JP2008232988A - Power storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly-reliable power storage device capable of estimating at high speed a both terminal voltage of a power storage element having an abnormal value. <P>SOLUTION: This device has a constitution wherein a power storage element voltage detection circuit 33 is connected to a power storage element module 29 comprising a plurality of power storage elements 31. During a starting time, if each both terminal voltage value of the power storage elements 31 determined through the power storage element voltage detection circuit 33 has an initial abnormal value, a control part 41 uses a mean value (H) of initial normal values of each both terminal voltage value as the both terminal voltage value in place of the initial abnormal value. During an ordinary using time, if each both terminal voltage value determined through the power storage element voltage detection circuit 33 has an abnormal value, the control part 41 determines an average changing rate (D) between a both terminal voltage value measured in the preceding time and a both terminal voltage value measured in this time of the power storage element 31 having a normal value, and uses a value determined by multiplying the both terminal voltage value measured in the preceding time of the power storage element 31 having the abnormal value by the average changing rate (D), as the both terminal voltage value in place of the abnormal value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power storage device that supplementarily supplies power when a voltage of a main power supply is lowered.

  In recent years, hybrid vehicles have been put on the market for environmental considerations and fuel efficiency improvements. This can improve efficiency because an automobile (hereinafter referred to as a vehicle) is driven not only by an engine but also by a motor. In addition, since this hybrid vehicle not only drives the motor by a power storage device that handles large electric power, but also performs an operation of storing regenerative energy during braking, the braking energy can be used effectively and fuel consumption can be reduced.

  Such a power storage device requires an output voltage of several hundred volts in order to drive the motor, but the rated voltage of a power storage element (for example, a secondary battery or an electric double layer capacitor) used in the power storage device is about several volts. Therefore, the number of power storage elements to be used is on the order of 100. Therefore, it is necessary to monitor the state by measuring the voltage values at both ends of a large number of power storage elements to suppress overcharge and overdischarge. A power storage device that measures the voltage values at both ends of such a large number of power storage elements is disclosed in Patent Document 1, for example. FIG. 7 shows a block circuit diagram of the power storage device. Note that FIG. 7 illustrates an example in which a secondary battery is used as a power storage element.

  For example, 100 secondary batteries 101 are connected in series as a whole power storage device to obtain a necessary voltage. The secondary battery 101 is not directly connected, but a module battery 103 in which 10 batteries are connected in series is formed, and 10 batteries are connected in series outside.

  Each secondary battery 101 is connected to a voltage detection circuit 105 for each module battery 103. The voltage detection circuit 105 has a function of switching and measuring the connection point voltage of each secondary battery 101. The voltage detection circuit 105 is controlled by the slave side control circuit 107, and the voltage value is read. As a result, the slave-side control circuit 107 can obtain the voltage values at both ends.

  Both-end voltage value measurement request signals and both-end voltage value data are transmitted / received to / from a control device, which will be described later, by the slave-side transmitting / receiving circuit 109. Note that a signal presence / absence detection circuit 111 is connected to the slave side control circuit 107, and thereby, control is performed so as to transmit when there is no signal of the signal system wiring 113 connected to the slave side transmission / reception circuit 109.

  By connecting ten assembled batteries 115 having such a configuration, it becomes possible to cover the necessary power, but the slave side transmission / reception circuits 109 built in each assembled battery 115 are also connected to each other by signal wiring 113. Has been. Since this signal system wiring 113 is also connected to the master-side transmission / reception circuit 119 built in the control device 117, the control device 117 can measure and read the voltage values at both ends of each secondary battery 101. Note that the control device 117 also includes a master-side control circuit 121 connected to the master-side transmission / reception circuit 119, thereby enabling monitoring of the state of the secondary battery 101. In order to reduce the influence of noise and the like of the power system wiring on the signal system wiring 113, the control circuit 117 incorporates an insulating circuit power source 123.

  With such a configuration, when the control device 117 transmits a both-end voltage value measurement request signal to each assembled battery 115, each voltage detection circuit 105 simultaneously measures the both-end voltage value, and the control device 117 receives both-end voltage value data. Will be sent. Therefore, it is possible to quickly read the voltage values at both ends of as many as 100 secondary batteries 101.

  However, even if countermeasures against noise are taken by the insulating circuit power supply 123 or the like, a part of the voltage value at both ends may be caused by noise that cannot be completely removed or sudden noise while reading a large number of voltage data at both ends. Can be an abnormal value. In addition, since the voltage value data at both ends is not sent, there may be an abnormal value because there is no voltage value at both ends. In these cases, the abnormal value can be determined by comparison with the assumed normal voltage value at both ends. However, if the abnormal value is left as it is, the overcharge and overdischarge of the secondary battery 101 may not be suppressed. There is.

  Therefore, it is necessary to estimate the voltage value at both ends of the secondary battery 101 having an abnormal value, and to perform overcharge and overdischarge monitoring and suppression control based on the estimated value. As such a method of estimating the voltage value across the secondary battery 101, for example, a method disclosed in Patent Document 2 below has been proposed. In Patent Document 2, when the control device 117 sequentially performs failure diagnosis for each assembled battery 115, the voltage value at both ends of the assembled battery 115 during failure diagnosis cannot be obtained. Therefore, the estimation is performed as follows. ing.

  First, the distribution of the voltage values at both ends of all the secondary batteries 101 when no failure diagnosis is performed on any of the assembled batteries 115 is calculated. Next, the voltage value data of both ends of the secondary batteries 101 other than the assembled battery 115 under failure diagnosis are stored. Finally, the both-ends voltage value of the secondary battery 101 built in the assembled battery 115 under failure diagnosis is estimated using the stored end-to-end voltage value data and the end-to-end voltage value distribution calculation result of all the secondary batteries 101. To do.

Using this method, the voltage value across the secondary battery 101 having an abnormal value due to the influence of noise or the like is estimated as follows. That is, if the distribution of the voltage values at all ends of the secondary battery 101 is calculated and an abnormal value occurs at the voltage values at both ends, the abnormal value is obtained using the other normal value and the voltage value distribution calculation result at both ends. The voltage value at both ends of the secondary battery 101 is estimated.
Japanese Patent No. 3581825 Japanese Patent No. 3702861

  According to the power storage device described above, even if the voltage value at both ends of the secondary battery 101 is an abnormal value, the expected normal value can be estimated by calculation. Since it is necessary to calculate the distribution of values, it takes time, and the voltage values at both ends cannot be monitored and controlled in a timely manner, resulting in a problem that reliability is lowered. That is, in the power storage device using the secondary battery 101 of the order of 100 as in the configuration of FIG. 7, since the parameter is large, it takes time to calculate the distribution of the voltage values at both ends. Since the calculation of the distribution of the both-end voltage value is performed every time the control device 117 measures the both-end voltage value of the secondary battery 101, the measurement interval of the both-end voltage value of the secondary battery 101 becomes longer. Therefore, there is a possibility that the voltage value at both ends cannot be monitored and controlled in a timely manner.

  An object of the present invention is to solve the above-described conventional problems, and to provide a highly reliable power storage device that can estimate the voltage value across the storage element having an abnormal value at high speed.

  In order to solve the conventional problem, a power storage device according to the present invention includes a power storage element module having a configuration in which a plurality of power storage elements are connected in series or series-parallel, and the power storage connected to both ends of each power storage element or in parallel. A storage element voltage detection circuit connected to both ends of each storage element group in which the elements are combined, and a control unit connected to the storage element voltage detection circuit, and each of the storage element or each storage element group When determining the voltage values at both ends, the control unit at the time of start-up, if there is an initial abnormal value at each of the voltage values at the both ends determined through the storage element voltage detection circuit, The average value (H) of the values is used as the voltage value at both ends instead of the initial abnormal value, and during normal use, if there is an abnormal value at each terminal voltage value obtained through the storage element voltage detection circuit Has a normal value The average change rate (D) of the previously measured both-end voltage value and the current measured both-end voltage value in the electricity storage element or the electricity storage element group is obtained, and the last measured both-end voltage of the electricity storage element or the electricity storage element group having the abnormal value is obtained. A value obtained by multiplying the value by the average rate of change (D) is used as the voltage value at both ends instead of the abnormal value.

  The power storage device of the present invention includes a plurality of power storage element modules having a configuration in which a plurality of power storage elements are connected in series or series-parallel, a power storage element voltage detection circuit connected to both ends of the power storage element module, and the power storage elements A control unit to which a voltage detection circuit is connected, and when determining the voltage values at both ends of the power storage element module, the control unit, when starting up, determines each of the power storage element voltage detection circuits obtained via the power storage element voltage detection circuit. If there is an initial abnormal value in the both-end voltage value, the average value (H) of the initial normal value of each of the both-end voltage values is used as the both-end voltage value instead of the initial abnormal value. If there is an abnormal value at each of the voltage values obtained through the voltage detection circuit, an average rate of change (D) between the voltage value at the previous measurement and the voltage value at the current measurement in the storage element module having a normal value is obtained. , A value obtained by multiplying the average rate of change in the last measured voltage across value (D) of said power storage device module having the abnormal value, in which in place of the abnormal value was set as the said end voltage value.

  According to the power storage device of the present invention, if there is an initial abnormal value in the voltage value of the power storage element or the power storage element group at the time of start-up, the average value (H) of other initial normal values is used as the voltage value at the both ends. Sometimes, if there is an abnormal value at the both-end voltage value, the storage element having a normal value, or the storage element having the abnormal value in the average rate of change (D) between the previous-measurement both-end voltage value and the current-measurement both-end voltage value Or, the value obtained by multiplying the voltage value measured at both ends of the power storage element group by this time is the voltage value measured at both ends, so that the voltage value of the power storage element having an abnormal value or the power storage element group is estimated only by simple four arithmetic operations. Can do. Accordingly, it is possible to monitor and control the voltage values at both ends in a timely manner with little calculation time, and the effect of increasing the reliability can be obtained.

  Further, according to the present invention, if there is an initial abnormal value in the voltage value at both ends of the energy storage device module at the time of starting, the average value (H) of other initial normal values is set as the voltage value at both ends, and the voltage value at both ends in normal use. If there is an abnormal value, multiply the previous measured both-end voltage value of the storage element module having a normal value and the average change rate (D) of the both-end measured voltage value by the previous measured both-end voltage value of the storage element module having the abnormal value. Since the measured value is used as the both-end measured voltage value this time, the both-end voltage value of the storage element module having an abnormal value can be estimated only by simple four arithmetic operations. Accordingly, it is possible to monitor and control the voltage values at both ends in a timely manner with little calculation time, and the effect of increasing the reliability can be obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings. In the following description, a case will be described in which a power storage device made of a capacitor is used in combination with a main power source made of a secondary battery and applied to a hybrid vehicle capable of rapid acceleration.

(Embodiment 1)
FIG. 1 is a block circuit diagram when power storage elements of a power storage device according to Embodiment 1 of the present invention are connected in series. FIG. 2 is a measurement flowchart of the voltage value across the storage element of the storage device according to Embodiment 1 of the present invention. FIG. 3 is an estimation flowchart of the abnormal both-ends voltage value of the power storage device according to Embodiment 1 of the present invention. FIG. 4 is a block circuit diagram when the power storage elements of the power storage device according to Embodiment 1 of the present invention are connected in series and parallel. In FIG. 1 and FIG. 4, thick lines indicate power system wiring, and thin lines indicate signal system wiring.

  In FIG. 1, the power storage device 11 is connected between a main power supply 15 and a load 17. The main power source 15 is a secondary battery, and the load 17 is a vehicle driving motor. Accordingly, the power of the main power supply 15 is supplied to the load 17 during normal motor driving, but the power is supplied from the power storage device 11 to the load 17 when the load 17 consumes a large amount of power in a short time, such as during rapid acceleration. It becomes composition.

  The power storage device 11 has the following configuration. First, a main power supply voltage detection circuit 21 that detects the voltage Vb is connected to the output of the main power supply 15. The input side and the output side of the power system wiring (thick line) of the main power supply voltage detection circuit 21 are connected to have the same voltage.

  A changeover switch 23 is connected between the main power supply voltage detection circuit 21 and the load 17. The changeover switch 23 has two states, on and off. In the first embodiment, a diode having an anode connected to the main power supply voltage detection circuit 21 and a cathode connected to the load 17 is used.

  A charging / discharging circuit 25 is connected to a connection point between the changeover switch 23 and the load 17. A plurality of power storage element modules 29 that store electric power are connected to the charge / discharge circuit 25. Therefore, charge / discharge control of the power storage element module 29 is performed by the charge / discharge circuit 25.

  Each power storage element module 29 has a configuration in which a plurality of power storage elements 31 are connected in series. An electric double layer capacitor was used for the electricity storage element 31. A plurality of power storage element modules 29 are also connected in series. As a result, a voltage for driving the load 17 is obtained.

  A storage element voltage detection circuit 33 is connected to each end of each storage element 31 for each storage element module 29. The storage element voltage detection circuit 33 includes a multiplexer and an output voltage proportional conversion circuit (both not shown). Therefore, the storage element voltage detection circuit 33 has a function of sequentially switching and measuring the voltage at the connection point between the storage elements 31. The output voltage proportional conversion circuit has a function of proportionally converting the measured voltage into a voltage that can be read by an AD converter built in the slave control circuit 35 formed of a microcomputer.

  Accordingly, each storage element voltage detection circuit 33 is connected to the slave-side control circuit 35. Therefore, by transmitting the storage element selection signal Csel from the slave-side control circuit 35 to the storage element voltage detection circuit 33, The storage element voltage detection circuit 33 selects the storage element 31 that is the voltage measurement target, and proportionally converts the obtained voltage to the slave side control circuit 35 to store the storage element voltage signal Vi (i = 1 to n + 1, where n The voltage Vi can be obtained by transmitting (the number of power storage elements 31 incorporated in the power storage element module 29).

  Each slave side control circuit 35 is connected to a slave side transmission / reception circuit 37. The slave side transmission / reception circuit 37 has a function of performing data transmission / reception between the slave side control circuit 35 and a control unit to be described later. Data received by the slave side transmission / reception circuit 37 is controlled by the slave side as a slave side data input signal Sin. The data transmitted to the circuit 35 and transmitted by the slave side control circuit 35 is received by the slave side transmission / reception circuit 37 as the slave side data output signal Sout.

  A plurality of power storage units 39 including the power storage element module 29, the power storage element voltage detection circuit 33, the slave side control circuit 35, and the slave side transmission / reception circuit 37 described above are provided as shown in FIG. . The power storage unit 39 may be provided with a signal presence / absence detection circuit as is conventional, but is omitted in FIG.

  Each power storage unit 39 is connected so that the power storage element modules 29 are in series as described above, and the slave side transmission / reception circuits 37 are also connected to each other by signal system wiring. Further, the signal system wiring is also connected to the master side transmission / reception circuit 43 connected to the control unit 41. The control unit 41 is configured by a microcomputer in order to control the entire power storage device 11.

  For these reasons, each of the slave side transmission / reception circuits 37 and the master side transmission / reception circuit 43 are connected by the signal system wiring, whereby various slave side data signals Sdata are transmitted and received. Note that data is exchanged between the control unit 41 and the master side transmission / reception circuit 43 by the master side data input signal Min and the master side data output signal Mout. Further, the control device 45 including the control unit 41 and the master-side transmission / reception circuit 43 may be provided with an insulating circuit power supply as in the related art, but is omitted in FIG.

  From the above, the storage element voltage detection circuit 33 and the control unit 41 are connected by the signal system wiring via the slave side control circuit 35, the slave side transmission / reception circuit 37, and the master side transmission / reception circuit 43. Further, the main power supply voltage detection circuit 21 and the charge / discharge circuit 25 are connected to the control unit 41. Therefore, the control unit 41 reads the voltage signal Vb of the main power supply 15 from the main power supply voltage detection circuit 21 and transmits a control signal cont to the charge / discharge circuit 25 in order to control the charge / discharge of the storage element 31. Further, the control unit 41 has a function of communicating with each other by performing transmission / reception of a data signal Data with a vehicle control circuit (not shown).

  Next, the operation of the power storage device 11 will be described.

  First, the operation of the normal power storage device 11 will be described. When the driver turns on an ignition key (not shown), the power storage device 11 is activated. At this time, in order to fully charge each storage element module 29, the control unit 41 transmits a control signal cont so as to charge-control the charge / discharge circuit 25. Thereby, the charging / discharging circuit 25 starts a charging operation. At this time, since the input side voltage of the charging / discharging circuit 25 is lower than the voltage Vb of the main power supply 15, the changeover switch 23 is automatically turned on and power is supplied to the charging / discharging circuit 25. When charging is completed, the charging / discharging circuit 25 continues to operate so as to maintain the charging voltage of each storage element 31.

  Thereafter, it is assumed that the load 17 consumes a large current due to acceleration during use of the vehicle. In this case, such an instantaneous large current cannot be supplied only by the electric power from the main power supply 15. Therefore, when the control unit 41 detects a decrease in the voltage Vb of the main power supply 15 measured by the main power supply voltage detection circuit 21 due to large current consumption, the control unit 41 transmits a control signal cont to control the discharge of the charge / discharge circuit 25. Thereby, the charging / discharging circuit 25 starts a discharging operation. At this time, since the full charge voltage of all the storage element modules 29 is higher than the voltage Vb of the main power supply 15, the changeover switch 23 is turned off. As a result, the electric power of the storage element module 29 is effectively supplied only to the load 17 without being supplied to the main power supply 15. Thereby, since the electrical storage element 31 is excellent in rapid charge / discharge characteristics, an instantaneous large current can be supplied to the load 17.

  Thereafter, the voltages of all the power storage element modules 29 decrease with time, so that the voltage Vb of the main power supply 15 recovered while the changeover switch 23 is turned off eventually becomes higher. At that time, since the changeover switch 23 is turned on, power is supplied from the main power supply 15 to the load 17. At this time, when the main power supply voltage detection circuit 21 detects the recovery of the voltage Vb, the control unit 41 transmits a control signal cont so that the charge / discharge circuit 25 is charged again. Thereby, the charging / discharging circuit 25 starts a charging operation, and supplements the electric power discharged from all the power storage element modules 29. As a result, all the storage element modules 29 are fully charged by the power of the main power supply 15 to prepare for the next acceleration or the like.

  By repeating such an operation, the electric power of all the energy storage element modules 29 is supplied to the load 17 as an auxiliary.

  Next, the measurement operation of the voltage value across the storage element for monitoring overcharge and overdischarge of each storage element 31 in the power storage device 11 and the estimation operation of the abnormal voltage value across the storage element 31 are respectively shown in the flowcharts of FIGS. It explains using. Since the control unit 41 has a software configuration that performs the entire operation by executing various subroutines as necessary from a main routine (not shown), the flowchart shown in FIG. 2 is shown in the form of a subroutine. . FIG. 2 also shows a flowchart of the control unit 41 and a flowchart of the slave side control circuit 35 limited to a portion that operates correspondingly. Since the flowchart of FIG. 3 is a subroutine executed from the flowchart of FIG. 2, FIG. 3 is also shown in the form of a subroutine.

  First, when the vehicle is started, an initial setting is performed in the main routine of the control unit 41 to clear all of the start flag KF and the abnormality counter F (j, i) of each power storage element 31. Here, the activation flag KF is 0 immediately after the activation, and becomes 1 when the abnormal both-end voltage value estimation operation is performed even once after the activation. Thereby, it can be distinguished whether it is immediately after starting by determining the value of the starting flag KF. The abnormality counter F (j, i) indicates the number of continuous abnormalities of the power storage element 31 determined by the numbers j and i. This is because when the abnormal value of the both-end voltage value in the same power storage element 31 is continuously obtained up to a predetermined number of times (three times in the first embodiment) via the power storage element voltage detection circuit 33, Used to determine that the element 31 is abnormal. Therefore, when a normal value is obtained in the both-end voltage value, 0 is added, and when an abnormal value is obtained, an abnormal counter F (j, i) is incremented by one. The abnormality counter F (j, i) is an array, the number j is 1 to m (m is the number of power storage units 39 and 10 in the first embodiment), and the number i is 1 to n (n Is the number of power storage elements 31 in the power storage element module 29 and is 10 in the first embodiment).

  With this initial setting, the control unit 41 periodically executes the subroutine of FIG. 2 to monitor overcharge and overdischarge of each storage element 31. When the subroutine of FIG. 2 is executed, first, a measurement request for the voltage value DVi across the storage element DVi (i = 1 to n) is transmitted to each storage unit 39 (step number S13). This is transmitted as a slave-side data signal Sdata from the master-side transmission / reception circuit 43 to the slave-side transmission / reception circuit 37 of each power storage unit 39 via the signal system wiring, and further transmitted to the slave-side control circuit 35. Since the slave side data signal Sdata is transmitted almost simultaneously to each slave side transmission / reception circuit 37, the measurement of the voltage value DVi across each storage element 31 described below is performed simultaneously. Thereby, the measurement of the both-end voltage value DVi is performed in parallel for each power storage element module 29, so that high-speed measurement is possible.

  When the measurement request for the both-end voltage value DVi issued in S13 is received, an interrupt is generated in the operation of each slave-side control circuit 35, and the interrupt routine of the slave-side control circuit 35 indicated by the dotted arrow is executed from S13 in FIG. Is done. In this interrupt routine, the interrupt prohibition process immediately after execution and the interrupt permission process after completion of execution are omitted. These processes are also omitted in the interrupt routine described below.

  When the interrupt routine is executed, first, 1 is assigned to the number i (S101), then the voltage Vi of the storage element 31 is read via the storage element voltage detection circuit 33, and the memory ( (S103). Note that the voltage Vi is the voltage at V1, V2,..., Vn + 1 shown at both ends of the power storage element 31 in FIG. Next, it is determined whether or not the number i is 1 (S105). If the number i is 1 (Yes in S105), the voltage Vi for calculating the both-ends voltage value DVi of the power storage element 31 cannot be measured, and the process jumps to S111 described later. On the other hand, if the number i is not 1 (No in S105), the voltage value DVi-1 at both ends is calculated by DVi-1 = Vi-Vi-1 and stored in the memory (S107). Since the both-end voltage value DVi-1 is calculated by this equation, when i is 1 (Yes in S105), i-1 = 0 and cannot be calculated. Therefore, if i = 1, the process jumps to S111.

  Here, the process returns to S107, and if the calculation of S107 is completed, it is determined whether or not the number i is equal to n + 1 (S109). If they are equal (Yes in S109), since the voltage values DVi across both power storage elements 31 have been obtained, the interrupt routine is terminated. On the other hand, if they are not equal (No in S109), the number i is incremented by 1 to obtain the next number (S111), and the process returns to S103 to obtain the both-end voltage value DVi.

  Since this interrupt routine simply repeats the operation of reading the voltage Vi and calculating the voltage value DVi at both ends, the time required for execution is substantially constant. Moreover, since the power storage units 39 are concurrently executing in parallel, the time until the end of all the voltage values DVi (measurement end time) is known. Therefore, returning to the flowchart of the control unit 41, the control unit 41 determines whether or not the measurement end time has elapsed (S15). If it has not elapsed (No in S15), the process returns to S15 and waits until it elapses. On the other hand, if it has elapsed (Yes in S15), each power storage unit 39 has obtained the respective voltage values DVi at both ends, and therefore the operation of reading all the voltage values DVi from each power storage unit 39 as follows. Do.

  First, 1 is assigned to the number j for identifying the power storage unit 39 (S17). Next, an output request for the storage element voltage value DVi (i = 1 to n) is transmitted to the power storage unit 39 of number j (S19). As a result, an interrupt occurs in the operation of the slave-side control circuit 35 built in the power storage unit 39 of number j, and the interrupt routine of the slave-side control circuit 35 indicated by the dotted arrow from S19 in FIG. 2 is executed.

  Thereby, the slave side control circuit 35 transmits the storage element both-end voltage value DVi that has already been calculated and stored in S107 (S121). As a result, the storage element both-end voltage value DVi is received in S21 of the control unit 41 indicated by a dotted arrow from S121 of FIG. Next, it is determined whether or not reception of all the storage element voltage values of DV1 to DVn is completed (S23). If the reception has been completed (Yes in S23), the process jumps to S37 to be described later. On the other hand, if reception has not been completed (No in S23), it is determined whether or not a predetermined time has elapsed (S25). Here, since the time at which all voltage values across the storage element are received is known, the time obtained by adding a margin such as a variation error to the time is defined as the predetermined time. Therefore, if it is normally received, all the voltage values of the both ends of the storage element built in the storage unit 39 with the number j are completely received within the predetermined time. Therefore, if the predetermined time has not elapsed (No in S25), since all the voltage values across the storage elements have not been received yet, the process returns to S21 and the reception operation is continued.

  On the other hand, if the predetermined time has passed (Yes in S25), all the voltage values across the storage element could not be received. For example, the reception was temporarily interrupted due to external noise or the like, the signal system wiring was disconnected, etc. It is conceivable that reception is not possible. Therefore, in order to distinguish whether the signal could not be received temporarily or whether the signal could not be received due to a failure such as a disconnection, the control unit 41 once again sends an output request for the voltage value DVi across the storage element to the power storage unit 39 of number j. Transmit (S27). Thereby, the interrupt routine (S121) of the slave side control circuit 35 indicated by the dotted arrow from S27 is executed. As a result, the voltage value DVi across the storage element is transmitted, and the voltage value across the storage element is received in S29 of the control unit 41 indicated by the dotted arrow from S121 in FIG. Next, it is determined whether or not reception of all the storage element voltage values of DV1 to DVn has been completed (S31). If the reception is completed (Yes in S31), it is considered that the reception could not be temporarily performed in S21. Therefore, the process proceeds to S37, which will be described later, with the voltage value across the storage element received in S29 as the normal reception value. On the other hand, if the reception has not been completed (No in S31), it is determined whether or not the predetermined time has passed (S33). If the predetermined time has not passed (No in S33), the process returns to S29 to receive operation. Continue. On the other hand, if the predetermined time has elapsed (Yes in S33), all the voltage values across the storage elements could not be received again, so that disconnection of the signal system wiring, failure of the transmission / reception circuit system, and the like are assumed. Accordingly, since the power storage device 11 cannot be used any more, the control unit 41 outputs an abnormal signal as the data signal Data to the vehicle side control circuit (S35), and the flowchart of FIG. By this operation, the vehicle-side control circuit prohibits the use of the power storage device 11, warns the driver of the failure, and prompts repair. In the first embodiment, the voltage value across the storage element is received up to twice, but this may be performed more frequently. In addition, the abnormal signal may include identification information (for example, numbers j and i) of the abnormal power storage element 31. In the case where the single power storage element 31 cannot be replaced, the abnormal power storage element Identification information (for example, number j) of the module 29 may be included. In these cases, since the vehicle control circuit can know which storage element 31 or storage element module 29 is abnormal, the serviceability and reliability of repair are improved by showing this to the repairer.

  Here, returning to S23 or S31, if reception of the storage element voltage value DVi (i = 1 to n) is normally completed (Yes in S23 or S31), the received storage element voltage value DVi is set as an array variable. Are sequentially substituted into the current measured voltage values V (j, i) (S37). At this time, if the entire voltage value stored in the power storage device 11 is necessary for control, the voltage V1 in FIG. 1 may be read separately. Next, the number j and the number m of the power storage units 39 are compared (S39). If j is not equal to m, j is incremented by 1 (S41) to make number j the number of the next power storage unit 39, and the process returns to S19. The operation of receiving DVi is sequentially performed. On the other hand, if j = m (Yes in S39), next, it is checked whether or not all the storage element voltage values DVi of any one of the storage units 39 are abnormal values. Thereby, if all the storage element voltage values DVi in any storage unit 39 are abnormal values, the storage element voltage detection circuit 33, except that each storage element 31 built in the storage unit 39 is all abnormal. It is assumed that at least one of the slave side control circuit 35 and the slave side transmission / reception circuit 37 is abnormal. If such a power storage unit 39 continues to be used as it is, the reliability of the power storage device 11 may be impaired. Therefore, the abnormality of the power storage unit 39 is determined at this stage. Specifically, this operation is as follows.

  First, 1 indicating the first power storage unit 39 is assigned to the number j (S43). Next, 1 indicating the first power storage element 31 in the power storage element module 29 is substituted for the number i to clear the abnormal both-end voltage value number TF (S45). Here, the abnormal both-end voltage value number TF indicates how many power storage elements 31 are abnormal in the power storage unit 39 of number j, and if the TF is equal to the number n of power storage elements 31 in the power storage element module 29. Therefore, the power storage unit 39 has abnormal voltage values across all the power storage elements.

  Next, it is determined whether or not the current measured both-ends voltage value V (j, i) is an abnormal value (S47). Here, the abnormal value is defined as a value exceeding a voltage value range (for example, from 0 V to the upper withstand voltage value 3 V of the storage element 31) that the storage element 31 can take. If it is not an abnormal value (No in S47), the process jumps to S51 described later. On the other hand, if it is an abnormal value (Yes in S47), the abnormal both-ends voltage value number TF is incremented by 1 (S49).

  Thereafter, the number i is compared with the number n of the power storage elements 31 in the power storage element module 29 (S51). If the two are not equal (No in S51), the abnormality determination of the voltage values at both ends of each power storage element 31 has not yet been completed in the power storage unit 39 of number j, so that the number i is incremented by 1 (S53). Returning to S47, the next abnormal value determination of the voltage value across the storage element is repeated. On the other hand, if the number i is equal to the number n of power storage elements 31 in the power storage element module 29 (Yes in S51), the abnormal voltage value TF is compared with the number n of power storage elements 31 in the power storage element module 29 (S55). ). If they are equal (Yes in S55), the voltage values at both ends of all the power storage elements 31 incorporated in the power storage unit 39 of number j are abnormal, and the power storage device 11 cannot be used any more. Therefore, the process jumps to S35 described above. On the other hand, if the number TF of abnormal both-end voltage values and the number n of power storage elements 31 in the power storage element module 29 are not equal (No in S55), the voltage values across the power storage elements 31 are not all abnormal values. The number j is compared with the number m of the power storage units 39 (S57). If the two are not equal (No in S57), the number j is incremented by 1 (S59) to return to S45 to determine the next abnormality of the power storage unit 39, and the subsequent operations are repeated. On the other hand, if the number j and the number m of the power storage units 39 are equal (Yes in S57), the abnormality determination of all the power storage units 39 is completed. 2 is executed (S61). After that, the measured both-end voltage value or the estimated both-end voltage value for all the power storage elements 31 is obtained. The flowchart ends. If there is an overcharge or overdischarge of each storage element 31 due to the obtained voltage value at both ends, the control unit 41 performs an operation such as controlling the charge / discharge circuit 25 to suppress them via the main routine. High reliability is obtained by doing.

  Next, details of the abnormal both-end voltage value estimation subroutine shown in FIG. 3 will be described.

  When the subroutine shown in FIG. 3 is executed, first, 1 indicating the first power storage unit 39 is substituted for the number j, and the number k of normal power storage elements and the total value S are cleared (S201). Here, the number k of normal power storage elements is a variable for counting the number of current power storage elements 31 having normal voltage values at both ends, and the total value S is the sum of normal voltage values at both ends, This is a variable for temporarily calculating the total value of the rate of change of the voltage value at both ends (details will be described later).

  Next, it is determined whether or not the activation flag KF is 0 (S203). If KF is not 0 (No in S203), the abnormal end-to-end voltage value estimation operation has already been performed after startup, so that the average rate of change of normal end-to-end voltage values in all power storage elements 31 is obtained. Then, the process jumps to S251 to be described later.

  On the other hand, if the activation flag KF is 0 (Yes in S203), the operation of estimating the abnormal both-end voltage value is performed for the first time after the activation, so the average value of the normal voltage values across all the storage elements 31 is obtained. Note that the reason why the average value is obtained in the first estimation operation of the abnormal both-end voltage value is that the average voltage change rate cannot be calculated because there is no voltage value at both ends of each storage element 31 previously measured or estimated.

  If Yes in S203, the operation of estimating the abnormal both-end voltage value of FIG. 3 will be performed from now on, so 1 is substituted into the activation flag KF (S205). Thus, the next time the operation of FIG. 3 is performed, the result of No is obtained in S203, so that the average change rate is calculated.

  Next, 1 indicating the first power storage element 31 in the power storage element module 29 is assigned to the number i (S207). Thereafter, it is determined whether or not the current measured both-end voltage value V (j, i) of the storage element 31 indicated by the numbers j and i is an initial abnormal value (S209). The definition of the initial abnormal value is the same as the definition of the abnormal value described in S47. If it is an initial abnormal value (Yes in S209), the process jumps to S213 to be described later. On the other hand, if it is not the initial abnormal value (No in S209), in order to obtain the average value of the initial normal value, the current measured both-end voltage value V (j, i) is added to the total value S, and the normal storage element The number k is incremented by 1 (S211 above).

  Thereafter, the number i is compared with the number n of the storage elements 31 in the storage element module 29 (S213). If they are not equal (No in S213), the abnormality determination of the voltage values at both ends of each power storage element 31 has not been completed in the power storage unit 39 of number j, so that the number i is incremented by 1 (S215). Returning to S209, the initial abnormal value determination of the voltage value across the next storage element is repeated. On the other hand, if the number i is equal to the number n of the power storage elements 31 in the power storage element module 29 (Yes in S213), the number j is compared with the number m of the power storage units 39 (S217). If they are not equal (No in S217), the number j is incremented by 1 (S219) in order to determine the next abnormality in the power storage unit 39, the process returns to S207, and the subsequent operations are repeated. On the other hand, if the number j is equal to the number m of the power storage units 39 (Yes in S217), the abnormality determination of all the power storage units 39 is completed.

  Next, an average value H of the voltage values at both ends of the power storage element 31 having the initial normal value is obtained. The average value H is obtained by H = S / k. At the same time, 1 indicating the first power storage unit 39 is assigned to the number j in order to perform an estimation operation in which the voltage value across the power storage element 31 having the initial abnormal value is an average value H (S221).

  Next, 1 indicating the first storage element 31 in the storage element module 29 is assigned to the number i (S223). Thereafter, it is determined whether or not the current measured both-end voltage value V (j, i) of the storage element 31 indicated by the numbers j and i is an initial abnormal value (S225). If it is not an initial abnormal value (No in S225), the process jumps to S229 described later. On the other hand, if it is an initial abnormal value (Yes in S225), H is substituted into the current measured both-end voltage value V (j, i) in order to set the estimated value of the both-end voltage value of the storage element 31 to the average value H. . At the same time, 1 is substituted into an abnormality counter F (j, i) for counting the number of times that the both-ends voltage value of the abnormal storage element 31 is an estimated value (S227 above).

  Thereafter, in order to update the previous measurement both-ends voltage value VO (j, i), the current measurement both-ends voltage value V (j, i) is substituted into VO (j, i) (S229). Note that VO (j, i) is an array variable as well as V (j, i). Next, the number i is compared with the number n of power storage elements 31 in the power storage element module 29 (S231). If the two are not equal (No in S231), the power storage unit 39 of number j has not yet finished determining the abnormality of the voltage values at both ends of each power storage element 31, so the number i is incremented by 1 (S233). Returning to S225, the initial abnormal value determination of the voltage value across the next storage element is repeated. On the other hand, if the number i is equal to the number n of the power storage elements 31 in the power storage element module 29 (Yes in S231), the number j is compared with the number m of the power storage units 39 (S235). If they are not equal (No in S235), the number j is incremented by 1 (S237) in order to determine the next abnormality of the power storage unit 39, the process returns to S223, and the subsequent operations are repeated. On the other hand, if the number j and the number m of the power storage units 39 are equal (Yes in S235), all the initial abnormal values in the voltage values at both ends of the power storage element 31 have been replaced with the estimated values, so the flowchart of FIG. To return to the flowchart of FIG.

  Here, returning to S203, if the activation flag KF is not 0 (No in S203), an abnormal value estimation operation is performed based on the average rate of change of the normal voltage values across all the power storage elements 31. Specifically, first, 1 indicating the first power storage element 31 in the power storage element module 29 is assigned to the number i (S251). Thereafter, it is determined whether or not the current measured both-end voltage value V (j, i) of the power storage element 31 indicated by the numbers j and i is an abnormal value (S253). If it is an abnormal value (Yes in S253), the process jumps to S257 described later. On the other hand, if it is not an abnormal value (No in S253), in order to obtain the average change rate of the normal value, the change rate of the voltage value of both ends of the storage element 31 indicated by numbers j and i, that is, the current measured voltage value V ( A value obtained by dividing j, i) by the previous measured both-ends voltage value VO (j, i) is added to the total value S, and the number of normal power storage elements k is added by 1 (S255).

  Thereafter, the number i is compared with the number n of power storage elements 31 in the power storage element module 29 (S257). If the two are not equal (No in S257), the abnormality determination of the voltage values at both ends of each power storage element 31 has not yet been completed in the power storage unit 39 of number j, so that the number i is incremented by 1 (S259). Returning to S253, the next abnormal value determination of the voltage value across the storage element is repeated. On the other hand, if the number i is equal to the number n of the power storage elements 31 in the power storage element module 29 (Yes in S257), the number j is compared with the number m of the power storage units 39 (S261). If they are not equal (No in S261), the number j is incremented by 1 (S263) in order to determine the next abnormality in the power storage unit 39, the process returns to S251, and the subsequent operations are repeated. On the other hand, if the number j is equal to the number m of the power storage units 39 (Yes in S261), the abnormality determination for all the power storage units 39 is completed.

  Next, the average rate of change D of the voltage value across the storage element 31 having a normal value is obtained. The average change rate D is obtained by D = S / k. At the same time, in order to perform an operation of estimating the voltage value across the storage element 31 having an abnormal value from the average rate of change D, 1 indicating the first storage unit 39 is substituted for the number j (S265).

  Next, 1 indicating the first power storage element 31 in the power storage element module 29 is assigned to the number i (S267). Thereafter, it is determined whether or not the current measured both-end voltage value V (j, i) of the power storage element 31 indicated by the numbers j and i is an abnormal value (S269). If it is not an abnormal value (No in S269), the voltage value V (j, i) measured at this time can be normally obtained, so the abnormal counter F (j, i) is cleared to 0 (S271). Then, the process jumps to S279 described later. On the other hand, if it is an abnormal value (Yes in S269), it is determined whether or not the abnormal counter F (j, i) is 2 (S273). If the abnormal counter F (j, i) is 2 (Yes in S273), the power storage element 31 with the number j, i has had an abnormal value three times in succession. There is a high possibility that it is not an abnormal value but an abnormal value due to short-circuiting, disconnection, or deterioration of the storage element 31. If such an electricity storage element 31 is continuously used as it is, the reliability of the electricity storage device 11 as a whole decreases, so in the case of Yes in S273, an abnormal signal is output from the control unit 41 to the vehicle control circuit (S275). The flowchart of FIG. 3 ends. The abnormal signal output operation and the subsequent operation of the vehicle control circuit are the same as those described in S35.

  On the other hand, if the abnormality counter F (j, i) is not 2 (No in S273), the voltage value at both ends of the power storage element 31 indicated by the numbers j and i is an abnormal value, so that an estimated value is calculated. Specifically, the previous and current voltage values of all the power storage elements 31 having normal values obtained in S265 are added to the previous measured both-end voltage value VO (j, i) of the power storage element 31 indicated by the numbers j and i. A value obtained by multiplying the average change rate D is substituted as an estimated value into the voltage value V (j, i) measured this time. Thereby, the abnormal value is replaced with the estimated value. At the same time, since the replacement with the estimated value is made, the abnormal counter F (j, i) is incremented by 1 (S277).

  Thereafter, in order to update the previous measurement both-ends voltage value VO (j, i), the current measurement both-ends voltage value V (j, i) is substituted into VO (j, i) (S279). Next, the number i is compared with the number n of power storage elements 31 in the power storage element module 29 (S281). If they are not equal (No in S281), the abnormality determination of the voltage values at both ends of each power storage element 31 has not yet been completed in the power storage unit 39 of number j, so that the number i is incremented by 1 (S283). Returning to S269, the next abnormal value determination of the voltage value across the storage element is repeated. On the other hand, if the number i is equal to the number n of the power storage elements 31 in the power storage element module 29 (Yes in S281), the number j is compared with the number m of the power storage units 39 (S285). If they are not equal (No in S285), the number j is incremented by 1 (S287) to determine the next abnormality in the power storage unit 39, and the process returns to S267 to repeat the subsequent operations. On the other hand, if the number j and the number m of the power storage units 39 are equal (Yes in S285), all the abnormal values in the voltage values at both ends of the power storage element 31 have been replaced with the estimated values, so the flowchart of FIG. The process ends, and the process returns to the flowchart of FIG.

  The operations described in FIG. 2 and FIG. 3 simply repeat simple four arithmetic operations, so that it is not necessary to calculate a distribution with respect to both-end voltage values having a large parameter and can be executed at a very high speed. As a result, since the measurement and estimation of the voltage values at both ends of the large number of power storage elements 31 can be performed in a short cycle, it is possible to quickly control the voltage values at both ends and determine the abnormality of the power storage device 11.

  As described above, the measurement operation of the voltage value across the storage element and the estimation operation of the abnormal voltage value are performed. Among these, the characteristic estimation operation is summarized as follows.

  First, at the time of start-up, if there is an initial abnormal value in the voltage value of each storage element 31 obtained via the storage element voltage detection circuit 33 (this corresponds to the measured voltage value V (j, i) at this time). The average value H of the initial normal values of the voltage values at both ends is used as the voltage value at both ends instead of the initial abnormal value.

  Next, during normal use after start-up, there is an abnormal value in the voltage value of each storage element 31 obtained through the storage element voltage detection circuit 33 (corresponding to the current measured voltage value V (j, i)). If there is, the average change rate D of the previously measured both-end voltage value VO (j, i) and the current measured both-end voltage value V (j, i) in the storage element 31 having a normal value is obtained, and the storage element 31 having the abnormal value is obtained. A value obtained by multiplying the previous measured both-end voltage value VO (j, i) by the average change rate D is used as the both-end voltage value instead of the abnormal value.

  With the above configuration and operation, it is possible to estimate the voltage value at both ends of the storage element 31 having an abnormal value only by simple four arithmetic operations, so that monitoring and control of the voltage values at both ends can be performed in a timely manner with almost no calculation time. Therefore, a highly reliable power storage device can be realized.

  In addition, although the electric double layer capacitor was used for the electrical storage element 31 in this Embodiment 1, this may be other electrical storage elements, such as an electrochemical capacitor. Further, the power storage element module 29 has a configuration in which a plurality of power storage elements 31 are connected in series. However, the storage element module 29 is not limited to this, and is connected in series-parallel as shown in FIG. 4 according to the power specifications required by the load 17. It is good. Although FIG. 4 shows the case where the number of parallel connections is 2, that is, the case where two power storage elements 31 are connected in parallel, this may be two or more. In this case, since the storage element group 47 in which the storage elements 31 connected in parallel are grouped together can be regarded as one storage element, by replacing the storage element 31 in FIG. The configuration described with reference to FIG. 1 and the operation described with reference to FIGS. Therefore, description of the details of FIG. 4 is omitted. However, in the configuration of FIG. 4, the voltage values at both ends are measured and estimated for each power storage element group 47.

  In the first embodiment, a configuration in which a plurality of (m) power storage element modules 29 are provided has been described.

(Embodiment 2)
FIG. 5 is a block circuit diagram of the power storage device according to Embodiment 2 of the present invention. FIG. 6 is a measurement and estimation flowchart of the voltage value across the storage element module of the storage device according to Embodiment 2 of the present invention. In FIG. 5, thick lines indicate power system wiring, and thin lines indicate signal system wiring.

  In the configuration of the second embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and different components will be mainly described. That is, the configuration characteristic in FIG. 5 is as follows.

  1) A configuration in which a plurality of power storage element modules 29 are always provided, and a voltage value between both ends of each power storage element module 29 is obtained.

  2) With the above configuration, the storage element voltage detection circuit 33 is connected to measure a voltage corresponding to both ends of the storage element module 29.

  3) Along with this, the voltage to be measured is reduced, so that one storage element voltage detection circuit 33 is provided and directly connected to the control unit 41.

  4) Therefore, the slave side control circuit 35, the slave side transmission / reception circuit 37, and the master side transmission / reception circuit 43 are eliminated, and the power storage unit 39 and the control device 45 are not distinguished.

  The configuration other than the above is the same as that of the first embodiment. Each power storage element module 29 is configured by connecting ten power storage elements 31 in series. In addition, since the voltage value at both ends is obtained only for each power storage element module 29 in the second embodiment, the voltage values at both ends for each power storage element 31 or each power storage element group 47 can be monitored as in the first embodiment. However, if it is possible to replace only for each storage element module 29 having an abnormality due to the structure of the storage device 11, for example, it is less necessary to obtain the voltage values at both ends of each storage element 31 or storage element group 47. . In such a case, it is only necessary to obtain the voltage values at both ends for each power storage element module 29 as in the second embodiment. Furthermore, according to this configuration, an effect that the configuration can be made extremely simple from the comparison between FIG. 1 and FIG. 5 is also obtained.

  Next, the operation of power storage device 11 in the second embodiment will be described. First, since the operation of the normal power storage device 11 is exactly the same as that of the first embodiment, the description thereof is omitted.

  Next, with reference to the flowchart of FIG. 6, the operation of measuring the voltage value at both ends of the storage element module and the operation of estimating the abnormal voltage value at both ends for monitoring overcharge and overdischarge of each storage element module 29 in the storage device 11 will be described. explain. As in the first embodiment, the control unit 41 has a software configuration that performs the entire operation by executing various subroutines as necessary from a main routine (not shown). The flowchart is shown in the form of a subroutine.

  First, when the vehicle is started, an initial setting is performed in the main routine of the control unit 41 to clear all of the start flag KF and the abnormality counter F (j) of each storage element module 29. Here, the activation flag KF is the same as that in the first embodiment. The abnormality counter F (j) indicates the number of continuous abnormalities of the power storage element module 29 determined by the number j. This is because when the abnormal value of the both-ends voltage value in the same storage element module 29 is continuously obtained up to a predetermined number of times (three times in the second embodiment) via the storage element voltage detection circuit 33, Used to determine that the storage element module 29 is abnormal. Therefore, when a normal value is obtained in the voltage values at both ends, an abnormal counter F (j) is incremented by 1 when an abnormal value is obtained. The abnormality counter F (j) is a one-dimensional array with respect to the two-dimensional array represented by F (j, i) in the first embodiment, and the number j is 1 to m (m is a storage element. The range of the number of modules 29 is 10 in the second embodiment.

  With this initial setting, the control unit 41 periodically executes the subroutine of FIG. 6 to monitor overcharge and overdischarge of each storage element 31. When the subroutine of FIG. 6 is executed, first, the abnormal both-end voltage value number TF is cleared (S501). Here, the number TF of abnormal both-end voltage values indicates how many storage element modules 29 are abnormal, and if the TF is equal to the number m of storage element modules 29, the storage device 11 has the voltage across all storage element modules 29. It means that the value is abnormal.

  Next, after substituting 1 for the number j (S503), the voltage Vj of the storage element module 29 is read through the storage element voltage detection circuit 33 and stored in a memory (not shown) built in the control unit 41. (S505). The voltage Vj is a voltage at V1, V2,..., Vn + 1 shown at both ends of the power storage element module 29 in FIG. Here, if the entire voltage value stored in the power storage device 11 is necessary for control, the voltage V1 may be referred to. Next, it is determined whether or not the number j is 1 (S507). If the number j is 1 (Yes in S507), the voltage Vj sufficient to calculate the current measured both-end voltage value V (j) of the storage element module 29 cannot be measured. In order to obtain the value, the number j is incremented by 1 to obtain the next number (S509), and the process returns to S505 to repeat the operation of measuring the voltage Vj. On the other hand, if the number j is not 1 (No in S507), the voltage value V (j-1) measured at this time is calculated by V (j-1) = Vj-Vj-1 and stored in the memory (S511). . Since the voltage value V (j−1) measured at this time is calculated by this formula, when j is 1 (Yes in S507), j−1 = 0 and cannot be calculated. Therefore, if j = 1, the process jumps to S509.

  Here, returning to S511, if the calculation of S511 is completed, it is determined whether or not the current measured both-ends voltage value V (j-1) is an abnormal value (S512). Here, the abnormal value is a voltage value range that can be taken by the storage element module 29 (for example, the lower limit is 0 V, and the upper limit withstand voltage value 3 V of the storage element 31 is multiplied by the number 10 of the storage elements 31 of each storage element module 29 as the upper limit. It is defined as a value exceeding 30V). If it is not an abnormal value (No in S512), the process jumps to S514 described later. On the other hand, if it is an abnormal value (Yes in S512), the abnormal voltage value TF is added by 1 (S513).

  Thereafter, it is determined whether or not the number j is equal to m + 1 (S514). If they are not equal (No in S514), the process jumps to S509 to obtain the voltage Vj + 1 of the next storage element module 29. On the other hand, if the numbers j and m + 1 are equal (Yes in S514), the current measured both-end voltage values V1 to Vm of all the storage element modules 29 have been obtained. The number m is compared (S515). If the two are equal (Yes in S515), the voltage values at both ends of all the power storage element modules 29 are abnormal, and the power storage device 11 cannot be used any more. Therefore, the process jumps to S567 described later. On the other hand, if the number TF of abnormal both-ends voltage value is not equal to the number m of the storage element modules 29 (No in S515), the end-to-end voltage values of the storage element module 29 are not all abnormal values. In this case, if there is an abnormal value in the voltage value across the storage element module 29, the operation for calculating the estimated value is performed as follows.

  First, 1 indicating the first power storage element module 29 is assigned to the number j, and the number k of normal power storage elements and the total value S are cleared (S516). Here, the number k of normal power storage elements and the total value S are the same variables as in the first embodiment.

  Next, it is determined whether or not the activation flag KF is 0 (S517). If KF is not 0 (No in S517), the abnormal end-to-end voltage value estimation operation has already been performed after startup, and thus the average rate of change of normal end-to-end voltage values in all power storage element modules 29 is obtained. Therefore, the process jumps to S551 described later.

  On the other hand, if the activation flag KF is 0 (Yes in S517), the operation of estimating the abnormal both-end voltage value is performed for the first time after the activation, so the average value of the normal both-end voltage values in all the storage element modules 29 is obtained. Note that the reason why the average value is obtained in the first estimation operation of the abnormal both-end voltage value is that the average rate of change cannot be calculated as in the first embodiment.

  If Yes in S517, the operation of estimating the abnormal both-end voltage value in FIG. 6 will be performed from now on, so 1 is substituted into the activation flag KF (S519). As a result, the next time the operation of FIG. 6 is performed, the result is No in S517, so that the average change rate is calculated.

  Next, it is determined whether or not the current measured both-end voltage value V (j) of the power storage element module 29 of number j is an initial abnormal value (S521). Note that the definition of the initial abnormal value is the same as the definition of the abnormal value described in S512. If it is an initial abnormal value (Yes in S521), the process jumps to S525 described later. On the other hand, if it is not the initial abnormal value (No in S521), in order to obtain the average value of the initial normal values, the current measured both-ends voltage value V (j) is added to the total value S, and the number of normal storage elements k Is incremented by 1 (S523).

  Thereafter, the number j and the number m of the storage element modules 29 are compared (S525). If the two are not equal (No in S525), the number j is incremented by 1 (S527) to determine whether the next storage element module 29 is abnormal, the process returns to S521, and the subsequent operations are repeated. On the other hand, if the number j is equal to the number m of the power storage element modules 29 (Yes in S525), the abnormality determination of all the power storage element modules 29 is completed.

  Next, an average value H of the voltage values at both ends of the power storage element module 29 having the initial normal value is obtained. The average value H is obtained by H = S / k. At the same time, in order to perform an estimation operation in which the voltage value across the storage element module 29 having the initial abnormal value is an average value H, 1 indicating the first storage element module 29 is substituted for the number j (S529 above).

  Next, it is determined whether or not the current measured both-end voltage value V (j) of the power storage element module 29 indicated by the number j is an initial abnormal value (S531). If it is not an initial abnormal value (No in S531), the process jumps to S535 described later. On the other hand, if it is an initial abnormal value (Yes in S531), H is substituted for the current measured both-end voltage value V (j) in order to set the estimated value of the both-end voltage value of the storage element module 29 to the average value H. At the same time, 1 is substituted into the abnormality counter F (j) for counting the number of times that the both-ends voltage value of the abnormal storage element module 29 is an estimated value (S533).

  Thereafter, in order to update the previous measurement both-ends voltage value VO (j), the current measurement both-ends voltage value V (j) is substituted into VO (j) (S535). Note that VO (j) is also a one-dimensional array variable like V (j). Next, the number j is compared with the number m of power storage element modules 29 (S537). If they are not equal (No in S537), the determination of the abnormality of the voltage value at both ends in all the power storage element modules 29 has not been completed, so the number j is incremented by 1 (S539) and the process returns to S531, and the next power storage The initial abnormal value determination of the voltage value across the element module is repeated. On the other hand, if the number j is equal to the number m of the storage element modules 29 (Yes in S537), all the initial abnormal values in the voltage values at both ends of the storage element module 29 have been replaced with the estimated values. This flowchart is finished.

  Here, the process returns to S517, and if the activation flag KF is not 0 (No in S517), an abnormal value estimation operation is performed based on the average rate of change of the normal voltage values in both power storage element modules 29. Specifically, first, it is determined whether or not the current measured both-end voltage value V (j) of the power storage element module 29 indicated by the number j is an abnormal value (S551). If it is an abnormal value (Yes in S551), the process jumps to S555 described later. On the other hand, if it is not an abnormal value (No in S551), in order to obtain the average change rate of the normal value, the change rate of the voltage value of both ends of the storage element module 29 indicated by the number j, that is, the current measured voltage value V (j ) Divided by the previous measured both-ends voltage value VO (j) is added to the total value S, and the number of normal power storage elements k is added by 1 (S553).

  Thereafter, the number j is compared with the number m of the storage element modules 29 (S555). If they are not equal (No in S555), the number j is incremented by 1 (S557) to determine whether the next storage element module 29 is abnormal, the process returns to S551, and the subsequent operations are repeated. On the other hand, if the number j is equal to the number m of the power storage element modules 29 (Yes in S555), the abnormality determination of all the power storage element modules 29 is completed.

  Next, the average rate of change D of the voltage value across the storage element module 29 having a normal value is obtained. The average change rate D is obtained by D = S / k. At the same time, in order to perform an operation of estimating the voltage value across the storage element module 29 having an abnormal value from the average rate of change D, 1 indicating the first storage element module 29 is substituted for the number j (S559).

  Next, it is determined whether or not the current measured both-end voltage value V (j) of the power storage element module 29 indicated by the number j is an abnormal value (S561). If it is not an abnormal value (No in S561), the voltage value V (j) measured at this time can be normally obtained, so the abnormal counter F (j) is cleared to 0 (S563), and S571 described later. Jump to. On the other hand, if it is an abnormal value (Yes in S561), it is determined whether or not the abnormal counter F (j) is 2 (S565). If the abnormal counter F (j) is 2 (Yes in S565), the power storage element module 29 with the number j has an abnormal value three times in succession. There is a high possibility that the storage element module 29 has an abnormal value due to short circuit, disconnection, deterioration, or the like. If such a power storage element module 29 is used as it is, the reliability of the power storage device 11 as a whole is lowered. Therefore, in the case of Yes in S565, an abnormal signal is output from the control unit 41 to the vehicle control circuit (S567). Then, the flowchart of FIG. The abnormal signal output operation and the subsequent operation of the vehicle control circuit are the same as those described in S35 of FIG. In addition, you may include the identification information (for example, number j) of the electrical storage element module 29 which was abnormal at this time in an abnormal signal.

  On the other hand, if the abnormality counter F (j) is not 2 (No in S565), since the voltage value at both ends of the power storage element module 29 indicated by the number j is an abnormal value, an estimated value is calculated. Specifically, as in the first embodiment, the both-ends voltage of all the storage element modules 29 having the normal value obtained in S559 as the previous measured both-end voltage value VO (j) of the storage element module 29 indicated by the number j. A value obtained by multiplying the previous average value change rate D and the current average change rate D is substituted into the current measured both-end voltage value V (j) as an estimated value. Thereby, the abnormal value is replaced with the estimated value. At the same time, since the replacement with the estimated value has been made, the abnormality counter F (j) is incremented by 1 (S569).

  Thereafter, in order to update the previous measurement both-ends voltage value VO (j), the current measurement both-ends voltage value V (j) is substituted into VO (j) (S571). Next, the number j is compared with the number m of the storage element modules 29 (S573). If the two are not equal (No in S573), the determination of the abnormality of the voltage value at both ends of each power storage element module 29 has not been completed yet, so the number j is incremented by 1 (S575) and the process returns to S561. Repeat the determination of the abnormal value of the voltage across the element. On the other hand, if the number j is equal to the number m of the storage element modules 29 (Yes in S573), all the abnormal values in the voltage values at both ends of the storage element module 29 have been replaced with the estimated values. The flowchart ends.

  As described above, since the operation described in FIG. 6 is merely a simple four arithmetic operation as in the first embodiment, it is not necessary to calculate the distribution for the voltage values at both ends having a large parameter, and the operation is performed at a very high speed. be able to. Further, since the measurement and estimation of the both-end voltage value is performed only for each power storage element module 29, the control of the both-end voltage value and the abnormality determination of the power storage device 11 can be performed more quickly than in the first embodiment.

  As described above, the measurement operation of the both-end voltage value of the storage element module and the estimation operation of the abnormal both-end voltage value are performed. Among these, the characteristic estimation operation is summarized as follows.

  First, at the time of start-up, if there is an initial abnormal value in the both-end voltage value of each storage element module 29 obtained via the storage element voltage detection circuit 33 (this corresponds to the measured both-end voltage value V (j)), An average value H of initial normal values of the voltage values at both ends is used as the voltage value at both ends instead of the initial abnormal value.

  Next, during normal use after start-up, there is an abnormal value in the voltage value of each storage element module 29 obtained through the storage element voltage detection circuit 33 (corresponding to the current measured voltage value V (j)). For example, the average change rate D between the previous measured both-ends voltage value VO (j) and the current measured both-ends voltage value V (j) in the storage element module 29 having a normal value is obtained, and the previous measurement of the storage element module 29 having the abnormal value is performed. A value obtained by multiplying the voltage value VO (j) at both ends by the average change rate D is used as the voltage value at both ends instead of the abnormal value.

  With the above configuration and operation, it is possible to estimate the voltage value at both ends of the storage element module 29 having an abnormal value only by simple four arithmetic operations. Therefore, monitoring and control of the voltage values at both ends in a timely manner with almost no calculation time. And a highly reliable power storage device can be realized.

  In the second embodiment, the configuration in which the storage element modules 29 are connected in series is shown. However, the storage element modules 29 may be connected in series and parallel.

  In the first and second embodiments, the case where the power storage device 11 is applied to a hybrid vehicle has been described. However, the present invention is not limited to this and can be applied to an auxiliary power source of an electric vehicle or a fuel cell vehicle.

  The power storage device according to the present invention can estimate the voltage value between both ends of a power storage element having an abnormal value at high speed and can obtain high reliability. Useful.

The block circuit diagram at the time of connecting the electrical storage element of the electrical storage apparatus in Embodiment 1 of this invention in series Flowchart of measurement of voltage value across power storage element of power storage device in Embodiment 1 of the present invention Flowchart for estimating abnormal both-ends voltage value of power storage device in Embodiment 1 of the present invention The block circuit diagram at the time of connecting the electrical storage element of the electrical storage apparatus in Embodiment 1 of this invention in series-parallel Block circuit diagram of a power storage device in Embodiment 2 of the present invention Flowchart measurement and estimation flowchart of power storage element module both-end voltage value of power storage device in Embodiment 2 of the present invention Block diagram of a conventional power storage device

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Power storage device 15 Main power supply 17 Load 21 Main power supply voltage detection circuit 23 Changeover switch 25 Charging / discharging circuit 29 Storage element module 31 Storage element 33 Storage element voltage detection circuit 41 Control part 47 Storage element group

Claims (7)

A storage element module having a series or series-parallel connection configuration of a plurality of storage elements;
A storage element voltage detection circuit connected to both ends of each storage element or both ends of each storage element group in which the storage elements connected in parallel are combined,
A controller to which the storage element voltage detection circuit is connected;
When determining the voltage values at both ends of the power storage element or the power storage element group, the control unit,
At the time of start-up, if there is an initial abnormal value in each of the both-end voltage values obtained through the storage element voltage detection circuit, the initial normal value average value (H) of each of the both-end voltage values is calculated as the initial abnormal value. Instead of the voltage value at both ends,
In normal use, if there is an abnormal value in each of the both-end voltage values obtained through the storage element voltage detection circuit, the storage element having a normal value or the previously measured both-end voltage value in the storage element group and this time The average change rate (D) of the measured both-end voltage value is obtained, and the value obtained by multiplying the previous measured both-end voltage value of the storage element or the storage element group having the abnormal value by the average change rate (D) A power storage device in which the voltage value at both ends is used instead of the value. When the control unit obtains the abnormal value of the both-end voltage value in the same storage element or the same storage element group continuously through the storage element voltage detection circuit up to a predetermined number of times, The power storage device according to claim 1, wherein an element or the power storage element group is determined to be abnormal. A plurality of the storage element modules;
2. The power storage device according to claim 1, wherein the control unit simultaneously measures the both-end voltage value for each of the storage element modules when obtaining the both-end voltage value of the storage element or the storage element group. . A plurality of storage element modules having a series or series-parallel connection configuration of a plurality of storage elements;
A storage element voltage detection circuit connected to both ends of the storage element module;
A controller to which the storage element voltage detection circuit is connected;
When determining the voltage values at both ends of the storage element module, the control unit,
At the time of start-up, if there is an initial abnormal value in each of the both-end voltage values obtained through the storage element voltage detection circuit, the initial normal value average value (H) of each of the both-end voltage values is calculated as the initial abnormal value. Instead of the voltage value at both ends,
In normal use, if there is an abnormal value in each of the both-end voltage values obtained through the storage element voltage detection circuit, the previous measurement both-end voltage value and the current measurement both-end voltage value in the storage element module having a normal value are obtained. An average rate of change (D) is obtained, and a value obtained by multiplying the previous measured both-ends voltage value of the power storage element module having the abnormal value by the average rate of change (D) is used as the both-ends voltage value instead of the abnormal value. A power storage device. The control unit determines that the storage element module is abnormal when the abnormal value of the both-end voltage value in the same storage element module is continuously obtained up to a predetermined number of times via the storage element voltage detection circuit. The power storage device according to claim 4, wherein the power storage device is determined. The power storage device according to claim 2, wherein the control unit outputs an abnormality signal when an abnormality is determined. The power storage device according to claim 6, wherein the abnormality signal includes identification information of the storage element having abnormality, the storage element group, or the storage element module.

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