CN111969676A - Battery connecting line breakage detection method based on active equalization - Google Patents
Battery connecting line breakage detection method based on active equalization Download PDFInfo
- Publication number
- CN111969676A CN111969676A CN202010774218.8A CN202010774218A CN111969676A CN 111969676 A CN111969676 A CN 111969676A CN 202010774218 A CN202010774218 A CN 202010774218A CN 111969676 A CN111969676 A CN 111969676A
- Authority
- CN
- China
- Prior art keywords
- battery
- active equalization
- voltage
- single battery
- detection method
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
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
- H02J7/0029—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
- H02J7/0013—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
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Secondary Cells (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The invention discloses a battery connecting line disconnection detection method based on active equalization.A BMS system executes the following algorithm to detect whether each single battery has a disconnection fault: step S1: presetting a plurality of parameter information; step S2: acquiring a plurality of voltage sampling values of each single battery under different working states of the active balancing unit; step S3: and obtaining the relation between the plurality of voltage sampling values and preset parameter information, and judging whether the corresponding single battery has a disconnection fault or not according to the relation. According to the technical scheme, the equalization circuit under the existing framework is used for realizing the disconnection detection through algorithm software, so that a special detection circuit is not required to be added, and the hardware cost is not increased; meanwhile, the method can be suitable for various battery environments and states, and can be used for easily positioning which sampling line is broken.
Description
Technical Field
The invention relates to the technical field of battery management systems of electric automobiles, in particular to a battery connecting line disconnection detection method based on active equalization.
Background
Because the single voltage and capacity of the storage devices such as storage batteries and super capacitors and the power generation devices such as photovoltaic systems (for convenience of explanation, batteries and battery packs are used for replacement in the following) are low, the single voltage and capacity are difficult to be directly used in large systems, and in practical application, a plurality of batteries are often required to be connected in series to improve the voltage, and a plurality of batteries are often connected in parallel to improve the capacity.
Because the production environment, the process parameters, the raw materials and the like are difficult to be completely consistent, each produced single battery has differences. And the difference between the unit cells may be enlarged as time goes by due to the difference in use environment. Due to the factors of chemical characteristics, each single battery has a safe operation range, including parameters such as voltage, current, temperature and power, and the operation range of each parameter has a great influence on the service life of the battery. Of these electrical parameters, the cell voltage is particularly important and must be limited to a reasonable range. After the single batteries are connected in series, the whole battery pack is charged and discharged together, the current or ampere hours passing through each battery are the same, and due to the difference between the single batteries, the situation that a single battery is fully charged firstly and the single battery is discharged firstly inevitably occurs. In addition, in order to ensure safety and battery life, the entire battery pack must be stopped from being charged as long as one battery is fully charged, and the entire battery pack must be stopped from being discharged as long as one battery is discharged, so the BMS must monitor each cell in real time. In an actual system, numerous factors such as structural design, harness quality, worker installation, mechanical shock/impact, etc., may cause the sampling harness between the BMS and the battery to be disconnected, causing the BMS to sample the battery voltage inaccurately.
As shown in fig. 1, due to the disconnection of the Bat4 sampling line, the input pin corresponding to the sampling line at the analog front end is suspended, the voltage is not constant, and the B4 and B5 battery voltages sampled by the BMS are incorrect and cannot reflect the real state of the battery, so that the battery system cannot operate normally and safely. Industries such as electric vehicles, energy storage power stations and communication base stations have high requirements on reliability, products are required to have a self-checking function, and errors can be automatically reported when faults occur.
In order to solve the problem of self-checking of the disconnection of the sampling line of the battery-related device, it is a conventional practice to add an RC filter circuit to the input terminal of the sampling line of the BMS, and to add two controllable current sources I1 and I2, as shown in fig. 2. When the disconnection detection is carried out, the two current sources are closed, the voltage of each battery is measured and recorded, then the two current sources are opened, and the voltage of each battery is measured and recorded again. If there is a wire break, as in the case of the B3+ sampling line in FIG. 2, C is turned on after the current source is turned onF3Discharged by the current source, so that the sampling voltage of the battery B3 is smaller; cF4Is charged by the current source so that the sampled voltage of battery B4 is larger. And comparing the voltage values sampled at the previous and subsequent times, and if the voltage values exceed a preset threshold value delta V, determining that the sampling line is broken.
However, the above prior art solutions have at least the following technical drawbacks:
firstly, when a power battery pack is charged and discharged at a large current, the battery has large voltage change, and particularly in the application occasion of an electric vehicle, when the battery is rapidly switched back and forth between different states of large-current discharge and brake energy feedback (charging), the delta V threshold value is difficult to select, and the compromise between the detection rate and the misjudgment is difficult.
Secondly, when the voltage of the single battery is relatively low, the current source discharge is difficult to ensure that the two previous sampling voltages have a large enough difference, and the phenomenon of missing judgment occurs.
Thirdly, before the detection algorithm is operated, the filter capacitor corresponding to the broken line number is discharged completely, and the current source has no charge to discharge, such as C in FIG. 2F3When the MCU is electrified, the MCU is not electrified, the voltage difference does not exist in the two voltage sampling processes, and the disconnection state cannot be detected.
In addition, when an active equalization circuit exists in the system, the active equalization circuit has a large-capacity filter capacitor, and the current capacity is far larger than the current of a current source for line break detection, while the voltage difference between the two previous sampling and the next sampling in the existing detection method is closely related to the parameters such as the filter capacitor value, the sampling interval time and the like, and when the active equalization circuit exists in the system, the line break detection algorithm can be seriously interfered.
Due to the above disadvantages, the existing detection scheme has a large risk of missing detection and false detection. Therefore, it is necessary to provide a technical solution to solve the technical problems of the prior art.
Disclosure of Invention
In view of the above, it is necessary to provide a method for detecting a broken battery connection line based on active equalization, in which an equalization circuit in the existing architecture is used to implement the broken line detection through algorithm software, so that a dedicated detection circuit is not required to be added, and the hardware cost is not increased; meanwhile, the method can be suitable for various battery environments and states, and can be used for easily positioning which sampling line is broken.
In order to solve the technical problems in the prior art, the technical scheme of the invention is as follows:
the battery connecting line disconnection detection method based on active equalization is characterized in that a BMS system is connected with each single battery in a power battery pack through a connecting line, and at least provided with an AFE front end and an active equalization unit, wherein the active equalization unit is used for performing charging or discharging operation on each single battery; the AFE front end is used for collecting voltage values of all the single batteries;
the BMS system performs the following algorithm to detect whether each of the unit batteries has a disconnection fault:
step S1: presetting parameter information in which V0+Represents the upper limit of the normal range of the cell, V0-Represents the lower limit of the normal range of the single battery; vOpening deviceRepresenting the output constant voltage value of the active equalization unit, which is significantly greater than V0+；VOpenerRepresents the lower limit value of the input voltage range of the active equalization unit, and the value is obviously less than V0-(ii) a Setting a first comparison threshold VHeight ofThe value of the voltage drop is obviously larger than the loop impedance voltage drop and V0+Sum of significantly less than VOpening deviceSetting a second comparison threshold VIs low inTo a value significantly less than V0-The difference with the loop impedance voltage drop is obviously greater than VOpener；
Step S2: in the active equalization ofObtaining a plurality of voltage sampling values of each single battery under different working states of the battery cell, wherein the voltage sampling values at least comprise a first voltage sampling value V0A second voltage sampling value VCharging deviceAnd a third voltage sample value VPutFirst voltage sample value V0The AFE front end samples the voltage of the single battery when the active equalization unit does not work; second voltage sampling value VCharging deviceThe voltage sampling value of the AFE front end to the single battery is obtained when the active equalization unit performs charging operation on the single battery; third voltage sampling value VPutThe voltage sampling value of the AFE front end to the single battery is obtained when the active balancing unit carries out discharging operation on the single battery;
step S3: obtaining a first voltage sampling value V0A second voltage sampling value VCharging deviceAnd a third voltage sample value VPutAnd the relation between the parameter information and the preset parameter information, and whether the corresponding single battery has the disconnection fault or not is judged according to the relation.
As a further improvement, when the first voltage sampling value is within the normal range of the battery, namely V0-＜V0＜V0+When, if VCharging device＞VHeight ofOr VPut＜VIs low inAnd judging that the corresponding single battery has a disconnection fault.
As a further improvement, when V0＞V0+When, if VPut＜VIs low inAnd judging that the corresponding single battery has a disconnection fault.
As a further improvement, when V0＜V0-When, if VCharging device＞VHeight ofAnd judging that the corresponding single battery has a disconnection fault.
As a further improvement, if VCharging device＞VHeight ofAnd V isPut＜VIs low inAnd judging that the corresponding single battery has a disconnection fault.
As a further improvement scheme, assuming that the power battery pack is formed by connecting N single batteries in series, N +1 connecting wires are shared between the BMS system and the power battery pack, and when the ith single battery and the (i + 1) th single battery are judged to have a disconnection fault by an algorithm, wherein i is more than 0 and less than N, the BAT-i connecting wire is judged to be disconnected;
otherwise, if the algorithm only judges that the 1 st single battery has a disconnection fault, the BAT-0 connection line is judged to be disconnected; or if the algorithm only judges that the Nth single battery has the disconnection fault, the BAT-N connection line is judged to be disconnected.
As a further improvement scheme, a plurality of single batteries share one active equalization unit, and each single battery is controlled one by the active equalization unit through switching of a switch.
As a further improvement, the first connection end of the active equalization unit is connected with the single battery, and the second connection end of the active equalization unit is connected with the energy storage unit; the energy storage unit is a single battery, a battery pack or an auxiliary power supply.
As a further improvement, the active equalization unit is a bidirectional active equalization circuit, and the output of the active equalization unit has constant current and constant voltage characteristics.
As a further improvement, the power battery pack is any one of a storage battery, a fuel cell, a super capacitor or a photovoltaic panel.
Compared with the prior art, the invention has the following technical effects:
1. the invention realizes the disconnection detection by using the equalization circuit under the existing framework through algorithm software, thereby not needing to increase a special detection circuit and not increasing the hardware cost;
2. the invention utilizes the active equalization unit to greatly disperse VSThe sampling values have great difference in two states of normal connection and disconnection of the sampling line, and simultaneously the parameter V is reasonably setOpening device、VOpener、VHeight ofAnd VIs low inThe value selection range can not only accurately judge the broken line, but also easily position which sampling line is broken.
3. The technical scheme of the invention has strong applicability, has no requirement on the application environment of the battery, and is applicable even in the environment with instantaneous large current charge and discharge, such as a hybrid vehicle; meanwhile, the range of the voltage of the battery is not required, and accurate judgment can be made no matter whether the battery is overcharged, overdischarged or in a normal range; in addition, the historical states of the battery and the BMS are not required, and the battery and the BMS can be detected at any time.
Drawings
Fig. 1 is a schematic diagram of a BMS sampling line disconnection.
Fig. 2 is a schematic diagram of a method for detecting a connection state of a sampling line in the prior art.
Fig. 3 is a schematic diagram of a BMS system with active equalization.
Fig. 4 is a schematic diagram of a BMS voltage sampling equivalent circuit with active equalization.
Fig. 5 is a flow chart of the active equalization-based battery connection line disconnection detection method of the present invention.
FIG. 6 is a diagram illustrating a timing sequence for detecting a disconnection of a sampling line according to a preferred embodiment of the present invention.
Fig. 7 is a schematic diagram of voltage variation of a single battery in different working states of the active balancing unit.
Fig. 8 is a schematic diagram of an equivalent circuit of a broken sampling line.
Fig. 9 is a schematic diagram of a battery pack and a cell balancing circuit.
Fig. 10 is a schematic diagram of an auxiliary power supply and a cell balancing circuit.
The following specific embodiments will further illustrate the invention in conjunction with the above-described figures.
Detailed Description
The technical solution provided by the present invention will be further explained with reference to the accompanying drawings.
Active equalization applications have been an industry trend in high capacity battery applications, such as electric vehicles, energy storage power stations, and the like. As shown in FIG. 3, each of the single batteries in the BMS system and the power battery pack is connected by a connecting wire, and taking the power battery pack as an example, the BMS system and the power battery pack share 9 connecting wires, which are numbered BAT-0 to BAT-8. The BMS system comprises an MCU, an AFE front end and an active equalization unit, wherein the active equalization unit is used for executing charging or discharging operation on each single battery according to a control instruction of the MCU; the AFE front end is used for collecting voltage values of all the single batteries and sending the voltage values to the MCU; the MCU is used for executing corresponding algorithms to control the power battery pack.
The invention realizes the detection of the disconnection of the connecting line by using the active equalization unit under the original framework in the figure 3. Referring to fig. 4, a schematic diagram of a BMS voltage sampling equivalent circuit with an active balancing unit is shown, wherein a single battery is taken as an example for balancing the single battery, that is, a first connection end of the active balancing unit is connected with the single battery, a second connection end is also connected with the single battery, and energy transfer is realized through different single batteries. B1 and B2 represent two cells; r1, R2, R3 and R4 are equivalent line impedances between the BMS product and the battery, including all impedances included in the balancing current loop, such as a lead impedance, a connector contact impedance, a fuse impedance, a PCB wiring impedance, a battery internal resistance and an artificially added integrated resistance, and since the equivalent impedances include a line distribution impedance, the impedances must exist and are only different in size for different application systems; AFE is an analog front end used to sample the battery voltage; vSRepresenting the voltage seen by the analog front end AFE.
Referring to fig. 5, which is a block flow diagram illustrating a method for detecting disconnection of a battery connection line based on active balancing according to the present invention, a BMS system executes the following algorithm to detect whether each battery cell has a disconnection fault:
step S1: presetting parameter information in which V0+Represents the upper limit of the normal range of the cell, V0-Represents the lower limit of the normal range of the single battery; vOpening deviceRepresenting the output constant voltage value of the active equalization unit, which is significantly greater than V0+；VOpenerRepresents the lower limit value of the input voltage range of the active equalization unit, and the value is obviously less than V0-(ii) a Setting a first comparison threshold VHeight ofThe value of the voltage drop is obviously larger than the loop impedance voltage drop and V0+Sum of significantly less than VOpening deviceSetting a second comparison threshold VIs low inTo a value significantly less than V0-The difference with the loop impedance voltage drop is obviously greater than VOpener；
Step S2: obtaining a plurality of voltage sampling values of each single battery under different working states of the active equalizing unit, whereinComprises less first voltage sampling values V0A second voltage sampling value VCharging deviceAnd a third voltage sample value VPutFirst voltage sample value V0The AFE front end samples the voltage of the single battery when the active equalization unit does not work; second voltage sampling value VCharging deviceIn order to obtain a voltage sampling value of the AFE front end to the single battery when the active equalization unit performs charging operation on the single battery; third voltage sampling value VPutThe voltage sampling value of the AFE front end to the single battery is obtained when the active balancing unit carries out discharging operation on the single battery;
step S3: obtaining a first voltage sampling value V0A second voltage sampling value VCharging deviceAnd a third voltage sample value VPutAnd the relation between the parameter information and the preset parameter information, and whether the corresponding single battery has the disconnection fault or not is judged according to the relation.
The technical scheme is that the large-amplitude discrete V of the active equalization unit is utilizedSThe sampling values have great difference in two states of normal connection and disconnection of the sampling line, and simultaneously the parameter V is reasonably setOpening device、VOpener、VHeight ofAnd VIs low inAnd the value range is selected, so that whether the single battery has a disconnection fault or not can be accurately judged.
The principle of the implementation of the technical solution is described in detail below, and taking the sampling line disconnection detection timing shown in fig. 6 as an example, it should be noted that the sampling line disconnection detection timing (Vs voltage sampling during static state, charging, and discharging) can be arbitrarily adjusted as long as the voltage comparison logic during charging, discharging, and non-operating is ensured.
Referring to fig. 6, the active equalization unit is first controlled not to operate, and the sampled battery voltage is recorded as a first voltage sampling value V0(ii) a Then controlling the active equalization unit to charge the battery, and recording the sampled battery voltage as a second voltage sampling value VCharging device(ii) a And finally, controlling the active equalization unit to discharge the battery, and recording the sampled battery voltage as a third voltage sampling value VPut。
Because the battery is an energy storage device, the change of the battery voltage needs time, the capacity of the power battery is large, the working equalizing current of the active equalizing module is small relative to the battery capacity, the voltage sampling period of the BMS is short, and the change of the equalizing current to the battery voltage is small and can be ignored within the range of a plurality of sampling periods.
When the sampling line is connected normally, the voltage V sampled by the AFE is simulated due to the clamping effect of the battery on the voltage, as shown in FIG. 4SIs the algebraic sum of the battery voltage and the voltage drop over the equivalent line impedance, which is the product of the impedance value and the passing through equalization current. For example, when the battery B2 is charged, the equalization current flows out from the active equalization unit, flows back to the active equalization unit after passing through R3, B2 and R4, the voltage drop caused by the equivalent line impedances R3 and R4 is the same as the positive direction of the voltage of the battery B2, that is, the voltage V sampled by the AFECharging deviceBattery B2 voltage V0+ line impedance drop > V0. Referring to fig. 7, voltage changes of the single battery under different working states of the active equalizing unit are shown, wherein a solid line represents the change of the sampling voltage when the sampling line is normally connected, and V is shown during the charging periodCharging deviceIs significantly greater than V0And is less than VHeight of. When the battery B2 is discharged, the equalizing current flows out of the active equalizing unit, flows back to the active equalizing circuit after passing through R4, B2 and R3, the voltage drop caused on the equivalent line impedances R3 and R4 is opposite to the positive direction of the voltage of the battery B2, namely the voltage V sampled by the AFEPutBattery B2 voltage V0Line impedance drop<V0As can be seen from the discharge period in fig. 7, VPutIs significantly less than V0And is greater than VIs low in。
When the sampling line is disconnected, as shown in FIG. 8, the voltage VSThe clamping effect of the battery is lost, and no equalizing current exists in the circuit. When charging battery B2, voltage V is due to no loadSRises rapidly to reach and maintain the output constant voltage value V of the active equalization circuit designOpening deviceIn fig. 7, the dotted line represents the change of the sampling voltage when the sampling line is disconnected, and the voltage V sampled at the analog front end in the charging stateS＝VOpening device(ii) a When discharging battery B2, voltage V is not present as input power from battery B2SRapidly descendsReaching the lower limit V of the input voltage range of the active equalization unitOpenerThen, the active equalization circuit stops working, the voltage does not continuously decrease, and the voltage V sampled by the front end is simulated in a discharging stateS＝VOpener。
It is clear from fig. 7 that there is a significant difference in the variation trend of the sampling voltage between the normal connection and disconnection state of the sampling line, and when the sampling line is normally connected, V isCharging deviceIs significantly lower than VHeight of，VPutIs obviously higher than VIs low in(ii) a When the sampling line is disconnected, VCharging device＝VOpening deviceIs obviously higher than VHeight of，VPut＝VOpenerIs significantly lower than VIs low in. Therefore, whether the connecting line is disconnected or not can be easily judged only by reasonably designing and comparing the threshold parameters. For this purpose, two comparison thresholds V are providedHeight ofAnd VIs low inRequires VHeight ofIs obviously larger than the sum of the line impedance voltage drop and the upper limit value of the battery voltage range and is obviously smaller than the output constant voltage value V of the active equalizationOpening device(ii) a Requirement VIs low inIs obviously smaller than the difference between the lower limit value of the battery voltage range and the line impedance voltage drop and is obviously larger than the lower limit value V of the input voltage range of the active equalization circuitOpenerNamely: vOpening device＞VHeight of＞(V0++ line impedance drop), (V0-Line impedance drop) > VIs low in＞VOpenerIn which V is0+Upper limit of normal battery range, V0-The lower limit of the normal battery range.
Based on the principle, the invention provides sampling line disconnection detection judgment logic, which specifically comprises the following steps:
when the first voltage sampling value V0In the normal range of the battery, i.e. V0-＜V0＜V0+When it is determined by one of the charging state and the discharging state, if VCharging device＞VHeight ofOr VPut＜VIs low inAnd judging that the corresponding single battery has a disconnection fault.
Otherwise, when V0＞V0+At this time, if the battery has an overcharge condition, the battery voltage itself is high (abnormal condition, such as charging)Abnormal motor, abnormal BMS, etc.), in the charged state, the connecting wire is normally connected, and V may also occurCharging device＞VHeight ofTherefore, in this case, accurate determination cannot be made in the state of charge, and it is necessary to exclude this case by discharge equalization. That is, when V0＞V0+When, if VPut＜VIs low inAnd judging that the corresponding single battery has a disconnection fault.
In the same way, when V0＜V0-At this time, if the battery has an over-discharge condition, V may occur when the battery voltage may be close to the starting voltage of the equalizing circuitPut＜VIs low inTherefore, in this case, accurate determination cannot be made in the discharge state, and it is necessary to exclude this case by charge equalization. That is, when V0＜V0-When, if VCharging device＞VHeight ofAnd judging that the corresponding single battery has a disconnection fault.
In addition, regardless of the first voltage sampling value V0In what range, if VCharging device＞VHeight ofAnd V isPut＜VIs low inAnd the corresponding single battery can be directly judged to have the disconnection fault.
According to the judgment logic, the technical scheme of the invention has no requirement on the range of the voltage of the battery, and can make correct judgment in the normal range, the overcharge state, the overdischarge state and other states; the historical states of the battery and the BMS are not required, and the battery and the BMS can be detected at any time.
By adopting the technical scheme, the equalization circuit under the existing framework is utilized to realize the disconnection detection through algorithm software, so that a special detection circuit is not required to be added, and the hardware cost is not increased; meanwhile, the invention can not only judge whether the disconnection fault occurs, but also accurately position which connecting line has the disconnection fault. Assuming that the power battery pack is formed by connecting N single batteries in series, N +1 connecting wires are shared between the BMS system and the power battery pack, and the number of the single batteries is expanded to N, as shown in the schematic diagram of fig. 3. When the ith single battery and the (i + 1) th single battery are judged to have the disconnection fault through the algorithm, if the connection line is disconnected, the BAT-i connection line is judged to be disconnected if i is more than 0 and less than N; because a disconnection fault occurs in one connecting wire, two adjacent single batteries can be influenced.
Otherwise, if only the 1 st single battery is judged to have the disconnection fault through the algorithm, the BAT-0 connection line is judged to be disconnected; or if the algorithm only judges that the Nth single battery has the disconnection fault, the BAT-N connection line is judged to be disconnected.
As can be seen from the above analysis, if only the sampled voltage of battery B1 is abnormal, BAT-0 is considered to be disconnected; if only the sampled voltage of the battery BN is abnormal, the BAT-N is considered to be disconnected;
if both B1 and B2 are abnormal, the BAT-1 is considered to be disconnected; and if both B2 and B3 are abnormal, the BAT-2 is considered to be disconnected, and the like.
In practical application, an independent active equalization unit can be configured for each single battery, or a plurality of single batteries can share one active equalization unit, and then the active equalization unit controls each single battery one by one through switch switching. For example, each 10 single batteries share one active equalization unit, and the switch may be a multiplexer, but is not limited thereto.
In a preferred embodiment, a first connection end of the active equalization unit is connected with the single battery, and a second connection end of the active equalization unit is connected with the energy storage unit; fig. 4 is an exemplary diagram of balancing the unit cells with respect to the unit cells, but the actual implementation is not limited thereto. In order to independently control the single batteries, one end of the active equalization unit is inevitably connected with the single batteries, and the other end of the active equalization unit can be an energy storage unit in any form, which mainly provides charging energy for the active equalization unit and receives discharging energy; the energy storage unit is a single battery, a battery pack or other forms of energy storage units such as an auxiliary power supply, and refer to fig. 9 and 10.
In practical application, the active equalization unit is designed as a bidirectional active equalization circuit, and the output of the bidirectional active equalization circuit has constant current and constant voltage characteristics. The constant voltage of the output voltage is far higher than the normal voltage range of the battery and smaller than the safe input voltage range of the analog front end AFE.
In the present invention, the power cell assembly is any of power storage or generation devices such as a battery, a fuel cell, a super capacitor, or a photovoltaic panel.
The technical scheme of the invention can be applied to a battery management system, a balance maintenance device, charging and discharging equipment, detection equipment and the like of storage devices such as a storage battery pack and a super capacitor pack and power generation devices such as a photovoltaic system and the like.
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. The battery connecting line disconnection detection method based on active equalization is characterized in that a BMS system is connected with each single battery in a power battery pack through a connecting line, and at least provided with an AFE front end and an active equalization unit, wherein the active equalization unit is used for performing charging or discharging operation on each single battery; the AFE front end is used for collecting voltage values of all the single batteries;
the BMS system performs the following algorithm to detect whether each of the unit batteries has a disconnection fault:
step S1: presetting parameter information in which V0+Represents the upper limit of the normal range of the cell, V0-Represents the lower limit of the normal range of the single battery; vOpening deviceRepresenting the output constant voltage value of the active equalization unit, which is significantly greater than V0+；VOpenerIndicate all initiativeThe lower limit value of the input voltage range of the balance cell is obviously less than V0-(ii) a Setting a first comparison threshold VHeight ofThe value of the voltage drop is obviously larger than the loop impedance voltage drop and V0+Sum of significantly less than VOpening deviceSetting a second comparison threshold VIs low inTo a value significantly less than V0-The difference with the loop impedance voltage drop is obviously greater than VOpener；
Step S2: obtaining a plurality of voltage sampling values of each single battery under different working states of the active equalizing unit, wherein the voltage sampling values at least comprise a first voltage sampling value V0A second voltage sampling value VCharging deviceAnd a third voltage sample value VPutFirst voltage sample value V0The AFE front end samples the voltage of the single battery when the active equalization unit does not work; second voltage sampling value VCharging deviceThe voltage sampling value of the AFE front end to the single battery is obtained when the active equalization unit performs charging operation on the single battery; third voltage sampling value VPutThe voltage sampling value of the AFE front end to the single battery is obtained when the active balancing unit carries out discharging operation on the single battery;
step S3: and calculating to obtain the relationship between the plurality of voltage sampling values and the preset parameter information, and judging whether the corresponding single battery has a disconnection fault or not.
2. The active equalization-based battery connection line disconnection detection method of claim 1, wherein when the first voltage sample value is within a battery normal range, i.e., V0-＜V0＜V0+When, if VCharging device＞VHeight ofOr VPut＜VIs low inAnd judging that the corresponding single battery has a disconnection fault.
3. The active equalization-based battery connection line disconnection detection method of claim 1, wherein when V is greater than V, the method is characterized in that0＞V0+When, if VPut＜VIs low inAnd judging that the corresponding single battery has a disconnection fault.
4. According to claimThe active equalization-based battery connection line disconnection detection method of claim 1, wherein when V is detected0＜V0-When, if VCharging device＞VHeight ofAnd judging that the corresponding single battery has a disconnection fault.
5. The active equalization-based battery connection line disconnection detection method of claim 1, wherein if V is greater than VCharging device＞VHeight ofAnd V isPut＜VIs low inAnd judging that the corresponding single battery has a disconnection fault.
6. The active equalization-based battery connecting line disconnection detection method according to any one of claims 1 to 5, wherein assuming that the power battery pack is formed by connecting N single batteries in series, N +1 connecting lines are shared between the BMS system and the power battery pack, and when the algorithm judges that the ith single battery and the (i + 1) th single battery have a disconnection fault, wherein 0< i < N, the BAT-i connecting line is judged to be disconnected;
otherwise, if the algorithm only judges that the 1 st single battery has a disconnection fault, the BAT-0 connection line is judged to be disconnected; or if the algorithm only judges that the Nth single battery has the disconnection fault, the BAT-N connection line is judged to be disconnected.
7. The active equalization-based battery connection line disconnection detection method according to any one of claims 1 to 5, wherein a plurality of single batteries share one active equalization unit, and each single battery is controlled one by the active equalization unit through switching of a switch.
8. The active equalization-based battery connecting line disconnection detection method according to claim 7, wherein a first connecting end of the active equalization unit is connected with a single battery, and a second connecting end of the active equalization unit is connected with an energy storage unit; the energy storage unit is a single battery, a battery pack or an auxiliary power supply.
9. The active equalization-based battery connection line disconnection detection method according to any one of claims 1 to 5, wherein the active equalization unit is a bidirectional active equalization circuit and the output of the active equalization unit has constant current and constant voltage characteristics.
10. The active equalization-based battery connection line disconnection detection method according to any one of claims 1 to 5, wherein the power battery pack is any one of a storage battery, a fuel cell, a super capacitor or a photovoltaic panel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010774218.8A CN111969676A (en) | 2020-08-04 | 2020-08-04 | Battery connecting line breakage detection method based on active equalization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010774218.8A CN111969676A (en) | 2020-08-04 | 2020-08-04 | Battery connecting line breakage detection method based on active equalization |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111969676A true CN111969676A (en) | 2020-11-20 |
Family
ID=73363810
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010774218.8A Withdrawn CN111969676A (en) | 2020-08-04 | 2020-08-04 | Battery connecting line breakage detection method based on active equalization |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111969676A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114509703A (en) * | 2022-01-10 | 2022-05-17 | 博科能源系统(深圳)有限公司 | Sampling line disconnection judging method, system, detector and storage medium |
| CN114910702A (en) * | 2021-02-08 | 2022-08-16 | 宝星智能科技(上海)有限公司 | A method for measuring line impedance in active battery balancing |
| CN116256655A (en) * | 2021-12-10 | 2023-06-13 | 比亚迪股份有限公司 | Method, device and readable storage medium for determining energy loss |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106371031A (en) * | 2016-09-27 | 2017-02-01 | 惠州市蓝微电子有限公司 | Battery pack wire fracture detection method and device |
| CN205982571U (en) * | 2016-07-20 | 2017-02-22 | 深圳市沃特玛电池有限公司 | Battery broken string detection circuitry |
| CN106602649A (en) * | 2016-12-20 | 2017-04-26 | 东莞钜威动力技术有限公司 | A disconnection detection circuit and detection method of a battery management system |
| JP2018125977A (en) * | 2017-02-01 | 2018-08-09 | トヨタ自動車株式会社 | Control apparatus of battery module |
| CN110879350A (en) * | 2019-12-20 | 2020-03-13 | 杭州协能科技股份有限公司 | Detection method of battery equalization circuit and battery management system |
-
2020
- 2020-08-04 CN CN202010774218.8A patent/CN111969676A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN205982571U (en) * | 2016-07-20 | 2017-02-22 | 深圳市沃特玛电池有限公司 | Battery broken string detection circuitry |
| CN106371031A (en) * | 2016-09-27 | 2017-02-01 | 惠州市蓝微电子有限公司 | Battery pack wire fracture detection method and device |
| CN106602649A (en) * | 2016-12-20 | 2017-04-26 | 东莞钜威动力技术有限公司 | A disconnection detection circuit and detection method of a battery management system |
| JP2018125977A (en) * | 2017-02-01 | 2018-08-09 | トヨタ自動車株式会社 | Control apparatus of battery module |
| CN110879350A (en) * | 2019-12-20 | 2020-03-13 | 杭州协能科技股份有限公司 | Detection method of battery equalization circuit and battery management system |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114910702A (en) * | 2021-02-08 | 2022-08-16 | 宝星智能科技(上海)有限公司 | A method for measuring line impedance in active battery balancing |
| CN116256655A (en) * | 2021-12-10 | 2023-06-13 | 比亚迪股份有限公司 | Method, device and readable storage medium for determining energy loss |
| CN114509703A (en) * | 2022-01-10 | 2022-05-17 | 博科能源系统(深圳)有限公司 | Sampling line disconnection judging method, system, detector and storage medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10228424B2 (en) | System and method for monitoring a DC power system | |
| CN106537718B (en) | Battery management | |
| EP2770606B1 (en) | Battery system monitoring device and charge storage device equipped with same | |
| EP1150132B2 (en) | Method of replacing secondary battery | |
| KR101473397B1 (en) | Apparatus and method for checking current sensor abnormality in battery pack | |
| US20010054877A1 (en) | Charge equalizing device for power storage unit | |
| US20120256598A1 (en) | Battery Pack Detection Circuit | |
| CN111969676A (en) | Battery connecting line breakage detection method based on active equalization | |
| JP6056581B2 (en) | Abnormality detection device for battery pack | |
| CN111999663A (en) | Battery connecting wire breakage detection device | |
| KR101745167B1 (en) | Method of detecting fault battery sell and system performing the same | |
| KR20130081215A (en) | Power supply | |
| CN109302852A (en) | Managing device and power-supply system | |
| CN107219467B (en) | Transformer substation storage battery nuclear capacity device with sulfur removal and repair functions and method | |
| CN103430035A (en) | Charging apparatus and method for determining conduction state | |
| CN111224417A (en) | An energy storage battery management system based on active control of monitoring sampling module | |
| CN113991797A (en) | Battery charging and discharging system and control method | |
| JP5361594B2 (en) | Lithium ion secondary battery system and power supply method to management device | |
| JP3545367B2 (en) | Battery pack voltage detector | |
| CN212861167U (en) | Interface circuit, distribution box, charging management system and vehicle | |
| CN112083342A (en) | Method and apparatus for monitoring battery | |
| CN105978107B (en) | Multi-battery-pack automatic charging and maintenance balance diagnosis system for electric automobile | |
| CN109103955A (en) | Lead-acid accumulator equilibrium and monitoring method and system | |
| CN111697659A (en) | Battery management circuit | |
| CN222190868U (en) | Battery diagnostic equipment and battery system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WW01 | Invention patent application withdrawn after publication | ||
| WW01 | Invention patent application withdrawn after publication |
Application publication date: 20201120 |