Energy storage battery management system based on AUTBUS

Abstract

The present invention discloses an energy storage battery management system based on AUTBUS, which relates to the technical field of energy storage management, and utilizes the AUTBUS network to collect the working parameters of an energy storage battery group and a power supply unit; wherein, a plurality of power supply units are connected in series in sequence, and a circuit switching unit is connected to the outside of the power supply unit; when a power supply unit fails or is under maintenance, the corresponding circuit switching unit is triggered, and the two power supply units before and after the power supply unit are connected in series, and a backup power supply unit is connected. The energy storage battery management system based on AUTBUS of the present invention uses the AUTBUS network as a communication medium for data transmission, and obtains an energy storage health prediction value that can judge the health status of the power supply unit by comprehensively analyzing the working parameters of the energy storage unit, and then controls the working state of the circuit switching unit according to the obtained energy storage health prediction value, so as to respond quickly and accurately to the faulty energy storage unit, and at the same time utilizes the switching effect of the circuit switching unit to reduce the impact range and difficulty of the maintenance.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage management, and in particular to an energy storage battery management system based on AUTBUS. Background Art

[0002] With the rapid economic development of various countries, the global energy demand has increased significantly. The limited traditional energy will be difficult to meet the demand in the near future. In addition, the "carbon reduction" goals of various countries have been proposed, and the development and utilization of renewable energy has become more urgent. The ocean, which accounts for 71% of the earth's area, is a treasure trove of green energy. Ocean energy is considered to be one of the largest renewable energy reserves, mainly including wave energy, tidal energy, tidal energy, temperature difference energy in a narrow sense, and offshore wind power, marine biomass energy and offshore floating photovoltaics in a broad sense. Among them, no matter what kind of power generation method is used, it is necessary to rely on energy storage batteries for energy storage. However, due to different manufacturers, different models, and different years of energy storage batteries, there will be certain differences in their energy storage capacity and energy storage life. Just like there are no two leaves in the world that are exactly the same, even the power supply units in the same energy storage battery will have differences, which makes it impossible to manage and control them in a targeted manner.

[0003] At present, the Chinese patent with the existing patent publication number: CN103227494B discloses a storage battery management system. The system adopts a distributed three-layer management system, including the bottom BMU, the middle BCMS and the top BAMS. Among them, the bottom BMU includes a voltage and temperature measurement module and a charging and discharging equalization module. The middle BCMS is the core of the battery management system, including a voltage and temperature processing module, a balancing control module, a relay control module, an AD acquisition module, and a core parameter calculation module. The top BAMS includes a battery information summary module, a system alarm information processing module, a BAMS_PCS communication module, and a BAMS_upper monitoring system communication module. The CAN2.0B communication protocol is used within the three-layer structure of the system to realize information transmission. The ModbusTCP protocol is used for communication between BAMS and the energy conversion PCS system and the upper monitoring system. Although all energy storage batteries are gathered together through a three-layer management system, it is impossible to respond accurately and promptly to the use of the energy storage battery group, resulting in a large amount of time required for troubleshooting and replacement when the battery is damaged, and the remaining service life of each energy storage unit cannot be fully utilized; another Chinese patent with patent publication number: CN110148800A discloses a lithium battery energy storage management system and a lithium battery energy storage system, which relates to the technical field of energy storage systems. In the management system, an information collection device and a fault recording module are respectively connected to a calculation and control module, wherein the information collection device includes at least one of the following: an environmental variable collection module, a power consumption side control module, a power generation side control module, an electric meter data collection module, a PCS control module, and a battery control unit; when a system failure occurs, the calculation and control module controls the fault recording module to perform a recording operation to record the fault information; the fault information includes information collected by various modules in the above information collection device at the time of the system failure; the calculation and control module analyzes the above fault information to determine the fault responsibility party corresponding to the fault. However, it is still impossible to fully utilize the remaining service life of the energy storage battery group, and there are problems of poor resource utilization and poor response efficiency.

[0004] However, during the implementation of the above technical solution, it was found that there were at least the following technical problems:

[0005] Due to different usage environments, the service life of energy storage batteries will also decay to varying degrees. Common decay factors include high temperature aging, low temperature aging, high current charging and discharging, overvoltage / undervoltage charging and discharging, etc., which will also affect the service life of energy storage batteries. Moreover, even the same batch of batteries of the same model and the same manufacturer will have differences. These differences will continue to expand with the increase of service life or usage environment, resulting in usage differences between energy storage batteries. The existing energy storage battery control system can only judge the quality of energy storage batteries by detecting the charging and discharging conditions of energy storage batteries. This detection is not only not comprehensive, but also cannot be adjusted in real time according to the battery conditions, resulting in some batteries that can still be used being replaced, seriously affecting the utilization of resources. Secondly, the existing energy storage batteries, the internal power supply units are mainly connected in series to form a whole, which results in that if any of the power supply units is damaged, the entire energy storage battery cannot be used, and the faulty power supply unit can only be checked one by one, wasting manpower and material resources. For this reason, we propose an energy storage battery management system based on AUTBUS. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In view of the deficiencies in the prior art, the present invention provides an energy storage battery management system based on AUTBUS, which uses the AUTBUS network as a communication medium for data transmission to transmit the collected working parameters, thereby improving the efficiency of long-distance transmission and reducing the packet loss rate; by comprehensively analyzing the working parameters of the energy storage unit, an energy storage health prediction value that can judge the health status of the power supply unit is obtained, and then according to the obtained energy storage health prediction value, the working state of the circuit switching unit is controlled, so as to respond quickly and accurately to the faulty energy storage unit, and at the same time, the switching effect of the circuit switching unit is utilized to reduce the impact range and difficulty of maintenance, thereby solving the technical problem that the existing energy storage battery management system cannot respond accurately and quickly when a fault occurs.

[0008] (II) Technical solution

[0009] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0010] Energy storage battery management system based on AUTBUS, the system includes:

[0011] The parameter acquisition module uses the AUTBUS network to collect the working parameters of the energy storage battery pack and the power supply unit. The working parameters include voltage, current, and working temperature;

[0012] Among them, several power supply units are connected in series in sequence, and the outside of the power supply unit is connected to a circuit switching unit;

[0013] When a power supply unit fails or is under maintenance, the corresponding circuit switching unit is triggered to connect the two power supply units before and after the power supply unit in series and connect to the standby power supply unit;

[0014] Parameter verification module: compares the working parameters of the power supply unit with the preset parameter range. If the working parameters of the power supply unit are within the parameter range, no response is made; otherwise, a parameter warning is issued; and according to the parameter warning, the circuit switching unit corresponding to the power supply unit is called;

[0015] The energy storage verification module builds an energy storage battery calculation model based on the collected working parameters of the power supply unit, obtains the energy storage power of the energy storage battery group, and compares the absolute value of the difference between the energy storage power and the working power of the energy storage battery group with the preset standard threshold range;

[0016] When the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack exceeds the preset standard threshold range, a correction warning is issued;

[0017] Data analysis module: When a correction warning is issued, the working parameters of the power supply unit in the energy storage battery pack are retrieved and analyzed, and a power supply unit analysis and calculation model is built to generate the energy storage health prediction value Gwk t , based on the predicted value of energy storage health Gwk t The size of each circuit switches the circuit switching units corresponding to the faulty power supply units in turn;

[0018] When the absolute value of the difference between the energy storage power and the working power of the energy storage battery group is less than the median of the standard threshold range, stop;

[0019] Status assessment module: Based on the working parameters of the faulty power supply unit before disconnection and the corresponding energy storage health prediction value Gwk t , generates the status evaluation value Unq of the faulty power supply unit t , according to the state evaluation value Unq t The size of the power supply strategy is enabled;

[0020] Furthermore, the system also includes:

[0021] Balance control module: sets the upper and lower current thresholds according to the working parameters of the energy storage battery pack, and compares them with the charging current sent by the power generation unit;

[0022] When the charging current is ≥ the upper current threshold, the power supply circuit of the energy storage battery group and the power generation unit is turned on;

[0023] When the charging current is less than the lower current threshold, the power supply circuit between the energy storage battery group and the power generation unit is disconnected;

[0024] When the upper current threshold > charging current ≥ lower current threshold, no response is made.

[0025] Furthermore, the operating temperature of the power supply unit is detected by an NTC thermistor, and the relationship between temperature and resistance is converted into a relationship between temperature and voltage. The relationship between temperature and voltage is as follows:

[0026]

[0027] In the formula, U t is the voltage of the thermistor at temperature T, I t is the current of the thermistor at temperature T, R t is the resistance of the thermistor at temperature T, R is the resistance of the thermistor at T N The standard resistance at room temperature, e is a constant, and B is the thermal constant of the thermistor.

[0028] Further, the parameter acquisition module includes an acquisition unit, a conversion unit and an edge control unit;

[0029] Among them, the acquisition unit converts the existing industrial communication into AUTBUS communication through the conversion unit; the conversion unit is networked through the AUTBUS bus and connected to the edge control unit; the edge control unit analyzes and processes the working parameters and sends them to the remote server.

[0030] Furthermore, the energy storage power of the energy storage battery pack includes the standard output power P 出 And the standard load power P 负 , the working parameters of the energy storage battery pack include the supply voltage U z , supply current I z , the formula is as follows:

[0031]

[0032] Where U oc is the open circuit voltage of the power supply unit, I is the load current of the power supply unit, and n is the number of power supply units in the energy storage battery pack;

[0033]

[0034] Where U d is the terminal voltage of the power supply unit;

[0035] When |P 出 -P 负 -U z I z |>standard threshold, a correction warning is issued;

[0036] When |P 出 -P 负 -U zI z |≤standard threshold, no response will be made.

[0037] Furthermore, under the condition that the system issues a correction warning, the working parameters of the power supply unit within the correction warning duration t are obtained to generate the energy storage health prediction value Gwk t , energy storage health prediction value Gwk t The formula is as follows:

[0038]

[0039] In the formula, is the average value of the power supply unit temperature during the correction warning duration t, P g is the power supply of the power supply unit, U max To correct the voltage U of the power supply unit during the warning duration t d The maximum value, U min To correct the voltage U of the power supply unit during the warning duration t d , K, W, and V are respectively the preset weight coefficients of the power supply unit temperature, the power supply unit power, and the terminal voltage of the power supply unit, and W>K>V>0, and A is the constant correction coefficient.

[0040] Furthermore, the switching steps of the circuit switching unit are as follows:

[0041] Step 1: Based on the predicted value of energy storage health Gwk t Sort the power supply units by size;

[0042] Step 2: Turn on the circuit switching units corresponding to the power supply units in sequence according to the order in step 1;

[0043] Step 3: recalculate the energy storage power of the battery pack while turning on the circuit switching unit, and when the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack approaches the standard threshold range, keep the working state of the circuit switching unit turned on;

[0044] Step 4: until the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack is less than the median of the standard threshold range, the circuit switching unit stops responding.

[0045] Further, the state evaluation value Unq of the faulty power supply unit is generated t , the formula is as follows:

[0046]

[0047] Where, L r is the actual power capacity of the faulty power supply unit, L bis the rated power capacity of the faulty power supply unit, C is the correction factor, 1>C>0;

[0048] The obtained state evaluation value Unq t Compare with a preset loss threshold group, the loss threshold group includes a first loss threshold and a second loss threshold, the first loss threshold is less than the second loss threshold;

[0049] When the state evaluation value Unq t ≥ the second loss threshold or Gwk t When the value is less than 1, a first-level warning is issued and the first-level power supply strategy is activated;

[0050] When the second loss threshold> the state evaluation value Unq t ≥ the first loss threshold, and Gwk t When the value is greater than 1, a level 2 warning is issued and a level 2 power supply strategy is activated;

[0051] When the state evaluation value Unq t < the first loss threshold, and Gwk t When >1, no response is given.

[0052] Furthermore, when a first-level warning signal is detected, a first-level power supply strategy is executed. The process of executing the first-level power supply strategy is as follows:

[0053] Open the circuit switching unit corresponding to the faulty power supply unit to separate the faulty power supply unit from the energy storage battery pack;

[0054] According to the number of faulty power supply units removed, the same number of backup power supply units are connected;

[0055] Detect whether the working parameters of the energy storage battery group return to the preset parameter range. If the working parameters of the energy storage battery group are within the preset parameter range, execute the secondary power supply strategy; if the working parameters of the energy storage battery group are not within the preset parameter range, shut down the energy storage battery group.

[0056] Furthermore, the process of executing the secondary power supply strategy is as follows:

[0057] The formula for calculating the upper limit of energy storage Pc of the faulty power supply unit is as follows:

[0058] Pc=ω n ×L b

[0059] In the formula, ω n is the energy storage of the power supply unit in year n;

[0060] Charging: When the power capacity of the power supply unit reaches 90% of the energy storage upper limit Pc, the circuit switching unit corresponding to the power supply unit is turned on to remove the power supply unit from the energy storage battery pack, and the same number of backup power supply units are connected according to the number of removed power supply units;

[0061] Discharge: When the power capacity of the power supply unit reaches 80% of the energy storage upper limit Pc, turn on the circuit switching unit corresponding to the power supply unit, separate the backup power supply unit from the energy storage battery pack, and then connect the power supply unit separated during charging to the energy storage battery pack.

[0062] (III) Beneficial effects

[0063] 1. The energy storage battery management system based on AUTBUS of the present invention uses AUTBUS network as the communication medium for data transmission to transmit the collected working parameters, which can improve the efficiency of long-distance transmission and reduce the packet loss rate; by comprehensively analyzing the working parameters of the energy storage unit, an energy storage health prediction value that can judge the health status of the power supply unit is obtained, and then according to the obtained energy storage health prediction value, the working state of the circuit switching unit is controlled, so as to respond quickly and accurately to the faulty energy storage unit, and at the same time, the switching effect of the circuit switching unit is utilized to reduce the impact range and difficulty of maintenance;

[0064] 2. By retrieving the working parameters of the faulty power supply unit before disconnection and the corresponding energy storage health prediction value Gwk t , get the status evaluation value Unq of the faulty power supply unit t Then, based on the obtained state evaluation value Unq t The size of the energy storage unit is used to call the corresponding power supply strategy, so as to make full use of the energy storage unit and reduce the loss of economy and resources, while not affecting the energy storage efficiency of the energy storage battery group and the energy storage system as a whole; by first comparing the obtained working parameters with the preset parameter interval threshold, and then comparing the difference between the energy storage power and the working power with the standard threshold interval, the workload required for calculation can be reduced;

[0065] In summary, the system designed in the present invention can realize a comprehensive evaluation and analysis of the power supply unit, improve energy utilization efficiency, battery health management and maintenance capabilities, and the stability evaluation capability of the energy storage grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings.

[0067] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0068] Figure 2 It is a partial flow chart of the present invention;

[0069] Figure 3 The hardware circuit diagram of the acquisition unit of the present invention;

[0070] Figure 4 is a circuit diagram of the equalizing circuit of the present invention;

[0071] Figure 5 FIG. 4 is a circuit diagram of a circuit switching unit of the present invention. DETAILED DESCRIPTION

[0072] The embodiment of the present application provides an AUTBUS-based energy storage battery management system to solve the technical problem that the existing energy storage battery management system cannot respond accurately and quickly when a fault occurs. The present application uses the AUTBUS network as a communication medium for data transmission to transmit the collected working parameters, which can improve the efficiency of long-distance transmission and reduce the packet loss rate; by comprehensively analyzing the working parameters of the energy storage unit, an energy storage health prediction value that can judge the health status of the power supply unit is obtained, and then according to the obtained energy storage health prediction value, the working state of the circuit switching unit is controlled, so as to respond quickly and accurately to the faulty energy storage unit, and at the same time, the switching effect of the circuit switching unit is utilized to reduce the impact range and difficulty of maintenance.

[0073] Example 1

[0074] The technical solution in the embodiment of the present application is to solve the technical problem that the existing energy storage battery management system cannot respond accurately and quickly when a fault occurs. The overall idea is as follows:

[0075] Hardware Design

[0076] Acquisition circuit

[0077] In order to ensure the accuracy and reliability of the algorithm input variables, the BQ76940 battery monitoring chip is used to measure the voltage, temperature, current and other parameters of the battery pack. Figure 3 It is a collection unit composed of BQ76940 and peripheral circuits;

[0078] In the analog quantity acquisition unit, each battery in the battery pack (i.e., power supply unit) passes through the RC filter circuit and is connected to the VC0~VC15 pins of the BQ76940 chip, and finally the voltage of 15 power supply units can be obtained. The charge and discharge current of the battery pack is obtained through the sampling resistor in the current loop connected to the SRP and SRN pins.

[0079] In terms of temperature collection, a 10 kilo-ohm NTC thermistor is connected through the TS1-TS3 pins. Based on the relationship between temperature and resistance, the relationship between temperature and collection voltage is converted to obtain the battery temperature. The relationship between temperature and voltage is as follows:

[0080] U t =I t ×R t (1-1)

[0081]

[0082] In the formula, U t is the voltage of the thermistor at temperature T, I t is the current of the thermistor at temperature T, R t is the resistance of the thermistor at temperature T, R is the resistance of the thermistor at T N The standard resistance value at room temperature, e is a constant, e = 2.71828, B is the thermal constant of the thermistor; Combining formula (1-1) and formula (1-2), we get the relationship between temperature and voltage in formula (1-3):

[0083]

[0084] Communication

[0085] CAN communication is carried out with the controller through the SCL and SDA pins, and the battery voltage, current and temperature data are transmitted to the controller for processing.

[0086] In order to ensure the stability of transmission, the CAN communication is networked and connected to the CAN to AUTBUS signal converter. The signal converter is networked through the AUTBUS bus and connected to the edge controller. The edge controller analyzes and processes the working parameters and sends them to the remote server. After the data is converted to AUTBUS communication through CAN, the problems of low communication rate and short transmission distance in CAN communication are solved. The signal converter nodes in the system are connected in a linear topology structure, and the terminal resistance is matched at the signal converter nodes at the beginning and end, which realizes long-distance and high-speed data transmission and reduces the packet loss rate. Due to the non-polar twisted pair connection characteristics of AUTBUS, on-site wiring and construction are simpler and more convenient, avoiding communication failures caused by reverse wiring and reducing debugging work. This application only uses the above-mentioned communication method as a medium for data transmission, and does not improve it, so it will not be described in detail here.

[0087] Equalization circuit

[0088] In order to solve the problem of inconsistent battery voltage, the schematic diagram of the balancing unit is as follows Figure 4-5As shown. The circuit consists of 15 pairs of MOS tubes, which are connected in parallel at both ends of 15 battery cells. Among them, one group of MOS tubes is controlled by a PWM signal, and the other group of MOS tubes is controlled by a complementary PWM signal. The two groups of MOS tubes complement each other alternately.

[0089] The MOS tubes in this circuit appear in pairs, such as Q1, Q2, Q3..., Q 30 There are 15 pairs in total, connected in parallel at both ends of 15 battery cells. 27 , Q 29 ) is controlled by a control signal, and another group of MOS tubes (Q2, Q4, Q6..., Q 28 , Q 30 ) is controlled by another complementary control signal, and the two groups of MOS tubes complement each other alternately. Taking the balancing process of battery cell 1 as an example, when the lower tube (Q1~Q 15 )Open, upper tube (Q2~Q 16 ) is turned off, the battery string (battery 1 to battery 7) is connected in parallel with the balancing capacitor Cap1. 16 ) open, lower pipe (Q1~Q 15 ) is turned off, the battery string (BAT2 to BAT8) is connected in parallel with the balancing capacitor Cap1. In this process, battery 1 and battery 8 are balanced with each other through capacitor Cap1, and the balancing current is shown in formula (4-1).

[0090] The voltage of a single cell is used as the balancing control variable. The difference between the highest and lowest voltages of each cell is calculated to see if it is greater than 50MV. If it is greater than 50MV, it indicates that the battery pack is unbalanced. The DSP controller controls the MOS tube signal drive circuit with a 50% duty cycle PWM, ultimately balancing the 15-cell battery pack.

[0091]

[0092]

[0093] In the above formulas (2-1) and (2-2), R b is the equivalent resistance of the balancing circuit in ohms, where f is the switching frequency in hertz and C is the capacitance in farads. BAT1 t and V BAT8 t are the voltages of battery 1 and battery 8 in volts, i BAT1t is the battery balancing current, in amperes. Since the structure of the balancing circuit is divided into upper and lower parts with battery 8 as the center, batteries 2 to 7 and batteries 9 to 15 can be balanced with battery 8, and finally the function of balancing the voltage of 15 series-connected battery groups is achieved. Compared with the traditional switch capacitor balancing circuit, the balancing circuit has the advantages of fast balancing speed and high balancing efficiency.

[0094] Circuit switching unit

[0095] Reference Figure 4 and Figure 5 As shown, a single-pole double-throw switch S is connected to the connection line between two adjacent power supply units, and a branch line connected in parallel with the power supply unit is connected. The switch S is connected to the contact a on the main line in a normally closed state. At this time, the current passes through the power supply unit connected in series with the contact a;

[0096] When the switch S is in the normally open state, it is connected to the contact b of the branch line. At this time, the current enters the branch line through the switch S, bypasses the power supply unit through the branch line, and thus removes the power supply unit from the power supply line.

[0097] When a power supply unit fails or is under maintenance, the corresponding circuit switching unit is triggered, the two power supply units before and after the power supply unit are connected in series, and the backup power supply unit is connected to provide a solution basis for subsequent adjustments. The number of backup power supply units is set according to needs. When the energy storage battery pack is working normally, the circuit switching unit corresponding to the backup power supply unit is always in a normally open state (that is, the switch S is connected to the contact b of the branch line). Only when one or more power supply units in the energy storage battery pack are damaged, the circuit switching unit is turned on to connect the backup power supply unit, thereby ensuring the overall constancy of the energy storage system.

[0098] Software Design

[0099] Preliminary data comparison

[0100] In order to conduct a preliminary review of the uploaded working parameters: compare the working parameters of the power supply unit with the preset parameter range. If the working parameters of the power supply unit are within the parameter range, no response is made; otherwise, a parameter warning is issued; and based on the parameter warning, the circuit switching unit corresponding to the power supply unit is called.

[0101] The working parameters of the power supply unit mainly include: open circuit voltage U oc , load current I, terminal voltage U d , working temperature T d etc., where the open circuit voltage U oc =[3V, 4.2V], load current I =[11A, 15A], terminal voltage U d =[2.8V, 3.6V], operating temperature T d=[0℃, 50℃], when the obtained value is not within the preset parameter range, it is counted as abnormal data and an early warning is issued directly.

[0102] At this time, the circuit switching unit can be used to connect the two power supply units in series, such as Figure 5 As shown, the backup power supply unit is connected, which not only provides time for repairs, but also does not affect the normal operation of the energy storage battery.

[0103] Energy storage power detection

[0104] According to the collected working parameters of the power supply unit, an energy storage battery calculation model is built to obtain the energy storage power of the energy storage battery group, and the absolute value of the difference between the energy storage power and the working power of the energy storage battery group is compared with the preset standard threshold range;

[0105] When the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack exceeds the preset standard threshold range, a correction warning is issued, that is, |P 出 -P 负 -U z I z |>standard threshold, a correction warning is issued; conversely, when |P 出 -P 负 -U z I z |≤standard threshold, no response is made, where U z is the supply voltage of the energy storage battery, I z is the supply current of the energy storage battery, P 出 is the standard output power, P 负 is the standard load power, the energy storage power of the energy storage battery pack = standard output power P 出 -Standard load power P 负 , U z I z Indicates the energy storage power of the energy storage battery, that is, energy storage power = U z I z .

[0106] Standard output power P 出 And standard load power P 负 , the formula is as follows:

[0107]

[0108] Where U oc is the open circuit voltage of the power supply unit, I is the load current of the power supply unit, and n is the number of power supply units in the energy storage battery pack;

[0109]

[0110] Where U d is the terminal voltage of the power supply unit.

[0111] Data analysis

[0112] When a correction warning is issued, the working parameters of the power supply unit in the energy storage battery pack are retrieved and analyzed, and a power supply unit analysis and calculation model is built to generate the energy storage health prediction value Gwk t , based on the predicted value of energy storage health Gwk t The size of turns on the circuit switching units corresponding to the faulty power supply units in turn.

[0113] Based on the predicted value of energy storage health Gwk t The power supply units are sorted according to their sizes; the circuit switching units corresponding to the power supply units are turned on in sequence according to the sorted order; the energy storage power of the battery pack is recalculated while the circuit switching units are turned on, and when the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack approaches the standard threshold interval, the working state of the circuit switching unit after being turned on is maintained, and then the power supply units in the next order are eliminated in sequence; until the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack is less than the median of the standard threshold interval, the circuit switching unit stops responding.

[0114] It should be noted that when the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack approaches the standard threshold range, it means that the eliminated power supply unit has an impact on the overall operation of the energy storage battery pack. Secondly, the extent of the impact of the power supply unit on the energy storage battery pack can be distinguished based on the degree of approach.

[0115] By obtaining the working parameters of the power supply unit within the correction warning duration t, the energy storage health prediction value Gwk is generated t , energy storage health prediction value Gwk t The formula is as follows:

[0116]

[0117] In the formula, is the average value of the power supply unit temperature during the correction warning duration t, P g is the power supply of the power supply unit, U max To correct the voltage U of the power supply unit during the warning duration t d The maximum value, U min To correct the voltage U of the power supply unit during the warning duration t d , K, W, and V are respectively the preset weight coefficients of the power supply unit temperature, the power supply unit power, and the terminal voltage of the power supply unit, and W>K>V>0, and A is the constant correction coefficient.

[0118] Among them, the power supply power P of the power supply unitg = Output power of the power supply unit (IU oc )-Load power of the power supply unit (IU d -IU oc ).

[0119]

[0120] Where, t is the duration of the correction warning (in seconds, 1 second is a period, for example, if the correction warning lasts for 50 seconds, then t = 50), i is a positive integer, T d The power supply unit temperature is calculated by adding up all the temperature data during the corrected warning duration and dividing by all the time periods.

[0121] When Gwk t When it is less than 1, it indicates that the faulty power supply unit is severely damaged and can no longer cooperate with the energy storage circuit to store energy. At this time, the circuit switching unit corresponding to the faulty power supply unit is turned on to remove the faulty power supply unit from the energy storage battery pack. According to the number of faulty power supply units removed, the same number of backup power supply units are connected to ensure the stability of the energy storage battery output, thereby avoiding the need to stop the energy storage battery for repair.

[0122] The weight coefficient is set to reflect the impact on the battery life when a single parameter changes. For example, when the voltage at the power supply unit terminal and the power supply power of the power supply unit remain unchanged, the weight coefficient K at 25°C is calculated. d , power supply unit load current I, power supply unit power P g =U d ×I, maintain the voltage U d The load current I of the power supply unit remains unchanged, the initial temperature is 25°C, and the service life of the lithium battery is X1; at 25+T L At 25℃, the service life of lithium battery is X2; at 25-T L When the temperature is 0.1℃, the service life of lithium battery is X3, T L Indicates the temperature change.

[0123]

[0124] Similarly, the power supply unit power P can be calculated g And the voltage U d The preset weight coefficients W and V.

[0125] Solution strategy

[0126] Based on the working parameters of the faulty power supply unit before disconnection and the corresponding energy storage health prediction value Gwk t , generates the status evaluation value Unq of the faulty power supply unitt , so as to classify the faulty power supply units, which are usually divided into three categories. The first category is the unusable category, which needs to be removed from the energy storage battery group in time; the second category is the qualified category. Due to the different conditions reflected by the power supply units during the power supply unit detection, there may be certain deviations, resulting in failures of some power supply units that were originally able to be used normally. Therefore, for this type of power supply unit, it is necessary to reconnect it to the energy storage battery group; as for the third category, it is the residual category between the qualified category and the unusable category. Although this type of battery cannot achieve the use effect of a good battery, it can still be used, and this application is to make full use of this type of battery in order to achieve the purpose of full use, so it is necessary to use the battery according to the state evaluation value Unq t The size of the power supply strategy is enabled;

[0127] Generates the status evaluation value Unq of the faulty supply unit t , the formula is as follows:

[0128]

[0129] Where, L r is the actual power capacity of the faulty power supply unit, L b is the rated power capacity of the faulty power supply unit, C is the correction factor, 1>C>0, 1>Unq t >0, when Unq t ≥1, it is recorded as Unq t =1, the faulty power supply battery is completely damaged;

[0130] The obtained state evaluation value Unq t Compare with a preset loss threshold group, the loss threshold group includes a first loss threshold and a second loss threshold, the first loss threshold is less than the second loss threshold;

[0131] When the state evaluation value Unq t ≥ the second loss threshold, and Gwk t When it is greater than 1, a first-level warning is issued and a first-level power supply strategy is activated.

[0132] When the second loss threshold> the state evaluation value Unq t ≥ the first loss threshold, and Gwk t When the value is greater than 1, a level 2 warning is issued and a level 2 power supply strategy is activated;

[0133] When the state evaluation value Unq t < the first loss threshold, and Gwk t When >1, no response is given.

[0134] Strategy 1: When a level 1 warning signal is detected, the level 1 power supply strategy is executed. The process of executing the level 1 power supply strategy is as follows:

[0135] Open the circuit switching unit corresponding to the faulty power supply unit to separate the faulty power supply unit from the energy storage battery pack;

[0136] According to the number of faulty power supply units removed, the same number of backup power supply units are connected to achieve a balance of the internal functional systems of the energy storage battery pack;

[0137] Check whether the working parameters of the energy storage battery pack have returned to the preset parameter range. If the working parameters of the energy storage battery pack are within the preset parameter range, the secondary power supply strategy is executed, indicating that the replaced power supply unit has worked. At this time, the replaced power supply unit is in a faulty state, and the faulty state needs to be distinguished again (determine whether the power supply unit belongs to the qualified class or the residual class between the qualified class and the unavailable class); if the working parameters of the energy storage battery pack are not within the preset parameter range, the energy storage battery pack is shut down.

[0138] Strategy 2: When a level 2 warning signal is detected, the process of executing the level 2 power supply strategy is as follows:

[0139] The formula for estimating the upper limit of energy storage Pc of the faulty power supply unit is as follows:

[0140] Pc=(1-Unq t )×L b

[0141] When the energy storage upper limit Pc of the faulty power supply unit is less than or equal to the rated power capacity L of the faulty power supply unit b When the temperature reaches 50%, a replacement warning will be issued to remind the staff to replace it in time;

[0142] When the energy storage upper limit Pc of the faulty power supply unit is greater than the rated power capacity L of the faulty power supply unit b When the charge and discharge rates are 50%, the following charging and discharging strategies are implemented;

[0143] During charging, when the power capacity of the power supply unit reaches 90% of the energy storage upper limit Pc, the circuit switching unit corresponding to the power supply unit is turned on to remove the power supply unit from the energy storage battery pack, and the same number of backup power supply units are connected according to the number of removed power supply units. At this time, the power capacity of the faulty power supply unit is maintained at 90% of the energy storage upper limit Pc to avoid overcharging;

[0144] During discharge, when the power capacity of the power supply unit reaches 80% of the energy storage upper limit Pc, the circuit switching unit corresponding to the power supply unit is turned on, the backup power supply unit is separated from the energy storage battery group, and then the power supply unit separated during charging is connected to the energy storage battery group. At this time, the power capacity of the faulty power supply unit is greater than that of the adjacent power supply unit, avoiding reverse charging.

[0145] Reverse charging: The electromotive force of the old battery decreases and its internal resistance increases. Through Ohm's law of the entire circuit, when the old and new batteries are connected in series, it can be calculated that the actual power consumed by the old battery is greater than the power it provides. This means that the old battery has become an electrical appliance that consumes electrical energy.

[0146] Auxiliary strategy: During daily charging, due to the inconstancy of the power generation efficiency of the power generation unit, and the voltage is regulated by the voltage regulator between the power generation unit and the energy storage battery group, the current received by the energy storage battery is uneven. For example, the power generation power of the photovoltaic power generation unit in strong sunlight is different from that in cloudy weather, which leads to the inconstancy of the current received by the energy storage battery. For this reason, we set an upper current threshold and a lower current threshold according to the working parameters of the energy storage battery group, and compare them with the charging current sent by the power generation unit;

[0147] When the charging current is ≥ the upper current threshold, the power supply circuit between the energy storage battery pack and the power generation unit is turned on. At this time, the charging current reaches the charging standard, so that the current is connected to the energy storage battery pack;

[0148] When the charging current is less than the lower current threshold, the power supply circuit between the energy storage battery pack and the power generation unit is disconnected. At this time, the charging current does not meet the charging standard, so the power access is disconnected;

[0149] When the upper current threshold > charging current ≥ lower current threshold, no response is made to provide a buffer for current fluctuations and avoid the need for repeated switching.

[0150] Example 2

[0151] Based on Example 1, the energy storage battery management method based on AUTBUS has the following steps:

[0152] Use AUTBUS network to collect the working parameters of energy storage battery pack and power supply unit, including voltage, current and working temperature;

[0153] Among them, several power supply units are connected in series in sequence, and the outside of the power supply unit is connected to a circuit switching unit;

[0154] When a power supply unit fails or is under maintenance, the corresponding circuit switching unit is triggered to connect the two power supply units before and after the power supply unit in series and connect to the standby power supply unit;

[0155] Compare the working parameters of the power supply unit with the preset parameter range. If the working parameters of the power supply unit are within the parameter range, no response is made; otherwise, a parameter warning is issued; and according to the parameter warning, the circuit switching unit corresponding to the power supply unit is called;

[0156] According to the collected working parameters of the power supply unit, an energy storage battery calculation model is built to obtain the energy storage power of the energy storage battery group, and the absolute value of the difference between the energy storage power and the working power of the energy storage battery group is compared with the preset standard threshold range;

[0157] When the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack exceeds the preset standard threshold range, a correction warning is issued;

[0158] When a correction warning is issued, the working parameters of the power supply unit in the energy storage battery pack are retrieved and analyzed, and a power supply unit analysis and calculation model is built to generate the energy storage health prediction value Gwk t , based on the predicted value of energy storage health Gwk t The size of each circuit switches the circuit switching units corresponding to the faulty power supply units in turn;

[0159] When the absolute value of the difference between the energy storage power and the working power of the energy storage battery group is less than the median of the standard threshold range, stop;

[0160] Based on the working parameters of the faulty power supply unit before disconnection and the corresponding energy storage health prediction value Gwk t , generates the status evaluation value Unq of the faulty power supply unit t , according to the state evaluation value Unq t The size of the power supply strategy is enabled;

[0161] The upper current threshold and the lower current threshold are set according to the working parameters of the energy storage battery pack, and compared with the charging current emitted by the power generation unit;

[0162] When the charging current is ≥ the upper current threshold, the power supply circuit of the energy storage battery group and the power generation unit is turned on;

[0163] When the charging current is less than the lower current threshold, the power supply circuit between the energy storage battery group and the power generation unit is disconnected;

[0164] When the upper current threshold > charging current ≥ lower current threshold, no response is made.

[0165] In the application, the several formulas involved are all calculated by removing the dimensions and taking their numerical values. The formula is a formula obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The formula is set by technical personnel in this field according to actual conditions.

[0166] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product. A person of ordinary skill in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution.

[0167] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0168] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. The energy storage battery management system based on AUTBUS is characterized by: The system includes: The parameter acquisition module uses the AUTBUS network to collect the working parameters of the energy storage battery pack and the power supply unit. The working parameters include voltage, current, and working temperature; The energy storage battery pack is composed of a number of power supply units connected in series, and the power supply units are externally connected to a circuit switching unit; When a power supply unit fails or is under maintenance, the corresponding circuit switching unit is triggered to connect the two power supply units before and after the power supply unit in series and connect to the standby power supply unit; The working parameters of the energy storage battery pack include the supply voltage U z and supply current I z The energy storage power of the energy storage battery pack includes the standard output power P 出 And the standard load power P 负 , the standard output power P 出 And standard load power P 负 The formula used is as follows: Where U oc is the open circuit voltage of the power supply unit, I is the load current of the power supply unit, and n is the number of power supply units in the energy storage battery pack; Where U d is the terminal voltage of the power supply unit; When |P 出 -P 负 -U z I z |>standard threshold, a correction warning is issued; When |P 出 -P 负 -U z I z |≤standard threshold, no response; Parameter verification module: compares the working parameters of the power supply unit with the preset parameter range. If the working parameters of the power supply unit are within the parameter range, no response is made; otherwise, a parameter warning is issued; and according to the parameter warning, the circuit switching unit corresponding to the power supply unit is called; Energy storage verification module: Based on the collected working parameters of the power supply unit, an energy storage battery calculation model is built to obtain the energy storage power of the energy storage battery group, and the absolute value of the difference between the energy storage power and the working power of the energy storage battery group is compared with the preset standard threshold range; When the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack exceeds the preset standard threshold range, a correction warning is issued; Data analysis module: When a correction warning is issued, the working parameters of the power supply unit in the energy storage battery pack are retrieved and analyzed, and a power supply unit analysis and calculation model is built to generate the energy storage health prediction value Gwk t , based on the predicted value of energy storage health Gwk t The size of each circuit switches the circuit switching units corresponding to the faulty power supply units in turn; Under the condition that the system issues a correction warning, obtain the working parameters of the power supply unit within the correction warning duration t and generate the energy storage health prediction value Gwk t , energy storage health prediction value Gwk t The formula used is as follows: In the formula, To correct the power supply unit temperature T within the warning duration t d The average value, P g is the power supply of the power supply unit, U max To correct the voltage U of the power supply unit during the warning duration t d The maximum value, U min To correct the voltage U of the power supply unit during the warning duration t d The minimum value of , K, W, V are respectively the preset weight coefficients of the power supply unit temperature, the power supply unit power and the power supply unit terminal voltage, and W>K>V>0, A is the constant correction coefficient; When Gwk t When the value is less than 1, the circuit switching unit corresponding to the power supply unit is turned on, the power supply unit is separated from the energy storage battery pack, and the same number of backup power supply units are connected according to the number of separated power supply units; When the absolute value of the difference between the energy storage power and the working power of the energy storage battery group is less than the median of the standard threshold range, stop; Status assessment module: Based on the working parameters of the faulty power supply unit before disconnection and the corresponding energy storage health prediction value Gwk t , generates the status evaluation value Unq of the faulty power supply unit t , and according to the state evaluation value Unq t The size of the power supply strategy is enabled; Generates the status evaluation value Unq of the faulty supply unit t , the formula is as follows: Where, L r is the actual power capacity of the faulty power supply unit, L b is the rated power capacity of the faulty power supply unit, C is the correction factor, and 1>C>0, 1>Unq t >0; The obtained state evaluation value Unq t Compare with a preset loss threshold group, where the loss threshold group includes a first loss threshold and a second loss threshold, and the first loss threshold is less than the second loss threshold; When the state evaluation value Unq t ≥ the second loss threshold, and Gwk t When the value is greater than 1, a first-level warning is issued and the first-level power supply strategy is activated; When the second loss threshold> the state evaluation value Unq t ≥ the first loss threshold, and Gwk t When the value is greater than 1, a level 2 warning is issued and a level 2 power supply strategy is activated; When the state evaluation value Unq t < the first loss threshold, and Gwk t When >1, no response is given.

2. The AUTBUS-based energy storage battery management system according to claim 1, characterized in that: The system also includes: Balance control module: sets the upper and lower current thresholds according to the working parameters of the energy storage battery pack, and compares them with the charging current sent by the power generation unit; When the charging current is ≥ the upper current threshold, the power supply circuit of the energy storage battery group and the power generation unit is turned on; When the charging current is less than the lower current threshold, the power supply circuit between the energy storage battery pack and the power generation unit is disconnected; When the upper current threshold > charging current ≥ lower current threshold, no response is made.

3. The AUTBUS-based energy storage battery management system according to any one of claims 1 or 2, characterized in that: The operating temperature of the power supply unit is detected by an NTC thermistor, and the relationship between temperature and resistance is converted into the relationship between temperature and voltage. The relationship between temperature and voltage is as follows: In the formula, U t is the voltage of the thermistor at temperature T, I t is the current of the thermistor at temperature T, R t is the resistance of the thermistor at temperature T, R is the resistance of the thermistor at T N The standard resistance at room temperature, e is a constant, and B is the thermal constant of the thermistor.

4. The AUTBUS-based energy storage battery management system according to claim 1, characterized in that: The parameter acquisition module includes an acquisition unit, a conversion unit and an edge control unit; When the acquisition unit is in working state, the conversion unit and the edge control unit are triggered at the same time. The conversion unit uploads the collected data to the edge control unit via AUTBUS communication, and the edge control unit analyzes and processes the working parameters and sends them to the remote server.

5. The AUTBUS-based energy storage battery management system according to claim 1, characterized in that: The switching steps of the circuit switching unit are as follows: Step 1: Based on the predicted value of energy storage health Gwk t Sort the power supply units by size; Step 2: Turn on the circuit switching units corresponding to the power supply units in sequence according to the order in step 1; Step 3: while turning on the circuit switching unit, recalculate the energy storage power of the battery pack, and when the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack approaches the standard threshold range, keep the working state of the circuit switching unit turned on; Step 4: until the absolute value of the difference between the energy storage power and the working power of the energy storage battery pack is less than the median of the standard threshold range, the circuit switching unit stops responding.

6. The AUTBUS-based energy storage battery management system according to claim 1, characterized in that: When a level 1 warning signal is detected, the level 1 power supply strategy is executed. The process of executing the level 1 power supply strategy is as follows: Open the circuit switching unit corresponding to the faulty power supply unit to separate the faulty power supply unit from the energy storage battery pack; According to the number of faulty power supply units removed, the same number of backup power supply units are connected; Detect whether the working parameters of the energy storage battery pack return to the preset parameter range. If the working parameters of the energy storage battery pack are within the preset parameter range, execute the secondary power supply strategy; If the operating parameters of the energy storage battery pack are not within the preset parameter range, the energy storage battery pack is shut down.

7. The AUTBUS-based energy storage battery management system according to claim 1, characterized in that: The process of implementing the secondary power supply strategy is as follows: The formula for estimating the upper limit of energy storage Pc of the faulty power supply unit is as follows: Pc=(1-Unq t )×L b When the energy storage upper limit Pc of the faulty power supply unit is less than or equal to the rated power capacity L of the faulty power supply unit b When the load reaches 50%, a replacement warning is issued; When the energy storage upper limit Pc of the faulty power supply unit is greater than the rated power capacity L of the faulty power supply unit b When the charge and discharge rates are 50%, the following charging and discharging strategies are implemented; During charging, when the power capacity of the power supply unit reaches 90% of the energy storage upper limit Pc, the circuit switching unit corresponding to the power supply unit is turned on to remove the power supply unit from the energy storage battery pack, and the same number of backup power supply units are connected according to the number of removed power supply units; During discharge, when the power capacity of the power supply unit reaches 80% of the energy storage upper limit Pc, the circuit switching unit corresponding to the power supply unit is turned on, the backup power supply unit is separated from the energy storage battery pack, and then the power supply unit separated during charging is connected to the energy storage battery pack.

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