JP2015045523A - Method for monitoring and controlling charge/discharge state of power storage facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for monitoring and controlling the charge/discharge state of a power storage facility, the method capable of grasping, by monitoring, the remaining charge amount state, the progress of characteristic change (degradation), and the serviceable time, etc., of a lithium ion battery in the power storage facility and thereby optimally maintaining the charge/discharge operation and extending the life of the lithium ion battery in the power storage facility.SOLUTION: In a power storage facility provided with a lithium ion battery, an electromotive voltage and an internal resistance of the lithium ion battery are obtained from detection data such as the charge/discharge voltages, charge/discharge currents, etc., of the lithium ion battery during charging/discharging. A remaining charge amount of the battery is determined from the electromotive voltage. Further, the determined remaining charge amount is corrected by a change amount of the internal resistance, and the charge/discharge state of the lithium ion battery is monitored by the corrected remaining charge amount.

Description

  The present invention relates to a charging / discharging operation state of a battery of a power storage facility equipped with a lithium ion battery (herein, sometimes simply referred to as “battery”), that is, a remaining state of charge of the battery, and a characteristic change (deterioration) progress. The present invention relates to a charge / discharge state monitoring control method for a power storage facility for monitoring and controlling a state, a dischargeable time, and the like.

  In order to effectively use a power storage facility equipped with a lithium ion battery, it is necessary to monitor the charge / discharge state of the battery as accurately as possible. As what monitors the charging / discharging state of such a battery, what is shown to patent document 1 is already known.

  In the charging / discharging state monitoring method of the power storage facility described in Patent Document 1, the internal resistance of a reference lithium ion battery is set as a reference internal resistance value, and the set reference internal resistance value and a predetermined charge / discharge current are set. A reference IV characteristic pattern was created in advance based on this reference IV characteristic pattern and an operating point indicated by an actual voltage or current during operation of the battery detected separately or created from the same voltage or current. It compares the actual IV characteristic pattern and monitors the charge / discharge state of the lithium ion battery.

  However, the invention of Patent Document 1 does not monitor the remaining state of charge of the lithium ion battery, the progress of characteristic change (deterioration), the usable time, and the like.

JP 2012-172991 A

  This invention makes it possible to monitor and grasp the remaining state of the charge amount of the lithium ion battery in the power storage facility, the progress of characteristic change (deterioration), the usable time, etc., and thereby the charge / discharge operation of the lithium ion battery in the power storage facility. It is an object of the present invention to provide a charge / discharge monitoring control system for a power storage facility that can be maintained optimally and can extend the life of a battery.

  In order to achieve such a problem, the invention of claim 1 is based on detection data such as charging / discharging voltage and charging / discharging current of a battery during charging / discharging of the lithium-ion battery in a power storage facility including a lithium-ion battery. Obtaining the electromotive voltage and internal resistance of the battery, determining the remaining charge amount of the battery from the electromotive voltage, further correcting the determined remaining charge amount by the amount of change in the internal resistance, and by the corrected remaining charge amount, It monitors the charge / discharge state of the lithium ion battery.

  According to a second aspect of the present invention, in the first aspect of the invention, a reference such as a reference internal resistance, a reference electromotive voltage, a reference charge amount with respect to the reference electromotive voltage, which is a reference in the initial use period, the intermediate use period and the end use period of the lithium ion battery Data is set, and actual data such as actual internal resistance, battery internal voltage drop, and actual voltage is obtained from the standard data and the actual battery voltage and actual battery current acquired during the charging / discharging operation of the lithium-on battery. The remaining charge amount of the current battery is determined by comparing the voltage with the actual electromotive voltage, and the determined remaining charge amount of the battery is based on the internal resistance change obtained by comparing the reference internal resistance and the actual internal resistance. Correction.

  According to a third aspect of the present invention, in the second aspect of the invention, the progress of characteristic change (deterioration) of the lithium ion battery is determined based on an internal resistance change amount obtained by comparing the reference internal resistance and the actual internal resistance. It is characterized by that.

  The invention of claim 4 is characterized in that, in any one of the inventions of claims 1 to 3, the dischargeable time is obtained by dividing the determined remaining charge amount of the battery by a predetermined discharge current. is there.

  The invention of claim 5 is the invention according to any one of claims 1 to 4, wherein the upper limit level (L0), the normal use level (Ll), the lower limit use level (L2), the use limit of the voltage of the lithium ion battery in advance. When the level (L3) is set and the actual battery voltage is in the range from the normal use level (L1) to the upper limit level (L0) during the charging operation of the lithium ion battery, the actual battery voltage is set to the upper limit. The lithium ion battery is continuously charged so as not to exceed the level (L0). When the actual battery voltage exceeds the upper limit level (L0), a warning is issued and the battery charging operation is stopped. During the discharge operation of the ion battery, when the actual battery voltage is in the range of the normal use level (Ll) to the use lower limit level (L2), the actual battery voltage is reduced to the use lower limit level ( 2) The discharge operation of the lithium ion battery is continued so as not to decrease further, and when the actual battery voltage is in the range of the use lower limit level (L2) to the use limit level (L3), an alarm is issued and the lithium ion battery is discharged. The discharge operation of the battery is limited so as not to exceed the use limit level (L3), and when the use limit level (L3) is reached, a warning is issued and the discharge operation of the lithium ion battery is stopped. Is.

  The characteristics of a lithium-ion battery vary depending on its electromotive voltage and internal resistance. The internal resistance of the battery increases with the calendar life over time, the cycle life with the number of charge / discharge cycles, and the temperature change. Therefore, if the battery charge amount is monitored from the electromotive voltage and internal resistance during operation of the lithium ion battery as in the present invention, the remaining state of the battery charge amount is monitored. It is possible to always grasp, and it is possible to grasp the state of characteristic deterioration of the battery in the power storage facility.

  Furthermore, if the remaining charge amount of the battery is corrected by the internal resistance change amount, the remaining charge amount of the battery can be grasped more accurately, and the progress of characteristic deterioration, and therefore the remaining life of the battery can be determined by the internal resistance change amount. Can be determined.

The block block diagram which shows the Example of this invention. The characteristic diagram used for operation | movement description of this invention. The operation waveform figure at the time of the constant current and constant voltage charge operation | movement of this invention. The operation | movement waveform diagram at the time of the charging current change of this invention. The operation | movement waveform diagram at the time of the constant current discharge operation | movement of this invention. The operation waveform figure at the time of the discharge current change of this invention. The operation | movement waveform diagram at the time of charging / discharging operation | movement of this invention.

  Before describing embodiments of the present invention, basic characteristics of a lithium ion battery will be described.

  The electromotive voltage, which is a basic characteristic of a lithium ion battery, changes according to the increase and decrease of the battery internal resistance, and the remaining charge amount changes depending on the electromotive voltage. Therefore, the electromotive voltage and the remaining charge amount of the battery change depending on the battery internal resistance of the battery. It will be.

The battery internal resistance that affects the battery characteristics varies depending on the following factors.
1) Change in charge amount and battery internal resistance Battery internal resistance is small in the charge amount, that is, in the region where the remaining charge amount is large (full charge region), and large in the region where the charge amount (remaining charge amount) is small (discharge end region). It is known that it changes according to the amount of charge.
2) Change in battery internal resistance as the usage period elapses Further, the battery internal resistance changes depending on the calendar life based on the battery use time and the cycle life based on the number of charge / discharge cycles, and increases as the remaining life becomes shorter.
3) Temperature change and internal resistance change Battery internal resistance changes with temperature change.

  As described above, the battery internal resistance changes depending on the state of charge, aging, and temperature of the battery.

  Further, when the battery charge amount due to the charge / discharge operation, that is, the remaining charge amount changes, the battery internal resistance changes. That is, if the remaining charge amount is increased by the charging operation, the electromotive voltage is increased and the internal resistance is decreased. If the remaining charge amount is decreased by the discharging operation, the electromotive voltage is decreased and the internal resistance is increased.

As described above, since the characteristics of the battery change depending on the correlation between the electromotive voltage and the internal resistance, the battery operating state can be monitored, evaluated, and managed by the following method.
A) The remaining charge amount of the storage battery can be predicted by the correlation between the electromotive voltage and the internal resistance.
B) The remaining life can be predicted from the progress of the characteristic change (deterioration) of the battery by the internal resistance change.
C) The dischargeable time can be predicted from the remaining charge amount.

  The battery capacity (charge capacity) is represented by Ah (ampere hour: current time product).

  For example, a battery with a battery capacity of 100 Ah is defined as a capacity that can be discharged for 1 hour with a discharge current of 100 A. If the charge / discharge efficiency is 100%, the battery is fully charged if charged with a charge current of 100 A for 1 hour. Will be able to.

  Naturally, since internal loss such as internal resistance is inherent in the battery, the charge / discharge efficiency does not reach 100%.

The general formula in the charge / discharge operation of the battery is the discharge operation formula VB = eB−IB × RB (1)
ＢeB = VB + IB × RB (2)
Charging operation formula VB = eB + IB × RB (3)
ＢeB = VB-IB × RB (4)
Indicated by Here, VB: battery terminal voltage, eB: battery electromotive voltage, IB: charge / discharge current, RB
: Battery internal resistance.

  It is clear from the equations (2) and (4) that the electromotive voltage eB of the battery is determined by the internal resistance RB and the charge / discharge current IB.

  Further, the electromotive voltage eB of the battery has a characteristic that varies depending on the remaining charge amount as indicated by characteristic lines Ae, Be, and Ce in FIG.

  FIG. 2 shows the relationship between the electromotive voltage of the battery and the remaining charge amount, and the relationship between the internal resistance and the remaining charge amount.

  The characteristic lines Ae, Be, and Ce in FIG. 2 are the electromotive voltages eB of the battery at the initial use period A, the intermediate use period B, and the final use period C of the battery, which are obtained in advance based on the design data or test data of the lithium ion battery. And a reference electromotive force characteristic line showing a relationship between the reference charge amount QV and the reference charge amount QV.

  Similarly, the characteristic lines AR, BR, and CR are the internal resistance RB of the battery in the initial use period A, the intermediate use period B, and the final use period C of the battery, which are obtained in advance based on the design data or test data of the lithium ion battery. It is a reference | standard internal resistance characteristic line which shows the relationship with the reference | standard charge amount QV.

  As shown in FIG. 2, in the reference electromotive voltage characteristic line Ae in the initial use A, when the electromotive voltage eB is 100%, the reference charge amount QV is 100%, but in the reference electromotive voltage characteristic line Be in the use period B, When the electromotive voltage eB is 100%, the reference charge amount QV is 67%. In the reference electromotive voltage characteristic line Ce at the end of use C, when the electromotive voltage eB is 100%, the reference charge amount QV is 50%. It becomes a decreasing characteristic.

  Further, as shown in FIG. 2, the internal resistance characteristic lines AR, BR, and CR are obtained when the internal resistance RB in the fully charged state (charge amount 100%) in the initial use A is set to the resistance index 1, and in the middle use B. Use time so that the internal resistance RB in the fully charged state (charge amount 67%) has a resistance index of 1.5, and the internal resistance RB in the fully charged state (charge amount 50%) at the end of use C has a resistance index of 2. It is set that the internal resistance RB increases with the increase of.

  From FIG. 2, it can be understood that the battery having a large internal resistance in the charge / discharge operation has a lower electromotive voltage due to an increase in the internal voltage drop, and a battery having a decreased electromotive voltage has a lower remaining charge.

  Naturally, a battery with a reduced remaining charge has a large internal voltage drop and a low electromotive voltage, and therefore the dischargeable time is shortened.

  In FIG. 2, the level of the electromotive voltage in the normal use range is changed from the L0 level (electromotive voltage 100%) to the L1 level (electromotive voltage 86%), and the normal use lower limit level is changed from the L1 level to the L2 level (electromotive voltage 84%). If the use limit level is changed from the L2 level to the L3 level (electromotive voltage 74%), the internal resistance increases as the use time elapses at the same electromotive voltage level. The electromotive voltage-charge amount characteristic at the end of use C changes as indicated by characteristic lines Ae, Be, Ce, and the charge amount at the time of full charge gradually decreases. This indicates that the charge amount of the battery can be corrected by the internal resistance.

  In the charge / discharge operation, electromotive voltage characteristic lines Ae, Be, Ce indicating the relationship between the charge amount and the electromotive voltage, and internal resistance characteristic lines AR, BR, CR indicating the relationship between the charge amount and the internal resistance are L0 to L0, respectively. Between Ll levels, it shows a characteristic that changes almost linearly, between Ll and L2 shows a characteristic that the amount of change in electromotive voltage and internal resistance increases than between L0 and L1, and between L2 and L3, there is a further change amount It shows a rapidly increasing characteristic.

  As shown by the electromotive voltage characteristic lines Ae, Be, and Ce, the full charge amount in the use period A is 100%, while the full charge amount in the in-use period B is the full charge amount in the initial use A. The full charge amount at the end of use C is further reduced to 1/2 = 50% of 100% of the full charge amount at the initial stage of use A. At this time, the internal resistance RB has a resistance index of 1 when fully charged in the initial use A (charge amount 100%), but at the time of full charge (charge amount 67%) in the middle period of use B. The internal resistance becomes a resistance index of 1.5, and at the end of use C, the internal resistance greatly increases to the resistance index of 2 when fully charged (charge amount 50%).

  In addition, the electromotive voltage levels of the use periods A, B, and C are the same values of L0 level: eBL0 (electromotive voltage 100%), L1 level: eBLl (electromotive voltage 86%), L2 level: eBL2 (electromotive voltage 84%), L3 level: If eBL3 (electromotive voltage 74%), as can be understood from the electromotive voltage characteristic lines Ae, Be, Ce, the charge amount at full charge is 100% in the initial use A and 67% in the intermediate use B At the end of use C, it decreases to 50%, and accordingly, the internal resistance RB increases from BLOA to BLOB, BLOC as indicated by the internal resistance characteristics AR, BR, CR.

  Therefore, in the charge amount correction, when the internal resistance in the initial stage of use is set as the reference internal resistance, and the increased internal resistance is expressed as an index with respect to the reference internal resistance, the charge amount can be corrected according to the internal resistance index.

  The present invention monitors and controls the charging / discharging operation of the battery by utilizing the characteristics of such a lithium ion battery. FIG. 1 shows a state of the charging / discharging operation state monitoring control device for a battery according to the embodiment of the present invention. A block diagram is shown.

  In FIG. 1, reference numeral 20 denotes a power storage facility that is an operation state monitoring target. The power storage facility 20 generates an electromotive voltage eB, a lithium ion battery 21 having an internal resistance RB, a power generator 22 that charges the battery 21, a propulsion device 23 that is driven by power supplied from the battery 21, and auxiliary power. It is comprised with the apparatus 24. FIG. Further, a voltage detector VD for detecting the battery terminal voltage VB and a current detector SH for detecting the charge / discharge current IB of the battery are provided.

  A reference internal resistance pattern setting unit 1, a reference electromotive voltage pattern setting unit 8, and a reference voltage setting unit 9 are provided as means for setting data serving as a reference for the battery of the power storage facility 20.

  The reference internal resistance pattern setting unit 1 includes a reference internal resistance characteristic line AR in the initial use A of the battery obtained by design or test, and a reference internal resistance characteristic line BR in the middle use B expected based on this. This is means for setting the reference internal resistance characteristic line BR at the end C as a reference internal resistance pattern.

  The reference electromotive voltage pattern setting unit 8 includes preset electromotive voltage characteristic lines Ae at the initial use A of the battery 21, electromotive voltage characteristic lines Be at the middle use B, and electromotive voltage characteristic lines at the end use C shown in FIG. The Ce pattern, the management voltage levels L0 to L3, and the like are set as reference electromotive voltage data.

  For example, in the case of the electromotive voltage characteristic line Ae in the initial use A, L0 level = electromotive voltage eBL0 (electromotive voltage 100%) = charge amount 100%, Ll level = electromotive voltage eBLl (electromotive voltage 86%) = charge amount 30% Etc. and the pattern of the characteristic line Ae are set. The patterns are also set and stored in the electromotive voltage characteristic line Be in the middle period of use B and the electromotive voltage characteristic line Ce in the period of use C. Furthermore, the L0 to Ll levels in the normal use range are ranges in which the electromotive voltage changes from 100% to 86%, the charge amount changes from 100% to 30%, and the internal resistance RB changes substantially linearly from RBL0A to RBL1A. The lower limit levels L1 to L2 are the ranges where the electromotive voltage decreases from 86% to 84% and the charging amount is decreased from 30% to 20%. The L2 to L3 levels of the use limit levels are the electromotive voltages from 84% to 74%. In addition, a reference operation pattern in which the charge amount is rapidly reduced to 20% to 10% or less is set and stored.

  In the reference voltage setting unit 9, the electromotive voltage at the L0 level shown in FIG. 2 is set as the reference electromotive voltage eBL0. The set reference electromotive voltage eBL0 is the maximum voltage at the time of full charge at which the charge amount is 100% in the initial use A of the battery to be used, and the reference voltage (100% electromotive voltage) of the entire operation range, To do.

  The minute current detector 2 detects that the charge / discharge current IBi of the battery detected by the current detector SH has become a minute current, and generates a detection signal S1 when this is detected. In the present invention, the minute current is set to a current of several percent of the rated current value of the battery, for example, about 5% or less.

  When the approximate electromotive voltage detection unit 3 receives the micro current detection signal S1 from the micro current detection unit 2, the approximate electromotive voltage detection unit 3 reads the terminal voltage VBi of the battery detected by the voltage detector VD and uses this as the approximate electromotive voltage eBri of the battery. It is a means to hold.

  The actual voltage / current storage unit 4 detects the change in the charge / discharge current IBi of the battery 21 detected by the current detector SH constantly monitored by the battery state monitoring processing unit 13, and outputs a measurement command signal S to be output from now on. This is means for reading and storing the actual voltage VBi and the actual current IBi of the battery detected by the voltage detector VD and the current detector SH. The actual voltage / current storage unit 4 reads and stores the actual voltage VBi2 and actual current IBi2 read and stored with the current measurement command signal S, and holds the actual voltage VBi1 and actual current IBi1 read and stored with the immediately preceding measurement command signal S. . Therefore, the actual voltage / current storage unit 4 stores and holds the actual voltage VBi1 and the actual current IBi1 immediately before the change of the current IBi of the battery 21, and the actual voltage VBi2 and the actual current IBi2 immediately after the change.

  Based on the actual voltage VBi1 and actual current IBi1 immediately before the current change stored in the actual voltage / current storage unit 4, and the actual voltage VBi2 and actual current IBi2 immediately after that, Alternatively, it is means for obtaining the actual internal resistance RBi by calculation using any of the equations (6).

RBi = (VBi2−VBi1) ÷ (IBi2−IBi1) (5)
RBi = (VBi1-VBi2) / (IBi1-IBi2) (6)
The equation (5) is used when the actual voltage VBi2 immediately after the actual voltage VBi1 just before the change is higher, and the equation (6) is used when the actual voltage VBi2 is immediately higher than the actual voltage VBi1 just before the change.

  The actual voltage drop calculation unit 6 calculates the following equation (7) or (8) from the actual internal resistance RBi obtained by the internal resistance calculation unit 5 and the actual currents IBi1 and IBi2 read from the actual voltage / current storage unit 4. It is a means for obtaining the actual voltage drop VBDi by calculation using either of them.

VBDi = RBi × IBi2 (7)
VBDi = RBi × IBi1 (8)
The actual electromotive voltage calculation unit 7 is charged from the actual voltage drop VBDi obtained by the actual voltage drop calculation unit 6 and the actual voltages VBi1 and VBi2 detected by the previous and subsequent measurement commands S stored in the actual voltage / current storage unit 4. Is a means for obtaining the actual electromotive voltage eBi by calculation using the equation (9) and at the time of discharge using the equation (10).

eBi = VBi1-VBDi (9)
eBi = VBi2 + VBDi (10)
The actual electromotive voltage eBi obtained by the actual electromotive voltage calculation unit 7 is given to the state monitoring processing unit 13 and the comparison correction calculation unit 11.

  The internal resistance comparison unit 10 compares the reference internal resistance characteristic lines AR, BR, CR set in the reference internal resistance pattern setting unit 1 with the actual internal resistance RBi obtained by the actual internal resistance calculation unit 5, A reference resistance value RBL close to the internal resistance RBi is selected, a change ratio of the actual internal resistance RBi with respect to the selected reference resistance value RBL is obtained, and this is output to the comparison correction calculation unit 11 as a charge amount correction value S2.

  For example, if the actual internal resistance RBi in FIG. 2 has a resistance index of 1.05, the reference internal resistance RBL0A (reference internal resistance at the initial use A) closest to the actual internal resistance RBi is selected to calculate the resistance change ratio. , The change ratio of the actual internal resistance (resistance index 1.05) to the reference value (resistance index 1.0) is 1.05 / 1 = 1.05, and the actual internal resistance RBi becomes the reference internal resistance RBL. On the other hand, since the increase is 5%, the reciprocal 1 / 1.05 is output as the charge amount correction value S2.

  The comparison correction calculation unit 11 obtains the reference charge amount QV with respect to the actual electromotive voltage eBi from the electromotive voltage characteristic lines Ae to Ce showing the relationship between the electromotive voltage and the charge amount shown in FIG. 2 set in the reference electromotive voltage data setting unit 8. Then, by multiplying this by the correction value S2 from the internal resistance comparison unit 10, a correction calculation of the reference charge amount QV based on the increase / decrease ratio of the actual internal resistance RBi with respect to the reference internal resistance is performed to obtain the corrected charge amount QZ.

  For example, in the initial use A, if the actual electromotive voltage eBi is eBLl = 86% in FIG. 2 and the actual internal resistance RBi is 1.1 in the resistance index, the electromotive voltage characteristic line Ae in the initial use A and the actual electromotive voltage 86% The reference charge amount QV = 30% is obtained from the intersection P0. Next, the internal resistance comparison unit 10 reads the reference internal resistance (= resistance index 1.1) at the point RBL1A where the reference charge amount QV = 30% on the characteristic line from the internal resistance characteristic line AR in the initial use A. Thus, the reference internal resistance RBL is set to 1.1 as a resistance index. Based on this, the charge amount correction value S2 is obtained as a ratio of the actual internal resistance RBi and the reference internal resistance RBL. In this case, the correction value S2 is 1 as shown in the following equation.

Correction value S2 = (actual internal resistance RBi = 1.1) /
(Reference internal resistance RBL = 1.1) = 1.0
Since the reference charge amount QV at the point P0 at the actual electromotive voltage eBi = 86% on the electromotive voltage characteristic line Ae is 30%, the comparison correction calculation unit 11 multiplies this by the correction value S = 1.0. The corrected charge amount QZ is 30%, which is output to the state monitoring processing unit 13.

  The current integrated charge amount calculation unit 12 integrates the detected actual charging / discharging current IBi of the battery in the addition direction at the time of charging, and in the subtraction direction at the time of discharging, The operation for obtaining the actual current integrated charge amount QH is performed. This method of obtaining the remaining charge amount is referred to herein as the AH method. When the deviation between the current accumulated charge amount QH obtained by the AH method and the corrected charge amount QZ becomes large, the current accumulated charge amount QH is corrected by replacing it with the corrected charge amount QZ, and the corrected current accumulated charge is corrected. The amount QHe is obtained. Therefore, QHe takes a value equal to QZ. The QH and QHe obtained here are output to the state monitoring processing unit 13. After the current integrated charge amount QH is corrected in this way, the current integrated charge amount calculation unit 12 integrates the charge / discharge current IBi based on the corrected current integrated charge amount QHe. An accumulated current charge amount QH is obtained.

  The state monitoring processing unit 13 detects the detected values detected by the respective units, the set set values, the battery actual voltage VBi, the actual current IBi, the reference electromotive voltage eBL, the reference internal resistance RBL, the actual The electromotive voltage eBi, the actual internal resistance RBi, and others are all read and stored, and monitoring control of each data, control of the display unit 14, and other control processes are performed.

  The state monitoring processing unit 13 has a function of predicting a dischargeable time. That is, the corrected charge amount QZ obtained by the comparison correction calculation unit 11 or the actual current accumulated charge amount QH or the corrected current accumulated charge amount QHe obtained by the current integrated charge amount calculation unit 12 is stored in the discharge current setting unit 16 in advance. The dischargeable time H is obtained by dividing by the set discharge current Is, and this is displayed on the display unit 14 to notify the operator.

  The display recording unit 14 displays the monitoring data collected in the monitoring processing unit 13 to assist the monitoring operation of the operator of the power storage facility, and if there is an abnormal state, activates the alarm unit 15 to alert the operator. Is notified.

Next, specific monitoring control items will be described.
1) Charge amount monitoring Conventionally, the charge amount monitoring method of the battery used is generally a method of monitoring the current accumulated charge amount QH obtained by the AH method by the current accumulated charge amount calculation unit 12 shown in FIG. However, in the method of monitoring the charge amount QH by the AH method, the charge amount QH accompanying the deterioration of the battery is not corrected.

  In the present invention, the charge amount is monitored by using both the method of monitoring the charge amount Q by the electromotive voltage (electromotive voltage method) and the method by the charge amount QH of the AH method. Correction of a decrease in the amount of charge due to battery deterioration is performed.

  In this invention, the charge amount (remaining charge amount) QV is obtained from the electromotive voltage value of the battery, and the corrected remaining charge amount QZ obtained by correcting the remaining charge amount by the change ratio of the internal resistance is monitored. The electromotive voltage method and the AH method are used together for monitoring, the AH method is used for monitoring the charge amount of a relatively short charge / discharge cycle, and the electromotive voltage method is the charge amount over a long period from the start of use to the end of use of the battery. It can also be used for monitoring.

  This is because, in the AH method, a battery with characteristic variation repeatedly accumulates charge / discharge operations, so that the characteristic variation is accumulated and expanded each time the current is accumulated. It is suitable for monitoring and managing the charge amount while correcting for the amount QZ, and the electromotive voltage method is suitable for monitoring and managing the charge amount that changes due to an increase in internal resistance that changes over a long period. This is because the charge amount can be more accurately monitored by using the combination.

  The discharge current IBs is designated in the discharge current designating unit 16, and the reference charge amount QV obtained by the electromotive voltage method and the charge amount QH obtained by the AH method are divided by this current (charge amount QV or QH) / (discharge current IBs). ), The dischargeable time H can be obtained, so that the dischargeable time H can be predicted. This calculation process is performed by the state monitoring processing unit 13.

Further, if the dischargeable time period H = QV ÷ IBi is calculated using the actual discharge current IBi, the dischargeable time period H by the actual discharge current IBi can be predicted.
2) Charging operation 2-1) Constant current and constant voltage charging operation (see FIG. 3)
FIG. 3 shows operation waveforms when constant current charging-constant voltage charging is performed. FIG. 3A shows temporal changes in the battery electromotive voltage eB and the battery terminal voltage VB, FIG. 3B shows the charging current IB, FIG. 3C shows the internal resistance RB, and FIG. 3D shows the voltage drop VBD over time. Showing change.

  When it is detected that the battery terminal voltage VB has reached the predetermined voltage VBC by charging in the constant current charging period tl to t2 to t4, the charge monitoring processing unit 13 sends a charging control command to the power generator 22 as a constant current charging control command. Is switched to a constant voltage charge control command, and constant voltage charge is performed at t2 to t4 to t5 to t7. When the battery voltage VB reaches the full charge voltage VBF, it is determined that the battery is fully charged and the charging is completed.

  A solid characteristic line Ae in FIG. 3A indicates a change in electromotive voltage in the initial use A at this time, and a dotted characteristic line AV similarly indicates a change in battery terminal voltage in the initial use A. Characteristic lines Be and BV indicate changes in electromotive voltage and terminal voltage in the middle period of use B, respectively. Characteristic lines Ce and CV show changes in the electromotive voltage and terminal voltage at the end of use C, respectively, and show a tendency that the electromotive voltage decreases as the internal resistance increases.

  As shown in FIG. 3C, the internal resistance RB decreases as charging progresses with time. The characteristic lines AR, BR, and CR shown here indicate the characteristics of the initial use A, the intermediate use B, and the final use C, respectively.

  Further, as shown in FIG. 3D, the battery internal voltage drop VBD exhibits a characteristic that decreases as the charging time proceeds, as in the case of the change in internal resistance. The characteristic lines AD, BD, and CD shown here indicate the characteristics of the initial use A, the intermediate use B, and the final use C, respectively.

  In the initial use A, charging is completed at time t5, the charging current becomes minute, and when the minute current detector 2 detects this and gives the signal Sl to the approximate electromotive voltage detector 3, the approximate electromotive voltage detector 3 holds the terminal voltage VBi as an approximate electromotive voltage eBri because the battery terminal voltage VBi at this time approximates the actual electromotive voltage.

  That is, since the battery internal voltage drop VBD (= IBi × RB) is small in the charge termination region where the charge current is small, the terminal voltage VBi and the electromotive voltage eBi are substantially equal. VBi is set as an approximate electromotive voltage eBri, which is supplied to the comparison correction calculation unit 11. The comparison correction calculation unit 11 obtains the charge amount QV corresponding to the approximate electromotive voltage eBri from the electromotive voltage characteristic line shown in FIG.

The approximate electromotive voltage eBRi detected by the approximate electromotive voltage detection unit 3 is compared with the actual electromotive voltage eBi obtained by the operation of the actual electromotive voltage calculation unit 7 by the comparison correction calculation unit 11 and compared with the actual electromotive voltage eBi. Is corrected by the approximate electromotive voltage eBri, so that a more accurate actual electromotive voltage eBi can be obtained. 2-2) Charging current change charging operation (see FIG. 4)
FIG. 4 shows operation waveforms when the charging current during the charging operation changes.

  In FIG. 4, the charging current is very small IB1 (for example, about 5% of the rated current of the battery) between the tl and t2 points at the beginning of charging, and this minute current IB1 is used as the minute current detection unit 2. Is detected and the signal S1 is supplied to the approximate electromotive voltage detector 3. The approximate electromotive voltage detector 3 reads the battery terminal voltage VBi detected by the voltage detector VD when the signal S1 is given, and holds this as the approximate electromotive voltage eBir.

  When the charging current increases from IBl to IB2 at the point t2, the state monitoring processing unit 13 detects this current change and sends the measurement command S to the actual voltage actual current detection storage unit 4, actual internal resistance calculation unit 5, actual voltage drop calculation. This is given to the unit 6, the actual electromotive voltage calculation unit 7, the internal resistance comparison unit 10, and the comparison correction calculation unit 11 for comparison and calculation.

  Receiving the measurement command S, the actual voltage actual current detection storage unit 4 reads, stores and holds the actual voltage BVi2 and the actual current IBi2 detected by the voltage detector VD and the current detector SH immediately after that. The actual voltage actual current detection storage unit 4 reads the actual voltage VBi2 and actual current IBi2 read and stored in the current measurement command S, and the actual voltage VBi1 and actual current immediately before read and stored in the previous measurement command S. IBi1 is also stored and held.

  In accordance with the measurement command S, the actual internal resistance calculation unit 5 calculates the actual voltages VBi1 and VBi2 immediately before and immediately after the current measurement signal S stored in the actual voltage / current storage unit 4, that is, immediately before and immediately after the current change, The currents IBi1 and IBi2 are read, and based on these, an operation for obtaining the internal resistance RBi by the above equation (5) or (6) is performed.

  In accordance with the measurement command S, the actual voltage drop calculation unit 6 also includes the actual internal resistance RBi given from the actual internal resistance calculation unit 5 and the actual currents IBi1 and IBi2 immediately before and after the current change read from the actual voltage / current storage unit 4 To calculate the actual voltage drop VBDi using the above-described equation (7) or (8).

  Further, the actual electromotive voltage calculation unit 7 determines the actual voltage drop VBDi obtained by the actual voltage drop calculation unit 6 according to the measurement command S and the actual voltage VBi1 immediately before and immediately after the current change read from the actual voltage current storage unit 4, An arithmetic process for obtaining the actual electromotive voltage eBi from VBi2 by the above-described equation (9) or (10) is performed.

  The comparison correction calculation unit 11 includes the electromotive voltage characteristic line and the internal resistance characteristic line shown in FIG. 2, the actual internal resistance RBi obtained by the actual internal resistance calculation unit 5, and the actual electromotive voltage eBi obtained by the actual electromotive voltage calculation unit 7. Comparing is performed to obtain the remaining reference charge amount QV and the corrected remaining charge amount QZ.

For example, in FIG. 2, if the actual electromotive voltage eBi is eBLl (electromotive voltage 86%) on the electromotive voltage characteristic line Ae at the initial use A and the actual internal resistance RBi is the resistance index 1.1, the electromotive voltage characteristic line Ae From the point P0 where the actual electromotive voltage eBV = eBLl (electromotive voltage 86%) intersects, the remaining reference charge amount QV = 30
% Is obtained.

  The reference resistance RBL1A point of the internal resistance characteristic line AR is selected as the resistance closest to the internal resistance on the internal resistance characteristic line intersecting with the vertical line of the actual internal resistance RBi = resistance index 1.1 and the charge amount of 30%. The internal resistance is determined to be a resistance index of 1.1. Since the ratio of the actual internal resistance RBi = 1.1 to the reference internal resistance RBL1A = 1.1 is 1, the charge amount correction value is 1.

For this reason, the correction charge amount QZ obtained by the comparison correction calculation unit 11 is: correction reference charge amount QV = (remaining reference charge amount QV = 30%) × (correction value = 1) = 30%
30% is obtained. In this case, since the actual internal resistance RBi and the reference internal resistance RBL are equal, the correction value is 1, and the correction charge amount QZ is equal to the remaining reference charge amount QV.

  Further, when the charging current further increases from IB2 to IB3 at the point t3, the state monitoring processing unit 13 detects this current change and outputs a measurement command S. The memory is updated by reading the voltage and the actual current, and each part performs arithmetic processing based on the updated data.

  The corrected remaining charge amount QZ when the data at this time is, for example, the initial use A, the actual electromotive voltage eB of the battery is 94% voltage, and the actual internal resistance RBi is the resistance index 1.2 is a comparative correction. It is obtained by the following calculation process in the calculation unit 11.

  First, a residual reference charge amount QV of 70% is obtained from a point P1 where the electromotive voltage characteristic line Ae shown in FIG. 2 set in the reference electromotive voltage pattern setting unit 8 and the electromotive voltage 94% intersect. Then, the actual internal resistance point is obtained at the intersection P2 between the vertical line of 70% charge and the horizontal line of the actual internal resistance = resistance index 1.2. The internal resistance at the point P2 = resistance index 1.2 is equal to the reference resistance at the intersection P3 between the reference internal resistance line AR in the initial use A shown in FIG. Is the closest.

Therefore, the internal resistance comparison unit 10 selects the resistance index 1.05 at the point P3 as the reference internal resistance closest to the actual internal resistance = resistance index 1.2, and calculates the charge amount correction value S2 based on this. I do. The charge amount correction value S2 at this time is
Charge amount correction value S2 = (actual internal resistance RBi = resistance index 1.2)
÷ (reference internal resistance RBL = resistance index 1.05) = 1.14
Based on this correction value S2, the correction charge calculating unit 11 obtains the correction charge amount QZ. The corrected charge amount QZ is
Corrected remaining charge QZ = (residual reference charge QV = 70%) ×
1 / (correction value S2 = 1.14) = 61%
To be 61%.

  In this case, since the actual internal resistance RBi is higher than the reference internal resistance RBL, the corrected remaining charge amount QZ is corrected to be on the decrease side with respect to the remaining reference charge amount QV.

  The following example is a calculation processing procedure when the actual electromotive voltage eBi obtained by measurement and calculation is 94% voltage and the actual internal resistance RBi is the resistance index 2.0 during use at the end of use C.

  As in the above case, first, the remaining reference charge amount QV of 33% from the intersection P4 of the electromotive voltage characteristic line Ce of the initial use C shown in FIG. Desired. The actual internal resistance point is plotted at the intersection P5 between the vertical line of the charge amount of 33% and the horizontal line of the actual internal resistance = resistance index 2. The actual internal resistance = 2 at the intersection P5 is closest to the reference resistance = resistance index 2.05 at the intersection P6 between the reference internal resistance line CR at the end-of-use period C shown in FIG. doing.

  Therefore, the internal resistance comparison unit 10 selects the resistance index 2.05 as the reference internal resistance closest to the actual internal resistance = resistance index 2, and performs a calculation process for obtaining the charge amount correction value S2.

Here, the obtained charge amount correction value S2 is:
Charge amount correction value S2 = (actual internal resistance RBi = resistance index 2) ÷
(Reference internal resistance RBL = resistance index 2.05) = 0.98
Based on this correction value S2, the correction remaining charge amount QZ obtained by the comparison correction calculation unit 11 is
Corrected remaining charge QZ = (residual reference charge QV = 33%) ×
1 / (correction value S2 = 0.98) = 34%
It becomes.

  In this case, since the actual internal resistance RBi has not increased from the reference internal resistance RBL, the corrected remaining charge amount QZ is corrected to an increase side with respect to the remaining reference charge amount QV.

  Naturally, in each of the calculation units 5, 6, 7, and 11, the data before the current change is reset and the calculation process is performed with the data at the time of change, but the data before the change is stored in the state monitoring processing unit 13 and time-series The battery operating state history can be monitored based on the data that changes in (1).

Further, when the charging current IB shifts from the IB3 to the minute charging current IB4 at the point t4 or when the charging current IB shifts to the minute discharging current IB5 at the point t5, the minute current detection unit 2 and the voltage detection unit 3 perform t4. The actual voltage VBi is read at each point t5 and held as the approximate electromotive voltage eBir.
3) Constant current discharge operation (see Fig. 5)
FIG. 5 shows that when a constant current is discharged from the electromotive voltage eBL0 at the L0 level at the point t0 to the electromotive voltage eBLl at the L1 level, the battery at the initial use A is at the point t3, the battery at the intermediate use B is at the point t2, and the final use C This shows that the battery can be discharged up to the tl point. Here, the characteristic lines Ae, Be, and Ce are characteristic lines showing changes in the internal electromotive voltage eB of the voltage in the initial use A, the intermediate use, and the final use C, respectively. Also. Characteristic lines AV, BV, and CV are characteristic lines that indicate changes in the terminal voltage VB of the voltage at the initial use A, the intermediate use, and the final use C, respectively. Characteristic lines AVD, BVD, and CVD indicating changes in the characteristic lines AR, BR, and CR indicating the internal resistance RB and the voltage drop VBD also indicate changes in the internal resistance and the voltage drop in the initial use A, the intermediate use, and the final use C, respectively. Is.

  When the discharge current drops from IB0 to IB1C, IB1B, and IB1A of minute currents corresponding to the battery usage period at any one of the points tl to t3, the minute current detector 2 and the approximate electromotive voltage detector 3 respectively. The actual voltage VBi is read by this operation and held as the approximate electromotive voltage eBir.

Naturally, the actual internal resistance RBi obtained by the actual internal resistance calculation unit 5 is given to the internal resistance comparison unit 10 and the comparison correction calculation unit 11 to obtain the battery internal resistance, electromotive voltage, and charge amount correction data described above, and Monitor the operating status.
4) Current change discharge operation (see Fig. 6)
When the discharge operation is performed with a minute current between the points t0 to tl in FIG. 6, the minute current detection unit 2 and the approximate electromotive voltage detection unit 3 read the actual voltage VBi and hold it as the approximate electromotive voltage eBir.

  When the discharge current increases from IB1 to IB2 at the time point tl, the state monitoring processing unit 13 detects a current change and outputs a measurement command S. The actual value immediately before and immediately after the current change stored in the actual voltage actual current storage unit 4 is output. Each calculation unit 5, 6, 7, 11 performs each calculation process according to the voltage and actual current data.

  Similar to the above description, the characteristic deterioration progress value CV obtained by processing the stored data immediately before the change, the actual voltage immediately after the change, the calculated value from the actual current data and the reference data by the comparison correction calculation unit 11, the remaining reference charge The amount QV and the corrected remaining charge amount QZ are given to the battery operation state processing unit 13 to monitor and manage the battery operation state.

  At the time of current change when the current IB increases from IB2 to IB3 at the point t2 and decreases from IB3 to IB4 at the point t3, the actual voltage VBi and the actual current IBi are read in the same manner as described above, and are necessary for each calculation unit. To monitor and manage battery status in search of new data.

Further, when the minute discharge IB5 is reached at the point t4, this is detected by the minute current detection unit 2, and the actual voltage VBi at that time is captured and held as the approximate electromotive voltage eBir by the approximate electromotive voltage detection unit 3.
5) Charging / discharging operation (see Fig. 7)
The charge / discharge operation will be described with reference to FIG.

  The discharge operation is performed with a minute current -IB1 between the points t0 and tl in FIG. 7, and the floating charging operation is performed with the charging current set to 0 A by operating the power generation device 22 between the points tl and t2. This is detected by the unit 2, and the actual voltage VBi at that time is fetched and held as the approximate electromotive voltage eBir by the approximate electromotive voltage detection unit 3, and the approximate electromotive voltage eBir is given to the comparison correction calculation unit 11.

  When the charging current is set to + IB1 of the constant current at the point t2 and the applied voltage (terminal voltage) VB to the battery 21 is set to VB2, and constant current charging is started, the state monitoring processing unit 13 detects a change in current at this point. The measurement command signal S is output, and the calculation units 5, 6, and 7 calculate the actual internal resistance RBi, the actual voltage drop VBDi, and the actual electromotive voltage eBi in the same manner as described above.

  Further, the deterioration state of the battery can be confirmed by comparing the actual electromotive voltage eBi calculated by the actual electromotive voltage calculation unit 7 with the approximate electromotive voltage eBi measured at the points t0 to tl and the reference data.

  When the electromotive voltage eB increases due to the progress of charging, the actual internal resistance RB decreases and the actual voltage drop VBD decreases.

  When the charging current becomes 0A at the time point t3 when the constant current charging is completed and a transition is made to floating charging, the state monitoring processing unit 13 detects a current change and outputs a measurement command signal S to calculate the calculation unit 5, 6 and 7, the actual internal resistance RBi, the actual voltage drop VBDi, and the actual electromotive voltage eBi are calculated.

  Further, the comparison correction calculation unit 11 obtains the remaining reference charge amount QV from the actual electromotive voltage eBi and the reference electromotive voltage patterns Ae, Be, and Ce set in the reference data setting unit 8, and further calculates the reference charge amount QV. The corrected remaining charge amount QZ and the characteristic change progress value CV are obtained by correction with the charge amount correction value S2 obtained by the internal resistance comparison unit 10, and are given to the state monitoring processing unit 13 for display and recording.

  In the comparison correction calculation unit 11, the characteristic change progress value CV is obtained from the internal resistance change amount = internal resistance index = internal resistance increase value. The state monitoring processing unit 13 monitors the characteristic change progress value CV to grasp the battery deterioration progress.

For example, if the internal resistance RBi at the start of use of the battery 21 is the internal resistance index 1, and the actual internal resistance index after a certain period of use thereafter is 1.5, the battery deterioration progress value CV is: Since it is shown in the ratio of both,
Battery degradation progress amount CV = (Internal resistance RBi at the start of use = Internal resistance index 1) ÷
(Internal resistance after use time RBi = Internal resistance index 1.5) = 67 (%)
Can be obtained by calculating. Thus, it is possible to grasp that the deterioration is progressing from the battery deterioration progress value CV = 67% obtained thereby until the battery capacity is reduced to 67% of the initial capacity.

When the battery current is shifted to the operation of discharging at −IB2 at the point t5, the state monitoring processing unit 13 detects this current change and outputs a measurement command signal S to each calculation unit to output the actual internal resistance as described above. Arithmetic processing for obtaining RBi, actual voltage drop VBDi, and actual electromotive voltage eBi is performed. Thereby, it is detected that the voltage VB of the battery 21 is lowered to VB4 and the electromotive voltage eB is lowered to eB4. Further, as the discharge operation proceeds, the internal resistance RB and the voltage drop VBD increase.

  When transitioning to a minute current at the point t6, the state monitoring processing unit 13 detects this current change and outputs a measurement command signal S to each calculation unit so that the actual internal resistance RBi, the actual voltage drop VBDi, and the actual occurrence are the same as described above. An arithmetic process for obtaining the voltage eBi is performed. Further, the approximate electromotive voltage detector 3 detects and holds the approximate electromotive voltage eBri.

  Further, during the period in which floating charging is performed with a minute current between points t6 to t8, the electromotive voltage data obtained here is read by the battery state monitoring process 13, and is monitored, displayed and recorded by the monitoring / display / recording unit 14. .

  The period between t8 and t9 is a period during which charging is performed at a constant current, and the period between t9 and tll is a period during which constant current charging is completed and a floating charging operation state is established. Further, the charging / discharging operation changes between the t11 to t12 points, the floating charging operation state between the t12 to t14 points, and the constant current charging state between the t14 to t15 points, and the battery current IB changes. At each time, the actual voltage VBi, the actual current IBi, the actual electromotive voltage eBi obtained from these, the actual internal resistance RBi, the preset reference electromotive voltage VBL, the reference internal resistance RBL, and the like are monitored to monitor the battery operating state. Process, display and record.

Next, the battery state monitoring process / display / recording operation performed by the battery state monitoring process 13 and the display recording unit 14 shown in FIG. 1 will be described.
1) Reference value management and actual operation management The reference internal resistance pattern setting unit uses the reference data of the reference electromotive voltage eBL, the reference charge amount QV, and the reference internal resistance RBL (use initial A / use middle B / use end C) described above. 1. Stored in the reference electromotive voltage pattern installation unit 8, the reference electromotive voltage installation unit 9, etc., and the actual internal resistance of these reference value data CS and actual electromotive voltage eBi, initial use A, intermediate use B, and final use C Based on the charge amount QV, the corrected charge amount QZ, and the characteristic change progress value CV obtained by comparing and calculating RBi with the comparison correction calculation unit 11, the state monitoring processing unit 13 monitors and manages the change in the operating state of the battery. .

For example, by displaying the actual electromotive voltage eBi obtained by the computing unit 7 on the display unit 14 displaying the reference electromotive voltage characteristic lines Ae, Be, and Ce shown in FIG. Can be grasped intuitively.
2) Management of characteristic change (degradation progress) The characteristic change (degradation progress) is determined by the change in internal resistance.

That is, the reference internal resistance characteristic lines AR, BR and CR on the reference internal resistance characteristic lines AR, BR and CR in the initial use A, the intermediate use B and the final use C of the battery 21 and the terminal voltage VBi of the battery 21 measured each time, The actual internal resistance RBi obtained by calculation from the charge / discharge current IBi is compared to determine the ratio, and the percentage of the actual internal resistance with respect to the reference internal resistance is monitored and managed as the battery characteristic deterioration progress value CV. By recording and holding this data in time series, it is possible to grasp and monitor characteristic changes due to time series.
3) Correction of actual current integration (AH) charge amount and AH charge amount Monitoring of the charge amount by the current integration (AH) charge amount QH obtained by the charge / discharge amount calculation unit 12 described above is performed in a relatively short period of time, for example, It is used for charge amount management in charge / discharge operation of one charge / discharge cycle.

The charge / discharge amount calculation unit 12 in FIG. 1 corrects the charge amount obtained by integrating the measured charge / discharge current IB (A) by time (H) and the actual current integration (AH) charge amount QH obtained by the comparison calculation unit 11. Correction is performed by replacing with QZ, and the remaining charge amount of the battery is monitored, recorded, and displayed by this corrected AH charge amount QHe.
4) Correction of reference charge amount QV and charge amount The method of monitoring the reference charge amount QV obtained from the battery electromotive voltage described above is based on the reference charge amount QV obtained from the reference electromotive voltage value eBL and the actual electromotive voltage eBi. The charge amount QZ corrected by the correction value S2 obtained by comparing and calculating the reference resistance value RBL and the actual internal resistance RBi is monitored and managed by the state monitoring processing unit 13, and recorded and displayed by the display recording unit 14. .

The reference charge amount QV obtained from the electromotive voltage is monitored for the long term (calendar life), and the charge amount monitoring by the AH charge amount QH obtained by integrating the current is monitored for a short period. Because it is the purpose, it is better to monitor, record, and display both in combination.
5) Prediction of dischargeable time As described above, if the corrected (remaining) charge amount QZ obtained by correcting the reference charge amount QV by the electromotive voltage method based on the change in the internal resistance is 40% of the rated capacity, QZ40% is converted to 40% of the rated AH charge amount QH, and this corrected AH charge amount QHe is obtained by dividing (AH ÷ A) by the discharge current Ds specified by the discharge current specifying portion 16 shown in FIG. The approximate dischargeable time H is predicted based on the remaining time H.
6) Monitoring, management, recording, and display of the actual voltage VBi and the actual current IBi The actual voltage VBi and the actual current IBi are monitored and managed as follows.
A) The actual internal voltage RBi, the actual voltage drop VBDi, and the actual electromotive voltage eBi are obtained by calculation from the actual voltage VBi and the actual voltage VBi measured at the time of change of the actual current IBi and the actual current IBi.
B) The L0 to L3 levels of the battery voltage shown in FIG. 2 are monitored.

  For example, if the actual electromotive voltage eBi indicates L0 or more in the charging operation, the battery is in an overcharged state, so an alarm or warning is issued from the alarm unit 15 in FIG.

  Further, in conjunction with the warning and warning, a generator control command signal SG is given to the generator control device 22 to limit the generator voltage so that the electromotive voltage eBi of the battery does not exceed the L0 level (FIG. 2). First, when the battery electromotive voltage eBi exceeds eBL0, a process for stopping charging is performed by, for example, reducing the output voltage of the generator.

  In the discharging operation, when the electromotive voltage reaches the range of L1 to L2 that is an electromotive voltage level with a small charge amount QV, an alarm or warning is issued from the alarm unit 15.

  For example, the motor control command signal SM is given to the motor control device 18 in conjunction with the alarm and warning to reduce the motor rotation speed so that the battery voltage does not drop below L2, that is, the battery load is reduced to reduce the discharge current IB. The control which suppresses is performed.

Further, when the battery electromotive voltage drops below the level L3 (eBL3), a process for cutting off the battery current is performed by stopping the electric motor.
7) Monitoring of characteristic deterioration progress As described above, the characteristic change of the lithium ion battery, that is, the characteristic deterioration progress CV is indicated by the rate of increase in internal resistance. Therefore, the reference internal resistance and the actual internal resistance are compared, and the characteristic change progress is monitored by the characteristic deterioration progress value CV compared and calculated by the correction calculation unit 10.

1: reference resistance pattern setting unit 2: minute current detection unit 3: approximate electromotive voltage detection unit 4: actual voltage / current storage unit 5: actual internal resistance calculation unit 6: actual voltage drop calculation unit actual voltage generation calculation unit 8: reference voltage generation Voltage pattern setting unit 9: Reference electromotive voltage installation unit 10: Internal resistance comparison unit 11: Comparison correction calculation unit 12: Current integrated charge amount calculation unit 13: State monitoring processing unit 14: Display recording unit 15: Alarm unit 20: Power storage equipment 21: Lithium ion battery.

Claims (5)

  In a power storage facility equipped with a lithium ion battery, an electromotive voltage and an internal resistance of the battery are obtained from detection data such as a charge / discharge voltage and a charge / discharge current of the battery during charge / discharge of the lithium ion battery. The remaining charge amount is determined, the determined remaining charge amount is corrected by the change amount of the internal resistance, and the charge / discharge state of the lithium ion battery is monitored by the corrected remaining charge amount. Facility charge / discharge status monitoring and control system.   The charging / discharging state monitoring control system for the power storage device according to claim 1, wherein a reference internal resistance, a reference electromotive voltage, and a reference charge amount with respect to a reference electromotive voltage, which are used in advance in the initial use period, the intermediate use period, and the final use period of the lithium ion battery The actual data such as the actual internal resistance, the battery internal voltage drop, and the actual electromotive voltage are obtained from the reference data and the actual battery voltage and the actual battery current acquired during the charge / discharge operation of the lithium-on battery. A comparison between the reference electromotive voltage and the actual electromotive voltage is performed to determine a remaining charge amount of the current battery, and the remaining charge amount of the determined battery is determined by comparing the reference internal resistance and the actual internal resistance. A charge / discharge state monitoring control system for a power storage facility, wherein correction is performed based on the amount.   3. The charging / discharging state monitoring control system for a power storage facility according to claim 2, wherein the progress of characteristic change (deterioration) of the lithium ion battery is determined based on an internal resistance change amount obtained by comparing the reference internal resistance with an actual internal resistance. A charge / discharge state monitoring control system for a power storage facility, characterized in that:   4. The charge / discharge state monitoring control system for a power storage facility according to claim 1, wherein a dischargeable time is obtained by dividing the determined remaining charge amount of the battery by a predetermined discharge current. Charging / discharging state monitoring and control system for power storage equipment.   5. The charge / discharge state monitoring and control method for a power storage facility according to claim 1, wherein an upper limit level (L0), a normal use level (Ll), and a use lower limit level of the voltage of the lithium ion battery are preliminarily determined. (L2), a use limit level (L3) is set, and when the actual battery voltage is in the range from the normal use level (L1) to the upper limit level (L0) during the charging operation of the lithium ion battery, The charging operation of the lithium ion battery is continued so that the actual battery voltage does not exceed the upper limit level (L0). When the actual battery voltage exceeds the upper limit level (L0), a warning is issued and the battery charging operation is performed. When the actual battery voltage is in the range of the normal use level (Ll) to the use lower limit level (L2) during the discharge operation of the lithium ion battery, The discharge operation of the lithium ion battery is continued so that the voltage does not drop below the lower limit use level (L2), and an alarm occurs when the actual battery voltage is in the range from the lower use limit level (L2) to the lower limit use level (L3). The discharge operation of the lithium ion battery is restricted so as not to exceed the use limit level (L3), and when the use limit level (L3) is reached, a warning is issued and the discharge operation of the lithium ion battery is stopped. A charge / discharge state monitoring control system for power storage equipment.

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