JP2015026527A - Self-discharge amount calculation device, self-discharge amount calculation program, and self-discharge amount calculation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a self-discharge amount calculation device that calculates a self-discharge amount through simple arithmetic processing.SOLUTION: A self-discharge amount calculation device 1 includes a battery temperature acquisition unit 102, a first memory 106, a self-discharge amount determination unit 103, and a self-discharge amount output unit 105. The battery temperature acquisition unit 102 acquires a battery temperature indicating a temperature of a battery and the first memory 106 stores therein information showing relations between battery temperatures and self-discharge amounts of the battery per unit time at the battery temperatures. The self discharge amount determination unit 103 specifies the self-discharge amount of the battery per unit time at the battery temperature acquired by the battery temperature acquisition unit by referring to the information stored in the first memory. Then, on the basis of the specified self-discharge amount, the self-discharge amount determination unit 103 determines a self-discharge amount of the battery within a predetermined time width including a certain timing. The self-discharge amount output unit 105 outputs the determined self-discharge amount.

Description

  The present invention relates to a self-discharge amount calculation device, a self-discharge amount calculation program, and a method thereof.

  It is known to use a secondary battery as a charging battery for power generation equipment such as solar power generation or wind power generation, and also as a driving battery for an electric vehicle. There are cases where a plurality of secondary batteries are connected in parallel in order to increase the amount of stored electricity, and a plurality of secondary batteries are connected in series in order to increase the discharge voltage. In addition to discharging according to the discharge instruction, the secondary battery discharges in accordance with the discharge instruction. When the secondary battery is not discharged according to the discharge instruction and is in a standby state where it is not charged, It is known to have a phenomenon called self-discharge.

  Various methods for calculating the self-discharge amount of the secondary battery are known. For example, a battery capacity monitoring method used for a battery management apparatus that calculates a battery capacity by a CPU (Central Processing Unit) is known. The CPU switches to the low power consumption mode and stops the operation of the peripheral device for monitoring the battery capacity in a standby state where neither charging nor discharging commands are given for a predetermined time or longer. Then, the CPU returns to the normal operation mode at regular time intervals and activates only some peripheral devices used for calculating the self-discharge amount to calculate the self-discharge amount.

  A power supply device having a voltage detection unit, a temperature detection unit, a current detection unit, a remaining capacity calculation unit, and a communication processing unit is known. The voltage detection unit, the temperature detection unit, and the current detection unit detect the voltage, temperature, and current of the secondary battery included in the battery unit, respectively. The remaining capacity calculation unit detects the discharge current and the discharge voltage when the battery is not driving the connected device, calculates the internal resistance and electromotive force of the battery, and calculates the calculated internal resistance and electromotive force of the battery. Based on this, the remaining capacity of the battery is estimated with reference to a previously created table.

JP-A-10-164664 JP 2006-194789 A

  In the conventional calculation method of the self-discharge amount of the secondary battery, the self-discharge amount is calculated by using the electric quantity related to the self-discharge amount such as the current and voltage of the secondary battery and the curve indicating the rate of decrease in the remaining capacity with respect to the battery temperature. Therefore, the calculation process for calculating the self-discharge amount is complicated.

  An object of the present invention is to provide a self-discharge amount calculating apparatus that calculates a self-discharge amount by simple arithmetic processing.

  In one embodiment, the self-discharge amount calculation device includes a battery temperature acquisition unit, a first memory, a self-discharge amount determination unit, and a self-discharge amount output unit. The battery temperature acquisition unit acquires a battery temperature indicating the temperature of the battery, and the first memory stores information indicating a relationship between the battery temperature and the self-discharge amount of the battery per unit time at the battery temperature. The self-discharge amount determination unit specifies the self-discharge amount of the battery per unit time at the battery temperature acquired by the battery temperature acquisition unit with reference to the information stored in the first memory. Then, the self-discharge amount determining unit determines the self-discharge amount of the battery within a predetermined time width including a certain timing based on the specified self-discharge amount. The self-discharge amount output unit outputs the self-discharge amount.

  According to the present invention, the self-discharge amount can be calculated by a simple calculation process.

It is a circuit block diagram of the storage battery system according to the first embodiment. It is a functional block diagram of the calculating part of the storage battery system shown in FIG. (A) is an example of the table which shows the relationship between battery temperature and the amount of self-discharge of a battery, (b) is a figure which shows the relationship between battery temperature and the variation | change_quantity of the amount of self-discharge, (c) is It is a figure which shows an example of the temperature prescribed | regulated to the table shown to (a). It is a figure which shows an example of the processing flow of a process of the calculating part shown in FIG. It is a circuit block diagram of the storage battery system which concerns on 2nd Embodiment. It is a functional block diagram of the calculating part of the storage battery system shown in FIG. It is a figure which shows an example of the processing flow of the process of the calculating part shown in FIG. (A) is a diagram showing an example of a change in the battery remaining amount due to self-discharge when the battery temperature is constant at T ₀ ℃, (b) the change in the battery remaining amount due to self-discharge when the battery temperature changes (C) is a figure which shows an example of the change of the battery remaining amount converted from the self-discharge amount computed by the self-discharge amount calculation apparatus. (A) is a figure which shows an example of the self-discharge amount per unit time when the temperature of the secondary battery is constant at the reference temperature, and (b) is a unit when the temperature of the secondary battery varies from the reference temperature. It is a figure which shows an example of the self-discharge amount per time, (c) is a figure which shows the correction amount in the example shown in (b).

  Hereinafter, a self-discharge amount calculating device, a self-discharge amount calculating program, and a method thereof according to the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments.

  First, before describing the self-discharge amount calculation device, self-discharge amount calculation program, and method thereof according to the embodiment, the problem of the conventional method for calculating the self-discharge amount of a secondary battery will be described in more detail.

  In the conventional calculation method of the self-discharge amount of the secondary battery, the self-discharge amount is calculated by using the electric quantity related to the self-discharge amount such as the current and voltage of the secondary battery and the curve indicating the rate of decrease in the remaining capacity with respect to the battery temperature. Is calculated. For this reason, the calculation process for calculating the self-discharge amount becomes complicated, and a CPU having high calculation performance is used as the calculation processing unit for calculating the self-discharge amount. In addition, since the self-discharge characteristics of the secondary battery are different for each battery, the calculation of the self-discharge of the secondary battery may be performed for each secondary battery. In order to calculate the self-discharge amount of each of the plurality of secondary batteries, if a CPU having high calculation performance is arranged for each secondary battery, the manufacturing cost of the storage battery system may increase.

  On the other hand, the performance of the secondary battery has been improved, and there is a possibility that a secondary battery with a small decrease in battery capacity due to the memory effect or aging deterioration may appear. In addition, depending on the length of the standby time in which the battery is not instructed to be discharged or charged, the self-discharge amount of the secondary battery is not used when the temperature does not change without using the rate of decrease in remaining capacity with respect to the battery temperature. It is possible to calculate the self-discharge amount assuming that is constant. The inventor of the present invention calculates the self-discharge amount by a simpler calculation when the decrease in battery capacity due to the memory effect or aging deterioration can be ignored and the self-discharge amount may be constant, such as when there is no temperature change. I found out that I can do it.

  FIG. 1 is a circuit block diagram of the storage battery system according to the first embodiment.

  The storage battery system 100 includes a plurality of secondary batteries 110 and a battery temperature detection device 111 that detects the temperature of each of the plurality of secondary batteries. The storage battery system 100 further includes a self-discharge amount calculation device 1 that calculates the self-discharge amount of each of the plurality of secondary batteries, and a system monitoring device 120 that monitors the storage battery system.

  Each of the secondary batteries 110 includes a secondary battery such as a lithium ion battery or a lead battery.

  The battery temperature detection device 111 includes a thermistor and is disposed on the side surface of the secondary battery 110 or the like, and transmits a battery temperature signal indicating the temperature of the secondary battery 110 to the self-discharge amount calculation device 1.

  The self-discharge amount calculating device 1 includes a battery temperature receiving unit 10, a calculation unit 11, and a self-discharge amount transmitting unit 12. The battery temperature reception unit 10 receives a battery temperature signal from the battery temperature detection device 111, changes the signal to a signal that can be read by the calculation unit 11, and transmits the signal to the calculation unit 11. The calculation unit 11 calculates the self-discharge amount of the secondary battery 110 based on the temperature of the secondary battery 110, and outputs a self-discharge amount signal indicating the calculated self-discharge amount of the secondary battery 110. 12 to send. The self-discharge amount transmission unit 12 transmits the self-discharge amount signal transmitted from the calculation unit 11 to the system monitoring device 120.

  The system monitoring device 120 monitors the state of the storage battery system 100 including the self-discharge amount of each of the plurality of secondary batteries 110, transmits a status signal indicating the monitoring state to a host device (not shown), and causes a failure in the storage battery system. When it occurs, a failure signal is transmitted to the host device.

  FIG. 2 is a functional block diagram of the calculation unit 11.

  The calculation unit 11 includes a timer unit 101, a battery temperature acquisition unit 102, a self-discharge amount determination unit 103, a self-discharge amount calculation unit 104, a self-discharge amount output unit 105, a first memory 106, and a second memory. 107.

  The timer unit 101 has a timer function, and outputs a temperature acquisition instruction to the battery temperature acquisition unit 102 every time a predetermined time elapses. The timer unit 101 outputs a temperature acquisition instruction to the battery temperature acquisition unit 102 every predetermined period by outputting a temperature acquisition instruction every time a predetermined time elapses. For example, a time such as several tens of seconds, 1 minute, or 5 minutes is given as an example of the predetermined time. The time interval at which the time measuring unit 101 outputs the temperature acquisition instruction depends on the time interval at which the temperature change of the secondary battery 110 that is the object of temperature measurement appears. What is necessary is just to set suitably according to what kind of usage is used.

  When the battery temperature acquisition unit 102 acquires a temperature acquisition instruction from the time measuring unit 101, the battery temperature acquisition unit 102 acquires a battery temperature corresponding to the battery temperature signal transmitted from the battery temperature reception unit 10, and uses the acquired battery temperature as a self-discharge amount determination unit. To 103.

  When the self-discharge amount determination unit 103 acquires the battery temperature from the battery temperature acquisition unit 102, the self-discharge amount determination unit 103 determines the self-discharge amount of the secondary battery 110 at the battery temperature acquired from the battery temperature acquisition unit 102. When determining the self-discharge amount of the secondary battery 110, the self-discharge amount determining unit 103 refers to a table indicating the relationship between the battery temperature and the battery self-discharge amount stored in the first memory 106. The self-discharge amount determining unit 103 outputs the determined self-discharge amount to the self-discharge amount calculating unit 104.

  When the self-discharge amount calculation unit 104 acquires the self-discharge amount from the self-discharge amount determination unit 103, the self-discharge amount calculation unit 104 adds the self-discharge amount acquired from the self-discharge amount determination unit 103 to the self-discharge amount stored in the second memory 107, The accumulated self-discharge amount is stored in the second memory 107. Each time the self-discharge amount calculation unit 104 acquires the self-discharge amount, the self-discharge amount stored in the second memory 107 is integrated. Therefore, the self-discharge amount stored in the second memory 107 includes a plurality of self-discharge amounts. Is accumulated.

  The self-discharge amount output unit 105 transmits a self-discharge amount signal indicating the self-discharge amount stored in the second memory 107 to the self-discharge amount transmitting unit 12 every time a predetermined number of self-discharge amounts are integrated. For example, the self-discharge amount output unit 105 may transmit a self-discharge amount signal indicating the self-discharge amount stored in the second memory 107 to the self-discharge amount transmitting unit 12 every time five self-discharge amounts are accumulated. it can.

  When the self-discharge amount output unit 105 transmits the self-discharge amount signal to the self-discharge amount transmission unit 12, the self-discharge amount output unit 105 resets the self-discharge amount stored in the second memory 107 to zero. The self-discharge amount stored in the second memory 107 is zeroed every time the self-discharge amount output unit 105 transmits the self-discharge amount signal to the self-discharge amount transmission unit 12. The amount is a self-discharge amount obtained by integrating a predetermined number of self-discharge amounts.

  FIG. 3A is an example of a table showing the relationship between the battery temperature stored in the first memory 106 and the amount of self-discharge of the battery. FIG. 3B is a diagram showing the relationship between the battery temperature and the amount of change in the self-discharge amount, and FIG. 3C is a diagram showing an example of the temperature defined in the table stored in the first memory 106. is there.

  The first memory 106 stores a table indicating the relationship between the battery temperature and the battery self-discharge amount. The first memory 106 does not store the curve indicating the rate of decrease in the remaining capacity with respect to the battery temperature, but stores the self-discharge amount of the secondary battery 110 in the time corresponding to the period in which the time measuring unit 101 outputs the temperature acquisition instruction. The table to be stored is stored. In the table shown in FIG. 3A, when the battery temperature is 50 ° C., the self-discharge amount of the battery at the time corresponding to the period in which the time measuring unit 101 outputs the temperature acquisition instruction is E1. In the table shown in FIG. 3A, when the battery temperature is 45 ° C., the self-discharge amount of the battery in the time corresponding to the period in which the time measuring unit 101 outputs the temperature acquisition instruction is E2. In the table shown in FIG. 3A, n self-discharge amounts corresponding to n temperatures from 50 ° C. to −10 ° C. are defined.

  The table stored in the first memory 106 is defined as a table unique to each of the plurality of secondary batteries 110 arranged in the storage battery system 100. The table stored in the first memory 106 is defined based on the measurement result of the self-discharge amount of the battery at each temperature measured at the time of shipment or the like for each of the plurality of secondary batteries 110 arranged in the storage battery system 100. Is done. The self-discharge characteristic of the secondary battery 110 has a large individual difference, and if the self-discharge amount of the plurality of secondary batteries 110 is determined by a single table, the individual difference of the self-discharge amount of the secondary batteries 110 may be an error. There is sex. Since the table stored in the first memory 106 is defined as a table unique to each of the plurality of secondary batteries 110 arranged in the storage battery system 100, the individual difference of the self-discharge amount of the secondary battery 110 is reflected. become.

  The temperature interval defined by the first memory 106 is defined so as to differ according to the amount of change in the self-discharge amount of the battery according to the temperature change of the secondary battery 110.

  As shown in FIG. 3B, the amount of change in the self-discharge amount of the secondary battery 110 changes according to the change in battery temperature. When the battery temperature is in the temperature range of 20 ° C. to 30 ° C., the amount of self-discharge of the secondary battery 110 varies greatly according to the change in the battery temperature of the secondary battery 110. That is, when the battery temperature is in the temperature range of 20 ° C. to 30 ° C., the amount of change Δh in the self-discharge amount of the secondary battery 110 is larger than the predetermined specified value h1. On the other hand, when the battery temperature is in the temperature range of −100 ° C. to 10 ° C., the amount of change in the self-discharge amount of the secondary battery 110 hardly changes even when the battery temperature changes. That is, when the battery temperature is in the temperature range of −100 ° C. to 10 ° C., the amount of change Δh in the self-discharge amount of the secondary battery 110 is smaller than the predetermined specified value h2.

  The temperature interval defined by the table stored in the first memory 106 is 0. 0 ° C. in the temperature range of 20 ° C. to 30 ° C. in which the amount of change Δh of the self-discharge amount of the secondary battery 110 is greater than the predetermined specified value h1. 5 ° C. On the other hand, the temperature interval defined by the table stored in the first memory 106 is in the temperature range of −10 ° C. to 10 ° C. where the amount of change Δh in the self-discharge amount of the secondary battery 110 is smaller than the predetermined specified value h2. 10.0 ° C. Further, the temperature interval defined by the table stored in the first memory 106 is 1.0 in the temperature range where the change amount Δh of the self-discharge amount of the secondary battery 110 is larger than the predetermined prescribed value h2 and smaller than h1. ° C. That is, in the temperature ranges of 10 ° C. to 20 ° C. and 30 ° C. to 50 ° C., the temperature interval defined by the table stored in the first memory 106 is 1.0 ° C.

  Since the interval of the battery temperature defined in the table differs according to the amount of change in the self-discharge amount of the secondary battery 110 according to the battery temperature, without increasing the amount of information stored in the table, The error of the self-discharge amount can be reduced. For example, when the self-discharge amount is specified every 1.0 ° C. from −10 ° C. to 50 ° C. in the table, 60 self-discharge amounts are stored. On the other hand, the table stored in the first memory 106 includes 52 pieces in a temperature range of −10 ° C. to 10 ° C., 20 pieces in a temperature range of 20 ° C. to 30 ° C., and 30 pieces in other temperature ranges, for a total of 52 pieces. The amount of self-discharge is memorized.

  The second memory 107 stores the self-discharge amount of the secondary battery 110 accumulated by the self-discharge amount calculation unit 104. The self-discharge amount stored in the second memory 107 is reset by the self-discharge amount output unit 105 every time a predetermined number of self-discharge amounts are integrated.

  FIG. 4 is a flowchart illustrating a processing flow of the calculation unit 11.

  First, in step S101, the time measuring unit 101 measures time until a predetermined time elapses. Next, in step S <b> 102, when a predetermined time has elapsed, the timer unit 101 outputs a temperature acquisition instruction to the battery temperature acquisition unit 102. Next, in step S <b> 103, the battery temperature acquisition unit 102 acquires the battery temperature and outputs the acquired battery temperature to the self-discharge amount determination unit 103. Next, in step S104, the self-discharge amount determination unit 103 refers to the table stored in the first memory 106, and determines the self-discharge amount of the secondary battery 110 at the battery temperature acquired from the battery temperature acquisition unit 102. . Next, in step S <b> 105, the self-discharge amount acquired from the self-discharge amount determining unit 103 is integrated with the self-discharge amount stored in the second memory 107, and the integrated self-discharge amount is stored in the second memory 107. Next, in step S106, the self-discharge amount output unit 105 determines whether or not a predetermined number of self-discharge amounts have been integrated. If it is determined that the predetermined number of self-discharge amounts are not integrated, the process returns to step S101. If it is determined that a predetermined number of self-discharge amounts have been integrated, the process proceeds to step S107.

  When it is determined that a predetermined number of self-discharge amounts have been integrated and the process proceeds to step S107, the self-discharge amount output unit 105 outputs a self-discharge amount signal indicating the self-discharge amount stored in the second memory 107. It transmits to the discharge amount transmission part 12. In step S <b> 108, the self-discharge amount output unit 105 resets the self-discharge amount stored in the second memory 107. When the process up to step S108 is finished, the process returns to step S101 again.

  In the storage battery system 100, the self-discharge amount calculating device 1 determines the self-discharge amount based on the battery temperature of the secondary battery 110 acquired every predetermined period, and integrates the determined self-discharge amount. Since the process performed by the self-discharge amount calculation device 1 is a simple process, the self-discharge amount is calculated without mounting a calculation device such as a CPU having high calculation performance.

  However, in the storage battery system 100, the self-discharge amount calculating device 1 calculates the calculated self-discharge amount regardless of whether the secondary battery 110 is in a discharged state, in a charged state, or in a standby state in which no discharge is charged. Is transmitted to the system monitoring device 120. In storage battery system 100, it is determined whether or not the self-discharge amount received by system monitoring device 120 based on the state of secondary battery 110 is the self-discharge amount when secondary battery 110 is in a standby state. In the storage battery system 100, the system monitoring device 120 determines whether or not the self-discharge amount received from the self-discharge amount calculation device 1 is in a standby state.

  FIG. 5 is a circuit block diagram of the storage battery system according to the second embodiment.

  The storage battery system 200 is different from the storage battery system 100 in that it has a self-discharge amount calculation device 2 instead of the self-discharge amount calculation device 1. The self-discharge amount calculating device 2 is different from the self-discharge amount calculating device 1 in that it has a battery state receiving unit 20. The self-discharge amount calculation device 2 is further different from the self-discharge amount calculation device 1 in that it has a calculation unit 21 instead of the calculation unit 11.

  The battery state receiving unit 20 receives from the system monitoring device 120 a battery charging start signal indicating that charging of the secondary battery 110 has started and a battery charging end signal indicating that charging of the secondary battery 110 has ended. It transmits to the calculating part 21. Further, the battery state receiving unit 20 receives from the system monitoring device 120 a battery discharge start signal indicating that the discharge of the secondary battery 110 has started and a battery discharge end signal indicating that the discharge of the secondary battery 110 has ended. And transmitted to the calculation unit 21.

  FIG. 6 is a functional block diagram of the calculation unit 21.

  The calculation unit 21 includes a battery state acquisition unit 201, a timing unit 202, a battery temperature acquisition unit 203, a self-discharge amount determination unit 204, a self-discharge amount calculation unit 205, a self-discharge amount output unit 206, and a first A memory 207 and a second memory 208 are included.

  The battery temperature acquisition unit 203, the self-discharge amount determination unit 204, the self-discharge amount calculation unit 205, and the self-discharge amount output unit 206 are respectively the battery temperature acquisition unit 102, the self-discharge amount determination unit 103, the self-discharge amount calculation unit 104, and the self-discharge amount calculation unit 104. It has the same function as the discharge amount output unit 105. The first memory 207 and the second memory 208 have the same functions as the first memory 106 and the second memory 107, respectively.

  When the battery state acquisition unit 201 acquires battery charge start information corresponding to the battery charge start signal or battery discharge start information corresponding to the battery discharge start signal, the battery state acquisition unit 201 outputs a time measurement end instruction to the time measurement unit. Further, when the battery state acquisition unit 201 acquires the battery charge end information corresponding to the battery charge end signal or the battery discharge end information corresponding to the battery discharge end signal, the battery state acquisition unit 201 outputs a time start instruction to the time measuring unit.

  The timer unit 202 has a timer function, and outputs a temperature acquisition instruction to the battery temperature acquisition unit 203 every time a predetermined time elapses. The timer unit 202 outputs a temperature acquisition instruction to the battery temperature acquisition unit 203 at predetermined intervals by outputting a temperature acquisition instruction every time a predetermined time elapses. For example, a time such as several tens of seconds, 1 minute, or 5 minutes is given as an example of the predetermined time. The time interval at which the time measuring unit 202 outputs the temperature acquisition instruction depends on the time interval at which the temperature change of the secondary battery 110 that is the target of temperature measurement appears. What is necessary is just to set suitably according to what kind of usage is used.

  When the time measuring unit 202 acquires a time measurement start instruction from the battery state acquisition unit 201, the time measuring unit 202 starts time measurement and outputs a temperature acquisition instruction to the battery temperature acquisition unit 102 at predetermined intervals. In addition, when the time measuring unit 202 acquires a time measurement end instruction from the battery state acquisition unit 201, the time measuring unit 202 ends the time measurement.

  The computing unit 21 determines whether or not the secondary battery 110 is in a standby state by receiving a battery charge start signal, a battery discharge start signal, a battery charge end signal, and a battery discharge end signal from the system monitoring device 120. .

  FIG. 7 is a flowchart illustrating a processing flow of the calculation unit 21.

  First, in step S201, the battery state acquisition unit 201 determines whether battery charge end information or battery discharge end information has been acquired. If the battery state acquisition unit 201 determines that the battery charge end information or the battery discharge end information has not been acquired, the process returns to step S201, and the battery state acquisition unit 201 waits for a predetermined standby time before step S201. Execute the process again. If the battery state acquisition unit 201 determines that the battery charging end information or the battery discharging end information has been acquired, the process proceeds to step S202.

  When the process proceeds to step S202, the timing unit 202 counts until a predetermined time elapses. Next, in step S <b> 203, when a predetermined time has elapsed, the timer unit 101 outputs a temperature acquisition instruction to the battery temperature acquisition unit 203. Next, in step S <b> 204, the battery temperature acquisition unit 203 acquires the battery temperature and outputs the acquired battery temperature to the self-discharge amount determination unit 204. Next, in step S <b> 205, the self-discharge amount determination unit 204 refers to the table stored in the first memory 207 and determines the self-discharge amount of the secondary battery 110 at the battery temperature acquired from the battery temperature acquisition unit 203. . Next, in step S <b> 206, the self-discharge amount acquired from the self-discharge amount determining unit 204 is integrated with the self-discharge amount stored in the second memory 208, and the integrated self-discharge amount is stored in the second memory 208.

  Next, in step S207, the battery state acquisition unit 201 determines whether battery charge start information or battery discharge start information has been acquired. If the battery state acquisition unit 201 determines that the battery charge start information or the battery discharge start information has not been acquired, the process proceeds to step S208. If the battery state acquisition unit 201 determines that the battery charge start information or the battery discharge start information has been acquired, the process ends.

  When it is determined that the battery state acquisition unit 201 has not acquired battery charge start information or battery discharge start information and the process proceeds to step S208, the self-discharge amount output unit 206 integrates a predetermined number of self-discharge amounts. It is determined whether or not it has been done. If it is determined that the predetermined number of self-discharge amounts are not integrated, the process returns to step S202. If it is determined that a predetermined number of self-discharge amounts have been integrated, the process proceeds to step S209.

  When it is determined that a predetermined number of self-discharge amounts have been integrated and the process proceeds to step S209, the self-discharge amount output unit 206 outputs a self-discharge amount signal indicating the self-discharge amount stored in the second memory 107 as a self-discharge amount signal. It transmits to the discharge amount transmission part 12. In step S <b> 210, the self-discharge amount output unit 206 resets the self-discharge amount stored in the second memory 107. When the process up to step S210 is finished, the process returns to step S202 again.

FIG. 8A is a diagram illustrating an example of a change in the remaining battery level due to self-discharge when the battery temperature is constant at T ₀ ° C. FIG. 8B is a battery due to self-discharge when the battery temperature changes. It is a figure which shows an example of the change of residual amount. FIG. 8C is a diagram illustrating an example of a change in the remaining battery level converted from the self-discharge amount calculated by the self-discharge amount calculation apparatuses 1 and 2. 8 (a) to 8 (c), the horizontal axis indicates the elapsed time from the end of charging or discharging of the secondary battery 110, that is, the start of self-discharge, and the vertical axis decreases by self-discharge. The remaining battery level of the secondary battery 110 is shown. In FIG. 8B, the solid line shows an example of the change in the remaining battery level due to self-discharge when the battery temperature changes, and the broken line shows an example of the change in the remaining battery level due to self-discharge in the case of FIG. Show. In FIG. 8B, a period indicated by A is a period in which the temperature of the secondary battery 110 is lower than T ₀ ° C, and a period indicated by B is a period in which the temperature of the secondary battery 110 is higher than T ₀ ° C. It is. In FIG. 8 (c), the solid line indicates the self-discharge amount calculated for each constant period P in the self-discharge amount calculation devices 1 and 2, and the alternate long and short dash line indicates the accumulated self-discharge amount for six periods P. Indicates the amount of self-discharge.

As shown in FIG. 8A, when the temperature of the secondary battery 110 is constant at T ₀ ° C., the self-discharge amount per predetermined time is constant. 8B, when the temperature of the secondary battery 110 is lower than T ₀ ° C. during the period indicated by A, the self-discharge amount of the secondary battery 110 is that the temperature of the secondary battery 110 is T ₀ ° C. It becomes larger than a fixed case. On the other hand, when the temperature of the secondary battery 110 is higher than T ₀ ° C as in the period indicated by B, the self-discharge amount of the secondary battery 110 is when the temperature of the secondary battery 110 is constant at T ₀ ° C. Smaller than.

  The self-discharge amount calculation devices 1 and 2 refer to a table indicating the relationship between the temperature of the secondary battery 110 and the self-discharge amount every predetermined cycle, and the self-discharge amount of the secondary battery 110 during a predetermined cycle. Is calculated. Then, the self-discharge amount calculating devices 1 and 2 integrate and output the calculated self-discharge amount. In the example shown in FIG. 8C, the self-discharge amount is determined for each period P, and the self-discharge amount obtained by integrating the self-discharge amounts for the six periods P is output.

  In the self-discharge amount calculation devices 1 and 2, the battery temperature and the self-discharge can be obtained without using the electric quantity related to the self-discharge amount such as the current and voltage of the secondary battery and the curve indicating the rate of decrease in the remaining capacity with respect to the battery temperature. The self-discharge amount is calculated with reference to a table showing the relationship with the amount. Furthermore, in the self-discharge amount calculation devices 1 and 2, the self-discharge amount is calculated without using a curve indicating the rate of decrease in remaining capacity with respect to the battery temperature. The self-discharge amount calculation devices 1 and 2 do not use an electric quantity related to the amount of self-discharge such as the current and voltage of the secondary battery and a curve indicating the rate of decrease in remaining capacity with respect to the battery temperature. It is possible to calculate the self-discharge amount without using it.

  Since a self-discharge amount calculation process is possible without using a CPU with high calculation performance, inexpensive calculation apparatuses may be adopted as the self-discharge amount calculation apparatuses 1 and 2 that execute the calculation process. Since an inexpensive arithmetic unit can be adopted as the self-discharge amount calculation devices 1 and 2, the self-discharge amount calculation device 1 or 2 can be arranged for each of the plurality of secondary batteries 110. Since the self-discharge amount calculating device 1 or 2 can be arranged for each of the plurality of secondary batteries 110, a table reflecting individual differences of the secondary batteries 110 is stored in the first memory 106 or the self-discharge of the self-discharge amount calculating device 1. It can be stored in the first memory 207 of the amount calculation device 2. Since the table reflecting the individual difference of the secondary battery 110 can be used, the self-discharge amount calculation apparatuses 1 and 2 can execute the arithmetic processing by reflecting the individual difference of the secondary battery 110.

  In the self-discharge amount calculation devices 1 and 2, the interval between the battery temperatures defined in the table indicating the relationship between the battery temperature and the battery self-discharge amount is the amount of change in the self-discharge amount of the secondary battery 110 according to the battery temperature. It is defined to be more different. In the self-discharge amount calculation devices 1 and 2, since the battery temperature interval specified in the table is specified to be different from the change amount of the self-discharge amount of the secondary battery 110 according to the battery temperature, it is stored in the table. The error of the self-discharge amount can be reduced without increasing the amount of information to be generated.

  In the self-discharge amount calculation devices 1 and 2, after a predetermined number of self-discharge amounts are integrated, the integrated self-discharge amount is output. However, every time the self-discharge amount is calculated every predetermined period, the self-discharge amount is output. The calculated self-discharge amount may be output without integrating the amount. In this case, the calculation unit 11 may not include the self-discharge amount calculation unit 104 and the second memory 107, and the calculation unit 21 does not include the self-discharge amount calculation unit 205 and the second memory 208. Also good.

  In addition, some or all of the functions of the calculation units 11 and 12 may be realized by hardware, and some of the functions of the calculation units 11 and 12 may be realized by software. When some of the functions of the computing units 11 and 12 are realized by software, a program for processing executed by some of the functions of the computing units 11 and 12 is stored in a storage device (not shown). As a storage device for storing the program, a portable recording medium such as a CD-ROM, a DVD disk and a USB memory, a semiconductor memory such as a flash memory, a hard disk drive, and the like are used.

  Moreover, although the calculating parts 11 and 21 have the time measuring part 101 and 202, respectively, the system monitoring apparatus 120 may have the function of the time measuring part 101 and 202. When the system monitoring device 120 has the functions of the time measuring units 101 and 202, the system monitoring device 120 acquires the battery temperature from the battery temperature detection device 111 every time a predetermined time elapses. A temperature acquisition instruction signal is transmitted to 1 and 2. When the calculation units 11 and 21 receive the temperature acquisition instruction signal, they acquire a battery temperature corresponding to the battery temperature signal transmitted from the battery temperature reception unit 10.

  The table stored in the first memory 106 or 207 may be rewritable. By making the table stored in the first memory 106 or 207 rewritable, it is stored in the first memory 106 or 207 at appropriate intervals in order to reflect the memory effect or the change in battery capacity due to aging. Table can be rewritten.

  The table stored in the first memory 106 or 207 has self-discharge amounts E1 to En, but has a correction amount that is a difference between the self-discharge amount at the reference temperature and the self-discharge amount at each temperature. It may be. For example, the table showing the relationship between the battery temperature and the self-discharge amount of the battery is the self-discharge amount in a predetermined time when the secondary battery 110 is 20 ° C. and the self-discharge between −10 ° C. and 50 ° C. A difference from the amount may be included as a correction amount.

  FIG. 9A shows an example of the amount of self-discharge per unit time when the temperature of the secondary battery is constant at the reference temperature, and FIG. 9B shows the temperature of the secondary battery fluctuating from the reference temperature. It is a figure which shows an example of the self-discharge amount per unit time in the case of doing. FIG. 9C is a diagram showing the correction amount in the example shown in FIG.

  In FIG. 9C, the table showing the relationship between the battery temperature and the battery self-discharge amount is a correction amount that is the difference between the self-discharge amount at the reference temperature and the self-discharge amount at each temperature. C1, C2, Cn -1 and Cn. When the correction amount is used, the self-discharge amount calculating device adds the correction amount stored in the table, thereby calculating the self-discharge amount during a predetermined elapsed time T when the temperature of the secondary battery is constant at the reference temperature. Calculate the difference from the discharge amount. Furthermore, the self-discharge amount calculating device calculates the self-discharge amount during a predetermined elapsed time T when the temperature of the secondary battery indicated by the broken line in FIG. 9C is constant at the reference temperature, and the calculated self-discharge. The amount of self-discharge during a predetermined elapsed time T is calculated by adding the difference in amount.

  When the table showing the relationship between the battery temperature and the battery self-discharge amount uses a correction amount that is the difference between the self-discharge amount at the reference temperature and the self-discharge amount at each temperature, the self-discharge amount at each temperature is The amount of information to be stored can be compressed as compared with the case of having it.

  Further, in the above embodiment, the table stored in the first memory 106 or 207 stores the self-discharge amount of the secondary battery 110 in the time corresponding to the period in which the time measuring unit 101 outputs the temperature acquisition instruction. However, this need not be the case. The unit time of the self-discharge amount stored in the first memory may store a self-discharge amount of the secondary battery 110 per unit time different from the period in which the time measuring unit 101 outputs the temperature acquisition instruction. . When the self-discharge amount of the secondary battery 110 per unit time is stored in the table stored in the first memory 106 or 207, the time corresponding to the period in which the time measuring unit 101 outputs the temperature acquisition instruction and the unit time The self-discharge amount is calculated by multiplying the ratio.

  In the table stored in the first memory 106 or 207, the temperature interval is divided into three temperature zones, namely, a temperature zone of 20 ° C to 30 ° C, a temperature zone of -100 ° C to 10 ° C, and other temperature zones. However, a table having a single temperature interval may be stored. In addition, the table showing the relationship between the battery temperature and the battery self-discharge amount may be divided into two temperature zones, and the temperature intervals may be different, or the temperature intervals may be divided into four or more temperature zones. Good.

DESCRIPTION OF SYMBOLS 1, 2 Self-discharge amount calculation apparatus 11, 21 Calculation part 110 Secondary battery 111 Battery temperature detection apparatus 120 System monitoring apparatus

Claims (7)

At a certain timing, a battery temperature acquisition unit that acquires a battery temperature indicating the temperature of the battery,
A first memory for storing information indicating a relationship between a battery temperature and a self-discharge amount of the battery per unit time at the battery temperature;
With reference to the information stored in the first memory, the self-discharge amount of the battery per unit time at the battery temperature acquired by the battery temperature acquisition unit is specified, and based on the specified self-discharge amount, A self-discharge amount determining unit for determining a self-discharge amount of the battery within a predetermined time width including the certain timing;
A self-discharge amount output unit for outputting the self-discharge amount;
A self-discharge amount calculating device comprising:   The information stored in the first memory indicates that the battery temperature in a temperature range in which the amount of change in the self-discharge amount of the battery according to the temperature change per unit time of the battery is greater than a threshold value is the temperature change of the battery. 2. The self-discharge amount calculating device according to claim 1, wherein a change amount of the self-discharge amount of the battery in accordance with is defined at an interval narrower than the battery temperature in a temperature zone smaller than the threshold value. The battery temperature acquisition unit acquires the battery temperature at at least two different timings having a predetermined time interval,
The self-discharge amount determining unit determines the self-discharge amount of the battery within the predetermined time width corresponding to the acquired battery temperature every time the battery temperature acquisition unit acquires the battery temperature,
A self-discharge amount calculating unit that integrates the self-discharge amount determined by the self-discharge amount determining unit; and a second memory that stores the self-discharge amount integrated by the self-discharge amount calculating unit;
The self-discharge amount output unit outputs a self-discharge amount stored in the second memory.
The self-discharge amount calculating device according to claim 1 or 2. Battery discharge start information indicating that battery discharge has started, battery discharge end information indicating that battery discharge has ended, battery charge start information indicating that battery charge has started, and battery charging ended A battery state acquisition unit for acquiring battery charge end information indicating that,
The self-discharge amount determining unit obtains the information stored in the first memory from the time when the battery discharge end information or the battery charge end information is acquired until the battery discharge start information or the battery charge start information is acquired. Referring to the battery self-discharge amount per unit time at the battery temperature acquired by the battery temperature acquisition unit, and based on the specified self-discharge amount, within a predetermined time width including the certain timing The self-discharge amount calculation device according to any one of claims 1 to 3, wherein the self-discharge amount of the battery in the battery is determined. Multiple batteries,
A plurality of battery temperature detection devices for detecting the temperature of each of the plurality of batteries;
A plurality of self-discharge amount calculating devices for calculating a self-discharge amount of each of the plurality of batteries, wherein the plurality of self-discharge amount calculating devices are respectively
A battery temperature acquisition unit that acquires a battery temperature indicating the temperature of the battery from the battery temperature detection device at a certain timing; and
A first memory for storing a table indicating a relationship between the battery temperature and a self-discharge amount of the battery per unit time at the battery temperature;
Referring to the information stored in the first memory, the self-discharge amount of the battery per unit time at the battery temperature acquired by each of the battery temperature detection devices is specified, and the specified self-discharge amount A self-discharge amount determining unit for determining a self-discharge amount of the battery within a predetermined time width including the certain timing, and
A plurality of self-discharge amount calculation devices having a self-discharge amount output unit for outputting the self-discharge amount;
A system monitoring device for acquiring a self-discharge amount from the plurality of self-discharge amount calculating devices;
A storage battery system comprising: At a certain timing, the battery temperature indicating the battery temperature is obtained,
With reference to a memory storing information indicating the relationship between the battery temperature and the battery self-discharge amount per unit time at the battery temperature, the battery self-discharge amount per unit time at the battery temperature is specified, Based on the identified self-discharge amount, the self-discharge amount of the battery within a predetermined time width including the certain timing is determined,
Outputting the self-discharge amount;
A self-discharge amount calculation program for causing a computer to execute processing. At a certain timing, the battery temperature indicating the battery temperature is obtained,
With reference to a memory storing information indicating the relationship between the battery temperature and the battery self-discharge amount per unit time at the battery temperature, the battery self-discharge amount per unit time at the battery temperature is specified, Based on the identified self-discharge amount, the self-discharge amount of the battery within a predetermined time width including the certain timing is determined,
Outputting the self-discharge amount;
A self-discharge amount calculation method executed by a computer.

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