WO2023143182A1 - 可单串独立工作的串联电池组自均衡装置及自均衡电芯 - Google Patents

可单串独立工作的串联电池组自均衡装置及自均衡电芯 Download PDF

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Publication number
WO2023143182A1
WO2023143182A1 PCT/CN2023/072350 CN2023072350W WO2023143182A1 WO 2023143182 A1 WO2023143182 A1 WO 2023143182A1 CN 2023072350 W CN2023072350 W CN 2023072350W WO 2023143182 A1 WO2023143182 A1 WO 2023143182A1
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Prior art keywords
self
balancing device
voltage
battery
discharge
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PCT/CN2023/072350
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English (en)
French (fr)
Inventor
王天才
王新明
李书英
王芳
张正
王振廷
Original Assignee
合肥品王新能源科技有限公司
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Publication of WO2023143182A1 publication Critical patent/WO2023143182A1/zh

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0013—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries acting upon several batteries simultaneously or sequentially
    • H02J7/0014—Circuits for equalisation of charge between batteries
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/00032—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by data exchange
    • H02J7/00036—Charger exchanging data with battery
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0013—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries acting upon several batteries simultaneously or sequentially
    • H02J7/0014—Circuits for equalisation of charge between batteries
    • H02J7/0016—Circuits for equalisation of charge between batteries using shunting, discharge or bypass circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0013—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries acting upon several batteries simultaneously or sequentially
    • H02J7/0014—Circuits for equalisation of charge between batteries
    • H02J7/0019—Circuits for equalisation of charge between batteries using switched or multiplexed charge circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00302—Overcharge protection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/0031—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using battery or load disconnect circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/0036—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using connection detecting circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/007—Regulation of charging or discharging current or voltage
    • H02J7/00712—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/007—Regulation of charging or discharging current or voltage
    • H02J7/00712—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters
    • H02J7/007182—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters in response to battery voltage
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/007—Regulation of charging or discharging current or voltage
    • H02J7/007188—Regulation of charging or discharging current or voltage the charge cycle being controlled or terminated in response to non-electric parameters
    • H02J7/007192—Regulation of charging or discharging current or voltage the charge cycle being controlled or terminated in response to non-electric parameters in response to temperature
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/007—Regulation of charging or discharging current or voltage
    • H02J7/007188—Regulation of charging or discharging current or voltage the charge cycle being controlled or terminated in response to non-electric parameters
    • H02J7/007192—Regulation of charging or discharging current or voltage the charge cycle being controlled or terminated in response to non-electric parameters in response to temperature
    • H02J7/007194—Regulation of charging or discharging current or voltage the charge cycle being controlled or terminated in response to non-electric parameters in response to temperature of the battery
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the invention relates to the technical field of equalization of series battery packs, in particular to a self-balancing device for a series battery pack that can work independently in a single string and a self-balancing cell using the self-balancing device.
  • a cell refers to a battery, usually also called a single cell or a single cell; a battery string is composed of several cells connected in parallel, the voltage remains unchanged, it can hold more power, and can flow out a larger current; a battery in series
  • the battery pack is composed of multiple battery strings in series, which has a higher voltage and greater total power than a single battery string.
  • Battery balancing is divided into two categories: active balancing and passive balancing.
  • Active equalization is achieved through energy transfer, which has the advantage of high efficiency, but due to its complex structure and high risk, it has not been widely used; passive equalization mainly consumes the energy of high-voltage battery strings to improve the consistency of battery voltage. Due to its simple structure and high reliability, it has been widely used.
  • the existing passive equalization method still has the following shortcomings, especially for lithium iron phosphate batteries, the effect is not good enough.
  • the existing technology is mainly to balance under the overall control of the main controller (MCU).
  • the working principle is that the battery front-end sampling chip AFE located in the high-voltage area collects the voltage and other information of all battery strings, and sends them to the The MCU in the low-voltage area, the MCU runs the equalization algorithm according to the voltage and other information, and then controls the opening and closing of the equalization management unit of the battery front-end sampling chip AFE located in the high-voltage area by isolating the communication line.
  • This balancing method has the following disadvantages:
  • the main controller needs communication to coordinate and manage all battery strings, which requires many communication lines.
  • the main controller needs communication to coordinate and manage all battery strings, which requires many communication lines.
  • the inside of the traditional battery cell does not contain control equipment. After the battery pack is assembled, an external equalization device is required. This requires battery pack manufacturers to purchase equalization equipment, which makes battery pack development more difficult.
  • the present invention provides a self-balancing device that can work independently for a single string, and can complete the balancing work of the entire battery pack. There is no need to balance the overall control of the host, and there is no need to cooperate with the isolated power supply and isolated communication device.
  • the workload of wiring reduces the difficulty of construction and saves costs; especially for applications with a large number of strings that cannot be installed with communication lines, such as electric buses or other electric vehicles that need to be equipped with equalization equipment after one year of operation, the mold is finalized and cannot be equipped with communication
  • the advantages of assembly convenience are more obvious.
  • the battery cells equipped with a self-balancing device can realize automatic balancing of the battery pack after forming a battery pack, which reduces the difficulty of developing the battery pack.
  • the present invention protects a self-balancing device for series battery packs that can work independently in a single string.
  • Each battery string in the series battery pack is equipped with at least one self-balancing device for improving or maintaining the balanced state of the battery pack.
  • Self-balancing The device is connected to the positive and negative electrodes of the battery string through a conductor, and the battery string provides the working voltage for the self-balancing device.
  • the self-balancing device includes a voltage detection unit, a timing unit and a discharge unit; the voltage detection unit is used to detect the voltage of the battery string, and compares it with the threshold voltage, and outputs the comparison result; the timing unit is used for timing and outputs the timing result; the discharge unit is used for Discharge the battery string.
  • the working process of the self-balancing device includes the following steps:
  • the voltage detection unit is realized by a voltage comparator or ADC.
  • step S1 the discharge unit starts to discharge the battery string, and the timing unit starts counting, it must also be satisfied that the voltage of the battery string is continuously higher than the equalization threshold V THB , and the duration ⁇ t2>220 milliseconds.
  • the work of the self-balancing device also includes the following process: during the timing of the timing unit, if the voltage at both ends of the battery string is greater than the equalization opening threshold V THB again, the timing unit does not restart timing.
  • the work of the self-balancing device also includes the following process: the discharge unit is configured to prohibit discharge or terminate discharge after the equalization prohibition condition is generated;
  • the balancing prohibition condition includes at least one of the following conditions: battery string voltage V i ⁇ lowest balancing voltage threshold V THU ; battery string voltage V i > voltage abnormally high threshold V THO ; self-balancing device temperature > high temperature protection threshold T THO ; and Ambient temperature ⁇ low temperature protection threshold T THU .
  • the self-balancing device also includes a thermal fuse, and the thermal fuse is connected in series with the self-balancing device. In the power supply channel, after the temperature of the self-balancing device is higher than the limit temperature of the fuse, the thermal fuse is disconnected, and the self-balancing device is powered off.
  • the timing unit includes a clock source and a counter
  • the clock source is an RC oscillator or a crystal oscillator
  • the counter is composed of n flip-flops cascaded, n>21.
  • timing function of the timing unit is realized by one or more of 555 series timers, MCU, ASIC, FPGA, PAL, PLD, and GAL.
  • the discharge unit includes a discharge circuit, and the discharge circuit is any one of the following: a constant current source discharge circuit; a resistor discharge circuit; discharge circuit.
  • the self-balancing device stops or terminates the equalizing discharge.
  • the present invention also protects a self-balancing battery cell, which includes the battery cell and the above-mentioned self-balancing device.
  • the present invention realizes the independent work of a single string and can achieve the effect of equalizing the whole battery pack. Since more equipment and isolated communication work together during the equalizing discharge, the consumption is lower. Less power, more energy-saving and environmental protection, and also save communication wires, greatly reducing the difficulty of installation and construction, and reducing costs.
  • the battery pack is composed of self-balancing cells including a self-balancing device. The battery pack has its own balancing function, which reduces the difficulty of developing the battery pack.
  • Figure 1 is a schematic diagram of the working status of various supporting components in the process of equalization and continuation under the overall control of the main controller;
  • Fig. 2 is a schematic diagram of the working state of various supporting components in the balancing process of the present invention
  • FIG. 3 is a schematic diagram of clock frequency division
  • Fig. 4A is a diagram of the internal structure of a self-equalizing device in a basic form of the present invention.
  • Fig. 4B is an internal structure diagram of a self-balancing device of the present invention.
  • Fig. 5 is the control flowchart of MCU timing unit
  • Fig. 6 is a block diagram of a self-balancing device and a schematic diagram of a self-balancing battery
  • Figure 7 is a schematic diagram of different types of discharge circuits
  • the embodiment of the present invention provides a self-balancing device for a series battery pack that can work independently in a single string.
  • Each battery string in the battery pack is equipped with at least one self-balancing device for improving or maintaining the balanced state of the battery pack. It is characterized in that the self-balancing device is connected to the positive and negative poles of the battery string through a conductor, and the battery string provides work for the self-balancing device. Voltage.
  • the self-balancing device includes a voltage detection unit, a timing unit and a discharge unit, wherein the voltage detection unit is used to detect the voltage of the battery string, and compares it with a threshold voltage to output a comparison result, and the timing unit is used for timing and outputting the timing result , the discharge unit is used to discharge the battery string.
  • the working process of the self-balancing device includes the following steps:
  • a self-balancing module that can work independently for a single string in the embodiment of the present invention: each battery string is equipped with a self-balancing device, and when the voltage of the battery string rises above the equalization opening threshold, the function of equalizing the discharge of the battery string is started, and the timing is started at the same time , turn off the equalization discharge after the timing is over, or turn off the equalization discharge when the equalization prohibition condition occurs; of course, after the equalization discharge ends, the equalization opening condition is met again, and the equalization discharge can be turned on again. At the same time, it meets the equalization enable and equalization prohibition conditions, and does not enable equalization discharge.
  • the self-balancing module can independently and automatically complete the startup and shutdown of the balance, without the overall control of the main controller, and without communicating with the main controller.
  • the self-balancing module automatically decides whether to Turn on the discharge function; after the charging is over, the self-balancing module can still ensure the continuation of the balance by timing off.
  • balance is performed under the overall control of the main controller (MCU) in the prior art, as shown in Figure 1.
  • the main controller, DC-DC voltage converter, MCU, and AFE are all In the working state, and the communication between the modules also needs to be continued; the state of using the present invention is shown in Figure 2; compared with the prior art in Figure 1, the self-balancing device proposed by the present invention that can work independently in a single string only needs Charging the battery pack is the same as conventional charging, and the self-balancing device can automatically open the equalization for the battery strings that meet the conditions.
  • the charger there is no need for the charger to be in the charging state all the time, and there is no need for the battery pack main controller MCU and DC-DC voltage converter.
  • extension MCU, and BMS AFE are all in working state, and there is no need for continuous communication between different strings; in the process of installing an equalizing device on an existing vehicle, using the self-balancing device of the present invention only needs to connect each self-balancing module to each There is no need to lay additional communication lines at both ends of the battery string.
  • step S1 when the voltage detection unit detects that the voltage at both ends of the battery string is greater than the equalization opening threshold V THB , the discharge unit starts to discharge the battery string, and the timing unit starts timing; the conditions for starting the equalization discharge of the battery string must meet: the battery The string voltage V i is greater than the equalization turn-on threshold V THB ; or after being greater than V THB , the battery string discharge and timing are started after a delay or other processing. Vi has not been greater than V THB , which does not constitute the starting condition for equalization discharge and timing. Once the equalization discharge and timing start, if the start condition of the discharge and timing disappears, the continuous operation of the equalization discharge and timing will not be affected.
  • Discharging and timing start conditions include the following situations: the battery string voltage V i rises from a low level and is greater than the equalization turn-on threshold V THB , the V i voltage is continuously greater than V THB , the V i voltage decreases from greater than V THB to less than V THB , or other The case where Vi is higher than V THB of the form.
  • the condition for closing the equalizing discharge includes: the end of the specified timing period ⁇ t1.
  • the balance discharge shutdown may also include some of the following conditions: battery string voltage V i ⁇ lowest equalization voltage threshold V THU ; string voltage V i > voltage abnormally high threshold V THO ; self-balancing device temperature > high temperature Protection threshold T THO ; or ambient temperature ⁇ low temperature protection threshold T THU .
  • V THB usually takes 3.4-3.64V
  • the recommended value is 3.55V
  • V THO usually takes 3.7-3.8V
  • the recommended value is 3.8V
  • V THU usually takes 2.0-3.3V
  • the recommended value is 2.2V
  • V THF Usually take 3.65-3.7V
  • the recommended value is 3.65V
  • ternary batteries V THB usually takes 4.0-4.18V, the recommended value is 4.1V
  • V THO usually takes 4.3-4.5V
  • the recommended value is 4.4V
  • V THU usually takes 2.2-3.6V
  • the recommended value is 2.8V
  • V THF is usually Take 4.2-4.4V
  • the recommended value is 4.4V.
  • V THB usually takes 2.65-2.8V, the recommended value is 2.7V;
  • V THU usually takes 1.5-2.3V, and the recommended value is 1.8V;
  • T THO usually takes 50-150 degrees Celsius, and the recommended value is 70 degrees Celsius;
  • T THU Usually take -20-0 degrees Celsius, the recommended value is 0 degrees Celsius; it is also applicable to lead-acid batteries, nickel-metal hydride batteries, etc., and will not be listed here.
  • each battery string in a series battery pack is equipped with a self-balancing device that can work independently for a single string.
  • the self-balancing device is connected to the positive and negative poles of the battery string through conductors, and the battery string provides the working voltage for the self-balancing device without additional power supply or isolated power supply, which is conducive to low power consumption design and cost reduction;
  • the self-balancing device detects and discharges the battery string;
  • the self-balancing device mainly includes a voltage detection unit, a timing unit and a discharging unit; the self-balancing device can complete the voltage judgment independently without communicating with the main controller of the battery pack, and the equalizing discharge is turned on and off. Save communication wire, construction and electricity costs.
  • ERSTN setting signal 415 in Figure 4B is connected to multiple places, and all signals named ERSTN are electrically connected together; Vi+ and Vi- are the positive and negative power supplies of the battery string respectively; the external input signal 423 is When high, the reset circuit 414 can make the voltage of the signal 415 go low and then high after the self-balancing device is powered on, and the modules 402, 403, 405, and 406 are set.
  • the flip-flop output Q is set to a high level.
  • the output level of the controllable tri-state gates 412 and 413 is equal to the input level when the enable signal is at high level, and its output is in a high-impedance state when the enable signal is at low level. Unless otherwise specified, in the following description, both the external input signal 423 and the signal 415 are at high level by default.
  • FIG. 450 is a voltage detection unit whose input terminals are respectively connected to the positive and negative poles of the battery string.
  • the output of the voltage detection unit is connected to the input terminal of the timing unit 451.
  • the signal output by the voltage detection unit changes from a low level to a high level, and is sent to the low pulse generating circuit of the timing unit.
  • the low pulse signal is set to the RC oscillation module and the counting module, the timing starts and the discharge start signal is output
  • the low level is given to the discharge unit 452, and the switch tube of the discharge unit is closed and starts to discharge; Disconnect, the discharge stops.
  • FIG. 4B The working principle of each subdivision module is described below based on FIG. 4B.
  • the basic structure of FIG. 4A corresponds to FIG. 4B.
  • the output 428 of the voltage detection unit 401 is directly connected to the input of the module 404, and the signal 420 directly controls the enabling terminal of the tri-state gate 413.
  • AND gate 416, module 402, module 403 and modules 407-410 are all removed.
  • the tri-state gate 412 is removed and its input and output are connected together, and ETSTN is set to a high level. For reasons such as safety, it is necessary to further expand the above basic structure, which will be described one by one below.
  • the voltage detection unit is used to collect the battery string voltage and compare it with the balance turn-on threshold V THB , and output the comparison result.
  • the voltage detection unit 401 includes, but is not limited to, the resistance voltage divider to collect the battery string voltage, input the non-inverting input terminal of the voltage comparator, and the inverting input terminal of the voltage comparator inputs a reference voltage source with a preset voltage, and the voltage comparison
  • the ratio of the input voltage of the non-inverting and inverting input terminals of the device is equal to the ratio of the battery string voltage V i and the balanced turn-on threshold V THB .
  • the output of the voltage comparator when the voltage of the non-inverting input terminal > the voltage of the inverting input terminal, the output of the voltage comparator is high level, otherwise the output is low level.
  • the voltage of the Zener tube connected to the reverse input terminal of the comparator in the voltage detection unit 401 is 1.2V
  • the resistance value connected to the same input terminal of the comparator and connected to Vi+ is 200K ohms, connected to the same input terminal and connected to
  • the resistance value to Vi- is 100K ohms
  • the voltage detection unit can also use ADC as the voltage detection method.
  • ADC includes but is not limited to an independent ADC, or an ADC that comes with an application-specific integrated circuit, or an ADC that comes with an MCU, or an ADC that comes with a general-purpose chip such as PLD, FPGA, and GAL. .
  • the timing unit is used for timing and outputting timing results.
  • the set signal 415 is at high level after power-on, and when the counting module 405 and the clock module 406 receive the low-level pulse from the controllable tri-state gate 413, the output Qn of the flip-flop Fn is at a low level Level, is used as the equalization discharge start signal; when the timing is over, Qn outputs high level, and is used as the end signal of the equalization discharge.
  • the implementation of the timing unit can be combined with a clock module and a counter, an adder, a subtractor or a frequency divider or other counting circuits.
  • the clock module is turned off by the final output level of the counting module, such as The AND gate 424 in Figure 4B is inserted into the clock loop, making the clock module This is achieved by stopping the oscillation, and the clock module restarts when the count is reset.
  • the timing unit of this embodiment uses the combination of the counting module 405 and the clock module 406 as shown in FIG. 4B to form a timing unit.
  • the clock module 406 generates a periodic continuous oscillating clock signal through the RC and supporting circuits in the figure.
  • the RC in the clock module 406 can be replaced by a crystal, and the clock module 406 can also be replaced by a crystal oscillator, a resonator or other oscillators.
  • the CKN channel of the flip-flop F1 is connected in series with an inverter, which has delay and reverse function, the engineer who implements this circuit should ensure that the delay time of the inverter is long enough to make the CK2 level change from low to high when the CKN falling edge after passing the inverter reaches F1, the high level signal at the D input terminal has been Stablize;
  • CK2 changes from low to high
  • CK2 generates a falling edge through the inverter and enters the flip-flop F1
  • F1 locks the stable high-level signal at its input terminal D.
  • the subsequent trigger is based on the same principle.
  • its own CKN receives a falling edge, it locks its own D input signal.
  • the high-level signal starts from the first stage and is gradually transmitted backwards one by one.
  • the CK/2 output by each flip-flop has already input itself to CKN
  • the operation of dividing the frequency by 2 is done, and the time delay of the latter stage is twice that of the previous stage.
  • the flip-flop CLK can also be triggered by a rising edge, it only needs to be reversed after CLK enters the flip-flop.
  • the flip-flop uses a D flip-flop or other flip-flops.
  • the flip-flop is a standard device in the prior art.
  • the internal structure of the D flip-flop with reset and set functions can refer to MC74HCT74A of ON-SEMI Company.
  • the embodiment is to disconnect the connection relationship between the output terminal of the AND gate 424 and the resistor, add a new two-input AND gate, connect the output terminal of the newly added AND gate to the disconnected end of the resistor, and the output terminal of the AND gate 424 connected to the first input terminal of the newly added AND gate, and the second input terminal of the newly added AND gate is connected to the output Qn of the flip-flop Fn of the counting module 405 .
  • the timing unit After the timing unit starts timing, before the timing ends, the voltage at both ends of the battery string is greater than the equalization opening threshold V THB again in step S1, the timing unit does not restart the timing, so the counting module 405 Will not get stuck on frequent starts. See AND gate 416 among Fig.
  • the output Qn of flip-flop Fn is low level during timing unit timing, and gate 416 outputs low level, and the output of controllable tri-state gate 413 is high resistance state, and its pull-up resistor will electric
  • the counting module 405 cannot receive the low-level pulse sent by the low-pulse generating circuit 404, and does not restart counting; when the timing ends, the Fn output Qn becomes high, and the output level of the controllable tri-state gate 413 follows Input level, the low level pulse sent by the low pulse generating circuit 404 can reach the counting module 405, and the timing can be restarted.
  • timing unit can be realized by ASIC, also can use programmable array logic PAL, programmable logic device PLD, field programmable gate array FPGA, ways such as general array logic GAL realize clock module 406 and counting as shown in Figure 4B Module 405.
  • the timing unit can be realized by using a microprocessor (MCU).
  • MCU microprocessor
  • Using the MCU built-in timer can realize a short time delay.
  • n is equal to 1048576, which can achieve a timing duration of about 29 hours. By setting different values of n, different durations can be obtained, which will not be repeated here.
  • the timing duration of the timing unit can easily reach 80 seconds, or even 2 hours to 10 days or longer. Since a large-capacity battery pack needs to discharge a lot of power every time it is turned on for equalization, short-term discharge is likely to cause heating problems caused by high power. After the time is prolonged, the average power becomes lower and the heating problem is solved.
  • Each flip-flop output Q1 , Q2 , Q3 . . . Qn of the counting module 405 is a different time base, which can be used directly or in combination to obtain a series of different durations for turning off the discharge unit. The longest duration of the timer is determined by the frequency of the oscillator and the total number of stages of the flip-flop chain.
  • the clock frequency generated by the clock module 402 and the clock module 406 is determined by the value of R and C and the delay of the supporting circuit.
  • the equalization turn-on threshold V THB ⁇ battery string full charge threshold voltage V THF Can be detected by adjusting the voltage In module 401 , the voltage division ratio of the non-inverting input terminal resistance of the comparator or the voltage of the reference voltage source is adjusted to realize the balanced turn-on threshold V THB ⁇ the battery string full charge threshold voltage V THF .
  • the voltages of multiple battery strings in the battery pack cannot be exactly the same, because during the charging process, if the voltage of any battery string exceeds V THF , the battery pack will be overcharged and stop charging .
  • the balance turn-on voltage is selected to be lower than V THF , which is beneficial for more battery strings to enter the balance state each time the battery pack is fully charged, improving the battery pack single charge. Equilibrium efficiency.
  • the start of equalization discharge and timing also needs to meet the voltage at both ends of the battery string being continuously higher than the equalization turn-on threshold V THB , and the recommended duration ⁇ t2>220 milliseconds. This is to prevent the voltage detection unit from erroneously starting the equalization discharge function due to the detection of interference . It is necessary to confirm whether the battery string voltage continues to exceed the equalization threshold V THB . Time, to ensure that it is not high-frequency interference.
  • the clock module 402 and the counting module 403 are in the reset state; when the voltage of the battery string is greater than the equalization threshold V THB , the clock module 402 and the counting module 403 start timing, and when the timing ends, the signal 420 From low to high, the Fm output signal 420 in the counting module 403 is output to its own reset circuit after passing through the inverter to realize self-resetting. After the reset, the counter can be activated under the condition that the voltage of the battery string is continuously higher than the opening voltage of the battery string. Interval generation equalization open signal. When the self-resetting function of the timer 403 is not used, that is, the AND gate 418 in FIG.
  • the advantage of this use is that it can prevent the problem that the equalization discharge cannot be stopped when the voltage detection unit makes an error and always outputs a high level; at the same time, after the signal 420 changes from low to high, it is generated by the low pulse generation circuit 404 Evenly open the low pulse signal, if the Qn output by the Fn of the counting module 405 is high at this time, the signal 420 is still high after passing through the AND gate 416, enabling the controllable tri-state gate, and the low pulse signal generated by the circuit 404 reaches the counting module 405 CN terminal of the flip-flop and the clock module 406, and set the flip-flop and the clock source.
  • the clock module 406 and the counting module 405 start timing, and the output Qn of the flip-flop Fn is low level, generating a discharge enable signal ;
  • the voltage Vi of the battery string is higher than the equalization threshold V THB .
  • the way is that the signal 420 is inverted before entering the AND gate 416, or the signal 420 does not participate in the control of the enable terminal of the controllable tri-state gate, so that Vi can be greater than V THB from low to high or less than V THB from high to low, Both can generate timing equalization start signal.
  • the engineer who implements this scheme should understand that the low level pulse is generated by using this time delay in conjunction with the XOR gate, and the pulse time should be long enough to be available In the reset counting module 405; the two inverters connected to the output end of the low pulse generating circuit 404 also have sufficient time delay, so that the signal 420 and its variation arrive at the enabling end of the controllable tri-state gate 413 always than reaching the controllable tri-state gate 413
  • the input terminal of the tri-state gate 413 is earlier, and the new enable terminal signal has enough time to prevent or allow the new input signal to pass through the tri-state gate.
  • the working principle of the counting module 403 and the clock module cooperating to time is similar to the counting module 405 and the clock module 406, and will not be repeated here.
  • the discharge unit is used for discharging the battery string, starts discharging the battery string after receiving the discharge start signal, and stops discharging the battery string after receiving the discharge stop signal.
  • the circuit is realized by using a controllable electronic switch in series with the discharge circuit.
  • the discharge circuit is used as a constant current source, such as the discharge circuit 411 in FIG.
  • the electronic switch can also use PMOS, triode, relay, etc., and then use the corresponding control level or control circuit.
  • the control signal of the chip can also be used to directly drive the discharge circuit to realize the discharge function.
  • the reference voltage source is input to the same input terminal of the op amp
  • the positive end of the feedback resistor 421 is connected to the same input end of the op amp
  • the collector of the NPN transistor is connected to the positive pole Vi+ of the battery string
  • the output of the operational amplifier is connected to the base of the NPN transistor
  • the negative terminal of the constant voltage source is connected to the negative terminal of the feedback resistor 421, and connected to the negative pole Vi- of the battery string through the NMOS tube.
  • the feedback resistor forms a negative feedback circuit to the reverse input terminal of the op amp.
  • the voltage causes the current flowing through the feedback resistor 421 to decrease, otherwise the current increases, which constitutes a constant current source within a certain voltage range.
  • the reference voltage source in the discharge circuit 411 is 1.2V
  • the feedback resistor 421 is 60 ohms
  • the advantage of the constant current source as a discharge circuit is that it is beneficial to different self-balancing devices, and the balancing effect is more consistent under different battery working conditions and voltages.
  • the triode in the discharge circuit 411 can also use NMOS, and can also use PMOS or PNP transistors, and the latter two need to be connected with the input terminals of the supporting operational amplifiers.
  • the NMOS is turned on, and the discharge unit starts to discharge, otherwise, the discharge stops.
  • the implementation of the discharge circuit in the discharge unit includes, but is not limited to, a constant current source, a resistor, a constant voltage source connected in series with a resistor, etc., as shown in FIG. 7 .
  • resistors as the discharge circuit, use one or more resistors in series and parallel to replace the 411 module.
  • the advantage of using pure resistors is that the cost is relatively low; you can also use resistors and constant voltage sources in series to form a discharge circuit, as shown in Figure 7.
  • Several discharge circuit forms can replace the 411 module in Fig. 4B.
  • the discharge circuit 701 in Figure 7 is a constant current source; the module 702 uses TL431 to form a constant voltage source above 2.5V, and is connected in series with a resistor to form a discharge circuit; the module 703 is a diode and a resistor connected in series, which is functioned by a constant voltage source, and the diode and The combination of metal substrates can provide better heat dissipation performance; 704 is a Zener diode or TVS connected in series with a resistor. It is recommended to choose a Zener diode or TVS of about 2.5V.
  • the advantage of using a constant voltage source as the discharge circuit is to prevent the battery from being completely emptied in the event that the discharge control part is out of control or the electronic switch is damaged.
  • the discharge unit is configured to prohibit discharge after the balance prohibition condition is generated, and the balance prohibition condition includes at least one of the following conditions: battery string voltage V i ⁇ lowest balance voltage threshold V THU , battery string voltage V i > voltage abnormally high threshold V THO , self-balancing device temperature > high temperature protection threshold T THO , ambient temperature ⁇ low temperature protection threshold T THU .
  • the equalization prohibition condition is limited to: battery string voltage Vi>abnormally high voltage threshold V THO .
  • the high-voltage detection module 407 for the circuit of this embodiment which can be realized through a voltage comparator and a reference power supply; during the process of discharging the battery string, it is found that the voltage of the battery string is lower than the minimum equalization voltage threshold V THU , and then continue Discharging may affect the battery life in the future or pose a hidden danger to battery safety.
  • the circuit implementation method is such as the low-voltage detection module 408; if the temperature of the self-balancing device is too high, it may damage the device circuit. Set the temperature of the self-balancing device to be higher than high temperature
  • the protection threshold T THO is balanced prohibition.
  • the high temperature detection module 409 when the ambient temperature is too low, discharging the lithium battery may damage the battery, so the ambient temperature is lower than the low temperature protection threshold T THU . See the low temperature detection module 410, where the ambient temperature can be understood as the atmospheric temperature or the battery temperature.
  • the voltage divider value at the temperature protection point can be calculated.
  • the other pair of resistors is taken as The value requirement is to make the divided voltage value of the two equal to the divided voltage value of the resistance and NTC at the protection temperature point, so that when the temperature is higher than the protection point temperature, the comparator outputs a low level, and when the temperature is lower than the protection point temperature, the output high level.
  • the NTC selects the NTC model of "Shenzhen Kaibu Electronics Co., Ltd.”: TCTR0603F100KF, 4300T, and its resistance at 80 degrees Celsius is 10.62K ohms, and the resistance connected in series with the NTC is 100K ohms.
  • the Vi-connected resistor uses 10.62K ohms, and the other resistor chooses 100K, so that high temperature protection of 80 degrees can be achieved.
  • the low temperature detection module 410 is based on a similar principle and will not be repeated here. Using the same rule, you can also use a PTC thermistor. The higher the temperature of the PTC resistor, the higher the resistance. The principle is similar. You can divide the voltage between the PTC and the resistor, and then form a temperature detection unit with a comparator.
  • the self-balancing device also includes a thermal fuse, which is connected in series in the power supply channel of the self-balancing device.
  • a thermal fuse which is connected in series in the power supply channel of the self-balancing device.
  • the thermal fuse 600 shown in FIG. 6 is used to ensure that the power supply of the self-balancing device is disconnected in case of thermal runaway for any reason, so as to ensure safety. It is recommended to choose a fusing temperature of 115 degrees Celsius for the thermal fuse, and other temperatures can also be selected according to the circuit itself and the application environment.
  • the self-balancing device stops or terminates the equalizing discharge, such as the EPDN signal 423 in Figure 4B, which can receive an external input signal, such as a manual switch, and the self-balancing device can be turned off in the warehouse mode device; or any other situation where it is necessary to terminate or stop an equalization discharge in progress.
  • the EPDN signal 423 receives an external input low-level or low-level pulse
  • both the timing unit and the discharge unit are set to the stop state. If the self-balancing unit is already in the discharge and timing state at this time, the timing and equalization will be terminated.
  • the EPDN signal 423 can also control the enable terminal of the controllable tri-state gate 412 by ANDing the output of the AND gate 422 to replace the original control connection in FIG. Only stop the ongoing equalization discharge, do not stop the timing or other units, after the high level is restored, the equalization discharge unit will return to its proper state.
  • the discharge time and discharge current are pre-designed according to the capacity of the balanced battery pack, so that the discharge power within the specified time is a small proportion of the total battery capacity; this embodiment is applied to a battery capacity of 100AH, and the balanced battery string is discharged
  • each charging can be automatically balanced and maintained once, and the battery string whose voltage exceeds the balanced opening voltage is discharged to achieve the purpose of improving or maintaining the balanced state of the battery pack.
  • the self-balancing module mentioned in the present invention can be externally connected to the existing battery pack, or can be directly integrated with the battery string, or integrated with a single battery cell to form a battery string with its own balance or a battery cell with its own balance.
  • the battery pack composed of such battery strings or cells has its own equalization function, which improves the efficiency of assembling the battery pack and reduces the failure rate of the battery pack assembly.
  • the bus is 10 meters long and has 8 battery sub-boxes, and each box has a 24-string, 500AH battery pack. Due to the large capacity of the bus battery pack, the traditional BMS cannot complete the equalization task, and a special equalization device is generally installed.
  • the modules are fixed to the batteries by bonding inside each battery box, and the construction cost is less than 1,000 yuan. If a battery pack assembled from self-balancing cells is used, there is no construction cost for balancing.
  • Balanced extension and host communication line X2, extension power line X2, coding line X2, because the laying of wiring harnesses cannot be laid in a straight line, plus 8 boxes interconnected, generally calculated by 3 times the length of the vehicle, the total length of the line is 10m*3*2* 3 180 meters.
  • the overall balancing device of the bus maintains the balance continuously, and the entire balancing package needs to consume about 20W of actual power.
  • the equalizing device in this embodiment is directly powered by the battery string itself, and the current consumption of the control device is easy to control.
  • the power consumption of the self-balancing device control part of all the battery strings of the entire bus is below 0.5W, which is 1/40 of the overall balance.

Abstract

本发明公开了一种可单串独立工作的串联电池组自均衡装置及自均衡电芯，电池组中的每一电池串配备一套独立的自均衡装置，自均衡装置由电池串供电，自均衡装置包括电压检测单元，计时单元和放电单元；当检测到电池串电压超过均衡开启阈值后，对电池串开启指定时长的放电，放电结束后停止均衡，每一套自均衡装置可独立完成均衡的开启、运行和结束，用于维持或改善串联电池组的均衡状态；利用使用该自均衡装置的自均衡电芯组装成电池组，使得电池组自带均衡功能。

Description

可单串独立工作的串联电池组自均衡装置及自均衡电芯
相关申请的交叉引用
本申请要求2022年01月26日提交的中国专利申请202210094433.2的权益，该申请的内容通过引用被合并于本文。
技术领域
本发明涉及串联电池组均衡技术领域，尤其是一种可单串独立工作的串联电池组自均衡装置及使用该自均衡装置的自均衡电芯。
背景技术
电芯指一节电池，通常也叫单体电芯或单体电池；电池串由若干个电芯并联在一起，电压不变，可容纳更多的电量，可以流出更大的电流；串联电池组由多个电池串串联组成，比单个电池串的电压更高，总功率更大。但是由于生产工艺差异、温度差异、微漏电、内部损伤等原因，各电池串的实时容量存在一定差异，这种差异随着使用时长的增加而不断累积，当出现个别电池串充电无法充满，而放电最先放空的情况时，就需要通过均衡技术使电池组容量最大化。
电池均衡分为主动均衡和被动均衡两大类。主动均衡通过能量转移的方法实现，具有效率高的优点，但由于结构复杂、风险高，并未被广泛使用；被动均衡主要通过将电压高的电池串的能量消耗掉，以提升电池电压的一致性，由于结构简单、可靠性高，得到广泛应用。但是现有被动均衡方式仍存在以下不足之处，特别是对于磷酸铁锂电池，效果不够好。
现有技术主要是在主控制器(MCU)的统筹控制下进行均衡，工作原理是位于高压区的电池前端采样芯片AFE采集所有电池串的电压等信息后，通过隔离通讯线路，统一送至位于低压区的MCU，MCU根据电压等信息运行均衡算法，再通过隔离通讯线路，控制位于高压区的电池前端采样芯片AFE自带的均衡管理单元的开启和关闭。此种均衡方式存在如下方面的缺点：
1、如图1所示，为了维持均衡，整个主控制器MCU及其配套供电DC、隔离通讯等部件及芯片之间、模块之间的通讯，如I2C、UART、CAN、485等，全部需要处于运行状态，除均衡本身外还要耗费额外的电能，对于电动大巴车，均衡持续需要20W左右的额外消耗，额外电能的耗费在长时间缓慢放电的均衡模式下尤为突出，因此目前市面上的电动车每次均衡时间通常控制在30min以内。
2、主控制器(MCU)需要通讯来统筹管理所有电池串，需要众多通讯线路，对于大巴车150串以上的应用，特别是旧车加装大功率均衡设备的场景，由于之前的线束铺设配套模具已经成型，新加的通讯线束的铺设是一大难题。
因此，传统电芯的内部不含控制设备，组成电池组后需要通过外加均衡设备，这就需要电池包厂家选购均衡设备，导致电池包开发难度加大。
发明内容
针对现有均衡方案存在的不足之处，本发明提供一种可单串独立工作的自均衡装置，可完成整个电池组的均衡工作。无需均衡主机统筹控制，无需配套隔离电源、隔离通讯装置配合工作，仅仅自均衡装置工作即可，特别是长时间均衡条件下，节能优势明显；可以省掉均衡模块和主机之间通讯线路及其布线工作量，降低施工难度，节省成本；特别是对于串数多，无法安装通讯线的应用，比如电动大巴车或其它电动汽车运行一年后需要加装均衡设备，其模具定型无法加装通讯线束，装配便利性的优势更加明显。配备了自均衡装置的电芯，组成电池组后可以实现电池组的自动均衡，降低了电池包的开发难度。
第一方面，本发明保护一种可单串独立工作的串联电池组自均衡装置，串联电池组中的每个电池串配备至少一个用于改善或维持电池组均衡状态的自均衡装置，自均衡装置通过导体连接至电池串正负极，电池串为自均衡装置提供工作电压。
自均衡装置包括电压检测单元、计时单元和放电单元；电压检测单元用于检测电池串的电压，并与阈值电压做比较，输出比较结果；计时单元用于计时并输出计时结果；放电单元用于对电池串进行放电。
自均衡装置工作过程包括如下步骤：
S1:当电压检测单元检测到电池串两端的电压＞均衡开启阈值电压VTHB后，放电单元开始对电池串进行放电，计时单元开始计时；
S2:计时时长达到预定时间Δt1，放电单元停止放电。
进一步的，均衡开启阈值电压VTHB＜电池串满充阈值电压VTHF，Δt1＞80秒。
进一步的，电压检测单元通过电压比较器或ADC实现。
进一步的，步骤S1中放电单元开始对电池串进行放电，计时单元开始计，还必须满足：电池串电压持续高于均衡开启阈值VTHB，持续时间Δt2＞220毫秒。
进一步的，自均衡装置工作还包括如下过程：计时单元计时过程中，再次出现电池串两端的电压大于均衡开启阈值VTHB后，计时单元不重新启动计时。
进一步的，自均衡装置工作还包括如下过程：均衡禁止条件产生后放电单元被配置为禁止放电或终止放电；
均衡禁止条件至少包括以下条件中的一个：电池串电压Vi＜最低均衡电压阈值VTHU；电池串电压Vi＞电压异常偏高阈值VTHO；自均衡装置温度＞高温保护阈值TTHO；以及环境温度＜低温保护阈值TTHU。
进一步的，自均衡装置还包括温度保险丝，温度保险丝串联在自均衡装置 供电通道中，自均衡装置温度高于保险丝极限温度后，温度保险丝断开，自均衡装置断电。
进一步的，计时单元包括时钟源和计数器，时钟源为RC振荡器或晶体振荡器，计数器由n个触发器级联组成，n＞21。
进一步的，计时单元的计时功能使用555系列定时器、MCU、专用集成电路、FPGA、PAL、PLD、GAL中的一种或一种以上的方式实现。
进一步的，放电单元包括放电电路，放电电路为以下任意一者：恒流源放电电路；电阻放电电路；以及由二极管、稳压管、稳压电源之中的至少一种和电阻串联后组成的放电电路。
进一步的，自均衡装置接收到外部输入停止信号后，自均衡装置停止或终止均衡放电。
第二方面，本发明还保护一种自均衡电芯，这种自均衡电芯包括电芯和上述自均衡装置。
本发明通过使用可单串独立工作的自均衡装置和策略，实现了可单串独立工作，可实现全电池组均衡的效果，由于均衡放电期间不需要更多设备及隔离通讯协同工作，消耗更少的电量，更节能环保，同时也节省通讯线材，大大降低了安装施工难度，降低了成本。使用包括自均衡装置的自均衡电芯组成电池组，电池组自带均衡功能，降低了电池包的开发难度。
附图说明
图1为主控制器统筹控制下均衡持续过程中各种配套组件工作状态示意图；
图2为本发明均衡持续过程中各种配套组件工作状态示意图；
图3为时钟分频示意图；
图4A为本发明一种基本形式的自均衡装置内部结构图；
图4B为本发明一种形式的自均衡装置内部结构图；
图5为MCU计时单元控制流程图；
图6为自均衡装置框图和自均衡电芯示意图；
图7为不同类型放电电路示意图；
具体实施方式
下面结合附图和具体实施方式对本发明作进一步详细的说明。本发明的实施例是为了示例和描述起见而给出的，而并不是无遗漏的或者将本发明限于所公开的形式。很多修改和变化对于本领域的普通技术人员而言是显而易见的。选择和描述实施例是为了更好说明本发明的原理和实际应用，并且使本领域的普通技术人员能够理解本发明从而设计适于特定用途的带有各种修改的各种实施例。
本发明实施例提供一种可单串独立工作的串联电池组自均衡装置，串联电 池组中的每个电池串配备至少一个用于改善或维持电池组均衡状态的自均衡装置，其特征在于，自均衡装置通过导体连接至电池串正负极，电池串为自均衡装置提供工作电压。
自均衡装置包括电压检测单元、计时单元和放电单元，其中所述电压检测单元用于检测电池串的电压，并与阈值电压做比较以输出比较结果，所述计时单元用于计时并输出计时结果，所述放电单元用于对电池串进行放电。
自均衡装置工作过程包括如下步骤：
S1：当所述电压检测单元检测到电池串两端的电压＞均衡开启阈值电压VTHB后，所述放电单元开始对电池串进行放电，所述计时单元开始计时；
S2：计时时长达到预定时间Δt1，所述放电单元停止放电。
本发明实施例的一种可单串独立工作的自均衡模块：每个电池串配备一个自均衡装置，当电池串电压升高超过均衡开启阈值后，启动对电池串均衡放电功能，同时开始计时，计时结束后关闭均衡放电，或者出现均衡禁止条件发生时关闭均衡放电；当然了，均衡放电结束后，再次符合均衡开启条件，可再次开启均衡放电。同时符合均衡开启和均衡禁止条件，不开启均衡放电。
自均衡模块可以独立自动完成均衡的启动和关闭，无需主控制器统筹控制，无需和主控制器通讯，电池包在即将充满电或充满电后，自均衡模块根据所属电池串电压高低自动决定是否打开放电功能；充电结束后，自均衡模块仍可以通过定时关闭的方式保证均衡的持续。电池组均衡配套组件工作状态，使用现有技术主控制器(MCU)的统筹控制下进行均衡如图1所示，均衡持续过程中，主控制器、DC-DC电压转换器、MCU、AFE均处于工作状态，且模块之间通讯也需要持续进行；使用本发明的状态如图2所示；相比于图1现有技术，本发明提出的可单串独立工作的自均衡装置，只需和常规充电一样对电池包充电，自均衡装置就可以自动对满足条件电池串打开均衡，均衡持续过程中无需充电机一直处于充电状态，也无需电池包主控制器MCU、DC-DC电压转换器、分机MCU、BMS AFE均处于工作状态，不同串之间也无需持续通讯；在现有车辆加装均衡装置的过程中，使用本发明自均衡装置，只需要将每个自均衡模块连接到各个电池串两端，无需铺设额外通讯线路。所述步骤S1：当电压检测单元检测到电池串两端的电压大于均衡开启阈值VTHB后，放电单元开始对电池串进行放电，计时单元开始计时；对电池串均衡放电开始的条件必须满足：电池串电压Vi大于均衡开启阈值VTHB；或者曾经大于VTHB后，做了延时或其它处理后再开始对电池串放电和计时，Vi未曾大于VTHB不构成均衡放电和计时的开始条件。一旦均衡放电和计时开始后，若所述放电和计时的开始条件消失，不影响均衡放电和计时的持续运行。放电和计时启动条件包括以下情形：电池串电压Vi从低升高后大于均衡开启阈值VTHB、Vi电压持续大于VTHB中、Vi电压由大于VTHB降低到小于VTHB、或其它形式Vi高于VTHB的情形。
均衡放电关闭条件包括：指定计时时长Δt1结束。当然了，均衡关闭后再次符合均衡放电开启条件还可以重新开启。为了进一步加强电池包的安全，均衡放电关闭还可以包括部分下列条件：电池串电压Vi＜最低均衡电压阈值VTHU；串电压Vi＞电压异常偏高阈值VTHO；自均衡装置温度＞高温保护阈值TTHO；或者环境温度＜低温保护阈值TTHU。
不同类型的电池，参数不同。对于磷酸铁锂电池：VTHB通常取3.4-3.64V，推荐值3.55V，VTHO通常取3.7-3.8V，推荐值3.8V，VTHU通常取2.0-3.3V，推荐值2.2V，VTHF通常取3.65-3.7V，推荐值3.65V。对于三元电池：VTHB通常取4.0-4.18V，推荐值4.1V，VTHO通常取4.3-4.5V，推荐值4.4V，VTHU通常取2.2-3.6V，推荐值2.8V，VTHF通常取4.2-4.4V，推荐值4.4V。对于钛酸锂电池：VTHB通常取2.65-2.8V，推荐值2.7V，VTHU通常取1.5-2.3V，推荐值1.8V；TTHO通常取50-150摄氏度，推荐值70摄氏度；TTHU通常取-20-0摄氏度，推荐值0摄氏度；对于铅酸电池、镍氢电池等也是可以适用的，此处不再一一列举。
下面对自均衡装置的具体结构进行介绍。
如图2，串联电池组中每个电池串配备一个可单串独立工作的自均衡装置。如图6的自均衡装置601，自均衡装置通过导体连接到电池串的正负极，电池串为自均衡装置提供工作电压，不需要另外供电或隔离供电，利于低功耗设计和降低成本；自均衡装置对电池串进行检测和放电；自均衡装置主要包括电压检测单元、计时单元和放电单元；自均衡装置无需与电池包主控制器通讯即可以独自完成电压判断，均衡放电开启和关闭，节省了通讯线材，施工及电力成本。
全局说明：图4B中ERSTN置位信号415连接到多个地方，名字为ERSTN的所有信号都是电气连在一起的；Vi+、Vi-分别为电池串的正负极电源；外部输入信号423为高时，复位电路414可以使信号415的电压在自均衡装置上电后先低后高，模块402、403、405、406被置位。计数模块403、计数模块405和图3中的触发器在输入端CN接收到低电平或低电平脉冲后，触发器输出Q被置位为低电平，在CKN接收到时钟下降沿时，锁定D端口输入信号并实现输出信号Q＝D。计数模块405在PN接收到低电平或低电平脉冲后，触发器输出Q被置位为高电平。可控三态门412和413在使能信号为高电平时其输出电平等于输入电平，使能信号为低电平时其输出为高阻态。除特别说明外，以下描述默认外部输入信号423和信号415均为高电平。
一种最基本结构如图4A所示，450为电压检测单元，其输入端分别连接至电池串的正负极，电压检测单元的输出连接至计时单元451的输入端，当电池电压超出均衡阈值后，电压检测单元输出的信号有低电平变为高电平，并发送给计时单元的低脉冲产生电路，低脉冲信号置位RC震荡模块和计数模块后，开始计时，并输出放电启动信号低电平给放电单元452，放电单元开关管闭合并开始放电；计时器持续计时，当计时结束，计时单元输出为高，放电单元452的开关管 断开，放电停止。
下面基于图4B来说明各个细分模块的工作原理，图4A的基本结构对应到图4B，电压检测单元401的输出428直接连接到模块404输入，信号420直接控制三态门413的使能端，与门416、模块402、模块403和模块407～410全部去掉。去掉三态门412并将其输入输出连接在一起，ETSTN置为高电平。为了安全等原因，需要将上述基本结构进一步扩充，下面逐一说明。
所述电压检测单元，用于采集电池串电压并与均衡开启阈值VTHB进行比较，并输出比较结果。如图4B中电压检测单元401，包括但不限于电阻分压采集电池串电压，输入电压比较器同相输入端，电压比较器的反相输入端输入预先设定好电压的基准电压源，电压比较器同相、反相输入端输入电压的比值与电池串电压Vi和均衡开启阈值VTHB的比值相等。根据电压比较器的特性，当同相输入端电压＞反相输入端电压时，电压比较器输出为高电平，反之输出为低电平。举例说明：电压检测单元401中连接比较器反向输入端的稳压管电压为1.2V，连接到比较器同向输入端且连接到Vi+的电阻值为200K欧姆，连接到同向输入端且连接到Vi-的电阻值为100K欧姆，就可以算出VTHB的值为1.2V*(200+100)/100＝3.6V。
电压检测单元也可采用ADC作为电压检测方式，ADC使用包括但不限于独立的ADC，或者专用集成电路自带ADC，或者MCU自带的ADC，或PLD、FPGA、GAL等通用芯片自带的ADC。实施方法包括但不限于以下方式：用基准电压源做ADC的参考电压，ADC采集电池串电压并输出对应的数字信号，输出的数字信号与预置的数字阈值做对比，若输出数字信号大于数字阈值，输出高电平，若小于数字阈值，则输出低电平；也可以把电池串电压作为ADC的参考电压，用ADC采集基准电压源，当采集到基准电压源小于指定数值阈值时，输出高电平，当采集到基准电压源大于指定数值阈值时，输出低电平，举例说明：基准电压源为1.2V，目标均衡开启阈值电压为3.6V，ADC采集电池串电压得到满幅值为4095，则数值阈值＝4095*1.2/3.6＝1365；也可以用ADC分别采集基准电压源和电池串的实际电压或电阻分压后的电池串电压，然后对比对应的预定数字阈值，并输出结果。
所述计时单元，用于计时并输出计时结果。见图4B，上电后置位信号415为高电平，当计数模块405和时钟模块406接收到来自可控三态门413发出的低电平脉冲后，触发器Fn的输出Qn为低电平，被用作均衡放电开始信号；计时结束，Qn输出高电平，被用作均衡放电结束信号。
下面逐步分析计时过程及电路工作原理：
计时单元的实现方式，可用时钟模块和计数器，加法器，减法器或分频器或其它计数电路结合，对于计数结束自动停止的功能，通过计数模块最终的输出的电平来关闭时钟模块，如图4B中的与门424插入到时钟回路中，使时钟模块 停止震荡来实现，当计数被重新置位后，时钟模块会重新开始。本实施例计时单元使用如图4B中的计数模块405和时钟模块406结合成为计时单元。时钟模块406是通过图中RC和配套电路产生周期性持续震荡时钟信号。时钟模块406中的RC可以用晶体替代，时钟模块406也可以被晶体振荡器、谐振器或其它振荡器替代。计数模块405包括一系列的触发器链，其中的触发器在时钟输入CKN下降沿触发锁定D输入信号并实现Q＝D，触发器F1的CKN通道串联的反相器，具有延时和反向功能，实施此电路的工程师做时序设计时应确保反相器延时时长可使CK2电平由低变高在经过反相器后的CKN下降沿到达F1时，D输入端的高电平信号已经稳定；
计时单元计时启动后，CK2由低变高时，CK2经过反相器产生下降沿进入触发器F1，F1锁住其输入端D已经稳定的高电平信号，后级触发器基于同样的原理在自身CKN接收到下降沿时锁住自身D输入端信号，高电平信号从第一级开始，被一级接一级逐步向后传输，每个触发器输出的CK/2已经把自身输入CKN做了频率除2的操作，后一级时间延迟是上一级的两倍。
CK/2的分频电路实现方式见图3，CKN下降沿触发锁定并实现Q＝D，将触发器的输出信号Q经过反向后输出给自身的D输入端，从而实现每两个CK周期，输出端Q产生一个周期信号，实现输出时钟频率降低为输入时钟频率的一半。
触发器CLK也可以使用上升沿触发，只需要在CLK进入触发器后反向即可。触发器使用D触发器或其它触发器，触发器属于现有技术的标准器件，带有复位和置位功能的D触发器内部结构可参考ON-SEMI公司的MC74HCT74A。
计时具体过程如图4B，在置位信号415为高电平的情况下，时钟模块406和计数模块405接收到来自可控三态门413低电平脉冲后，所述低电平脉冲为低电平期间，模块405所有触发器Q输出端被初始化为低电平，所述低电平脉冲由低变高后，计时开始，触发器D输入端的高电平开始从第一级触发器F1向后传输，当传输到最后一级Fn，Fn输出信号Qn由低变为高电平，计时结束。由图4B电路可知Qn通过可控三态门412控制放电单元的开启和关闭，可控三态门412的使能为高电平时，Qn为低电平时开启放电单元，Qn为高电平时，关闭放电单元。
为了实现低功耗，在计数结束后停止时钟震荡，等待被重新启动。实施方式是断开与门424的输出端和电阻的连接关系，新添加一个二输入与门，用新加的与门的输出端连接到所述电阻断开的一端，与门424的输出端连接到所述新加与门的第一个输入端，所述新加与门的第二个输入端连接到计数模块405的触发器Fn输出Qn。
计时单元启动计时后，计时未结束前，步骤S1中再次出现电池串两端的电压大于均衡开启阈值VTHB后，计时单元不重新启动计时，这样计数模块405就 不会陷于频繁启动。见图4B中的与门416，计时单元计时期间触发器Fn的输出Qn为低电平，与门416输出低电平，可控三态门413输出为高阻态，其上拉电阻将电平拉到高电平，计数模块405接收不到低脉冲产生电路404发出的低电平脉冲，不重新启动计数；当计时结束，Fn输出Qn变高，可控三态门413输出电平跟随输入电平，低脉冲产生电路404发出的低电平脉冲可以达到计数模块405，计时可重新开始。
所述计时单元，可由专用集成电路实现，也可使用可编程阵列逻辑PAL、可编程逻辑器件PLD、现场可编程门阵列FPGA，通用阵列逻辑GAL等途径实现如图4B所示时钟模块406和计数模块405。
所述计时单元，可使用现有技术555系列定时器实现，选取CMOS低压的7555系列，选取合适的RC值，如R选2兆欧姆，C选470微法，根据公式τ＝R*C，计时可达15分钟。
所述计时单元，可以使用微处理器(MCU)实现。使用MCU自带定时器可以实现短时间的延时，比如MCU自带定时器可以延时Δt3＝100ms，然后配合软件计时，可实现长时间计时。实施方法见图5：定义一个变量i，初始值为0，接收到计时启动信号后，循环执行每隔Δt3时长让变量i自动加1，直至变量i等于或大于指定值n，跳出循环，复位变量i＝0，并发出计时结束信号。比如n等于1048576，可实现约29小时的计时时长，设定不同的n的值，可以得到不同的时长，此处不在赘述。
所述计时单元计时时长很容易达到80秒，甚至2小时到10天或更长。由于大容量电池包每次开启均衡，需要放掉比较多的电量，短时间内放电容易引起大功率导致的发热问题，时间延长之后，平均功率变低，发热问题解决。计数模块405的每个触发器输出Q1、Q2、Q3……Qn是不同的时间基数，可以直接使用或结合使用得到一系列不同的时长，用于关闭放电单元。计时器的最长时长由振荡器频率和触发器链的总级数决定，若振荡器频率为20KHZ，则一个振荡周期是50us，一个n位计数器和周期为τ的时钟组成的计时单元，计时时长为t＝2^n*τ，一个32位计数单元理论最长计时时长t＝2^32*50us≈60小时，同样的，一个40位计数器最长可达640天。由于计算值为一整个周期，而图4B中计时单元可用时间为半个周期，是上述计算值的一半。时钟模块402和时钟模块406产生的时钟频率有R，C的值和配套电路延迟决定，对于低频振荡器，电路延迟在整个时钟周期中占比很小，可以忽略，选R＝1M，C＝50PF，根据RC震荡周期公式τ＝R*C，可以得出周期大致为τ＝1000000*50*10^(-12)＝50us，频率为20KHZ，调整R，C的值，可以得到不同的频率。不同频率的时钟和不同级数的计数器配合，可以得到各种不同的计时时长，各种时长对应的RC值及计数器级数值可根据公式t＝2^n*R*C具体计算，此处不再赘述。
所述均衡开启阈值VTHB＜电池串满充阈值电压VTHF。可通过调整电压检测 模块401中比较器同相输入端电阻的分压比例或调整基准电压源的电压，来实现均衡开启阈值VTHB＜电池串满充阈值电压VTHF。电池包中多个电池串电压不可能完全相同，由于在充电过程中，任何电池串电压超过VTHF，电池包会被过充保护而停止充电，如果选取VTHF作为均衡开启电压，则绝大多数情况下整个电池包只有一个电池串符合均衡条件，均衡开启电压选取低于VTHF的值，有利于每次电池包充满电后，有更多的电池串进入均衡状态，提升电池包单次均衡效率。
均衡放电和计时的开启还要满足电池串两端的电压持续高于均衡开启阈值VTHB，推荐持续时间Δt2＞220毫秒。这是为了防止电压检测单元因检测到干扰而误启动均衡放电功能，需要确认电池串电压是否持续超过均衡开启阈值VTHB，均衡放电启动条件必须满足电池串电压持续高于均衡开启阈值VTHB一段时间，来确保不是高频干扰。在电池串电压小于均衡开启阈值VTHB时，时钟模块402和计数模块403处于复位状态，当电池串电压大于均衡开启阈值VTHB后，时钟模块402和计数模块403开始计时，计时结束，信号420由低变高，计数模块403中的Fm输出信号420通过反相器后输出给自己的复位电路，实现自复位，复位后的计数器在电池串电压持续高于电池串开启电压的条件下，可以间隔的产生均衡开启信号。不使用计时器403自复位功能时，也就是不使用图4B中的与门418，将信号417和信号419直接连在一起，这样均衡放电和计时的开启的必要条件是电池串电压由低到高超过均衡开启阈值，这样使用的好处是可以防止电压检测单元出错一直输出高电平的情况下，均衡放电一直无法停止的问题；同时信号420由低变高后，通过低脉冲产生电路404产生均衡开启低脉冲信号，如果此时计数模块405的Fn输出的Qn为高，信号420通过与门416后依然为高，使能可控三态门，电路404产生的低脉冲信号到达计数模块405的触发器CN端和时钟模块406，并使触发器和时钟源置位，低脉冲结束后，时钟模块406和计数模块405开始计时，触发器Fn输出Qn为低电平，产生放电使能信号；在有些应用中需要充电结束后才开启均衡，可以利用电池串电压Vi在高于均衡开启阈值VTHB之后，充电停止，所述Vi电压由高到低，低于VTHB之后开启均衡，实现方式是信号420在进入与门416之前取反，或者信号420不参与可控三态门的使能端控制，这样可以实现Vi由低到高大于VTHB或Vi由高到低小于VTHB，均能产生计时均衡开始信号。
其中低脉冲产生电路404中的反相器电路具有长延时和反向功能，实施此方案的工程师应该明白，利用此延时配合异或门产生低电平脉冲，此脉冲时间应足够长可用于复位计数模块405；低脉冲产生电路404输出端连接的两个反相器也具有足够的延时，使信号420及其变化到达可控三态门413的使能端总是比到达可控三态门413输入端更早，并且新的使能端信号有足够的时间阻止或放行新的输入信号通过三态门。其中计数模块403和时钟模块配合计时的工作原理同计数模块405及时钟模块406类似，此处不在赘述。
所述放电单元，用于对电池串放电，接收到放电开启信号后开始对电池串放电，接收到放电停止信号，停止对电池串放电。电路使用一个可控电子开关和放电电路串联实现，本实施例使用放电电路为恒流源，如图4B的放电电路411，和其串联的NMOS为可控电子开关，通过控制NMOS的开启实现对电池串的放电，关闭NMOS关闭对电池串放电。当然了电子开关也可以使用PMOS、三极管、继电器等，然后使用与之对应的控制电平或控制电路。对于小电流均衡，也可以使用芯片的控制信号直接驱动放电电路实现放电功能。图4B中的放电电路411，是恒流源的一种形式：基准电压源输入运放的同向输入端，反馈电阻421的正端连接至运放同向输入端，同时接到NPN三极管发射极，NPN三极管的集电极连接到电池串正极Vi+，运放输出接到NPN三极管基极，恒压源负端和反馈电阻421的负端连接，并通过NMOS管连接到电池串负极Vi-。反馈电阻到运放反向输入端形成一个负反馈电路，经过反馈电阻421的电流越大，输入到运放反向输入端的电压越高，运放输出电压越低，降低了到达NPN三极管基极电压，导致流经反馈电阻421的电流减小，反之就电流变大，这就组成了一个在一定电压范围内的恒流源。放电电路411中的基准电压源取1.2V，反馈电阻421取60欧姆，可得到恒流源电流I＝基准电压/反馈电阻＝20毫安。恒流源作为放电电路的好处是有利于不同的自均衡装置，在不同电池工况下和电压下，取得均衡效果更具有一致性。放电电路411中的三极管也可以使用NMOS，也可以使用PMOS或PNP三极管，后两者需要配套的运放输入端互换连接关系。可控三态门412输入为高电平且被使能后，NMOS被打开，放电单元开启放电，反之停止放电。
所述放电单元中的放电电路实现方式包括但不仅限于恒流源、电阻、恒压源与电阻串联等，见图7。对于使用电阻作为放电电路，使用一个或一个以上电阻经过串并联后，取代411模块，使用纯电阻的优势是成本比较低；也可以使用电阻和恒压源串联后组成放电电路，图7中为几种放电电路形式，可以取代图4B中的411模块。图7中放电电路701是恒流源；702模块使用TL431组成2.5V以上的恒压源，和电阻串联后组成放电电路；703模块是二极管和电阻串联，由恒压源的作用，且二极管和金属基板结合后可以提供更好的散热表现；704是稳压二极管或TVS和电阻串联，推荐选取2.5V左右稳压管或TVS。使用恒压源作为放电电路的好处是在放电控制部分失控或电子开关损坏的情况下，防止电池完全被放空。
均衡禁止条件产生后所述放电单元被配置为禁止放电，均衡禁止条件至少包括以下条件中的一个：电池串电压Vi＜最低均衡电压阈值VTHU，电池串电压Vi＞电压异常偏高阈值VTHO，自均衡装置温度＞高温保护阈值TTHO，环境温度＜低温保护阈值TTHU。
当电压检测单元连接电池串的线路出现断路或错接时，会导致相邻电池串 的检测电压异常偏高或偏低。为防止电压检测单元连接电池串的线路出现断路导致的误判，将均衡禁止条件限制为：电池串电压Vi＞异常偏高电压阈值VTHO。在电路实现上，本实施例电路见高压检测模块407，通过一个电压比较器和基准电源即可实现；对电池串放电过程中，发现电池串电压已经低于最低均衡电压阈值VTHU，再继续放电可能影响电池接下来的续航或者对电池安全构成隐患，此时设置为均衡禁止，电路实现方法如低压检测模块408；自均衡装置温度过高可能会损害装置电路，设置自均衡装置温度大于高温保护阈值TTHO为均衡禁止，电路实施方法见高温检测模块409；环境温度过低情况下对锂电池放电可能会损伤电池，所以环境温度小于低温保护阈值TTHU也设置为均衡禁止，电路实施方式见低温检测模块410，此处环境温度可理解为大气温度或者电芯温度。
任何均衡禁止条件产生之后，对应比较器会输出低电平，所有均衡禁止条件比较器输出通过与操作汇集成一路输出，来控制模块可控三态门412的使能端，从而实现任何均衡禁止条件产生后，关闭放电单元411禁止放电的效果，均衡禁止条件消失后，恢复放电功能。断开信号426和与门输入端425，信号426和信号427相与之后的结果输出到与门输入端425，则任何均衡禁止条件发生后，终止正在进行的计时和均衡放电，直到下一次重新开启计时和均衡放电。
温度测试的原理解释及举例：拿高温检测模块409作为例子，电阻和NTC热敏电阻串联分压后连接到比较器的同相输入端，另外两个固定电阻分压后连接到比较器反向输入端；这两组分压装置共电源和共地；NTC是一种热敏电阻，温度越高其电阻值越低，每个温度对应一个固定的电阻值，选定要保护的温度点，就可以根据选定NTC的规格书查询到其在该温度下对应的阻值，选取一个固定阻值的电阻和NTC分压后，就可以算出在温度保护点的分压值，另外一对电阻取值要求是，让此二者分压值等于电阻和NTC在保护温度点的分压值，这样当温度高于保护点温度，比较器输出低电平，当温度低于保护点温度时，输出高电平。进一步的，NTC选取“深圳开步电子有限公司”的NTC型号：TCTR0603F100KF，4300T，其80摄氏度对应阻值为10.62K欧姆，与NTC串联的电阻选100K欧姆，比较器反向输入端连接并和Vi-连接的电阻使用10.62K欧姆，另外一个电阻选100K，这样就可以实现高温保护80度。低温检测模块410也是类似原理，不再赘述。利用同样的规则，也可以用PTC热敏电阻，PTC电阻温度越高，电阻越高，原理类似，可以通过PTC和电阻分压，再和比较器组成温度检测单元。
为进一步加强安全，所述自均衡装置还包括温度保险丝，温度保险丝串联在自均衡装置供电通道中，自均衡装置温度高于保险丝极限温度后，温度保险丝断开，自均衡装置断电。如图6中的温度保险丝600，用于保证在任何原因热失控的情况下断开自均衡装置电源，以确保安全。温度保险丝建议选择115摄氏度熔断温度，也可以根据电路自身和应用环境选择其它温度。
所述自均衡装置接收到外部输入停止信号后，自均衡装置停止或终止均衡放电，如图4B中的EPDN信号423，可接收外部输入信号，比如一个手动开关，在仓储模式下可以关闭自均衡装置；或者其它需要终止或停止正在进行中的均衡放电的情形。EPDN信号423接收到外部输入低电平或低电平脉冲后，计时单元和放电单元都置位到停止状态，如果此时自均衡单元已经处于放电和计时状态，则会终止此次计时和均衡放电；EPDN信号423也可以和与门422的输出相与后的结果控制可控三态门412的使能端，取代图4B中原有控制连接，则EPDN信号423接收到外部输入低电平后仅仅停止正在进行的均衡放电，不停止计时或别的单元，恢复高电平后，均衡放电单元恢复应有的状态。
放电时间和放电电流根据被均衡电池组容量预先设计好，以在指定时间内放电电量为电池总容量的一个小的比例即可；本实施例应用于电池容量100AH，被均衡的电池串均衡放电时间18小时，放电电流大约25mA，这样均衡放电电量时18*25mA＝0.45AH，占电池总容量的0.45％。符合用户每天充一次电或几天充一次电的习惯，每次充电都可以自动均衡维护一次，对电压超出均衡开启电压的电池串进行放电，达到改善或维护电池组均衡状态的目的。
本发明提及的自均衡模块可以外接于现有电池组，也可以直接与电池串集成为一体，或和单个电芯集成在一起，形成一个自带均衡的电池串或自带均衡的电芯，用这种电池串或电芯组成的电池组，自带均衡功能，提高了组装电池包的效率和降低电池包装配故障率。
以大巴车安装均衡设备为例子说明自均衡装置的成本优势：大巴车长10米，有8个电池分箱，每个箱体有一个24串，500AH的电池组。由于大巴车电池包容量太大，传统BMS无法完成均衡任务，一般会加装专用均衡装置。
使用实施例中的自均衡装置，做成单个分立电路板模块，只需在每个电池串两端连接一片自均衡电路板模块，每个模块均衡线总长度0.2米，全部8个箱体均衡线总长度为0.2*24*8＝35.2米。模块在各个电池箱内部通过粘结的方式固定到电池上，施工成本一千元以内。如果适用自均衡电芯组装的电池组，则无均衡方面的施工成本。
使用统筹控制的均衡装置，每个箱体一个均衡分机，8个均衡分机连接到均衡主机。要做的内容为：1.连接均衡分机均衡线，24个电池串共25根线，每根均衡线长度大概1.5米，每个箱体均衡线总长度为：1.5*25＝37.5米，8个箱体均衡线总长度300米。均衡分机和主机通讯线X2，分机电源线X2，编码线X2，由于线束铺设不可能直线铺设，加上8个箱体互联，一般按车长3倍计算，线总长度10m*3*2*3＝180米。各分机之间和主机连接需要用接插件9套，航空插头9套，由于通讯等线束在电池包外部，需要对电池箱打孔和防水处理，需要对线束进行套管和包扎，需要隔离通讯，隔离供电。比第一种方案多出的线束、接插件、航空插头等成本两千元人民币以上，施工成本在两千元人民币以上。如果是旧车 加装，还需要对现有设备进行改造以适用加装均衡装备，成本更高，大巴车后装一套统筹控制的均衡设备，2020年市场价格三万元人民币。
从节能的角度看，大巴车统筹均衡装置维持均衡持续，整个均衡配套需要额外消耗20W左右的实际功率，而本实施例种的均衡装置，由于电池串自身直接供电，控制装置电流消耗很容易做到1mA以下，整个大巴车所有的电池串配套自均衡装置控制部分耗电功率在0.5W以下，是统筹均衡的1/40。
显然，所描述的实施例仅仅是本发明的一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域及相关领域的普通技术人员在没有作出创造性劳动的前提下所获得的所有其他实施例，都应属于本发明保护的范围。

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  1. 一种可单串独立工作的串联电池组自均衡装置，串联电池组中的每个电池串配备至少一个用于改善或维持电池组均衡状态的自均衡装置，其特征在于，自均衡装置通过导体连接至电池串正负极，电池串为自均衡装置提供工作电压；
    自均衡装置包括电压检测单元、计时单元和放电单元，其中所述电压检测单元用于检测电池串的电压，并与阈值电压做比较以输出比较结果，所述计时单元用于计时并输出计时结果，所述放电单元用于对电池串进行放电；
    自均衡装置工作过程包括如下步骤：
    S1：当所述电压检测单元检测到电池串两端的电压＞均衡开启阈值电压VTHB后，所述放电单元开始对电池串进行放电，所述计时单元开始计时；
    S2：计时时长达到预定时间Δt1，所述放电单元停止放电。
  2. 根据权利要求1所述的串联电池组自均衡装置，其特征在于，均衡开启阈值电压VTHB＜电池串满充阈值电压VTHF，Δt1＞80秒。
  3. 根据权利要求1所述的串联电池组自均衡装置，其特征在于，所述电压检测单元通过电压比较器或ADC实现。
  4. 根据权利要求1所述的串联电池组自均衡装置，其特征在于，步骤S1中所述放电单元开始对电池串进行放电，所述计时单元开始计时，还必须满足：电池串电压持续高于均衡开启阈值VTHB，持续时间Δt2＞220毫秒。
  5. 根据权利要求1所述的串联电池组自均衡装置，其特征在于，自均衡装置工作还包括如下过程：所述计时单元计时过程中，再次出现电池串两端的电压大于均衡开启阈值VTHB后，所述计时单元不重新启动计时。
  6. 根据权利要求1所述的串联电池组自均衡装置，其特征在于，自均衡装置工作还包括如下过程：均衡禁止条件产生后，所述放电单元被配置为禁止放电或终止放电；
    均衡禁止条件至少包括以下条件中的一个：
    电池串电压Vi＜最低均衡电压阈值VTHU；
    电池串电压Vi＞电压异常偏高阈值VTHO；自均衡装置温度＞高温保护阈值TTHO；以及
    环境温度＜低温保护阈值TTHU。
  7. 根据权利要求1所述的串联电池组自均衡装置，其特征在于，自均衡装置还包括温度保险丝，所述温度保险丝串联在自均衡装置供电通道中，自均衡装置温度高于保险丝极限温度后，所述温度保险丝断开，自均衡装置断电。
  8. 根据权利要求1所述的串联电池组自均衡装置，其特征在于，所述计时单元包括时钟源和计数器，所述时钟源为RC振荡器或晶体振荡器，所述计数器由n个触发器级联组成，n＞21。
  9. 根据权利要求1所述的串联电池组自均衡装置，其特征在于，所述计时单元的计时功能使用555系列定时器、MCU、专用集成电路、FPGA、PAL、PLD、GAL中的一种或一种以上的方式实现。
  10. 根据权利要求1-9任意一项所述的串联电池组自均衡装置，其特征在于，所述放电单元包括放电电路，所述放电电路为以下任意一者：
    恒流源放电电路；
    电阻放电电路；以及
    由二极管、稳压管、稳压电源之中的至少一种和电阻串联后组成的放电电路。
  11. 根据权利要求10所述的串联电池组自均衡装置，其特征在于，自均衡装置接收到外部输入停止信号后，自均衡装置停止或终止均衡放电。
  12. 一种自均衡电芯，其特征在于，包括电芯和权利要求1至11中任意一项所述的自均衡装置。
PCT/CN2023/072350 2022-01-26 2023-01-16 可单串独立工作的串联电池组自均衡装置及自均衡电芯 WO2023143182A1 (zh)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117507920A (zh) * 2024-01-04 2024-02-06 质子汽车科技有限公司 充电系统及充电方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101471577A (zh) * 2007-12-29 2009-07-01 比亚迪股份有限公司 双节可充电电池电压平衡电路
DE102014017079A1 (de) * 2014-11-19 2015-06-11 Daimler Ag Vorrichtung zum Ladezustandsausgleichn von Batteriezellen eines Batteriesystems
CN204465076U (zh) * 2015-03-13 2015-07-08 河北超创电子科技有限公司 多节电池串联电池组在线均衡装置
CN113098113A (zh) * 2021-05-24 2021-07-09 淮北市千锂鸟新能源科技有限公司 串联电池组的智能均衡方法及均衡装置
CN113162186A (zh) * 2021-04-30 2021-07-23 合肥品王新能源科技有限公司 一种串联电池组的均衡方法及装置
CN216699589U (zh) * 2022-01-26 2022-06-07 合肥品王新能源科技有限公司 可单串独立工作的串联电池组自均衡装置及自均衡电芯

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101471577A (zh) * 2007-12-29 2009-07-01 比亚迪股份有限公司 双节可充电电池电压平衡电路
DE102014017079A1 (de) * 2014-11-19 2015-06-11 Daimler Ag Vorrichtung zum Ladezustandsausgleichn von Batteriezellen eines Batteriesystems
CN204465076U (zh) * 2015-03-13 2015-07-08 河北超创电子科技有限公司 多节电池串联电池组在线均衡装置
CN113162186A (zh) * 2021-04-30 2021-07-23 合肥品王新能源科技有限公司 一种串联电池组的均衡方法及装置
CN113098113A (zh) * 2021-05-24 2021-07-09 淮北市千锂鸟新能源科技有限公司 串联电池组的智能均衡方法及均衡装置
CN216699589U (zh) * 2022-01-26 2022-06-07 合肥品王新能源科技有限公司 可单串独立工作的串联电池组自均衡装置及自均衡电芯

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117507920A (zh) * 2024-01-04 2024-02-06 质子汽车科技有限公司 充电系统及充电方法
CN117507920B (zh) * 2024-01-04 2024-03-22 质子汽车科技有限公司 充电系统及充电方法

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