WO2023022225A1 - 二次電池の容量保持率推定方法及び二次電池の容量保持率推定プログラム並びに二次電池の容量保持率推定装置 - Google Patents
二次電池の容量保持率推定方法及び二次電池の容量保持率推定プログラム並びに二次電池の容量保持率推定装置 Download PDFInfo
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- 238000012360 testing method Methods 0.000 claims abstract description 114
- 230000006866 deterioration Effects 0.000 claims abstract description 50
- 238000005259 measurement Methods 0.000 claims abstract description 16
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- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 2
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- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/392—Determining battery ageing or deterioration, e.g. state of health
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Definitions
- the present invention provides a single chargeable/dischargeable secondary battery cell, a storage battery comprising a plurality of chargeable/dischargeable secondary battery cells connected in series or in parallel, a storage battery, a commercial power supply, and a power generation device, which are connected and connected.
- the above-mentioned power storage system is often used in charge and discharge cycles once or twice a day, and the capacity retention rate of the secondary battery may gradually decrease due to cycle deterioration and aging deterioration. I know it.
- the capacity of the secondary battery after being used for a long period of time cannot be determined without actual measurement. It is becoming necessary to predict the capacity retention of batteries.
- in order to meet the demand for reducing the environmental load there is a demand for extending the usage period of power storage systems, etc., and it is becoming necessary to predict the life of secondary batteries in the future.
- a method that prepares a large number of complicated state-of-charge maps to correct the capacity retention rate and a prediction formula for the capacity retention rate are known.
- a prediction formula for the capacity retention rate one using a root law or a power law is known.
- the capacity decrease rate of a secondary battery is proportional to the power of 1/2 of the amount of current flowing through the secondary battery (accumulated current value) or the power of 1/2 of the time the secondary battery is left standing. It is known to be determined by the multiplicative law (root law).
- the formula is as follows, and if the square root of the amount of current flowing (current amount) integrated over time is obtained, the state of deterioration (or the rate of decrease in capacity) of the secondary battery can be estimated. can be done.
- Non-Patent Document 1 Such a method treats a battery as an assembly of partial cells, and can estimate the service life from the prediction of its failure rate, which is expressed by the following equation.
- the method of estimating the capacity retention rate using the Weibull law shows good agreement with the measured values compared to the root law and the power law. requires more accurate lifetime prediction.
- a first aspect of the present invention for solving the above problems is In a secondary battery capacity retention (SOH) estimation method for estimating the capacity retention of a secondary battery using the Weibull law, Determining the Weibull coefficients m f and ⁇ f corresponding to the float capacity retention rate and the float capacity retention rate of the following formula (1) from the measured values of the float test for determining the capacity retention rate, Weibull coefficients m c and ⁇ c corresponding to the cycle capacity retention rate and the cycle capacity retention rate of the following formula (2) are determined from the measured values of the cycle test for determining the capacity retention rate, A method for estimating a capacity retention rate of a secondary battery, wherein the capacity retention rate in a period t or the number of cycles N is estimated from the float capacity retention rate and the cycle capacity retention rate of the secondary battery.
- SOH secondary battery capacity retention
- a second aspect of the present invention is The capacity retention rate obtained from the float test is used as the measured float capacity retention rate, and the measured float capacity retention rate is Weibull plotted in relation to ln (period) and ln (ln (1/capacity retention rate)).
- the method for estimating the capacity retention rate of a secondary battery according to the first aspect is characterized in that the cycle capacity retention rate is obtained from the Weibull coefficients m c and ⁇ c and the equation (2).
- a third aspect of the present invention is The method for estimating the capacity retention of a secondary battery according to the first or second aspect is characterized in that the capacity retention is obtained from the four arithmetic operations of the float capacity retention and the cycle capacity retention.
- a fourth aspect of the present invention is The capacity retention of the secondary battery according to any one of the first to third aspects, characterized in that the capacity retention rate is estimated as the capacity retention rate in the period t or the number of cycles N by the following formula (A). in the rate estimation method.
- a fifth aspect of the present invention is The capacity retention of the secondary battery according to any one of the first to third aspects, characterized in that the capacity retention rate is estimated as the capacity retention rate in the period t or the number of cycles N by the following formula (B). in the rate estimation method.
- a sixth aspect of the present invention is in a secondary battery capacity retention rate estimation program for estimating the capacity retention rate (SOH) of a secondary battery using the Weibull law,
- SOH capacity retention rate
- a seventh aspect of the present invention is The capacity retention rate obtained from the float test is used as the measured float capacity retention rate, and this float component capacity retention rate is Weibull plotted in relation to ln (period) and ln (ln (1/capacity retention rate)).
- An eighth aspect of the present invention is Capacity retention of the secondary battery according to the sixth or seventh aspect, wherein the capacity retention rate is obtained by causing a computer to function and execute a procedure for obtaining the capacity retention rate from the four arithmetic operations of the float capacity retention rate and the cycle capacity retention rate. in the rate estimation program.
- a ninth aspect of the present invention is Any one of 6th to 8th, wherein the capacity retention rate is estimated as the capacity retention rate in the period t or the number of cycles N by the following formula (A). According to one aspect, there is provided a program for estimating a capacity retention rate of a secondary battery.
- a tenth aspect of the present invention is According to any one of the sixth to eighth aspects, the capacity retention rate is obtained by causing a computer to function and execute a procedure for estimating the capacity retention rate in the period t or the number of cycles N according to the following formula (B).
- a secondary battery capacity retention rate estimation program according to an aspect.
- An eleventh aspect of the present invention is A secondary battery capacity retention estimation device for performing a secondary battery capacity retention estimation method, storage means storing data of the cycle test and the float test; Data acquisition means for acquiring data of the secondary battery in operation, the period t and the number of cycles N from the secondary battery, a procedure for obtaining the Weibull coefficients m f and ⁇ f corresponding to the float capacity retention rate and the float capacity retention rate of the following formula (1) from the measured values of the float test; a procedure for obtaining the Weibull coefficients m c and ⁇ c corresponding to the cycle capacity retention rate and the cycle capacity retention rate of the following formula (2) from the measured values of the cycle test; estimating the capacity retention (SOH) of the secondary battery by performing a procedure for estimating the capacity retention at period t or the number of cycles N from the float capacity retention and the cycle capacity retention of the secondary battery;
- the device for estimating the capacity retention rate of a secondary battery is characterized by:
- a twelfth aspect of the present invention is The capacity retention rate obtained from the float test is used as the measured float capacity retention rate, and this float component capacity retention rate is Weibull plotted in relation to ln (period) and ln (ln (1/capacity retention rate)).
- the eleventh aspect of the apparatus for estimating the capacity retention rate of a secondary battery is characterized by: performing the procedure of obtaining the cycle capacity retention rate from the Weibull coefficients m c and ⁇ c and the equation (2).
- a thirteenth aspect of the present invention is According to the eleventh or twelfth aspect of the apparatus for estimating the capacity retention of a secondary battery, the capacity retention is obtained by performing a procedure for obtaining the capacity retention from the four arithmetic operations of the float capacity retention and the cycle capacity retention. .
- a fourteenth aspect of the present invention comprises: The secondary battery according to any one of the eleventh to thirteenth aspects, wherein the capacity retention rate is estimated as the capacity retention rate in the period t or the number of cycles N by the following formula (A). It is in the battery capacity retention estimation device.
- a fifteenth aspect of the present invention comprises: The secondary battery according to any one of the eleventh to thirteenth aspects, wherein the capacity retention rate is estimated as the capacity retention rate in the period t or the number of cycles N by the following formula (B). It is in the battery capacity retention estimation device.
- the capacity retention rate of the secondary battery is accurately maintained over a long period of time by separately calculating the float capacity retention rate due to deterioration over time and the cycle capacity retention rate due to deterioration due to the number of charge/discharge cycles. It is possible to provide a secondary battery capacity retention rate estimation method, a secondary battery capacity retention rate estimation program, and a secondary battery capacity retention rate estimation device for estimating the capacity retention rate of a secondary battery.
- FIG. 2 is a functional block diagram showing an example of a schematic configuration of a control unit in FIG. 1;
- FIG. 1 is a schematic flow diagram of the method of the present invention;
- FIG. It is a figure which shows an example which carried out the Weibull plot of the result of the float test. It is a figure which shows an example which carried out the Weibull plot of the result of the cycle test.
- FIG. 2 shows the results of Example 1;
- FIG. 2 shows the results of Example 1;
- FIG. 10 is a diagram showing the results of Example 2;
- FIG. 10 is a diagram showing the results of Example 2;
- FIG. 10 is a diagram showing the results of Example 2;
- FIG. 10 is a diagram showing the results of Example 2;
- FIG. 10 is a diagram showing the results of Example 3; FIG. 10 is a diagram showing the results of Example 3; FIG. 10 is a diagram showing the results of Example 4; FIG. 10 is a diagram showing the results of Example 4; FIG. 10 is a diagram showing the results of Example 5; FIG. 10 is a diagram showing the results of Example 5; FIG. 10 is a diagram showing the results of Example 6; FIG. 10 is a diagram showing the results of Example 6; FIG. 11 shows the results of Example 7; FIG. 11 shows the results of Example 7; FIG. 10 is a diagram showing the results of Example 8; FIG. 10 is a diagram showing the results of Example 8;
- FIG. 1 is a diagram showing an example of a schematic configuration of a storage battery system to which the method of the present invention is applied.
- a storage battery system 1 includes a storage battery 2, which is a secondary battery that stores electric power, and a power adjustment device 3.
- the power adjustment device 3 includes a commercial power supply 4, a load 5, and a , for example, a photovoltaic power generation device 6 as a power generation device that generates power using natural energy is connected.
- the storage battery 2 is configured to be able to charge and discharge electric power, and is composed of a single or a plurality of rechargeable secondary battery cells 2a.
- a lithium ion battery for example, a lithium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead battery, or the like can be used.
- a lithium ion battery is used as the storage battery 2 .
- the plurality of secondary battery cells 2a are connected based on the functions and capabilities required as a storage battery, and may be connected in series or in parallel. good.
- the power adjustment device 3 is a so-called power conditioner that rectifies AC power supplied as a commercial power source 4, converts DC power from the storage battery 2 or the solar power generation device 6 into AC power, and outputs the AC power to the load 5. , a plurality of switches (first switch 31 to fifth switch 35), and a control unit 40 that controls the power adjustment device 3 in general.
- the inverter 30 is a bi-directional inverter having a function of converting input DC power into AC power and outputting the same and a function of converting input AC power into DC power and outputting the same.
- the commercial power source 4 is supplied with power from an electric utility, and in this embodiment, AC power is supplied.
- the power generation device is, for example, a power generation device that generates power using natural energy (renewable energy) such as sunlight, solar heat, hydraulic power, wind power, geothermal heat, wave power, temperature difference, and biomass.
- natural energy such as sunlight, solar heat, hydraulic power, wind power, geothermal heat, wave power, temperature difference, and biomass.
- a photovoltaic device 6 was used.
- the power adjustment device 3 of such a storage battery system 1 converts the DC power generated by the solar power generation device 6 by the control unit 40 into AC power via the storage battery 2 and the inverter 30 and supplies it to the load 5 at a desired timing and rate. control is performed.
- the control unit 40 controls the control unit 40 to convert AC power supplied from the commercial power source 4 into DC power via the load 5 and the inverter 30 and supply the storage battery 2 with the DC power at a desired timing.
- the power adjusting device 3 is provided with a plurality of switches (first switch 31 to fifth switch 35) which are switches that can be opened and closed under the control of the control unit 40.
- switches first switch 31 to fifth switch 35
- a first switch 31 provided between the solar power generation device 6 and the inverter 30, a second switch 32 provided between the inverter 30 and the storage battery 2, the commercial power source 4 and the load 5
- a third switch 33 provided between the branch point 50 and the inverter 30, a fourth switch 34 provided between the branch point 50 and the commercial power supply 4, and between the branch point 50 and the load 5 and a fifth switch 35 provided in the .
- the control unit 40 controls the opening and closing of the first switch 31 to the fifth switch 35 to charge and discharge the storage battery 2 described above, control the supply destination of the commercial power supply 4, and the like.
- the first switch 31 to the fifth switch 35 are controllable by the controller 40 .
- a circuit breaker for wiring may be used, which is not controlled by the control section 40 .
- control unit 40 of the power adjusting device 3 will be further described with reference to FIG. 2 is a functional block diagram showing a schematic configuration of the control section 40. As shown in FIG. 2
- control unit 40 controls the entire power adjustment device 3, and includes power generation device monitoring means 41, storage battery monitoring means 42, and charge/discharge control means 43.
- the power generation device monitoring means 41 detects the power generation state of the photovoltaic power generation device 6 . That is, the power generation device monitoring means 41 detects whether the solar power generation device 6 is in a power generation state or a non-power generation state. Moreover, the power generation device monitoring means 41 may detect the power generation amount in the power generation state of the photovoltaic power generation device 6 .
- the storage battery monitoring means 42 measures the charging/discharging current, voltage, ambient and battery temperature, operating time, number of cycles, etc. of the storage battery 2, and estimates the SOC, SOH, and the like.
- the storage battery monitoring means 42 of the present embodiment is a monitoring device (CMU : Cell Monitor Unit).
- the storage battery monitoring means 42 detects an abnormality in the voltage, current, temperature, or the like of the secondary battery cell 2a or the group of secondary battery cells 2a, and notifies the charge/discharge control means 43 of the occurrence of the abnormality.
- the charging/discharging control means 43 controls the inverter 30 and the first to fifth switches 31 to 35 based on various conditions to control charging/discharging of the storage battery 2 and power supply from the commercial power source 4 .
- the power generation device monitoring means 41, the storage battery monitoring means 42, and the charge/discharge control means 43 are examples of a central processing unit (CPU) and a storage means that constitute the power adjustment device 3. It can be realized by a readable and writable memory (RAM: Random Access Memory) and a read-only memory (ROM: Read Only Memory) for storing various programs.
- CPU central processing unit
- RAM Random Access Memory
- ROM Read Only Memory
- the method of the present invention is applied to such a storage battery system, but of course, the application is not limited to this storage battery system.
- the method of the present invention estimates the capacity retention rate of a secondary battery that is actually used. That is, data such as the temperature, current, voltage, operating time, number of cycles, etc. of the operating secondary battery are obtained, and the capacity retention rate SOH is estimated based on this data.
- Such a method of the present invention may be performed by the storage battery monitoring means 42, but the data collected by the storage battery monitoring means 42 is transmitted to an external arithmetic device, and the method of the present invention is carried out by the arithmetic device that has acquired the data. You may
- a secondary battery capacity retention rate estimating apparatus that implements such a method of the present invention includes, for example, storage means storing data of at least one of a cycle test and a float test, secondary battery data during operation, period t and the number of cycles N from the secondary battery, and a calculation device for performing various calculations.
- the storage means, data acquisition means, and arithmetic device are preferably provided by a server connected via a network such as the Internet, but may be a computer connected to the network.
- the capacity retention rate (SOH) of a secondary battery is distinguished between the float capacity retention rate due to deterioration due to use of the secondary battery and the cycle due to deterioration due to charging and discharging, and the float capacity retention rate for estimating each is , is the capacity retention rate based on the measured value of the float test. Also, the cycle capacity retention is a capacity retention based on cycle test measurements.
- FIG. 1 A schematic flow diagram of one example of the method of the present invention is shown in FIG.
- the capacity retention (SOH) of the secondary battery is estimated by separately estimating the float capacity retention obtained from the float test and the cycle capacity retention obtained from the cycle test.
- a secondary battery of a predetermined type is operated, and a float test (S10) in which a change in capacity during operation is measured for each SOC (S1) and for each temperature (S2). Then, a cycle test in which the SOC of a predetermined type of secondary battery is charged from 0% to 100% and discharged from 100% to 0% is defined as one cycle, and the SOC is repeatedly increased and decreased for a constant cycle period at a predetermined temperature S2.
- a cycle test S20 to be performed is performed.
- the float deterioration coefficient (S11) obtained from the measured value of the float test and the time (S12) are introduced into the float deterioration formula (1) (S13) to obtain the float capacity retention rate (S14 ).
- the cycle deterioration coefficient (S21) obtained from the measured value of the cycle test and the number of cycles (S22) are introduced into the cycle deterioration formula (2) (S23), and the cycle capacity retention is calculated. (S24).
- the capacity retention rate (SOH(t)) of the target battery cell or the like is estimated using the following estimation formula (A) for the capacity retention rate SOH (step S30).
- the storage battery monitoring means 42 acquires the temperature, current, voltage, operation period, etc. for each secondary battery cell 2a or for each battery cell group composed of a plurality of secondary battery cells 2a. Then, using this, the capacity retention rate of the target battery cell or the like is estimated by the following estimation formula (A) of the capacity retention rate SOH.
- the Weibull coefficients m f , ⁇ f , m c , and ⁇ c depend on the capacity, structure, material, etc. of the battery cell, and therefore differ for each type of battery cell. Therefore, it is preferable to use battery test cells of the same type. If the test battery cells of the same type are not used, the estimation result of the capacity retention rate deviates from that of the power storage system. Even test battery cells of the same type differ depending on the average charging rate (average SOC), which is the state of use. Therefore, it is necessary to obtain Weibull coefficients m f , ⁇ f , m c and ⁇ c for each average SOC. Moreover, since the Weibull coefficients m f , ⁇ f , m c and ⁇ c change depending on the operating temperature, it is preferable to obtain them for each temperature.
- the average SOC of the operating battery is obtained from the temperature, current, and voltage of the battery cells, etc., obtained by the storage battery monitoring means 42, and the Weibull coefficients m f , ⁇ f , and m c corresponding to the obtained average SOC and temperature are obtained. and ⁇ c are selected, and the capacity retention rate SOH at period t or cycle number N is estimated from the float capacity retention rate and the cycle capacity retention rate of the secondary battery.
- the method of the present invention is premised on a method for estimating the capacity retention of a secondary battery in which a secondary battery is an aggregate of partial batteries and the capacity retention of the secondary battery is predicted by the Weibull law based on the prediction of the failure rate of the partial battery.
- the capacity retention rate of the secondary battery is estimated by distinguishing between the float capacity retention rate by the float test and the cycle capacity retention rate by the cycle test, respectively, and the float capacity retention rate and the cycle capacity retention rate of the secondary battery It is characterized by estimating the capacity retention rate in period t or cycle number N from the rate.
- the effect of the present invention is great in determining the life of the secondary battery.
- the float capacity retention rate is the capacity retention rate based on the measurement of the float test, and is the deterioration depending on the usage period of the secondary battery
- the cycle capacity retention rate is the capacity based on the measurement of the cycle test. It is the retention rate, and it is the deterioration depending on the number of cycles, with charging and discharging as one cycle.
- the method of estimating the capacity retention rate in the period t or the number of cycles N from the float capacity retention rate and the cycle capacity retention rate of the secondary battery is not particularly limited, and an estimation method may be appropriately selected according to the purpose.
- an estimation method may be appropriately selected according to the purpose.
- the capacity retention rate after long-term use can be estimated more accurately, and the life of the secondary battery can be improved.
- the effect of the present invention in determining is great.
- a method of estimating the capacity retention in a period t or the number of cycles N from the float capacity retention and the cycle capacity retention of the secondary battery is specifically exemplified by the float capacity retention and the cycle capacity retention.
- a method of obtaining from the four arithmetic operations of the rate can be mentioned.
- the capacity retention rate as the capacity retention rate in the period t or the number of cycles N by the following formula (A) or the following formula (B).
- Formula (A) is preferably used when there is a strong correlation between cycle deterioration and float deterioration, and in other cases, formula (B) is preferably used.
- the secondary battery is operated at a predetermined temperature and fixed at a predetermined SOC, and the change in capacity over the operating time is measured.
- the test is performed in the same manner by changing to a different operating temperature state or a different SOC.
- the voltage is fixed at an SOC of 50%, and a test is performed to confirm the capacity by leaving the battery for a long period of time at different temperatures such as 25°C, 45°C, and 60°C.
- the SOC is fixed at other voltage ratios, and tests are conducted to confirm the capacity at 25°C, 45°C, and 60°C.
- One cycle is defined as a period in which a predetermined type of secondary battery is charged from SOC 0% to 100% and discharged from SOC 100% to 0%, and the SOC is repeatedly increased and decreased for a constant period of the cycle. For example, if charging and discharging are performed three times a day, three cycles can be performed in one day, 300 cycles in 100 days, and 3000 cycles in 1000 days. The capacity corresponding to the period corresponding to the number of cycles is measured to obtain the total cycle test capacity retention for Weibull coefficient determination.
- the measured value obtained is the capacity for each number of cycles when the secondary battery is operated at a predetermined temperature. It is sufficient that the number of cycles corresponds to the measured value, and the measurement may be performed for each cycle, for each predetermined number of times, or irregularly. For more accurate SOH estimation, it is preferable to have as many measurements as possible.
- the capacity retention rate is a value obtained by dividing the capacity after deterioration by the capacity at the start of the test, and is the ratio of the capacity after deterioration to the initial capacity retention rate. That is, the total cycle test capacity retention is the value obtained by dividing the measured value obtained by the cycle test by the initial full charge capacity.
- the actual measurement value for determining the coefficient may be obtained directly from the secondary battery whose capacity retention rate SOH is to be estimated, for example, the power storage system described above. For a predetermined operation period from the start of operation, measure the capacity when the SOC reaches a predetermined value to obtain an actual measurement value for determining the float coefficient. Measured values for factor determination can be obtained.
- the method of counting the number of cycles when obtaining the actual measurement value for determining the cycle coefficient can be determined as appropriate. For example, a set of charging or discharging in which the capacity moves by 50% or more of the full charge capacity may be counted as one cycle, or each time a specific SOC ratio is passed twice may be counted as one cycle.
- a case where the accumulated actual charge/discharge capacity coincides with the capacity of one charge/discharge cycle of the battery may be counted as one cycle. Since the battery temperature does not change significantly depending on the environment in which the power storage system is placed, the battery temperature can be measured and the average temperature can be used.
- the capacity retention rate is a value obtained by dividing the capacity after deterioration by the capacity at the start of the test, and is the ratio of the capacity after deterioration to the initial capacity retention rate. That is, the capacity retention rate is a value obtained by dividing the measured value obtained from the power storage system by the initial full charge capacity.
- the capacity retention rate of the power storage system can be estimated.
- the capacity retention rate obtained from the float test is used as the measured float capacity retention rate, and the float capacity retention rate is plotted in Weibull plots in relation to ln (period) and ln (ln (1/capacity retention rate)).
- a Weibull plot of the capacity retention rate is created, a linear float deterioration prediction line is estimated from the Weibull plot of the float capacity retention rate, and Weibull coefficients m f and ⁇ f are obtained from the slope and intercept of the float deterioration prediction line.
- FIG. 4 is an example of a Weibull plot of the results of this float test, plotting the measured values of SOC 50% at 25 ° C., SOC 50% at 45 ° C., and SOC 50% at 60 ° C. Weibull under each condition The coefficients m f , ⁇ f can be determined. Then, the float component capacity retention rate can be obtained.
- the capacity retention rate obtained from the cycle test is used as the measured cycle capacity retention rate, and this cycle capacity retention rate is Weibull plotted in relation to ln (number of cycles) and ln (ln (1/capacity retention rate)).
- a Weibull plot of the cycle capacity retention rate is created, a linear cycle deterioration prediction line is estimated from the Weibull plot of the cycle capacity retention rate, and the Weibull coefficients m c and ⁇ c are calculated from the slope and intercept of the cycle deterioration prediction line. demand.
- FIG. 5 is an example of Weibull plotting of the results of the cycle test. Weibull coefficients m c and ⁇ c can be obtained under the measurement conditions. Then, the cycle component capacity retention rate can be obtained.
- the capacity is 50Ah.
- the element is housed in a SUS metal case.
- a float test and a cycle test were performed using this secondary battery. Float tests were conducted at various SOCs and temperatures. The cycle test was 6 cycles per day at various SOCs and temperatures.
- FIG. 6 shows the result of estimating the capacity retention rate from equations (1), (2), and (A) using these Weibull coefficients as Weibull prediction A.
- FIG. 6 shows actual data together with predicted values, and it was confirmed that the predicted values substantially match the actual data.
- 7(a) shows changes in the number of cycles of the actual machine
- FIG. 7(b) shows changes in the SOC of the actual machine
- FIG. 7(c) shows changes in the temperature of the actual machine. .
- Example 2 A float test and a cycle test were performed using the same type of secondary battery as in Example 1. Float tests were conducted at various SOCs and temperatures. The cycle test was 6 cycles per day at various SOCs and temperatures. Data was obtained for a system in which 16 secondary batteries of the same type were connected in series (battery capacity: 2.5 kWh), and the average SOC was found to be 97.0%. Also, the average temperature was 27.8°C. Also, the Weibull coefficient mf from the float test corresponding to the average SOC and average temperature was 0.962004, and ⁇ f was 4.269083. Also, the Weibull coefficient m c from the cycle test was 0.04926, and ⁇ c was 57.4858.
- FIG. 8 shows the result of estimating the capacity retention rate from equations (1), (2), and (A) using these Weibull coefficients as Weibull prediction A.
- FIG. 8 shows actual data together with predicted values, and it was confirmed that the predicted values substantially match the actual data.
- 9(a) shows changes in the number of cycles of the actual machine
- FIG. 9(b) shows changes in the SOC of the actual machine
- FIG. 9(c) shows changes in the temperature of the actual machine. .
- Example 3 A float test and a cycle test were performed using the same type of secondary battery as in Example 1. Float tests were conducted at various SOCs and temperatures. The cycle test was 6 cycles per day at various SOCs and temperatures. Data was obtained for a system in which 16 secondary batteries of the same type were connected in series (battery capacity: 2.5 kWh), and the average SOC was found to be 77.9%. Also, the average temperature was 31.5°C. The Weibull coefficient mf from the float test results corresponding to the average SOC and average temperature was 0.355503, and ⁇ f was 7.313371. Further, the Weibull coefficient mc from the cycle test results was 0.665076, and ⁇ c was 10.78985.
- FIG. 10 shows the result of estimating the capacity retention rate from equations (1), (2), and (A) using these Weibull coefficients as Weibull prediction A.
- FIG. 10 shows actual data together with predicted values, and it was confirmed that the predicted values substantially match the actual data.
- 11(a) shows changes in the number of cycles of the actual machine
- FIG. 9(b) shows changes in the SOC of the actual machine
- FIG. 9(c) shows changes in the temperature of the actual machine. .
- Example 4 A float test and a cycle test were performed using the same type of secondary battery as in Example 1. Float tests were conducted at various SOCs and temperatures. The cycle test was 6 cycles per day at various SOCs and temperatures. Data was obtained for a system in which 16 secondary batteries of the same type were connected in series (battery capacity: 2.5 kWh), and the average SOC was found to be 96.7%. Also, the average temperature was 30.5°C. Also, the Weibull coefficient mf from the float test corresponding to the average SOC and average temperature was 0.507544, and ⁇ f was 5.396954. Also, the Weibull coefficient mc from the cycle test was 0.105096 and ⁇ c was 44.51101.
- FIG. 12 shows Weibull prediction A, which is the result of estimating the capacity retention rate from equations (1), (2), and (A) using these Weibull coefficients.
- FIG. 12 shows the actual data together with the predicted values, and it was confirmed that the predicted values substantially matched the actual data.
- 13(a) shows changes in the number of cycles of the actual machine
- FIG. 13(b) shows changes in the SOC of the actual machine
- FIG. 13(c) shows changes in the temperature of the actual machine. .
- Example 5 A float test and a cycle test were performed using the same type of secondary battery as in Example 1. Float tests were conducted at various SOCs and temperatures. The cycle test was 6 cycles per day at various SOCs and temperatures. Data was obtained for a system in which 16 secondary batteries of the same type were connected in series (battery capacity: 2.5 kWh), and the average SOC was found to be 92.1%. Also, the average temperature was 28.2°C. Also, the Weibull coefficient mf from the float test corresponding to the average SOC and average temperature was 0.270603, and ⁇ f was 9.341202. Also, the Weibull coefficient mc from the cycle test was 0.659873 and ⁇ c was 10.65732.
- FIG. 14 shows the predicted values and the actual data, and it was confirmed that the predicted values substantially matched the actual data.
- 15(a) shows changes in the number of cycles of the actual machine
- FIG. 15(b) shows changes in the SOC of the actual machine
- FIG. 15(c) shows changes in the temperature of the actual machine. .
- Example 6 A float test and a cycle test were performed using the same type of secondary battery as in Example 1. Float tests were conducted at various SOCs and temperatures. The cycle test was 6 cycles per day at various SOCs and temperatures. Data was obtained for a system in which 16 secondary batteries of the same type were connected in series (battery capacity: 2.5 kWh), and the average SOC was found to be 97.0%. Also, the average temperature was 27.8°C. Also, the Weibull coefficient mf from the float test corresponding to the average SOC and average temperature was 0.962004, and ⁇ f was 4.269083. Also, the Weibull coefficient m c from the cycle test was 0.04926, and ⁇ c was 57.4858.
- FIG. 16 shows the result of estimating the capacity retention rate from equations (1), (2), and (B) using these Weibull coefficients as Weibull prediction B.
- FIG. FIG. 16 shows the actual data together with the predicted values, and it was confirmed that the predicted values substantially matched the actual data.
- 17(a) shows changes in the number of cycles of the actual machine
- FIG. 17(b) shows changes in the SOC of the actual machine
- FIG. 17(c) shows changes in the temperature of the actual machine. .
- Example 7 A float test and a cycle test were performed using the same type of secondary battery as in Example 1. Float tests were conducted at various SOCs and temperatures. The cycle test was 6 cycles per day at various SOCs and temperatures. Data was obtained for a system in which 16 secondary batteries of the same type were connected in series (battery capacity: 2.5 kWh), and the average SOC was found to be 77.9%. Also, the average temperature was 31.5°C. Also, the Weibull coefficient mf from the float test corresponding to the average SOC and average temperature was 0.962004, and ⁇ f was 4.269083. Also, the Weibull coefficient m c from the cycle test was 0.04926, and ⁇ c was 57.4858.
- FIG. 18 shows Weibull prediction B, which is the result of estimating the capacity retention ratio from the equations (1), (2), and (B) using these Weibull coefficients.
- FIG. 18 shows the actual data together with the predicted values, and it was confirmed that the predicted values substantially matched the actual data.
- FIG. 19(a) shows changes in the number of cycles of the actual machine
- FIG. 19(b) shows changes in the SOC of the actual machine
- FIG. 19(c) shows changes in the temperature of the actual machine.
- Example 8 A float test and a cycle test were performed using the same type of secondary battery as in Example 1. Float tests were conducted at various SOCs and temperatures. The cycle test was 6 cycles per day at various SOCs and temperatures. Data was obtained for a system in which 16 secondary batteries of the same type were connected in series (battery capacity: 2.5 kWh), and the average SOC was found to be 96.7%. Also, the average temperature was 30.5°C. Also, the Weibull coefficient mf from the float test corresponding to the average SOC and average temperature was 0.507544, and ⁇ f was 5.396954. Also, the Weibull coefficient mc from the cycle test was 0.105096 and ⁇ c was 44.51101.
- FIG. 20 shows the result of estimating the capacity retention rate from equations (1), (2), and (B) using these Weibull coefficients as Weibull prediction B.
- FIG. FIG. 20 shows actual data together with predicted values, and it was confirmed that the predicted values substantially match the actual data.
- 21(a) shows changes in the number of cycles of the actual machine
- FIG. 21(b) shows changes in the SOC of the actual machine
- FIG. 21(c) shows changes in the temperature of the actual machine. .
- the present invention can be effectively used in industrial fields that construct storage battery systems that use storage batteries as power sources, and in industrial fields that maintain and operate such systems.
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Abstract
Description
ワイブル則を用いて二次電池の容量保持率を推定する二次電池の容量保持率(SOH)推定方法において、
容量保持率を求めるフロート試験の測定値からフロート容量保持率に対応するワイブル係数mf、ηfおよび下記式(1)のフロート容量保持率を求め、
容量保持率を求めるサイクル試験の測定値からサイクル容量保持率に対応するワイブル係数mc、ηcおよび下記式(2)のサイクル容量保持率を求め、
前記二次電池のフロート容量保持率および前記サイクル容量保持率により、期間tまたはサイクル数Nでの容量保持率を推定する
ことを特徴とする二次電池の容量保持率推定方法にある。
前記フロート試験から得られた容量保持率を測定フロート容量保持率とし、前記測定フロート容量保持率をln(期間)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、フロート容量保持率のワイブルプロットを作成し、
前記フロート容量保持率のワイブルプロットから直線式のフロート劣化予測線を推定し、
当該フロート劣化予測線の傾き及び切片から前記ワイブル係数mf及びηfを求め、
前記ワイブル係数mf及びηfと前記式(1)から前記フロート容量保持率を求め、
前記サイクル試験から得られた容量保持率を測定サイクル容量保持率とし、前記測定サイクル容量保持率をln(サイクル数)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、サイクル容量保持率のワイブルプロットを作成し、
前記サイクル容量保持率のワイブルプロットから直線式のサイクル劣化予測線を推定し、
当該サイクル劣化予測線の傾き及び切片から、前記ワイブル係数mc及びηcを求め、
前記ワイブル係数mc及びηcと前記式(2)から前記サイクル容量保持率を求める
ことを特徴とする第1の態様の二次電池の容量保持率推定方法にある。
前記容量保持率は、前記フロート容量保持率および前記サイクル容量保持率の四則演算から求める
ことを特徴とする第1又は第2の態様の二次電池の容量保持率推定方法にある。
前記容量保持率は、下記式(A)により、期間tまたはサイクル数Nでの容量保持率として推定する
ことを特徴とする第1~第3の何れか一つの態様の二次電池の容量保持率推定方法にある。
前記容量保持率は、下記式(B)により、期間tまたはサイクル数Nでの容量保持率として推定する
ことを特徴とする第1~第3の何れか一つの態様の二次電池の容量保持率推定方法にある。
ワイブル則を用いて二次電池の容量保持率(SOH)を推定する二次電池の容量保持率推定プログラムにおいて、
容量保持率を求めるフロート試験の測定値からフロート容量保持率に対応するワイブル係数mf、ηfおよび下記式(1)のフロート容量保持率を求める手順と、
容量保持率を求めるサイクル試験の測定値からサイクル容量保持率に対応するワイブル係数mc、ηcおよび下記式(2)のサイクル容量保持率を求める手順と、
前記二次電池のフロート容量保持率および前記サイクル容量保持率により、期間tまたはサイクル数Nでの容量保持率を推定する手順とをコンピュータを機能させて実行させる
ことを特徴とする二次電池の容量保持率推定プログラムにある。
前記フロート試験から得られた容量保持率を測定フロート容量保持率とし、このフロート成分容量保持率をln(期間)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、フロート容量保持率のワイブルプロットを作成する手順と、
前記フロート容量保持率のワイブルプロットから直線式のフロート劣化予測線を推定する手順と、
当該フロート劣化予測線の傾き及び切片から前記ワイブル係数mf及びηfを求める手順と、
前記ワイブル係数mf及びηfと前記式(1)から前記サイクル容量保持率を求める手順と、
前記サイクル試験から得られた容量保持率を測定サイクル容量保持率とし、このサイクル容量保持率をln(サイクル数)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、サイクル容量保持率のワイブルプロットを作成する手順と、
前記サイクル容量保持率のワイブルプロットから直線式のサイクル劣化予測線を推定する手順と、
当該サイクル劣化予測線の傾き及び切片から、前記ワイブル係数mc及びηcを求める手順と、
前記ワイブル係数mc及びηcと前記式(2)から前記サイクル容量保持率を求める手順と
をコンピュータを機能させて実行させることを特徴とする第6の態様の二次電池の容量保持率推定プログラムにある。
前記容量保持率は、前記フロート容量保持率および前記サイクル容量保持率の四則演算から求める手順をコンピュータに機能させて実行させる
ことを特徴とする第6又は第7の態様の二次電池の容量保持率推定プログラムにある。
前記容量保持率は、下記式(A)により、期間tまたはサイクル数Nでの容量保持率として推定する手順をコンピュータに機能させて実行させることを特徴とする第6~第8の何れか一つの態様の二次電池の容量保持率推定プログラムにある。
前記容量保持率は、下記式(B)により、期間tまたはサイクル数Nでの容量保持率を推定する手順をコンピュータを機能させて実行させることを特徴とする第6~第8の何れかの態様の二次電池の容量保持率推定プログラムにある。
二次電池の容量保持率推定方法を行う二次電池の容量保持率推定装置であって、
サイクル試験及びフロート試験のデータを格納した記憶手段と、
稼働中の二次電池データ、期間tおよびサイクル数Nを、二次電池から取得するデータ取得手段とを具備し、
前記フロート試験の測定値からフロート容量保持率に対応するワイブル係数mf、ηfおよび下記式(1)のフロート容量保持率を求める手順と、
前記サイクル試験の測定値からサイクル容量保持率に対応するワイブル係数mc、ηcおよび下記式(2)のサイクル容量保持率を求める手順と、
前記二次電池のフロート容量保持率および前記サイクル容量保持率により、期間tまたはサイクル数Nでの容量保持率を推定する手順とを実施して二次電池の容量保持率(SOH)を推定する
ことを特徴とする二次電池の容量保持率推定装置にある。
前記フロート試験から得られた容量保持率を測定フロート容量保持率とし、このフロート成分容量保持率をln(期間)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、フロート容量保持率のワイブルプロットを作成する手順と、
前記フロート容量保持率のワイブルプロットから直線式のフロート劣化予測線を推定する手順と、
当該フロート劣化予測線の傾き及び切片から前記ワイブル係数mf及びηfを求める手順と、
前記ワイブル係数mf及びηfと前記式(1)から前記サイクル容量保持率を求める手順と、
前記サイクル試験から得られた容量保持率を測定サイクル容量保持率とし、このサイクル容量保持率をln(サイクル数)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、サイクル容量保持率のワイブルプロットを作成する手順と、
前記サイクル容量保持率のワイブルプロットから直線式のサイクル劣化予測線を推定する手順と、
当該サイクル劣化予測線の傾き及び切片から、前記ワイブル係数mc及びηcを求める手順と、
前記ワイブル係数mc及びηcと前記式(2)から前記サイクル容量保持率を求める手順と
を実施することを特徴とする第11の態様の二次電池の容量保持率推定装置にある。
前記容量保持率は、前記フロート容量保持率および前記サイクル容量保持率の四則演算から求める手順を実施する
ことを特徴とする第11又は第12の態様の二次電池の容量保持率推定装置にある。
前記容量保持率は、下記式(A)により、期間tまたはサイクル数Nでの容量保持率として推定する手順を実施する
ことを特徴とする第11~第13の何れか一つの態様の二次電池の容量保持率推定装置にある。
前記容量保持率は、下記式(B)により、期間tまたはサイクル数Nでの容量保持率として推定する手順を実施する
ことを特徴とする第11~第13の何れか一つの態様の二次電池の容量保持率推定装置にある。
図1は、本発明の方法を実施する対象となる蓄電池システムの概略構成の一例を示す図である。図1に示すように、蓄電池システム1は、電力を蓄える二次電池である蓄電池2と電力調整装置3とを具備し、電力調整装置3には、商用電源4と、負荷5と、さらには、例えば、自然エネルギーを用いて発電する発電装置としての太陽光発電装置6とが接続されている。
二次電池の容量保持率(SOH)を、二次電池の使用による劣化に起因するフロート容量保持率と、充放電による劣化に起因するサイクルとを区別し、それぞれを推定するフロート容量保持率は、フロート試験の測定値に基づく容量保持率とする。また、サイクル容量保持率は、サイクル試験測定値に基づく容量保持率である。
本発明では、二次電池の容量保持率(SOH)の推定を、フロート試験から得られるフロート容量保持率と、サイクル試験から得られるサイクル容量保持率とを別々に推定することで行う。
フロート容量保持率の推定では、フロート試験の測定値から求めたフロート劣化係数(S11)と時間(S12)とをフロート劣化式(1)に導入し(S13)、フロート容量保持率を求める(S14)。
そして、本発明では、以下の容量保持率SOHの推定式(A)を用い(ステップS30)対象の電池セル等の容量保持率(SOH(t))を推定する。
式(A)は、サイクル劣化とフロート劣化に強い相関関係がある場合に用いることが好ましく、それ以外の場合は、式(B)を用いることが好ましい。
(係数決定用フロート試験)
所定タイプの二次電池について、二次電池を所定温度で稼働し、所定SOCに固定して行い、稼働時間での容量の変化を測定する。また、必要に応じて、異なる稼働温度の状態、また、異なるSOCに変更して同様に試験を行う。例えば、SOC50%の電圧に固定して、25℃、45℃、60℃のように異なる温度毎に長期放置して容量確認する試験を行う。また、SOCを他の割合の電圧に固定して、25℃、45℃、60℃で容量を確認する試験を行う。
所定タイプの二次電池についてSOC0%から100%まで充電し、SOC100%から0%まで放電する期間を1サイクルとし、サイクルの期間一定で、繰り返しSOCを増減させる。例えば、1日に充放電を3回と定めて充放電を行った場合は、1日で3サイクルできることになり、100日で300サイクル、1000日で3000サイクルすることができる。
サイクル数に対応する期間に対応する容量を測定し、ワイブル係数決定するための総サイクル試験容量保持率を取得する。
係数決定用実測値は、容量保持率SOHを推定する対象となる二次電池、例えば、上述した蓄電システムから直接求めてもよい。稼働開始から所定の稼働期間について、所定SOCになった時に容量を測定することでフロート係数決定用実測値を取得し、稼働開始から所定のサイクル回数になった時に、容量を測定することでサイクル係数決定用実測値を取得することができる。サイクル係数決定用実測値を取得する際のサイクル数のカウント方法は、適宜決めることができる。例えば、容量が満充電容量の50%以上動いた充電や放電のセットを1サイクルとカウントしてもよいし、特定のSOCの割合を2回通過するごとに1サイクルとカウントしてもよいし、積算した実際の充放電容量がその電池の充放電の1サイクルの容量と一致した場合を1サイクルとカウントしてもよい。電池温度は蓄電システムの置かれた環境によって大幅に変化しないので、電池温度を測定し、平均温度を用いることができる。
フロート試験から得られた容量保持率を測定フロート容量保持率とし、このフロート容量保持率をln(期間)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、フロート容量保持率のワイブルプロットを作成し、フロート容量保持率のワイブルプロットから直線式のフロート劣化予測線を推定し、当該フロート劣化予測線の傾き及び切片からワイブル係数mf及びηfを求める。
サイクル試験から得られた容量保持率を測定サイクル容量保持率とし、このサイクル容量保持率をln(サイクル数)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、サイクル容量保持率のワイブルプロットを作成し、前記サイクル容量保持率のワイブルプロットから直線式のサイクル劣化予測線を推定し、当該サイクル劣化予測線の傾き及び切片から、ワイブル係数mc及びηcを求める。
推定対象と同じタイプの二次電池について、所定温度、所定SOCに対応したワイブル係数mf、ηf、mc及びηcを選定し、これを上述した予測式(A)に導入し、期間tの容量保持率SOHを推定する。
二次電池(PD50S03):正極にリン酸鉄リチウム、負極に黒鉛、電解液としてエチレンカーボネート(EC):ジメチルカーボネート(DMC)=3:7に1.2Mの6フッ化リン酸リチウム(LiPF6)を支持電解質として入れたもの、正極と負極は積層式のエレメントでポリオレフィンのセパレータを挟んで向き合って配置されている。容量は50Ah。エレメントはSUS製の金属ケースに収納されている。
この二次電池を用いてフロート試験並びにサイクル試験を行った。
フロート試験は各種SOCおよび温度にて試験を行った。
サイクル試験は、各種SOCおよび温度にて1日6サイクルとした。
また、平均SOC、平均温度に対応するフロート試験からのワイブル係数mfは0.270603、ηfは9.341202であった。
また、サイクル試験からのワイブル係数mcは0.659873、ηcは10.65732であった。
なお、図7(a)には、実機のサイクル回数の変化を示し、図7(b)には、実機のSOCの変化を示し、図7(c)には、実機の温度の変化を示す。
実施例1と同種の二次電池を用いてフロート試験並びにサイクル試験を行った。
フロート試験は各種SOCおよび温度にて試験を行った。
サイクル試験は、各種SOCおよび温度にて1日6サイクルとした。
同種の二次電池を16個直列したシステム(電池容量2.5kWh)についてデータを取得して平均SOCを求めたところ、97.0%であった。また、平均温度は、27.8℃であった。
また、平均SOC、平均温度に対応するフロート試験からのワイブル係数mfは0.962004、ηfは4.269083であった。
また、サイクル試験からのワイブル係数mcは0.04926、ηcは57.4858であった。
なお、図9(a)には、実機のサイクル回数の変化を示し、図9(b)には、実機のSOCの変化を示し、図9(c)には、実機の温度の変化を示す。
実施例1と同種の二次電池を用いてフロート試験並びにサイクル試験を行った。
フロート試験は各種SOCおよび温度にて試験を行った。
サイクル試験は、各種SOCおよび温度にて1日6サイクルとした。
同種の二次電池を16個直列したシステム(電池容量2.5kWh)についてデータを取得して平均SOCを求めたところ、77.9%であった。また、平均温度は、31.5℃であった。
また、平均SOC、平均温度に対応するフロート試験の結果からのワイブル係数mfは0.355503、ηfは7.313371であった。
また、サイクル試験結果からのワイブル係数mcは0.665076、ηcは10.78985であった。
なお、図11(a)には、実機のサイクル回数の変化を示し、図9(b)には、実機のSOCの変化を示し、図9(c)には、実機の温度の変化を示す。
実施例1と同種の二次電池を用いてフロート試験並びにサイクル試験を行った。
フロート試験は各種SOCおよび温度にて試験を行った。
サイクル試験は、各種SOCおよび温度にて1日6サイクルとした。
同種の二次電池を16個直列したシステム(電池容量2.5kWh)についてデータを取得して平均SOCを求めたところ、96.7%であった。また、平均温度は、30.5℃であった。
また、平均SOC、平均温度に対応するフロート試験からのワイブル係数mfは0.507544、ηfは5.396954であった。
また、サイクル試験からのワイブル係数mcは0.105096、ηcは44.51101であった。
なお、図13(a)には、実機のサイクル回数の変化を示し、図13(b)には、実機のSOCの変化を示し、図13(c)には、実機の温度の変化を示す。
実施例1と同種の二次電池を用いてフロート試験並びにサイクル試験を行った。
フロート試験は各種SOCおよび温度にて試験を行った。
サイクル試験は、各種SOCおよび温度にて1日6サイクルとした。
同種の二次電池を16個直列したシステム(電池容量2.5kWh)についてデータを取得して平均SOCを求めたところ、92.1%であった。また、平均温度は、28.2℃であった。
また、平均SOC、平均温度に対応するフロート試験からのワイブル係数mfは0.270603、ηfは9.341202であった。
また、サイクル試験からのワイブル係数mcは0.659873、ηcは10.65732であった。
なお、図15(a)には、実機のサイクル回数の変化を示し、図15(b)には、実機のSOCの変化を示し、図15(c)には、実機の温度の変化を示す。
実施例1と同種の二次電池を用いてフロート試験並びにサイクル試験を行った。
フロート試験は各種SOCおよび温度にて試験を行った。
サイクル試験は、各種SOCおよび温度にて1日6サイクルとした。
同種の二次電池を16個直列したシステム(電池容量2.5kWh)についてデータを取得して平均SOCを求めたところ、97.0%であった。また、平均温度は、27.8℃であった。
また、平均SOC、平均温度に対応するフロート試験からのワイブル係数mfは0.962004、ηfは4.269083であった。
また、サイクル試験からのワイブル係数mcは0.04926、ηcは57.4858であった。
なお、図17(a)には、実機のサイクル回数の変化を示し、図17(b)には、実機のSOCの変化を示し、図17(c)には、実機の温度の変化を示す。
実施例1と同種の二次電池を用いてフロート試験並びにサイクル試験を行った。
フロート試験は各種SOCおよび温度にて試験を行った。
サイクル試験は、各種SOCおよび温度にて1日6サイクルとした。
同種の二次電池を16個直列したシステム(電池容量2.5kWh)についてデータを取得して平均SOCを求めたところ、77.9%であった。また、平均温度は、31.5℃であった。
また、平均SOC、平均温度に対応するフロート試験からのワイブル係数mfは0.962004、ηfは4.269083であった。
また、サイクル試験からのワイブル係数mcは0.04926、ηcは57.4858であった。
なお、図19(a)には、実機のサイクル回数の変化を示し、図19(b)には、実機のSOCの変化を示し、図19(c)、実機の温度の変化を示す。
実施例1と同種の二次電池を用いてフロート試験並びにサイクル試験を行った。
フロート試験は各種SOCおよび温度にて試験を行った。
サイクル試験は、各種SOCおよび温度にて1日6サイクルとした。
同種の二次電池を16個直列したシステム(電池容量2.5kWh)についてデータを取得して平均SOCを求めたところ、96.7%であった。また、平均温度は、30.5℃であった。
また、平均SOC、平均温度に対応するフロート試験からのワイブル係数mfは0.507544、ηfは5.396954であった。
また、サイクル試験からのワイブル係数mcは0.105096、ηcは44.51101であった。
なお、図21(a)には、実機のサイクル回数の変化を示し、図21(b)には、実機のSOCの変化を示し、図21(c)には、実機の温度の変化を示す。
2…蓄電池
2a…二次電池セル
3…電力調整装置
4…商用電源
5…負荷
6…太陽光発電装置(発電装置)
30…インバータ
31…第1スイッチ
32…第2スイッチ
33…第3スイッチ
34…第4スイッチ
35…第5スイッチ
40…制御部
41…発電装置監視手段
42…蓄電池監視手段
43…充放電制御手段
Claims (15)
- 前記フロート試験から得られた容量保持率を測定フロート容量保持率とし、前記測定フロート容量保持率をln(期間)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、フロート容量保持率のワイブルプロットを作成し、
前記フロート容量保持率のワイブルプロットから直線式のフロート劣化予測線を推定し、
当該フロート劣化予測線の傾き及び切片から前記ワイブル係数mf及びηfを求め、
前記ワイブル係数mf及びηfと前記式(1)から前記フロート容量保持率を求め、
前記サイクル試験から得られた容量保持率を測定サイクル容量保持率とし、前記測定サイクル容量保持率をln(サイクル数)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、サイクル容量保持率のワイブルプロットを作成し、
前記サイクル容量保持率のワイブルプロットから直線式のサイクル劣化予測線を推定し、
当該サイクル劣化予測線の傾き及び切片から、前記ワイブル係数mc及びηcを求め、
前記ワイブル係数mc及びηcと前記式(2)から前記サイクル容量保持率を求める
ことを特徴とする請求項1記載の二次電池の容量保持率推定方法。 - 前記容量保持率は、前記フロート容量保持率および前記サイクル容量保持率の四則演算から求める
ことを特徴とする請求項1又は2記載の二次電池の容量保持率推定方法。 - ワイブル則を用いて二次電池の容量保持率(SOH)を推定する二次電池の容量保持率推定プログラムにおいて、
容量保持率を求めるフロート試験の測定値からフロート容量保持率に対応するワイブル係数mf、ηfおよび下記式(1)のフロート容量保持率を求める手順と、
容量保持率を求めるサイクル試験の測定値からサイクル容量保持率に対応するワイブル係数mc、ηcおよび下記式(2)のサイクル容量保持率を求める手順と、
前記二次電池のフロート容量保持率および前記サイクル容量保持率により、期間tまたはサイクル数Nでの容量保持率を推定する手順とをコンピュータを機能させて実行させる
ことを特徴とする二次電池の容量保持率推定プログラム。
- 前記フロート試験から得られた容量保持率を測定フロート容量保持率とし、このフロート成分容量保持率をln(期間)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、フロート容量保持率のワイブルプロットを作成する手順と、
前記フロート容量保持率のワイブルプロットから直線式のフロート劣化予測線を推定する手順と、
当該フロート劣化予測線の傾き及び切片から前記ワイブル係数mf及びηfを求める手順と、
前記ワイブル係数mf及びηfと前記式(1)から前記サイクル容量保持率を求める手順と、
前記サイクル試験から得られた容量保持率を測定サイクル容量保持率とし、このサイクル容量保持率をln(サイクル数)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、サイクル容量保持率のワイブルプロットを作成する手順と、
前記サイクル容量保持率のワイブルプロットから直線式のサイクル劣化予測線を推定する手順と、
当該サイクル劣化予測線の傾き及び切片から、前記ワイブル係数mc及びηcを求める手順と、
前記ワイブル係数mc及びηcと前記式(2)から前記サイクル容量保持率を求める手順と
をコンピュータを機能させて実行させる
ことを特徴とする請求項6に記載の二次電池の容量保持率推定プログラム。 - 前記容量保持率は、前記フロート容量保持率および前記サイクル容量保持率の四則演算から求める手順をコンピュータに機能させて実行させる
ことを特徴とする請求項6又は7記載の二次電池の容量保持率推定プログラム。 - 二次電池の容量保持率推定方法を行う二次電池の容量保持率推定装置であって、
サイクル試験及びフロート試験のデータを格納した記憶手段と、
稼働中の二次電池データ、期間tおよびサイクル数Nを、二次電池から取得するデータ取得手段とを具備し、
前記フロート試験の測定値からフロート容量保持率に対応するワイブル係数mf、ηfおよび下記式(1)のフロート容量保持率を求める手順と、
前記サイクル試験の測定値からサイクル容量保持率に対応するワイブル係数mc、ηcおよび下記式(2)のサイクル容量保持率を求める手順と、
前記二次電池のフロート容量保持率および前記サイクル容量保持率により、期間tまたはサイクル数Nでの容量保持率を推定する手順とを実施して二次電池の容量保持率(SOH)を推定する
ことを特徴とする二次電池の容量保持率推定装置。
- 前記フロート試験から得られた容量保持率を測定フロート容量保持率とし、このフロート成分容量保持率をln(期間)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、フロート容量保持率のワイブルプロットを作成する手順と、
前記フロート容量保持率のワイブルプロットから直線式のフロート劣化予測線を推定する手順と、
当該フロート劣化予測線の傾き及び切片から前記ワイブル係数mf及びηfを求める手順と、
前記ワイブル係数mf及びηfと前記式(1)から前記サイクル容量保持率を求める手順と、
前記サイクル試験から得られた容量保持率を測定サイクル容量保持率とし、このサイクル容量保持率をln(サイクル数)とln(ln(1/容量保持率))との関係でワイブルプロットすることで、サイクル容量保持率のワイブルプロットを作成する手順と、
前記サイクル容量保持率のワイブルプロットから直線式のサイクル劣化予測線を推定する手順と、
当該サイクル劣化予測線の傾き及び切片から、前記ワイブル係数mc及びηcを求める手順と、
前記ワイブル係数mc及びηcと前記式(2)から前記サイクル容量保持率を求める手順とを実施する
ことを特徴とする請求項11記載の二次電池の容量保持率推定装置。 - 前記容量保持率は、前記フロート容量保持率および前記サイクル容量保持率の四則演算から求める手順を実施する
ことを特徴とする請求項11又は12記載の二次電池の容量保持率推定装置。
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WO2023176592A1 (ja) * | 2022-03-18 | 2023-09-21 | 大阪瓦斯株式会社 | 劣化状態予測方法、劣化状態予測装置、および劣化状態予測プログラム |
WO2024177130A1 (ja) * | 2023-02-22 | 2024-08-29 | エリーパワー株式会社 | 二次電池ユニット充電状態推定装置、二次電池ユニット充電状態推定方法及び二次電池ユニット充電状態推定プログラム |
CN117471340A (zh) * | 2023-12-27 | 2024-01-30 | 中航锂电(洛阳)有限公司 | 一种估算电池系统容量保持率的方法及系统 |
CN117471340B (zh) * | 2023-12-27 | 2024-04-02 | 中航锂电(洛阳)有限公司 | 一种估算电池系统容量保持率的方法及系统 |
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