 as the charging loop, and taking the remaining 1 battery 36 offline in the charging/discharging loop as an offline battery; step S2: the control unit 57 is configured to detect an open-circuit voltage, a turn-on voltage and a turn-on current of each of the batteries 31 to 36, where the turn-on voltage and the turn-on current are output for a predetermined number of times N, N>1; step S3: the control unit 57 calculates the on-voltage of the nth time of each of the cells 31 to 36 and the open-circuit voltage closest to the on-voltage of the nth time at the detection time, and the on-current of the nth time of each of the cells 31 to 36 to obtain an internal resistance value of the nth time of each of the cells 31 to 36, where N is a positive integer and N is 1 to N, and specifically: satisfies the following formula (1): r (n) ═ VBC(n)–VOC) (n), wherein R (n) represents the n-th calculated internal resistance value, V, of each cell 31-36BC(n) represents the on-voltage, V, detected for the nth time for each cell 31-36OCI (n) the open circuit voltage of each cell 31-36 closest to the turn-on voltage at the n-th time at the detection time, i (n) the turn-on current of each cell 31-36 detected at the n-th time, when n is greater than or equal to 2, calculating an absolute difference between the internal resistance value of the n-1-th time and the internal resistance value of the n-th time of each cell 31-36, and dividing a result of the absolute difference by the internal resistance value of the n-1-th time as a resistance change amount of each cell 31-36 at the n-th time, the control unit being capable of simultaneously performing fault detection and maintaining the operation of the charge/discharge system in the process of obtaining the resistance change amount of each cell; step S4: judging whether each battery 31-36 is faulty or not according to the resistance change amount of each battery 31-36 at the nth time; and step S5: for example in the fiveAs a result of comparing the respective electrical properties of the batteries 31-35 with the electrical properties of the off-line batteries 36, when one of the batteries 35 of the five batteries 31-35 meets a switching condition, or when one of the batteries 35 of the five batteries 31-35 determines that there is a fault, the control unit 57 controls the switching circuit 55 connected to the battery 35 to take the battery 35 off-line from the charging/discharging loop to become a new off-line battery, so as to allow the battery 35 to temporarily rest, and at the same time, add the off-line battery 36 to the charging/discharging loop, and allow the six batteries 31-36 to maintain the 5 batteries in the charging/discharging loop during system operation.
Referring to fig. 1 and fig. 3, in the battery failure detection method according to the present invention, for example, the switching condition is that the resistance variation amount of the nth battery 35 of one of the batteries 31 to 35 is greater than a preset resistance difference value, and the preset resistance difference value is set to range from 1% to 5%, so as to determine that the battery 35 is failed.
The above-described embodiments are illustrative of the battery failure detection method when charging, which can also be used when discharging a battery with reference to fig. 1, but since if a battery fails when discharging, the battery storage capacity thereof is more rapidly decreased, and therefore, the comparison method of the alternate rest electric quantity of the charge/discharge system having six batteries 31 to 36 of fig. 1 can be used for replacement, that is, the battery failure detection method of the present invention, in the embodiment, when discharging, it is determined that a switching condition is satisfied, for example, the switching condition is that the storage capacity of the one 35 having the smallest storage capacity among the five batteries 31 to 35 is smaller than the storage capacity of the off-line battery 36, or when discharging, the switching condition means that the turn-on voltage of the cell 35 with the lowest turn-on voltage among the five cells 31-35 is less than the open-circuit voltage of the offline cell 36.
In another embodiment (not shown) of the present invention, the steps of the battery failure detection method are used in a charge/discharge system having M batteries, similar to the aforementioned embodiment of the battery failure detection method, and the difference is only between a plurality of control units, first, step S1: a plurality of control units electrically connected to each other for distributing and connecting the M switching circuitsA circuit for controlling the M switching circuits to form the charge/discharge circuit; step S2: the control units are used for detecting an open-circuit voltage, a conduction voltage and a conduction current of each distributed battery, and the conduction voltage and the conduction current are output for a preset number of N times>1; step S3: the control units calculate the conducting voltage of the nth time of each distributed battery, the open-circuit voltage which is closest to the conducting voltage of the nth time at the detection time, and the conducting current of the nth time of each distributed battery to obtain an internal resistance value of the nth time of each distributed battery, wherein N is a positive integer and N is 1 to N, and specifically: satisfies the following formula (1): r (n) ═ VBC(n)–VOC) (n), wherein R (n) represents the n-th calculated internal resistance value of each cell, VBC(n) denotes the on-voltage, V, of the nth detection of each cellOCRepresents the open circuit voltage of each cell closest to the turn-on voltage at the nth time in detection time, and i (n) represents the turn-on current of the nth detection of each cell; when n is greater than or equal to 2, calculating an absolute difference value between the internal resistance value of each cell distributed at the n-1 th time and the internal resistance value of each cell distributed at the n-1 th time, and dividing a result of the absolute difference value by the internal resistance value of each cell distributed at the n-1 th time to obtain a resistance variation of each cell distributed at the n-th time, wherein the cells can be simultaneously detected by faults and the operation of the charge/discharge system can be maintained in the process of obtaining the resistance variation of each cell distributed by the control unit; step S4: judging whether each battery has a fault according to the resistance variation of the nth time of each battery; and step S5: comparing the M-X batteries with the X offline batteries respectively, taking the X batteries which are judged to be in fault or meet a switching condition offline from the charging/discharging loop to become new offline batteries, and adding the X offline batteries into the charging/discharging loop so as to maintain the M-X batteries in the charging/discharging loop when the system is in operation.
A battery failure detection method (not shown) according to another embodiment of the present invention for detecting a failure in a single battery includes: first, step S11: a control unit 57 for detecting an open-circuit voltage, a turn-on voltage and a turn-on current of a battery, wherein the open-circuit voltage of the battery can be detected or switched off to disconnect the battery when the power system is shut down or the battery is not needed to supply power, the turn-on voltage and the turn-on current are output for a predetermined number N times, where N > 1; step S12: the control unit 57 calculates the on voltage of the battery at the nth time and the open-circuit voltage closest to the on voltage at the nth time at the detection time, and the on current of the battery at the nth time to obtain an internal resistance value of the battery at the nth time, N being a positive integer and N being 1 to N; step S13: when n is greater than or equal to 2, calculating an absolute difference value between the internal resistance value of the battery at the n-1 th time and the internal resistance value of the battery at the n-1 th time, and taking a result of dividing the absolute difference value by the internal resistance value of the battery at the n-1 th time as a resistance variation of the battery at the n-1 th time; and step S14: and judging whether the battery is in fault according to the resistance variation of the battery at the nth time.
In step S12, the control unit 57 calculates the on-voltage of the battery at the nth time and the open-circuit voltage closest to the on-voltage at the nth time at the detection time, and the on-current of the battery at the nth time to obtain an internal resistance value of the battery at the nth time, where N is a positive integer and N is 1 to N, specifically: satisfies the following formula (1): r (n) ═ VBC(n)–VOC) (n), wherein R (n) represents the internal resistance value calculated the nth time of the battery, VBC(n) represents the on-voltage, V, of the nth detection of the batteryOCIndicating the open circuit voltage of the battery closest to the turn-on voltage for the nth time at a detection time, i (n) indicating the turn-on current of the battery detected for the nth time, calculating an absolute difference value between the internal resistance value of the battery detected for the n-1 th time and the internal resistance value of the battery detected for the nth time when n is greater than or equal to 2, and dividing a result of the absolute difference value by the internal resistance value of the n-1 th time as a resistance variation amount of the battery detected for the nth time, wherein the control unit controls the open circuit voltage of the battery to be the most similar to the turn-on voltage for the nth time, and the control unit controls the open circuit voltage of the battery to be the most similar to the open circuit voltage of the battery detected for the nth time, and the conduction current of the battery to be the most similar to the current of the nth time at the detection time when n is greater than or equal to 2In the process of obtaining the resistance variation amount of the battery, the battery can be simultaneously fault-detected and the operation of the charge/discharge system is maintained.
In step S14, it is determined whether the battery is faulty according to the resistance variation of the battery at the nth time, where the resistance variation is greater than a preset resistance difference value, and the preset resistance difference value ranges from 1% to 5%, and the battery is determined to be faulty.
Finally, it is emphasized that the components disclosed in the embodiments of the present invention are merely examples, which are not intended to limit the scope of the present application, and other equivalents and modifications may be substituted for the components disclosed in the embodiments of the present invention.

Claims (13)

1. A battery failure detection apparatus for use in a charge/discharge system having M cells, M being a positive integer, comprising:
m switching circuits, wherein the M switching circuits are connected with the M batteries in a one-to-one manner, so that M-X batteries in the M batteries form a charging/discharging loop, X is a positive integer, and the rest X batteries are offline in the charging/discharging loop to serve as X offline batteries; and
at least one control unit connected to the M switching circuits and controlling the M switching circuits to form the charge/discharge circuit, the control unit detecting an open circuit voltage, a turn-on voltage and a turn-on current of each battery, the turn-on voltage and the turn-on current being output a predetermined number N of times, N >1,
wherein the control unit calculates the turn-on voltage of the nth time of each cell and the open-circuit voltage closest to the turn-on voltage of the nth time at a detection time, and the turn-on current of the nth time of each cell to obtain an internal resistance value of the nth time of each cell, N being a positive integer and N being 1 to N, calculates an absolute difference between the internal resistance value of the nth-1 time and the internal resistance value of the nth time of each cell when N is greater than or equal to 2, and divides the result of the absolute difference and the internal resistance value of the nth-1 time as a resistance variation of the nth time of each cell, the control unit being capable of simultaneously performing fault detection and maintaining the operation of the charge/discharge system during the process of obtaining the resistance variation of each cell,
judging whether each battery is in fault according to the nth resistance variation of each battery, comparing the M-X batteries with the X offline batteries respectively, taking the X batteries which are judged to be in fault or meet a switching condition offline from the charging/discharging loop to become new offline batteries, adding the X offline batteries into the charging/discharging loop, and keeping the M-X batteries in the charging/discharging loop when the M batteries are in system operation.
2. The battery failure detection apparatus according to claim 1, wherein the switching condition is that the resistance change amount of the battery at the n-th time is satisfied to be larger than a resistance difference preset value, and the battery failure is determined.
3. The battery failure detection apparatus according to claim 2, wherein the preset value of the resistance difference is set to range from 1% to 5%.
4. The battery failure detection apparatus according to claim 1, wherein each of the M switching circuits includes a series switch and a bypass switch, the series switch connects the battery in series, the bypass switch connects the series switch and the battery and forms a parallel connection with the series switch and the battery, and the control unit is configured to drive the series switch and the bypass switch of the switching circuit coupled to each battery in correspondence to turn off or on.
5. The battery fault detection device according to claim 1, further comprising a voltage measurement unit and a current measurement unit, the voltage measurement unit and the current measurement unit being electrically connected to the M batteries, respectively, for measuring the open-circuit voltage, the on-state voltage, and the on-state current of each battery, respectively, and the control unit being electrically connected to the voltage measurement unit and the current measurement unit, respectively, for detecting the open-circuit voltage, the on-state voltage, and the on-state current of each battery.
6. The battery failure detection apparatus according to claim 1, further comprising an alarm unit that issues an alarm signal when the control unit determines that the battery has failed.
7. A battery fault detection method for use in a charge/discharge system having M batteries, M being a positive integer, comprising:
the control unit is connected with the M switching circuits and controls the M switching circuits to enable M-X batteries in the M batteries to form a charging/discharging loop, X is a positive integer, and the rest X batteries are offline in the charging/discharging loop to serve as X offline batteries;
the control unit is used for detecting the open-circuit voltage, the conducting voltage and the conducting current of each battery, the conducting voltage and the conducting current are output for a preset number of N times, and N is greater than 1;
the control unit calculates the turn-on voltage of an nth time of each cell and the open-circuit voltage closest to the turn-on voltage of the nth time at a detection time, and the turn-on current of the nth time of each cell to obtain an internal resistance value of the nth time of each cell, N being a positive integer and N being 1 to N, and when N is greater than or equal to 2, calculates an absolute difference between the internal resistance value of the nth-1 time and the internal resistance value of the nth time of each cell, and divides the absolute difference by the internal resistance value of the nth-1 time as a resistance variation of the nth time of each cell, the control unit being capable of simultaneously being fault-detected and maintaining the operation of the charge/discharge system in the process of obtaining the resistance variation of each cell;
judging whether each battery has a fault according to the resistance variation of the nth time of each battery; and
comparing the M-X batteries with the X offline batteries respectively, taking the X batteries which are judged to be in fault or meet a switching condition offline from the charging/discharging loop to become new offline batteries, and adding the X offline batteries into the charging/discharging loop so as to maintain the M-X batteries in the charging/discharging loop when the system is in operation.
8. The battery failure detection method according to claim 7, wherein the switching condition is that the resistance change amount of the battery at the n-th time is satisfied to be larger than a resistance difference preset value, and the battery failure is determined.
9. The battery failure detection method according to claim 8, wherein the preset value of the resistance difference is set to range from 1% to 5%.
10. The battery failure detection method according to claim 7, wherein the switching condition is that, at the time of discharge, the storage capacity of X batteries having the smallest storage capacity among the M-X batteries is smaller than the storage capacity of the X offline batteries.
11. The battery fault detection method according to claim 7, wherein, at the time of discharge, the switching condition is that the on-voltage of X batteries, among the M-X batteries, whose on-voltage is lowest is smaller than the open-circuit voltage of the X offline batteries.
12. The battery failure detection method according to claim 7, wherein the control unit calculates the on-voltage of the nth time of each battery, the open-circuit voltage that is closest to the on-voltage of the nth time at the detection time, and the on-current of the nth time of each battery to obtain the internal resistance value of the nth time of each battery, N being a positive integer and N being 1 to N, specifically: satisfies the following formula (1): r (n) ═ VBC(n)–VOC) (n), wherein R (n) represents the nth count of each cellCalculated said internal resistance value, VBC(n) denotes the on-voltage, V, of the nth detection of each cellOCRepresents the open circuit voltage of each cell closest to the turn-on voltage at the nth time in the detection time, and i (n) represents the turn-on current of the nth detection of each cell.
13. A battery fault detection method, comprising:
the control unit is used for detecting the open-circuit voltage, the conducting voltage and the conducting current of the battery, wherein the conducting voltage and the conducting current are output for a preset number of N times, and N is more than 1;
the control unit calculates the turn-on voltage of the nth time of the battery, the open-circuit voltage closest to the turn-on voltage of the nth time at a detection time, and the turn-on current of the nth time of the battery to obtain an internal resistance value of the nth time of the battery, N being a positive integer and N being 1 to N;
when n is greater than or equal to 2, calculating an absolute difference value between the internal resistance value of the battery at the n-1 th time and the internal resistance value of the battery at the n-1 th time, and dividing the absolute difference value by the internal resistance value of the battery at the n-1 th time to obtain a result as the resistance variation of the battery at the n-1 th time; and
and judging whether the battery is in fault according to the resistance variation of the battery at the nth time.
CN202010751258.0A 2020-07-30 2020-07-30 Battery fault detection device and method Pending CN114062951A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010751258.0A CN114062951A (en) 2020-07-30 2020-07-30 Battery fault detection device and method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010751258.0A CN114062951A (en) 2020-07-30 2020-07-30 Battery fault detection device and method

Publications (1)

Publication Number Publication Date
CN114062951A true CN114062951A (en) 2022-02-18

Family

ID=80227520

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010751258.0A Pending CN114062951A (en) 2020-07-30 2020-07-30 Battery fault detection device and method

Country Status (1)

Country Link
CN (1) CN114062951A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115001119A (en) * 2022-08-03 2022-09-02 广东电网有限责任公司惠州供电局 Storage battery high-resistance judgment and self-healing control system and method
CN117970186A (en) * 2024-04-02 2024-05-03 山东普源电力工程有限公司 Fault diagnosis method and system for distribution room

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115001119A (en) * 2022-08-03 2022-09-02 广东电网有限责任公司惠州供电局 Storage battery high-resistance judgment and self-healing control system and method
CN117970186A (en) * 2024-04-02 2024-05-03 山东普源电力工程有限公司 Fault diagnosis method and system for distribution room
CN117970186B (en) * 2024-04-02 2024-06-07 山东普源电力工程有限公司 Fault diagnosis method and system for distribution room

Similar Documents

Publication Publication Date Title
EP1837944B1 (en) Electric power supply control apparatus
KR101497602B1 (en) Balancing system for battery and Method for balancing of battery using the same
JP3615507B2 (en) Battery charge rate adjustment circuit
EP2838152B1 (en) Discharging device for electricity storage device
CN103138017B (en) Battery control apparatus
KR101788513B1 (en) A Battery Management Apparatus for Uninterruptible Power Supply
JP5274110B2 (en) Power supply for vehicle
JP5323818B2 (en) Method for diagnosing defects in a stand-alone system driven by an intermittent power supply
JP5743634B2 (en) Deterioration measuring device, secondary battery pack, deterioration measuring method, and program
US20090267565A1 (en) Method and system for cell equalization with charging sources and shunt regulators
CN103138026A (en) Battery pack control device
CN113811781B (en) Battery diagnosis device and method
CN114062951A (en) Battery fault detection device and method
CN112154339A (en) Battery pack diagnostic apparatus
US20220311065A1 (en) Device and method for monitoring at least three battery cells of a battery
CN101271991A (en) Battery pack
JP2003243042A (en) Detecting method and device for degree of deterioration of lithium battery as component of package battery
US11774499B2 (en) Relay diagnosis device, relay diagnosis method, battery system, and electric vehicle
JP5332062B2 (en) Uninterruptible power supply system and battery charging method
JP5219653B2 (en) Power supply
CN115037007B (en) Discharge balancing method for battery device
TWI712814B (en) Device and method thereof for battery failure detection
TWI686034B (en) A monitoring device for a multi-cell battery pack
JP2020115718A (en) Charging device
US11225211B1 (en) Vehicle power supply backup

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20220218

WD01 Invention patent application deemed withdrawn after publication