JP2015068784A - Battery-pack-state diagnostic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately diagnose a state of each of a plurality of secondary batteries constituting a group of secondary batteries connected in series and ensure detecting the state even under the influence of noise.SOLUTION: A battery-pack-state diagnostic device includes: a battery pack 14 configured in which a plurality of secondary batteries is connected in series; measuring means (sensor units 15-1 to 15-n) each provided for one or each of the plurality of secondary batteries included in the battery pack 14 and each measuring a terminal voltage of the one or each of the plurality of secondary batteries; measurement timing transmitting means (arithmetic unit 13) transmitting measurement timing to the measuring means; determining means (arithmetic unit 13) determining a state of the one or each of the plurality of secondary batteries on the basis of information on the measured terminal voltage. The measurement timing transmitting means notifies the measuring means of measuring start timing so that all the measuring means executing measurement can measure the terminal voltage at the same timing, and determines the state of the one or each of the plurality of secondary batteries on the basis of the obtained information on the terminal voltage.

Description

  The present invention relates to an assembled battery state diagnosis apparatus.

  Patent Document 1 discloses a technology relating to a power storage device that converts grid power to DC power to charge a lead storage battery, converts the power stored in the lead storage battery to AC power, and supplies the load to a load.

JP 2007-215262 A

  By the way, in the technique disclosed by patent document 1, although the detail of a structure of a lead storage battery is not disclosed, as a lead storage battery used for such a purpose, a some lead storage battery is connected in series. There are many things to be constructed. When using lead storage batteries connected in series in this way, not all lead storage batteries deteriorate or break down at the same time, and there may be variations in the progress of deterioration or breakdown. More specifically, when ten lead storage batteries 14-1 to 14-10 are connected in series as shown on the left side of FIG. 22, only the lead storage battery 14-3 is shown as shown in the center of FIG. May break down. Alternatively, as shown on the right side of FIG. 22, the lead storage battery 14-7 may deteriorate most quickly, and the lead storage battery 14-4 may deteriorate next. However, the technique disclosed in Patent Document 1 cannot monitor the state of each lead-acid battery. In general, in the case of a power storage device, since a large current flows through a lead storage battery, an AC / DC inverter, etc., when monitoring a lead storage battery, the influence of noise generated by such current or external noise There is a problem that it is easy to receive.

  The present invention has been made in view of the above points, and accurately diagnoses the state of individual secondary batteries constituting a plurality of secondary batteries connected in series, and reliably under the influence of noise. It is an object of the present invention to provide an assembled battery state diagnosis device that can be detected.

In order to solve the above-mentioned problem, the present invention is provided with one assembled battery configured by connecting a plurality of secondary batteries in series and one or a plurality of secondary batteries included in the assembled battery, Based on information on the terminal voltage of each of the one or more secondary batteries, measurement timing transmission means for transmitting measurement timing to the measurement means, and information on the terminal voltage measured by the measurement means, Determination means for determining the state of each of the one or more secondary batteries, and the measurement timing transmission means is a measurement means so that all measurement means that perform measurement perform measurement at the same timing. Is notified of the timing of the start of measurement, and the state of each of the one or more secondary batteries based on the information on the terminal voltage obtained by each measuring means And judging a.
According to such a configuration, it is possible to accurately diagnose the state of individual secondary batteries constituting a plurality of secondary batteries connected in series, and to reliably detect even the influence of noise.

In addition, the present invention is characterized in that the determination means determines the state of the one or more secondary batteries based on a change with time in the terminal voltage measured by the measurement means after charging.
According to such a configuration, it is possible to accurately determine the state of the secondary battery by executing charging before measurement and reducing the influence on the measurement due to the previous discharge.

In the present invention, the determination means determines the state of the one or more secondary batteries based on a change with time of the terminal voltage after charging the assembled battery by 85% or more of the chargeable capacity. It is characterized by.
According to such a configuration, according to such a configuration, the state of the secondary battery can be accurately determined by more reliably reducing the influence on the measurement due to the immediately preceding discharge. Moreover, in the case of a lead-acid battery with high resistance to overcharge, the SOC is exceeded and the battery is continuously charged to correct the SOC imbalance between the secondary batteries. In addition, it is possible to reduce lead sulfate on the electrode plate of the lead storage battery, reduce the deterioration factor of the current battery, and more accurately estimate the unrecoverable deterioration state of the battery.

Further, according to the present invention, the determination means refers to the charge / discharge history of the assembled battery, and when the charge amount in a certain period immediately before the start of measurement exceeds the discharge amount by a predetermined amount, based on the change with time of the terminal voltage. The state of each of the one or more secondary batteries is determined.
According to such a configuration, it is possible to accurately determine the state of the secondary battery by further reducing the influence on the measurement by the immediately preceding discharge by selecting the timing for performing the measurement.

Moreover, the present invention is characterized in that the measurement timing transmission means notifies the measurement start timing by wireless transmission.
According to such a configuration, it is possible to increase resistance to noise as compared with a case where transmission timing is transmitted by wire.

Further, the present invention provides power conversion means for converting the AC power of the grid power to DC power to charge the assembled battery, and converting the DC power of the assembled battery to AC power and discharging it to the grid power. It is used for the electric power storage apparatus which has.
According to such a configuration, deterioration of the secondary battery can be reliably detected by accurately diagnosing the state of the secondary battery included in the power storage device that is frequently charged and discharged.

Further, the present invention includes an intermittent means that is arranged between the power conversion means and the assembled battery, and interrupts the exchange of electric power between them. Alternatively, when measuring a plurality of secondary batteries, the power transmission / reception between the power conversion means and the assembled battery is stopped by interrupting the intermittent means.
According to such a configuration, the timing of stopping charging can be accurately controlled, so that the state of the secondary battery can be accurately determined.

  According to the present invention, the state of an assembled battery that can accurately diagnose the state of individual secondary batteries constituting a plurality of secondary batteries connected in series and can be reliably detected even under the influence of noise. A diagnostic device can be provided.

It is a figure which shows the structural example of the electric power storage apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the structural example of the control part shown in FIG. It is a figure which shows the structural example of the calculating part shown in FIG. It is a figure which shows the structural example of the sensor part shown in FIG. It is a figure which shows the structural example of the main | base station shown in FIG. It is a figure for demonstrating the difference of operation | movement of UPS and this embodiment. It is a figure for demonstrating the difference of operation | movement of UPS and this embodiment. It is a figure for demonstrating the change of OCV. It is a figure for demonstrating the change of OCV. It is a figure for demonstrating the relationship between a charging / discharging log | history and the change of OCV. It is a figure for demonstrating the relationship between the change of charge and OCV, and the relationship between the change of discharge and OCV. It is a figure for demonstrating the change of OCV when charge and discharge are made immediately before. It is a figure for demonstrating the change of OCV of a some secondary battery. It is a figure which shows the relationship between SOC and battery voltage by the kind of secondary battery. It is a figure for demonstrating operation | movement of 1st Embodiment. It is a flowchart for demonstrating operation | movement of the control part of 1st Embodiment. It is a flowchart for demonstrating operation | movement of the calculating part of 1st Embodiment. It is a flowchart for demonstrating operation | movement of the sensor part of 1st Embodiment. It is a figure which shows the structural example of the electric power storage apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the other example of the flowchart shown in FIG. It is a figure which shows the other example of the flowchart shown in FIG. It is a figure which shows the progress of deterioration when a some secondary battery is connected in series.

  Next, an embodiment of the present invention will be described.

(A) Description of Configuration of First Embodiment of the Present Invention FIG. 1 is a diagram illustrating a configuration example of an assembled battery state diagnosis device according to a first embodiment of the present invention. As shown in this figure, the power storage device 10 includes a power conversion unit 11, a control unit 12, a calculation unit 13, a secondary battery group 14, and a parent device 16, and is connected to a system power 30 and a load 50. The In FIG. 1, a thick line indicates a power line. The power storage device 10 converts the AC power supplied from the grid power 30 into DC power, charges the secondary battery group 14, and converts the DC power stored in the secondary battery group 14 into AC power as necessary. Converted and supplied to the load 50. Thereby, for example, the secondary battery group 14 is charged at night when the power consumption of the load 50 is low and the power rate is low, and the secondary battery group 14 is high during the day when the power consumption is high and the power rate is high. By converting the electric power stored in the AC into AC power and supplying it to the load 50, the power consumption can be leveled and the electric power charge can be suppressed. Further, by suppressing the peak of power consumption, the power consumption can be suppressed within the contract power.

  Here, the power conversion unit 11 is configured by a bidirectional inverter, for example, and converts the AC power supplied from the system power 30 into DC power according to the control of the control unit 12 to charge the secondary battery group 14. At the same time, the DC power stored in the secondary battery group 14 is converted to AC power having the same voltage, frequency, and phase as the grid power 30 and supplied to the load 50.

  As shown in FIG. 2, the control unit 12 includes a CPU (Central Processing Unit) 121, a ROM (Read Only Memory) 122, a RAM (Random Access Memory) 123, a timekeeping unit 124, a communication unit 125, a presentation unit 126, The bus 127 is a main component, and each unit of the apparatus is controlled based on a program stored in the ROM 122. Here, the CPU 121 controls each unit of the apparatus by executing a program stored in the ROM 122. The ROM 122 stores programs executed by the CPU 121 and data. The RAM 123 temporarily stores programs and data executed by the CPU 121. The timekeeping unit 124 generates and outputs information such as month, date, day of the week, and time. The communication unit 125 exchanges information between the power conversion unit 11 and the calculation unit 13. The presenting unit 126 is configured by, for example, a liquid crystal display or the like, converts various information into visible information, and presents it to a user (or an administrator or an operator (hereinafter simply referred to as “user”)). To do. The bus 127 connects the CPU 121, the ROM 122, the RAM 123, the timing unit 124, the communication unit 125, and the presentation unit 126 to each other, and enables data exchange between them.

  The calculation unit 13 communicates with the sensor units 15-1 to 15-n provided in the secondary battery group 14 via the master unit 16, and when the start of measurement is instructed from the control unit 12, The measurement start signal is transmitted to the sensor units 15-1 to 15-n via the machine 16, and the data measured by the measurement start signal is received via the parent machine 16, and the secondary battery group 14 is The states of the secondary batteries 14-1 to 14-n to be configured are obtained by arithmetic processing and notified to the control unit 12. FIG. 3 shows a configuration example of the calculation unit 13. As shown in FIG. 3, the calculation unit 13 includes a CPU 131, a ROM 132, a RAM 133, a time measuring unit 134, an I / F unit 135, and a bus 136. The CPU 131, the ROM 132, and the RAM 133 have the same functions as the CPU 121, the ROM 122, and the RAM 123 described above. The timer 134 generates and outputs time information. The I / F unit 135 is connected to the control unit 12 and the parent device 16 and exchanges information with them.

  The secondary battery group 14 is configured by connecting a plurality of secondary batteries 14-1 to 14-n in series. In addition, the secondary batteries 14-1 to 14-n are configured by, for example, a lead storage battery, a lithium ion battery, a nickel cadmium battery, a nickel metal hydride battery, or a NAS (sodium / sulfur) battery. Each of the secondary batteries 14-1 to 14-n may be configured by a single secondary battery or may be configured by connecting a plurality of secondary batteries in parallel. These secondary batteries 14-1 to 14-n are accommodated in, for example, a rack of racks and connected to the base unit 16 by radio, but the sizes of the secondary batteries 14-1 to 14-n are also different. Since it is large and has a large number of racks, the shelf-like rack is very large. Furthermore, when charging / discharging these batteries, a large current flows and a large noise is generated in the power conversion unit 11 due to switching of a semiconductor element or the like. Since the rack cannot be shielded, noise from the outside also enters the rack.

  The sensor units 15-1 to 15-n are provided adjacent to the secondary batteries 14-1 to 14-n, and the secondary battery 14 according to an instruction received from the calculation unit 13 via the parent device 16. Voltages and temperatures of −1 to 14-n are measured, and information obtained by the measurement is supplied to the arithmetic unit 13 via the parent device 16. FIG. 4 shows a detailed configuration example of the sensor units 15-1 to 15-n. Since the sensor units 15-1 to 15-n have the same configuration, these will be described as the sensor unit 15. As shown in FIG. 4, the sensor unit 15 includes a CPU 151, a ROM 152, a RAM 153, a timing unit 154, a wireless communication unit 155, an A / D (Analog to Digital) conversion unit 156, a bus 157, a voltage sensor 158, and a temperature sensor. 159. Here, the CPU 151, ROM 152, and RAM 153 have the same functions as the CPU 121, ROM 122, and RAM 123 described above. The timer 154 generates and outputs time information. The wireless communication unit 155 performs wireless communication with the base unit 16 via the antenna 155a. The A / D conversion unit 156 A / D converts the analog signals output from the voltage sensor 158 and the temperature sensor 159 into digital signals based on the control of the CPU 151 and outputs the digital signals. The voltage sensor 158 detects and outputs terminal voltages of the secondary batteries 14-1 to 14-n. The temperature sensor 159 detects and outputs the temperature of the secondary batteries 14-1 to 14-n itself, for example, the temperature of the positive electrode of the secondary battery or its surrounding temperature.

  FIG. 5 is a diagram illustrating a configuration example of the base unit 16. As shown in FIG. 5, the parent device 16 includes a CPU 161, a ROM 162, a RAM 163, an I / F unit 164, a wireless communication unit 165, and a bus 166. Here, the CPU 161, the ROM 162, and the RAM 163 have the same functions as the CPU 121, the ROM 122, and the RAM 123 described above. The I / F unit 164 is connected to the calculation unit 13 and exchanges information with the calculation unit 13. The wireless communication unit 165 includes an antenna 165a and performs wireless communication with the sensor units 15-1 to 15-n.

(B) Description of Operation of First Embodiment of the Invention Next, operation of the first embodiment will be described. In the following, the operation of the first embodiment of the present invention will be described after comparing the operation with UPS (Uninterruptible Power Supply) and explaining the problems when a plurality of secondary batteries are connected in series.

  FIG. 6 is a diagram for comparing the operation of the UPS and the first embodiment. The left side of FIG. 6 shows the operation status of the secondary battery in the UPS, and the right side shows the operation status of the secondary battery group 14 in the first embodiment. In the UPS, the secondary battery is maintained in a state where the SOC (State of Charge) is close to 100%, and when a power failure occurs, the secondary battery is operated in the “area used only during the UPS operation”. On the other hand, in the first embodiment, a range of 0% to 20% of the SOC is set as a discharge margin, a range of 90% to 100% is set as a charge margin, and a range of 20% to 90% is set. Set as a use area. That is, in the UPS, since the secondary battery is not discharged except when a power failure occurs, the SOC is maintained close to 100%. However, in the first embodiment, the SOC is 20% because charging and discharging are repeated. Used in the range of ~ 90%.

  FIG. 7 is a diagram showing temporal changes in the voltage, current, SOC, and ΔSOC of the secondary battery of the UPS. As shown on the left side of FIG. 7, in the UPS, the voltage, current, and SOC hardly change with time. For this reason, ΔSOC indicating the temporal change of the SOC hardly changes with time. On the other hand, in the first embodiment, since charging / discharging is repeated, as shown in the second from the top of the figure, a charging / discharging current flows through the secondary battery group 14, and accordingly the first from the top of the figure. As shown, the terminal voltage of the secondary battery group 14 changes, and the SOC also changes between 20% and 90%. For this reason, as shown in the bottom of the figure, ΔSOC also changes with time.

Next, changes with time in OCV (Open Circuit Voltage) will be described. FIG. 8 is a diagram showing the time-dependent change in OCV after charging when the secondary batteries 14-1 to 14-n constituting the secondary battery group 14 are lead storage batteries. Moreover, the figure described under the figure which shows a time-dependent change of OCV has shown ion distribution inside a secondary battery. As shown in this figure, when charging is stopped, first, a voltage drop corresponding to the conductor resistance occurs predominantly. Next, the electrochemical reaction that occurs near the electrode plate, which has a high reaction rate, proceeds dominantly, and the concentration of ions near the electrode plate begins to decrease. The voltage decreases. Thereafter, since the ion concentration of the entire electrolyte solution, which is a slow phenomenon, is homogenized by diffusion or the like, the voltage decreases with a gentle slope. Then, when dozens of hours have elapsed since the charge was stopped, each reaction converges and becomes stable. As a result of the convergence of each reaction, the overall voltage drop amount per unit time becomes small. Since it becomes equal to the stable voltage (internal potential of the secondary battery), the voltage measurement value is constant in the voltage measurement at intervals of several minutes. As described above, in the lead storage battery, the OCV changes very slowly, but this is about 1 × 10 ⁻⁵ [cm ² / sec] of diffusion of sulfate ions contained in the sulfuric acid that is the electrolyte of the lead storage battery. This is because it takes about 1 day to diffuse 1 cm. In addition, a lithium ion battery is mentioned as one of the secondary battery candidates other than lead acid battery. Since the reaction rate of the lithium ion battery and the ion diffusion rate of the electrolytic solution are faster than those of the lead-acid battery, the time until the battery voltage during the OCV measurement is stabilized is shortened and requires about 1 hour.

  As described above, since the OCV of the secondary batteries 14-1 to 14-n changes simultaneously with a reaction with a fast reaction rate and a reaction that proceeds slowly, the states of the secondary batteries 14-1 to 14-n In order to obtain accurately, it is necessary to evaluate individually according to reaction rate. Therefore, as shown in FIG. 9, the present inventor samples voltages in a region where the OCV voltage change is fast (F_fast) and a slow region (F_slow), and estimates the battery state from the data in these regions (for example, Patent No. 4702859 and WO2012 / 066643). According to such a method, the state quantity of the battery can be estimated for each battery reaction rate factor.

  By the way, as shown in FIG. 10A, when the state immediately before the OCV is measured is in a charge-dominant state, a standard voltage change as shown in FIGS. 8 and 9 is shown. As shown in (B), a voltage change different from a standard voltage change may occur in a discharge dominant state. This will be briefly described. The time-dependent change in OCV after charging and discharging (OCV (t)) is as shown in FIG. That is, after charging, a post-charge voltage curve having a convex shape as shown below is shown, and after discharging, a post-discharge voltage curve having a convex shape as shown in the bottom of the diagram is shown. In FIG. 11, the voltage change curves after charging and discharging are substantially the same in order to simplify the drawing.

  As shown in FIG. 12, even if the state immediately before measuring the OCV is charging, if there is a discharging state before that, the voltage change also reflects the influence of discharging. It is not a gentle change, but a change in which a local recess is generated as shown in FIG. Therefore, in order to measure an accurate stable voltage, it is necessary to pay attention not only to the previous charge / discharge state, but also to the charge / discharge state before a certain period.

  In the first embodiment, the secondary battery group 14 is configured by connecting a plurality of secondary batteries 14-1 to 14-n in series. For example, five secondary batteries 1 to 5 are connected in series. When connected, as shown in FIG. 13, the voltage change of each secondary battery has different characteristics due to differences in the individual deterioration states of the batteries even when the same charge is applied to the battery group connected in series. Indicates. More specifically, in FIG. 13, the secondary battery 3 is most deteriorated, the secondary battery 5 is next deteriorated, and the secondary batteries 1, 2, and 4 are continuously deteriorated. It has become. By the way, when measuring the voltage change of a some secondary battery and estimating a state in this way, it is necessary to synchronize the measurement timing of a some secondary battery. For example, when the measurement start timing differs between secondary batteries, the measurement start timing is t1 shown in FIG. 13 for a certain secondary battery, while the measurement start timing is t2 (t2> t1) for another secondary battery. There are some cases. In such a case, since the voltage at the start of measurement is different, an accurate voltage cannot be estimated. In particular, since the voltage change immediately after stopping charging is abrupt, a slight time lag causes a large error. Therefore, in the first embodiment, control is performed so that the measurement start timing is synchronized among the secondary batteries 14-1 to 14-n, and the sampling timing is also synchronized.

  Next, the operation of the first embodiment will be described. Hereinafter, after the outline of the operation will be described, the detailed operation will be described with reference to the flowcharts of FIGS. First, the general operation will be described. When determining the deterioration of the secondary battery group 14, first, the control unit 12 requests the calculation unit 13 to measure the secondary battery group 14. This request is requested when the user inputs the scheduled measurement date and time to the RAM 123 of the control unit 12 in advance, and the CPU 121 matches the timing unit 124 and the scheduled measurement date and time stored in the RAM 123. Can be done. Further, instead of setting in advance, the user may determine that measurement is to be performed, and the request may be made by operating an operation unit (not shown).

  First, the CPU 121 of the control unit 12 instructs the power conversion unit 11 to perform charging. The power conversion unit 11 converts AC power from the grid power 30 into DC power, and supplies the secondary battery group 14 for charging. The power conversion unit 11 detects the SOC of the secondary batteries 14-1 to 14-n constituting the secondary battery group 14 by, for example, cumulatively adding the current supplied to the secondary battery group 14. For example, charging is performed until the SOC becomes 85% or more. Here, the reason why charging is performed until the SOC becomes 85% or more will be described. FIG. 14 shows the relationship between the charge capacity (SOC) of the secondary battery and the battery voltage for each battery type. Curve C1 shows the characteristics of Ni, Co-based lithium ion batteries, curve C2 shows the characteristics of phosphate iron-based lithium ion batteries, and curve C3 shows the characteristics of lead-acid batteries. As shown in these curves C1 to C3, when any curve exceeds 85%, the amount of increase in voltage increases, and the charge voltage increases rapidly with respect to the amount of charge (the slope of the curve suddenly increases). In this region, the irreversible reaction of the battery occurs, so the life of the secondary battery is also shortened. For this reason, generally, it is desirable to set 85% or more as a reference value for determination.

  For example, when the secondary batteries 14-1 to 14-n are lead storage batteries, a specific number of 85% or more can be set to 100%, for example. In the case of a lead-acid battery, it is desirable to continue to perform a charging process equivalent to 5% with ΔSOC after the SOC reaches 100%. In the case of a lithium ion battery, the charging process is executed so that the SOC becomes a preset value of 80 to 100% (specifically, 85% described above). By such an operation, the state immediately before the OCV measurement is made to be in a charging dominant state, so that it is possible to prevent an irregular voltage change as shown in FIG. Moreover, in the case of a lead-acid battery with high resistance to overcharge, the SOC is exceeded and the battery is continuously charged to correct the SOC imbalance between the secondary batteries. In addition, it is possible to reduce lead sulfate on the electrode plate of the lead storage battery, reduce the deterioration factor of the current battery, and more accurately estimate the unrecoverable deterioration state of the battery.

  As a more specific charging method, there is an increasing tendency of the amount of increase in charging voltage with respect to the increase in chargeable capacity in the relationship between the increase in chargeable / dischargeable capacity and the increase in charging voltage when charging a secondary battery. Charge until it appears. For example, when the secondary battery group 14 is a lead storage battery, it is charged with a constant current (Constant Current) up to 2.4 V per cell, and after reaching the corresponding voltage, it is switched to a constant voltage charge. Charging is continued and the charging current decreases to about 0.02 CA, 5 hours elapses, or the current integrated value (current × time) after switching to constant voltage charging is 5 of the rated capacity [Ah]. When it reaches%, charging stops. In addition to this, for example, the charging current during constant current charging may be changed in multiple stages.

  For example, as a condition for fully charging an iron phosphate-based lithium ion battery, for example, constant current charging is performed up to 3.6 V with a current equivalent to 0.3 to 1.0 CA in terms of C rate, After reaching 3.6V, constant voltage charging can be carried out until reaching 0.05 CA. However, this is an example of charge control for performing full charge, and is not limited to this full charge condition. The C rate corresponds to a discharge current that discharges the entire capacity in one hour.

  When charging by the power conversion unit 11 is completed, the control unit 12 instructs the power conversion unit 11 to end charging and instructs the calculation unit 13 to start measurement. As a result, the supply of power from the power conversion unit 11 to the secondary battery group 14 is stopped. In addition, when the CPU 131 of the calculation unit 13 receives an instruction to end charging from the control unit 12, the CPU 131 refers to the output signal of the time measuring unit 134 and determines whether or not a certain time has elapsed. When a certain time has elapsed from the end of charging and the measurement start timing is reached, measurement start signals are sent to all the sensor units 15-1 to 15-n via the wireless communication unit 165 of the base unit 16. At the same time. In addition, as a method of transmitting a measurement start signal simultaneously, it can transmit by multipoint simultaneous communication, for example.

  The CPU 151 of the sensor units 15-1 to 15-n receives the measurement start signal simultaneously via the wireless communication unit 155. When the measurement start signal is received, the CPU 151 determines whether or not the sampling timing is reached. When the sampling timing is reached, the CPU 151 instructs the A / D conversion unit 156 to perform A / D conversion. . As a method for determining whether or not it is the sampling timing, for example, it is determined that it is the sampling timing when a predetermined time has elapsed after receiving the measurement start signal, or the calculation unit 13 determines the predetermined time. Is measured at the same time to the sensor units 15-1 to 15-n, and the CPU 151 determines that the timing is the sampling timing when the time output from the time measuring unit 154 coincides with the received measurement start time. Or you may. In order to synchronize the timing unit 154 included in the sensor units 15-1 to 15-n, for example, a signal for synchronization is transmitted from the parent device 16, and the timing unit 154 is adjusted based on this signal. All the timekeeping units 154 may be synchronized.

  The sensor units 15-1 to 15-n measure the terminal voltages and temperatures of the secondary batteries 14-1 to 14-n by the voltage sensor 158 and the temperature sensor 159 based on the measurement start signal from the calculation unit 13, and A After A / D conversion by the / D conversion unit 156, it is stored in the RAM 153 as measurement data. A similar operation is executed in all of the sensor units 15-1 to 15-n. Thus, the measured terminal voltage and temperature data are transmitted to the main unit 16 for each of the sensor units 15-1 to 15-n when a transmission request for the measurement result is made from the main unit 16. When the transfer of all the data is completed, the arithmetic unit 13 waits for a predetermined period corresponding to the sampling period, and then again sends the measurement start signal to all the sensor units 15-1 to 15-n via the master unit 16. Send to. FIG. 15 is a diagram for explaining the operations of the arithmetic unit 13 and 15-1 to 15-n. In FIG. 15, a measurement start signal is transmitted by radio from the master unit 16 to all the sensor units 15-1 to 15-n at timing t1 (see FIG. 15A). The sensor units 15-1 to 15-n that have received the measurement start signal sample the terminal voltages and temperatures of the secondary batteries 14-1 to 14-n in synchronization with the timing t2. And the data measured by sampling are transmitted with respect to the main | base station 16 in order of the sensor parts 15-1 to 15-n. The base unit 16 supplies the received data to the calculation unit 13. Similar processing is repeated at timings t3 and t4 and timings t5 and t6. Note that the period at which the measurement start signal is transmitted is, for example, τ. However, since the measurement is started after a certain timing after the measurement start signal is transmitted, the period τ is a sampling period.

  The above operation is repeatedly executed for a predetermined time. And when required data are obtained, the calculating part 13 complete | finishes the process which performs a request | requirement with respect to the sensor parts 15-1 to 15-n. Next, the calculation unit 13 refers to the obtained data, and estimates the deterioration state of the secondary batteries 14-1 to 14-n based on the voltage changes of the secondary batteries 14-1 to 14-n. To do. As a method for estimating the deterioration state, for example, the amount of change from the reference voltage (ΔV (t)) of the change with time of the voltage is referred to the reaction rate component based on the reference function created for each reaction rate in advance. Fitting the synthesis function to ΔV (t) and estimating the battery state by comparing the fitting function, which is a component of the synthesis function, with a reference function created in advance for each reaction rate To do. At this time, an integrated value of the voltage may be obtained for each of a plurality of regions for each reaction rate, and the state may be estimated based on the integrated value. In addition, since the characteristics of the secondary batteries 14-1 to 14-n change depending on the temperature, the estimation result may be corrected based on the temperature.

  Next, the calculation unit 13 transmits the estimated deterioration state of the secondary batteries 14-1 to 14-n to the control unit 12. The control unit 12 presents the degradation state of the secondary batteries 14-1 to 14-n to the presentation unit 126 based on the received degradation state. By confirming the information presented in this way, the user can know the state of each of the secondary batteries 14-1 to 14-n and whether there is a secondary battery that needs to be replaced. You can also know whether or not.

  As described above, according to the first embodiment of the present invention, the sensor units 15-1 to 15-n are provided for the plurality of secondary batteries 14-1 to 14-n connected in series, The terminal voltage and temperature are measured based on the measurement start signal transmitted from the machine 16, and the states of the secondary batteries 14-1 to 14-n are estimated based on the measured data. The state of the secondary battery can be reliably estimated.

  In addition, since the plurality of sensor units 15-1 to 15-n measure the terminal voltages and temperatures of the secondary batteries 14-1 to 14-n in synchronization with the measurement start signal from the parent device 16. All the secondary batteries 14-1 to 14-n are measured at the same timing. Thereby, since all the secondary batteries 14-1 to 14-n can be measured on the same conditions, a state can be compared accurately. In addition, since the measured data is sequentially transmitted from the sensor units 15-1 to 15-n to the base unit 16, it is necessary to use a wireless communication unit 155, 165 whose communication capability is not so high. it can.

  In addition, since the sensor units 15-1 to 15-n and the parent device 16 exchange information by wireless communication, the influence of noise can be reduced as compared with the case of wired communication. That is, since the power conversion unit 11 performs the switching operation, electromagnetic radiation noise is generated, and a current corresponding to the switching operation flows through the circuit in the power conversion unit 11 and the secondary battery group 14. Moreover, since the secondary battery group 14 is comprised by many secondary batteries 14-1 to 14-n with large size as mentioned above, the sensor parts 15-1 to 15-n with which these are equipped are wired-connected. In this case, the number of signal lines increases and the length of the signal lines becomes very long. In such a large number and long signal lines, a noise voltage is induced by electromagnetic radiation noise from the power conversion unit 11, the secondary battery group 14, or an external device. On the other hand, in the case of an in-vehicle secondary battery group, for example, as disclosed in Japanese Patent No. 5088557, it is common to package a battery and store it in a suitcase-sized housing. In such a configuration, since the housing can shield against noise from the outside, there is little need to consider the influence of noise from the outside of the housing even when communication is performed by wire. However, as in the present application, for example, when the secondary battery group 14 is configured by combining about 200 secondary batteries of about 1000 Ah, it is necessary to store them in the housing of a package of several meters square, The signal line becomes an antenna and may receive electromagnetic radiation noise from the outside and malfunction. As a countermeasure against such noise, generally, when a signal of several tens of meters is transmitted and received, a current loop method of 4 to 20 mA that can be controlled not by voltage but by current is adopted. Alternatively, when a contact signal is transmitted / received, for example, the contact voltage is changed from, for example, DC 24 V to DC 100 V, so that the effect of noise becomes relatively small with respect to the ON / OFF binary effect. It has been taken. However, when the current loop method is adopted, a current source is required between all the base units and the sensor unit, and when used for communication, the current value does not need to be variable. On the other hand, there is a problem that the cost of the apparatus increases. Also, when synchronizing at the contact point, it is necessary to provide a DC 24 V or DC 100 V power source or receiving element on the sensor unit side, which raises a problem of cost increase. In addition, it is possible to use shielded cables and coaxial cables with noise countermeasures, but the wiring distance is long, the wiring with expensive cables becomes long, the cost increases, and the workability of the cable is poor. Become. Therefore, in the present embodiment, by using wireless communication, the influence of noise can be reduced, and the signal line wiring work can be simplified.

  Next, detailed operation of the first embodiment will be described with reference to FIGS. First, FIG. 16 is a diagram for explaining the flow of processing executed in the control unit 12. When the processing of FIG. 16 is started, the following steps are executed.

  In step S10, the CPU 121 of the control unit 12 sets a maintenance plan. Specifically, based on an instruction from the user, the date / time information for executing maintenance is input, and the input date / time information is stored in the RAM 123. Note that the date and time when the maintenance is executed is set to a date and time when the power storage device 10 is not used (for example, 12:00 on Sunday).

  In step S11, the CPU 121 of the control unit 12 determines whether or not the set date / time has been reached. If it is determined that the set date / time has been reached (step S11: Yes), the process proceeds to step S12. The same process is repeated for (Step S11: No). More specifically, the CPU 121 compares the current date and time information supplied from the timing unit 124 with the date and time information stored in the RAM 123, and determines that the set date and time have been reached if they are the same. Then, the process proceeds to step S12.

  In step S12, the CPU 121 of the control unit 12 sends a control signal to the power conversion unit 11 to execute a charging process. As a result, the power conversion unit 11 converts the AC power supplied from the system power 30 into DC power, and charges the secondary batteries 14-1 to 14-n constituting the secondary battery group 14. As a charging method, constant current (CC) charging can be performed for a certain period, and then constant voltage (CV) charging can be performed. This is an example of a charging method, and charging may be performed by setting the charging current in multiple stages. Further, as the charge stop condition, it may be determined by the increment amount of the current integrated value from SOC = 100%, or the charging time or current value during the low voltage charging may be determined based on the threshold value.

  In step S13, the CPU 121 of the control unit 12 determines whether or not the secondary batteries 14-1 to 14-n are fully charged, and when the fully charged state is reached (step S13: Yes). Advances to step S14, otherwise returns to step S12 and repeats the same processing (step S13: No). In addition, as a standard of full charge, generally, SOC can be defined as 85% or more, and individually, for example, when the secondary batteries 14-1 to 14-n are lead storage batteries. In other words, when the total usable capacity of the battery is converted to SOC 100%, charging is executed so that it becomes 105% of the SOC. In the case of a lithium ion battery, charging is performed so that a preset value (for example, 85%) of 80 to 100% is obtained with respect to the total usable capacity of the battery. Note that the total usable capacity is a new battery, and the total usable capacity is equal to the rated capacity of the battery. However, as the deterioration progresses, the usable capacity decreases and changes to the new rated capacity. It is desirable to change the amount of charge equivalent to full charge according to the change in the total usable capacity of the battery.

  In step S <b> 14, the CPU 121 of the control unit 12 outputs a power conversion unit stop signal for stopping the operation of the power conversion unit 11. Thereby, the power conversion unit 11 ends the charging process for the secondary batteries 14-1 to 14-n and stops its operation for a certain period.

  In step S15, the CPU 121 of the control unit 12 requests the calculation unit 13 to start measurement. As a result, the processing unit 13 executes the process of FIG.

  In step S16, the CPU 121 of the control unit 12 determines whether or not the measurement by the calculation unit 13 has been completed. If it is determined that the measurement has been completed (step S16: Yes), the process proceeds to step S17. In the case (step S16: No), the same processing is repeated. For example, if it is determined by the notification from the calculation unit 13 that the measurement has been completed, the determination is Yes and the process proceeds to step S17.

  In step S <b> 17, the CPU 121 of the control unit 12 receives the determination result of the state of the secondary batteries 14-1 to 14-n from the calculation unit 13. More specifically, since the calculation unit 13 determines the deterioration state of the secondary batteries 14-1 to 14-n by a process described later, the CPU 121 of the control unit 12 receives this deterioration state as a determination result.

  In step S18, the CPU 121 of the control unit 12 determines whether there is a secondary battery to be replaced, and if it is determined that there is a secondary battery to be replaced (step S18: Yes), the step is performed. The process proceeds to S19, and in other cases (step S18: No), the process ends. More specifically, with reference to the determination result received in step S17, if there is a secondary battery whose deterioration state is determined to exceed a predetermined threshold, the process proceeds to step S19.

  In step S <b> 19, the CPU 121 of the control unit 12 presents the secondary battery to be replaced to the presentation unit 126. More specifically, when there is a secondary battery to be replaced among the secondary batteries 14-1 to 14-n, the identification number assigned to the secondary battery and the installation location are indicated. Information is presented to the presentation unit 126. Thereby, the user can specify the secondary battery that needs to be replaced.

  Next, with reference to FIG. 17, processing executed in the calculation unit 13 will be described. When the process of FIG. 17 is started, the following steps are executed.

  In step S30, the CPU 131 of the calculation unit 13 determines whether or not the measurement start is requested from the control unit 12, and when the measurement start is requested (step S30: Yes), the process proceeds to step S31. In the case (step S30: No), the same processing is repeated. More specifically, when the request by the process of step S15 in FIG. 16 is received, the process proceeds to step S31.

  In step S31, the CPU 131 of the calculation unit 13 refers to the time measuring unit 134 to determine whether or not the measurement start timing is reached, and when it is determined that the measurement start timing is reached (step S31: Yes), the process proceeds to step S32. In other cases (step S31: No), the same processing is repeated. More specifically, for example, in the case of the first measurement, after receiving a measurement start request, when a predetermined time has elapsed, the process proceeds to step S32 as the measurement start timing, In the case of the second and subsequent measurements, it is determined whether or not a certain time (= τ) corresponding to the sampling period has elapsed since the previous measurement. Proceed to step S32. The fixed time can be set to, for example, 60 seconds in “normal measurement” described later. Of course, other times may be used. Note that the measurement start timing may be held as time information, the time information may be compared with the time information output from the time measuring unit 134, and may be determined as the measurement start timing when they match.

  In step S32, the CPU 131 of the calculation unit 13 wirelessly transmits a normal measurement start signal to all the sensor units 15-1 to 15-n via the master unit 16. The normal measurement start signal is simultaneously received by all of the sensor units 15-1 to 15-n. Note that the normal measurement start signal is a signal indicating that sampling is performed at a normal rate instead of performing high-speed sampling as in a high-speed measurement start signal described later. For example, sampling is performed at a cycle of 60 seconds. The

  In step S33, the CPU 131 of the calculation unit 13 makes a normal measurement result transmission request to a predetermined sensor unit. For example, the sensor units 15-1 to 15-n make normal measurement requests in a predetermined order. Specifically, a normal measurement result transmission request is made in the order of the sensor units 15-1 to 15-n.

  In step S34, the CPU 131 of the calculation unit 13 receives measurement result data from the predetermined sensor unit that has made the request in step S33. For example, when the normal measurement result transmission request is made in the order of the sensor units 15-1 to 15-n in step S33, the measurement result data is received in order of the sensor units 15-1 to 15-n. To do.

  In step S35, the CPU 131 of the calculation unit 13 determines whether or not a predetermined time has elapsed since the measurement start signal was transmitted with reference to the time measuring unit 134, and determines that the predetermined time has elapsed ( In step S35: Yes, the process proceeds to step S37. In other cases (step S35: No), the process proceeds to step S36. More specifically, even if the measurement result data is not received from all of the sensor units 15-1 to 15-n, a situation where the next measurement is not in time must be avoided. If the predetermined shorter time τ0 (τ0 <τ) has elapsed, the process proceeds to step S36.

  In step S36, the CPU 131 of the calculation unit 13 determines whether or not the measurement result data has been received from all the sensor units 15-1 to 15-n, and the measurement results from all the sensor units 15-1 to 15-n. If it is determined that data has been received (step S36: Yes), the process proceeds to step S37, and otherwise (step S36: No), the process returns to step S33.

  In step S37, the CPU 131 of the calculation unit 13 determines whether or not to end the measurement. If it is determined to end the measurement (step S37: Yes), the process proceeds to step S38, and otherwise (step S37: No) returns to step S31 and repeats the same process as described above. More specifically, when all the measurements for determining the state of the secondary battery are completed, the process proceeds to step S38.

  In step S38, the CPU 131 of the calculation unit 13 is based on the terminal voltage and temperature measurement data of the secondary batteries 14-1 to 14-n received from the sensor units 15-1 to 15-n by the above-described processing. The process which determines each deterioration state of the secondary batteries 14-1 to 14-n is performed.

  In step S39, the CPU 131 of the calculation unit 13 transmits information indicating the determination results of the respective deterioration states of the secondary batteries 14-1 to 14-n obtained by the process of step S38 to the control unit 12.

  Next, processing executed in the sensor units 15-1 to 15-n will be described with reference to FIG. In addition, since the process performed in the sensor parts 15-1 to 15-n is the same, these are demonstrated as the sensor part 15 below. When the process of FIG. 18 is started, the following steps are executed.

  In step S50, the CPU 151 of the sensor unit 15 determines whether or not a normal measurement start signal has been received. If it is determined that the normal measurement start signal has been received (step S50: Yes), the process proceeds to step S51. Otherwise (step S50: No), the same process is repeated. More specifically, when the normal measurement start signal transmitted by the process of step S32 shown in FIG. 17 is received, the process proceeds to step S51.

  In step S51, the CPU 151 of the sensor unit 15 refers to the output of the time measuring unit 154, determines whether or not the sampling timing is reached, and if it is determined that the sampling timing is reached (step S51: Yes), the process proceeds to step S52. In other cases (step S51: No), the same processing is repeated. More specifically, in order to perform measurement in synchronization with all of the sensor units 15-1 to 15-n, for example, when a predetermined time elapses after receiving a normal measurement start signal, it is a sampling timing. And the process can proceed to step S52. In addition to this, the time at which the measurement is started is determined and transmitted from the main unit 16 to the sensor units 15-1 to 15-n. When the predetermined time is reached, it is determined that the sampling timing has come. Then, the process can proceed to step S52.

  In step S52, the CPU 151 of the sensor unit 15 acquires the outputs of the voltage sensor 158 and the temperature sensor 159. Since the temperature change is slower than the terminal voltage change, there is little error in the acquired data even if the timing is slightly shifted. For this reason, the output of the voltage sensor 158 can be obtained with priority over the temperature sensor 159. It was acquired. Resulting data is stored in the RAM 153.

  In step S53, the CPU 151 of the sensor unit 15 determines whether or not a normal measurement result transmission request has been received from the base unit 16, and if it is determined that a normal measurement result transmission request has been received (step S53: Yes). The process proceeds to step S54, and otherwise the same process is repeated (step S53: No).

  In step S <b> 54, the wireless communication unit 155 of the sensor unit 15 transmits the measurement result data to the calculation unit 13. More specifically, the wireless communication unit 155 of the sensor unit 15 acquires measurement result data stored in the RAM 153 and transmits the measurement result data to the wireless communication unit 165 of the parent device 16.

  In step S55, the CPU 151 of the sensor unit 15 determines whether or not all the measurements have been completed. If it is determined that the measurement has not been completed (step S55: No), the process returns to step S50 and is the same as described above. This process is repeated, and in other cases (step S55: Yes), the process ends. Note that when a signal indicating the end of measurement is received from the computing unit 13, it may be determined that all measurements have been completed.

  According to the above processing, the sensor units 15-1 to 15-n can be measured in synchronization, and the deterioration states of the secondary batteries 14-1 to 14-n are individually known. It becomes possible. In addition, by transmitting and receiving data by wireless communication, it is possible to reduce the influence of noise. That is, the influence of noise can be reduced by attenuating the noise generated from the power conversion unit 11 relative to the radio communication signal by using a filter configured by hardware or software, for example. Further, for example, by using a digital modulation method, it is possible to reduce the influence on external noise. Of course, an analog modulation method (for example, frequency modulation) that has little influence on noise may be used.

(C) Description of Configuration of Second Embodiment of Present Invention Next, a second embodiment of the present invention will be described. FIG. 19 is a diagram illustrating a configuration example of the second embodiment of the present invention. In FIG. 19, parts corresponding to those in FIG. In FIG. 19, a switch 20 is added compared to FIG. The rest of the configuration is the same as in FIG. The switch 20 is configured by, for example, an electromagnetic relay or a semiconductor switch, and is inserted between the power conversion unit 11 and the secondary battery group 14 and controlled by the control unit 12. The control unit 12 can disconnect the secondary battery group 14 from the power conversion unit 11 at a desired timing by turning off the switch 20.

(D) Operation Description of Operation of Second Embodiment of the Invention Next, operation of the second embodiment will be described. In the second embodiment, during normal operation, the control unit 12 turns on the switch 20. As a result, the power conversion unit 11 and the secondary battery group 14 are connected, and power can be exchanged between them. On the other hand, when determining the deterioration state of the secondary battery group 14, the control unit 12 outputs a signal for stopping the power conversion unit 11 in step S14 of FIG. 16, and then turns off the switch 20 at a desired timing. Control to the state. By such control, the charging current supplied from the power conversion unit 11 to the secondary battery group 14 can be turned off at a desired timing. More specifically, when a stop signal is transmitted to the power conversion unit 11, the power conversion unit 11 performs, for example, processing for protecting a semiconductor for switching until the stop, A predetermined time corresponding to the operating state is required before stopping. For this reason, it takes a certain time from when the stop signal is transmitted from the control unit 12 to the power conversion unit 11 until the power conversion unit 11 actually detects the operation, and this constant time is an operation of the power conversion unit 11. It depends on the state and model. However, when the switch 20 is turned off, the charging current can be cut off at a desired timing. Instead of controlling the switch 20 by the control unit 12, the switch 20 may be controlled by the calculation unit 13. According to such a configuration, the calculation unit 13 that measures the secondary battery group 14 can control the switch 20 to be in an OFF state at an optimal timing.

  As described above, in the second embodiment of the present invention, the switch 20 is provided between the power conversion unit 11 and the secondary battery group 14, and the switch 20 is controlled by the control unit 12. The charging current supplied from the power conversion unit 11 to the secondary battery group 14 can be cut off at a desired timing. Thereby, since the start timing of measurement can be set accurately, it is suitable, for example, when it is necessary to start measurement after a lapse of a predetermined time from the interruption of the charging current.

(F) Description of Modified Embodiment The above embodiment is an example, and it is needless to say that the present invention is not limited to the case described above. For example, in each of the above embodiments, the deterioration state of the secondary battery group 14 is detected based on the maintenance plan. However, for example, it is executed based on a direct instruction from the user, or past operations are performed. Based on the situation, it may be possible to automatically find and execute a time zone in which the frequency of occurrence of charging / discharging is low.

  Further, in each of the above embodiments, the secondary battery group 14 is fully charged before measuring the state of the secondary battery group 14. For example, the SOC of the secondary battery group 14 is several percent to several You may control so that it may increase 10%. Or you may make it carry out charge control so that the charge-and-discharge log | history of 1 to several hours immediately before a measurement may become predominate. Instead of positively charging, the timing at which the charge / discharge history of one to several hours immediately before the measurement is dominant is detected, and the state of the secondary battery group 14 is detected at that timing. Also good. As a method for determining whether or not the charge / discharge history has become dominant in charge, for example, it can be realized by determining whether or not the charge amount for one to several hours immediately before the measurement exceeds the discharge amount by a predetermined amount. Specifically, for example, in the case of a sealed lead-acid battery, it is necessary for at least about 3 hours for the voltage change factor accompanying the diffusion of the electrolyte to converge. It is desirable to store and judge. For example, in the case of an iron phosphate-based lithium ion battery, it takes about 30 minutes for the cause of the voltage change accompanying the diffusion of the electrolyte to converge, so the charge / discharge history for the past 30 minutes is stored as data. Is desirable. Or you may determine the present charging / discharging log | history using the method of determining charging / discharging log | history as described in Unexamined-Japanese-Patent No. 2012-225740.

  In the second embodiment described above, the stop signal is output to the power conversion unit 11 and then the switch 20 is turned off. However, after the switch 20 is turned off, the power conversion unit 11 is stopped. A signal may be output.

  Further, in each of the above embodiments, the measurement start signal is transmitted to all the sensor units 15-1 to 15-n at once. However, after transmitting the measurement start signal individually, the measurement start signal is synchronized. Measurement may be performed. For example, the measurement start time may be individually transmitted to the sensor units 15-1 to 15-n, and the measurement may be started in synchronization when the measurement start time is reached. Further, not all of the sensor units 15-1 to 15-n may perform measurement, but some of them may perform measurement.

  Further, in each of the above embodiments, the sensor units 15-1 to 15-n are configured to acquire the outputs of the voltage sensor 158 and the temperature sensor 159 once for one measurement. The output may be acquired a plurality of times, and an average value of these outputs may be obtained and sent to the calculation unit 13.

  In each of the above embodiments, the measurement result data is transmitted to the calculation unit 13 in a predetermined order (the order of the sensor units 15-1 to 15-n). Or may be transmitted on a first-come-first-served basis.

  Further, in each of the above embodiments, the sensor units 15-1 to 15-n transmit the measurement data to the calculation unit 13 for each measurement, but for example, the measurement data for a plurality of times are collected together. You may make it transmit. For example, the measurement data for 10 times may be transferred collectively. In that case, not all the data of the sensor units 15-1 to 15-n can be transmitted in a plurality of sampling periods instead of being transmitted all within one sampling period.

  Further, in each of the embodiments described above, the timer units 154 are provided in the sensor units 15-1 to 15-n, and it is determined whether or not the sampling timing has come by referring to the output of the timer units 154. For example, the sampling timings of the sensor units 15-1 to 15-n may be synchronized by performing sampling in synchronization with a signal transmitted from the master unit 16 at the same time.

  Further, in each of the above embodiments, one sensor unit is provided for one secondary battery, but one sensor unit may be provided for a plurality of secondary batteries. For example, one sensor unit can be provided for a plurality of secondary batteries connected in series. Alternatively, when a plurality of secondary batteries are connected in parallel, one sensor unit can be provided for the plurality of secondary batteries connected in parallel. In addition, when a plurality of secondary batteries are connected in parallel, one sensor unit is provided for the plurality of secondary batteries, and means for selecting any one secondary battery (for example, a switch) And the sensor unit may be connected by selecting a target secondary battery. According to such a configuration, it is possible to detect the respective states of a plurality of secondary batteries connected in parallel.

  Further, in each of the above embodiments, the normal measurement is performed in FIGS. 17 and 18. However, for example, as shown in FIGS. 20 and 21, high-speed measurement may be performed. More specifically, FIG. 20 is a flowchart for explaining an example of processing executed in the calculation unit 13. In FIG. 20, parts corresponding to those in FIG. In FIG. 20, compared with FIG. 17, steps S32 and S33 are replaced with steps S60 and S61, and processes of steps S62 and S63 are added. In the process illustrated in FIG. 20, in step S <b> 61, the calculation unit 13 transmits a high-speed measurement request to all the sensor units 15-1 to 15-n via the parent device 16 at the same time. Note that high-speed measurement refers to, for example, measuring at a 1-second cycle. Of course, other periods may be used. As a result, as will be described later with reference to FIG. 21, the sensor units 15-1 to 15-n execute high-speed measurement processing. In step S61, the calculation unit 13 sends a high-speed measurement result transmission request to a predetermined sensor unit via the master unit 16. As a result of the request, a high-speed measurement result is wirelessly transmitted from a predetermined sensor unit. Then, as in the case described above, data from all the sensor units is received, and when the predetermined number of times of measurement is executed, the process proceeds to step S62. In step S62, the high-speed measurement process is terminated, and in step S63, the normal measurement process similar to that shown in steps S31 to S37 of FIG. 17 is executed, and the secondary battery is based on the results of the high-speed measurement process and the normal measurement process. A state determination process is executed in step S38, a determination result is transmitted in step S39, and the process ends.

  FIG. 21 is a flowchart for explaining an example of processing executed in the sensor unit 15. In FIG. 21, parts corresponding to those in FIG. In FIG. 21, compared with FIG. 18, steps S50 and S53 are replaced with steps S70 and S72, and the processes of steps S71 and S73 are added. The rest is the same as FIG. In the process shown in FIG. 21, when a high-speed measurement start signal is received from the calculation unit 13, for example, measurement is performed at a cycle of 1 second, and when measurement is completed a predetermined number of times (for example, once), Yes is determined in step S <b> 71. In step S72, if a high-speed measurement result transmission request is received from the calculation unit 13 in step S72, it is determined Yes and the process advances to step S54 to transmit measurement result data to the calculation unit 13. When the measurement is completed, the process proceeds to step S73, a normal measurement process (a process similar to steps S50 to S55 in FIG. 18) is executed, and the process ends. According to the embodiment as described above, for example, data can be measured finely by high-speed measurement for a certain period of time after the end of charging, and data can be roughly measured by normal measurement after a certain period of time has elapsed. . The normal measurement after the high-speed measurement may not be executed.

  Moreover, in each above embodiment, although the power storage device 10 supplied electric power with respect to the load 50, it is connected only to the system | strain power 30 without providing the load 50, for example, by photovoltaic power generation You may make it use for the supply (for example, power sale) to system electric power.

  Moreover, in each above embodiment, although the calculating part 13 transmitted the measurement start signal, you may make it a part other than this transmit a measurement start signal. For example, the control unit 12 may transmit a measurement start signal.

DESCRIPTION OF SYMBOLS 10 Power storage device 11 Power conversion part 12 Control part 13 Calculation part 14 Secondary battery group (assembled battery)
14-1 to 14-n Secondary battery 15-1 to 15-n Sensor unit 16 Communication line 30 System power 50 Load

Claims (7)

An assembled battery composed of a plurality of secondary batteries connected in series;
One measuring device provided for each of the one or more secondary batteries included in the assembled battery, and measuring each terminal voltage of the one or more secondary batteries;
Measurement timing transmission means for transmitting measurement timing to the measurement means;
Determination means for determining each state of the one or more secondary batteries based on information on the terminal voltage measured by the measurement means,
The measurement timing transmission means notifies the measurement start timing to the measurement means so that all measurement means that perform measurement perform measurement at the same timing, and information on the terminal voltage obtained by each measurement means An assembled battery state diagnosis device, wherein the state of each of the one or more secondary batteries is determined based on the above.   2. The assembled battery according to claim 1, wherein the determination unit determines a state of each of the one or more secondary batteries based on a change with time of a terminal voltage measured by the measurement unit after charging. State diagnosis device.   The determination means determines the state of each of the one or more secondary batteries based on a change with time of the terminal voltage after charging the assembled battery by 85% or more of a chargeable capacity. The assembled battery state diagnosis device according to 2.   The determination means refers to the charge / discharge history of the assembled battery, and when the charge amount in a certain period immediately before the start of measurement exceeds the discharge amount by a predetermined amount, based on the change with time of the terminal voltage, the one or more two The state diagnosis apparatus for an assembled battery according to claim 2, wherein each state of the secondary battery is determined.   5. The assembled battery state diagnosis apparatus according to claim 1, wherein the measurement timing transmission unit notifies the measurement start timing by wireless transmission.   Used for a power storage device having power conversion means for converting AC power of the grid power to DC power to charge the assembled battery, and converting DC power of the assembled battery to AC power and discharging to the grid power The assembled battery state diagnosis apparatus according to claim 1, wherein It is arranged between the power conversion means and the assembled battery, and has an interrupting means for interrupting the transfer of power between them,
When the measuring unit measures the one or more secondary batteries, the determination unit stops the power transfer between the power conversion unit and the assembled battery by interrupting the intermittent unit. ,
The assembled battery state diagnosis apparatus according to claim 6.

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