CN107528353B - Series battery voltage equalization method and equalization circuit - Google Patents
Series battery voltage equalization method and equalization circuit Download PDFInfo
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- CN107528353B CN107528353B CN201610449034.8A CN201610449034A CN107528353B CN 107528353 B CN107528353 B CN 107528353B CN 201610449034 A CN201610449034 A CN 201610449034A CN 107528353 B CN107528353 B CN 107528353B
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- 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
- H02J7/0018—Circuits for equalisation of charge between batteries using separate charge circuits
Abstract
The invention provides a voltage equalization method and an equalization circuit for series batteries, wherein in the charging process, if the voltage of any single battery is found to be higher than the average voltage by a threshold value, the battery is discharged through a discharge circuit, so that the voltage of the battery is reduced to the average value, and the circuit adopts a chip to realize the equalization of the single battery in a battery pack. The balance is only carried out in the charging process of the battery, and the battery is not discharged at other time, so that the defects of the conventional balance system are overcome.
Description
Technical Field
The invention relates to the field of power battery use, in particular to a battery equalization method and an equalization circuit when a large number of batteries are connected in series.
Background
With the increasing environmental pollution, new energy technologies such as electric vehicles have attracted attention and developed rapidly all over the world, and the battery energy storage becomes a bottleneck in the development of electric vehicles. Due to the requirement of the driving range of the electric vehicle and the limitation of low voltage and low capacity of the battery cells, a large number of battery cells are required to be connected in series in the power battery pack to provide the required driving voltage and driving capability. However, due to the existing manufacturing technology and unavoidable external environment differences such as temperature, initial capacity, operating voltage, residual capacity and the like among a large number of cells cannot be completely consistent, and a single cell is overcharged and overdischarged in the use process of the battery, so that the service life and safety of the battery are affected. And because the existence of the barrel effect influences the capacity of the whole battery pack, the positive feedback effect makes the loss of the battery monomer with small capacity more serious. A good battery equalization technology can greatly reduce the inconsistency among the battery cells, thereby effectively avoiding the occurrence of overcharge or overdischarge of certain battery cells in the battery pack and further maintaining the service characteristics of the battery pack. Therefore, the battery equalization technology occupies an important position in the battery management system of the electric automobile. Here, the battery includes a storage battery commonly used at present, such as a lead-acid storage battery, a chemical battery such as a lithium battery, and a physical battery such as a super capacitor, and the chemical battery and the physical battery need to be balanced due to individual difference of the single batteries when being connected in series.
Chinese patent publication No. CN 104113110 a discloses a battery equalization circuit, which includes:
the battery pack comprises N battery units which are connected in series, wherein the battery units are divided into odd-numbered groups and even-numbered groups according to numbers, each battery unit is provided with an anode and a cathode, and N is an integer greater than 1.
An inductor for storing and releasing energy.
And the balance control switch comprises N +1 controllable switches, wherein N is the number of the battery cells.
The controllable switches connect the anode and the cathode of the battery monomer to the inductor, wherein the controllable switches are divided into odd groups and even groups according to the number, the odd groups of controllable switches are connected to one pole of the inductor, and the even groups of controllable switches are connected to the other pole of the inductor.
And the balance controller is used for detecting and processing data such as real-time voltage, current, SOC (system on chip) and the like of the battery monomer, formulating a balance control strategy and controlling the balance control switch to be turned on and off.
The balancing circuit judges whether the single battery needs to be balanced by monitoring the voltage or SOC of the single battery in real time, and realizes energy transfer between the single battery and the single battery or between the single battery and a plurality of batteries.
However, the circuit needs to be in the balancing process all the time, so that energy transfer exists among the batteries, energy loss exists in the energy transfer process, and even the product is possibly heated, so that the service life of the product is influenced, and the circuit is not suitable for being used as an integrated circuit.
Disclosure of Invention
The invention aims to overcome the defects of all equalizing circuits in the existing series battery pack and provides a series battery voltage equalizing method and an equalizing circuit.
The technical scheme adopted by the invention for realizing the technical purpose is as follows: a method for equalizing the voltage of serially connected batteries features that if the voltage of any single battery is higher than the average voltage by a threshold value, the battery is discharged by a discharge circuit to lower its voltage to the average value.
The balance is only carried out in the charging process of the battery, and the battery is not discharged at other time, so that the defects of the conventional balance system are overcome.
Further, the method for balancing the voltages of the series-connected batteries comprises the following steps:
step 4, subtracting the average voltage value at the moment from the real-time voltage value of the single battery, if the real-time voltage value is larger than a set threshold value, turning to step 5, and if the real-time voltage value is not larger than the set threshold value, ending the balancing process;
and 5, discharging the two ends of the single battery by using the discharging circuit.
Further, in the above method for balancing voltages of series-connected batteries: in the step 1, a group of series resistors are connected to two ends of the series battery pack, wherein the number of the series resistors is consistent with the number of the single batteries in the battery pack, and the resistance values of the resistors are the same; the voltage across any resistor is measured as the average voltage of each cell in the battery.
Further, in the above method for balancing voltages of series-connected batteries: in the step 2, the average voltage value of each single battery in the battery pack measured at the previous time is compared with the average voltage value of each single battery in the battery pack measured at the next time, and if the average voltage value of each single battery in the battery pack measured at the next time is greater than the average voltage value of each single battery in the battery pack measured at the previous time, it is determined that the battery pack is being charged.
Further, in the above method for balancing voltages of series-connected batteries: the method also comprises a step of carrying out overvoltage protection on the single battery, wherein the voltage of the single battery detected in real time is judged in the step, and if the voltage is greater than the specified maximum voltage of the single battery, the discharging circuit is controlled to discharge the single battery and indicate the discharge.
The invention also provides a series battery voltage equalization circuit, which comprises a single battery processing module for performing equalization processing on each single battery in the series battery pack; the single battery processing module is arranged in an integrated circuit chip and comprises:
the average voltage detection circuit measures the average voltage of each single battery in the battery pack connected in series in real time;
a charging state detection circuit for judging whether the battery pack is in a charging process;
the real-time detection circuit of the voltage of the single battery detects the real-time voltage of the single battery in real time;
a comparison circuit;
an AND logic gate circuit;
a discharge circuit;
the input end of the charging state detection circuit is connected with the output end of the average voltage detection circuit, and when the charging is carried out, the output of the charging state detection circuit is effective;
the input end of the comparison circuit is the output end of the single battery voltage real-time detection circuit and the output end of the average voltage detection circuit, and when the signal of the output end of the single battery voltage real-time detection circuit is higher than a set value of the signal of the output end of the average voltage detection circuit, the comparison circuit outputs an effective signal;
two input ends of the AND logic gate circuit are respectively connected with the output end of the charging state detection circuit and the output end of the comparison circuit, and the discharge circuit is driven to work when the output end of the AND logic gate circuit is effective;
the discharge circuit is arranged at two ends of the single battery.
Further, in the above series battery voltage equalization circuit: the average voltage detection circuit comprises a first voltage detection module and a group of divider resistors with the same number as the single batteries in the series battery pack, all the divider resistors are connected in series at two ends of the series battery pack in the same resistance value, and the first voltage detection module detects the voltage at two ends of any one divider resistor.
Further, in the above series battery voltage equalization circuit: the charging state detection circuit comprises an operational amplifier U1, a resistor R1, a resistor R2 and a capacitor C; the output of the average voltage detection circuit is connected with the non-inverting end of the operational amplifier U1 through a resistor R1, the output of the average voltage detection circuit is connected with the non-inverting end of the operational amplifier U1 through a resistor R2, and the capacitor C is connected with the non-inverting end of the operational amplifier U1 and the negative pole of the single battery.
Further, in the above series battery voltage equalization circuit: the discharging circuit comprises a discharging triode Q and a discharging current-limiting resistor R4, the output of the AND logic gate circuit is connected with the base electrode of the discharging triode Q, one end of the discharging current-limiting resistor R4 is connected with the emitting electrode of the discharging triode Q, the other end of the discharging current-limiting resistor R4 is connected with the negative electrode of the single battery, and the collecting electrode of the discharging triode Q is connected with the positive electrode of the single battery.
Further, in the above series battery voltage equalization circuit: the output ends of the average voltage detection circuit and the single battery voltage real-time detection circuit also comprise output circuits for processing output signals to improve the output load capacity.
The invention will be explained in more detail below with reference to the drawings and examples.
Drawings
Fig. 1 is a unit cell process module according to the present invention.
Fig. 2 is a schematic diagram of a charge state detection circuit in embodiment 1 of the present invention.
Fig. 3 is a schematic diagram of a discharge circuit in embodiment 1 of the present invention.
Fig. 4 is a schematic diagram of a series battery pack equalization circuit according to embodiment 1 of the present invention.
Detailed Description
In the embodiment, when the series battery pack is charged, each single battery is processed to equalize the voltage of each single battery in the battery pack, and the single battery may be a secondary battery of a chemical battery, such as a lead-acid battery or a lithium battery, which is commonly used at present, or a physical battery, such as a super capacitor, and hereinafter, the single battery refers to such a physical battery or a chemical secondary battery.
In this embodiment, it is mainly embodied that a three-pin chip or a six-pin chip is used to equalize the single batteries in a group of series battery packs, and during equalization, equalization is performed only during charging of the series battery packs, so that the operating state of the battery packs needs to be detected, if charging is performed, the real-time voltage of each single battery is detected, if the voltage of a certain single battery is higher than the average voltage, the battery is discharged, and the voltage of the battery is reduced to meet the requirement, if the battery is a 2.7V super capacitor battery, during charging, the voltage of the single battery is higher than the uneven voltage by 40mV, and the discharge circuit can be driven to discharge the single battery. The method for the three-pin chip or the six-pin chip comprises the following specific steps:
And 3, detecting the real-time voltage of the single battery in real time.
Step 4, subtracting the average voltage value at the moment from the real-time voltage value of the single battery, if the real-time voltage value is larger than a set threshold value, turning to step 5, and if the real-time voltage value is not larger than the set threshold value, ending the balancing process; in the present embodiment, the threshold value may be set to 40mV, and the unit cell is discharged as long as the voltage of the unit cell exceeds the average voltage by 40 mV.
In addition, in the charging process, if the voltage after charging exceeds a threshold value, the charging needs to be stopped, for example, a 2.7V super capacitor, and the charging is stopped when the voltage is charged to 2.7V, so in the charging process, it is also necessary to determine whether the charging is completed, and if the charging completion condition is met, the charging is immediately stopped.
The present embodiment can implement the above functions by using an integrated circuit chip, which has only six pins as shown in fig. 1, and has the following functional circuits in the chip, which is a single battery processing circuit for processing a single battery. Such an integrated circuit chip is provided for each cell in the series battery pack, and all integrated circuit chips are connected as shown in fig. 4 to equalize the entire series battery pack.
The average voltage detection circuit measures the average voltage of each single battery in the battery pack connected in series in real time; the average voltage detection circuit comprises a first voltage detection module and a group of divider resistors equal to the number of single batteries in the series battery pack, and in the embodiment, the divider resistors are arranged outside a chip, so that in the practical application process, the resistors with the same size can be selected locally to ensure the accuracy of the average voltage detection result. All the divider resistors have the same resistance value and are connected in series at two ends of the series battery pack, and the first voltage detection module detects the voltage at two ends of any one divider resistor, namely the average voltage. Here, the first voltage detection module is a module for detecting a voltage, and is only a module for distinguishing other voltage detection modules in the future. As shown in fig. 1 and 4, the divider resistor is a resistor outside the chip, and therefore two more pins, such as pins 1 and 2 shown in fig. 1, need to be provided for the chip, and in practicing chip design, the divider resistor may also be integrated into an integrated circuit chip, so that the number of pins of the chip may be reduced, for example, the divider resistors are directly connected in series from pins 4 and 5 above, the divider resistors with the same resistance are integrated into the chip, and the average voltage can be obtained by measuring the voltage across the divider resistor. Since the voltage dividing resistors are arranged in the integrated circuit chip, in practical use, if the equalizing chips of each single battery in the series battery pack are not in a batch, it is not easy to ensure that the resistance values of each voltage dividing resistor are exactly equal, which may cause inaccurate average voltage detection.
A charging state detection circuit for judging whether the battery pack is in a charging process; the input end of the charging state detection circuit is connected with the output end of the average voltage detection circuit, and when the charging is carried out, the output of the charging state detection circuit is effective. The circuit has many forms at present, and the present embodiment adopts a circuit of a schematic diagram as shown in fig. 2, and the charge state detection circuit includes an operational amplifier U1, a resistor R1, a resistor R2, and a capacitor C; the output of the average voltage detection circuit is connected with the in-phase end of the operational amplifier U1 through a resistor R1, the output of the average voltage detection circuit is connected with the out-phase end of the operational amplifier U1 through a resistor R2, and a capacitor C is connected with the out-phase end of the operational amplifier U1 and the cathode of the single battery. In addition, the circuit may also have a discharge resistor R3 for discharging the non-inverting terminal of the operational amplifier U1. The circuit is very simple, only the input analog signal of the average voltage is delayed once to be compared with the later voltage, if the later comparison is higher than the former voltage, the effective signal is output, but the circuit needs a capacitor C, namely a capacitor C outside an integrated circuit chip, so that the chip is provided with a pin 3, if other circuits are adopted, the capacitor C is not needed, for example, in the practical use process, a rising edge judgment circuit consisting of other circuit structures such as AD detection, digital delay and the like is used, whether charging is judged can be realized, and therefore the capacitor C is not arranged in a super-large scale. Therefore, eventually the chip may not require pins No. 1, 2, 3.
The real-time detection circuit of the voltage of the single battery detects the real-time voltage of the single battery in real time; the circuit may detect the voltage across the battery cell as in the previous first voltage detection module. The existing technology for detecting the voltage at two ends of the single battery is many, and is suitable for the design of an integrated circuit.
Comparison circuit and AND logic gate circuit, discharge circuit.
The discharging circuit is a CCS circuit for discharging both ends of the battery cell, as shown in fig. 3, the discharging circuit includes a discharging triode Q and a discharging current limiting resistor R4, the output of the and logic gate circuit is connected to the base of the discharging triode Q, one end of the discharging current limiting resistor R4 is connected to the emitter of the discharging triode Q, the other end is connected to the cathode of the battery cell, and the collector of the discharging triode Q is connected to the anode of the battery cell. In practical use, the discharge circuit is a discharge circuit with a minimum time length, which, once activated, maintains a minimum set discharge time.
The input end of the comparison circuit is the output end of the single battery voltage real-time detection circuit and the output end of the average voltage detection circuit, and when the signal of the output end of the single battery voltage real-time detection circuit is higher than a set value of the signal of the output end of the average voltage detection circuit, the comparison circuit outputs the effective signal.
Two input ends of the AND logic gate circuit are respectively connected with the output end of the charging state detection circuit and the output end of the comparison circuit, and the discharge circuit is driven to work when the output end of the AND logic gate circuit is effective.
In addition, the output ends of the average voltage detection circuit and the single battery voltage real-time detection circuit also comprise output circuits for processing output signals to improve the output load capacity.
As shown in fig. 4, the equalizing circuit is an equalizing circuit for equalizing a series battery pack consisting of n batteries, and the equalizing circuit is processed by a single battery processing chip, and n resistors with the same large series resistance value are connected between a positive pole PT1 and a negative pole PT2 of the battery pack when in use, wherein n is any integer larger than 1. The 1 st pin and the 2 nd pin of the chip processed by each single battery are connected between a resistor, the 3 rd pin is connected with the cathode of the single battery through a capacitor, the 4 th pin and the 5 th pin are connected at two ends of the single battery in a bridging manner, and the 6 th pin of each chip is connected in parallel to output TP3 and is connected with an indicating device such as a display lamp.
Claims (4)
1. A series battery voltage equalization circuit comprises a single battery processing module for equalizing each single battery in a series battery pack; the method is characterized in that: the single battery processing module is arranged in an integrated circuit chip and comprises:
the average voltage detection circuit measures the average voltage of each single battery in the battery pack connected in series in real time;
a charging state detection circuit for judging whether the battery pack is in a charging process;
the real-time detection circuit of the voltage of the single battery detects the real-time voltage of the single battery in real time;
a comparison circuit;
an AND logic gate circuit;
a discharge circuit;
the input end of the charging state detection circuit is connected with the output end of the average voltage detection circuit, and when the charging is carried out, the output of the charging state detection circuit is effective; the charge state detection circuit comprises an operational amplifier U1, a resistor R1, a resistor R2 and a capacitor C outside the integrated circuit chip in the integrated circuit chip; the output of the average voltage detection circuit is connected with the in-phase end of an operational amplifier U1 through a resistor R1, the output of the average voltage detection circuit is connected with the out-phase end of the operational amplifier U1 through a resistor R2, the out-phase end of the operational amplifier U1 is connected with one end of a capacitor C through a pin of an integrated circuit chip, and the other end of the capacitor C is connected with the negative electrode of a single battery;
the input end of the comparison circuit is the output end of the single battery voltage real-time detection circuit and the output end of the average voltage detection circuit, and when the signal of the output end of the single battery voltage real-time detection circuit is higher than a set value of the signal of the output end of the average voltage detection circuit, the comparison circuit outputs an effective signal;
two input ends of the AND logic gate circuit are respectively connected with the output end of the charging state detection circuit and the output end of the comparison circuit, and the discharge circuit is driven to work when the output end of the AND logic gate circuit is effective;
the discharging circuit is connected with two ends of the single battery by using two pins of the integrated circuit chip.
2. The series battery voltage equalization circuit of claim 1, wherein: the average voltage detection circuit comprises a first voltage detection module arranged in an integrated circuit chip, and a group of divider resistors which are arranged outside the integrated circuit chip and equal to the number of single batteries in a series battery pack, wherein all the divider resistors have the same resistance value, the group of divider resistors are connected in parallel at two ends of the series battery pack, and the first voltage detection module is respectively connected with two ends of any divider resistor by using two pins of the integrated circuit chip.
3. The series battery voltage equalization circuit of claim 1, wherein: the discharging circuit comprises a discharging triode Q and a discharging current-limiting resistor R4, the output of the AND logic gate circuit is connected with the base electrode of the discharging triode Q, one end of the discharging current-limiting resistor R4 is connected with the emitting electrode of the discharging triode Q, the other end of the discharging current-limiting resistor R4 is connected with the negative electrode of the single battery by using the pin of the integrated circuit chip, and the collector electrode of the discharging triode Q is connected with the positive electrode of the single battery by using the pin of the integrated circuit chip.
4. The series battery voltage equalization circuit according to any one of claims 1 to 3, characterized in that: the output ends of the average voltage detection circuit and the single battery voltage real-time detection circuit also comprise output circuits for processing output signals to improve the output load capacity.
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| CN111196156B (en) * | 2018-11-16 | 2022-02-25 | 宝沃汽车（中国）有限公司 | Equalization circuit fault detection method and system of battery monitoring unit and vehicle |
| CN110091880B (en) * | 2019-05-23 | 2020-05-22 | 湘潭牵引机车厂有限公司 | Power management system of tunnel engineering electric locomotive based on super capacitor |
| CN114301143B (en) * | 2022-01-06 | 2024-04-05 | 南京工程学院 | Battery pack electric quantity balancing system based on Internet of things |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101017986A (en) * | 2006-12-29 | 2007-08-15 | 哈尔滨工业大学 | Monocase battery voltage balance method and balancer in the charging/discharging process of the dynamic battery group |
| JP2008295184A (en) * | 2007-05-24 | 2008-12-04 | Suzuki Motor Corp | Charging device |
| CN103208828A (en) * | 2012-01-17 | 2013-07-17 | 中国科学院广州能源研究所 | Management system for serial connected battery packs |
| CN103762626A (en) * | 2013-12-31 | 2014-04-30 | 江苏嘉钰新能源技术有限公司 | Equalizing charge control circuit |
-
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- 2016-06-21 CN CN201610449034.8A patent/CN107528353B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101017986A (en) * | 2006-12-29 | 2007-08-15 | 哈尔滨工业大学 | Monocase battery voltage balance method and balancer in the charging/discharging process of the dynamic battery group |
| JP2008295184A (en) * | 2007-05-24 | 2008-12-04 | Suzuki Motor Corp | Charging device |
| CN103208828A (en) * | 2012-01-17 | 2013-07-17 | 中国科学院广州能源研究所 | Management system for serial connected battery packs |
| CN103762626A (en) * | 2013-12-31 | 2014-04-30 | 江苏嘉钰新能源技术有限公司 | Equalizing charge control circuit |
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