JP2014006099A - Deterioration determination method and device for storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine the deterioration of a storage battery with high accuracy.SOLUTION: The impedance of each frequency is measured by supplying AC current changed in frequency to a storage battery to discharge it. A phase difference curve is created by detecting an impedance phase difference from a measurement value. The deterioration of the storage battery is determined based on a phase difference area determined by the phase difference curve within a predetermined frequency range.

Description

  The present invention relates to a storage battery deterioration determination method and a deterioration determination apparatus that can be repeatedly used by charging.

  A lead storage battery or the like is generally used as a secondary battery that can be repeatedly used by charging. In lead-acid batteries, sulfation is deposited on the negative electrode plate by repeated charge and discharge. The sulfation is a spongy lead sulfate crystal and has low solubility, and when deposited on the negative electrode plate, the reaction area of the negative electrode plate is reduced, leading to deterioration of the lead storage battery and hindering charging. For these reasons, it has been conventionally performed to determine the deterioration of a lead storage battery. In this deterioration judgment, an alternating current impedance measuring method for measuring an internal impedance in the storage battery by applying an alternating voltage is frequently used.

  The AC impedance measurement method measures the internal impedance that changes according to the frequency of the AC voltage by applying AC to the storage battery, and can be measured using the positive and negative electrodes in the storage battery without disassembling the storage battery. Good. Patent Document 1 discloses a conventional method for determining deterioration of a lead storage battery by an AC impedance measurement method.

  The deterioration determination described in Patent Document 1 is to change the frequency of the alternating current supplied to the storage battery, measure the impedance of each frequency to obtain a frequency characteristic curve of the impedance, and the reactance component is zero based on the frequency characteristic curve. And the deterioration of the storage battery is judged based on the impedance value.

JP 2007-333494 A

  In general, in the impedance measured by the storage battery, the resistance of the electrode plate appears as an actual resistance component, and the resistance of charge transfer between the electrode plate and the electrolytic solution appears as a reactance component. As the number of times of charging the storage battery increases, the internal resistance increases, and both the actual resistance component and the reactance component increase. In the deterioration determination described in Patent Document 1, measurement is performed at a frequency at which the reactance component of the impedance becomes zero. However, even when the reactance component that increases with the number of times of charging is set to zero, the actual resistance component has a high value. Yes. Therefore, even if the deterioration is determined based on the impedance value with the reactance component being zero, it is difficult to determine the deterioration with high accuracy.

  The present invention has been made in consideration of such problems, and an object of the present invention is to provide a storage battery deterioration determination method and a deterioration determination apparatus capable of determining deterioration of a storage battery with high accuracy.

  According to the storage battery degradation determination method of the present invention, the impedance of each frequency is measured by supplying an alternating current having a changed frequency to the storage battery and discharging it, and the phase difference of the impedance is detected from the measured value. And a deterioration curve of the storage battery is determined based on a phase difference area determined by the phase difference curve within a predetermined frequency range.

  In this case, the phase difference of the impedance is detected for the measurement storage battery and the reference storage battery, and after the phase difference curve is created for the measurement storage battery and the reference storage battery, the phase difference curve of the reference storage battery and the phase difference curve of the measurement storage battery It is preferable to determine the deterioration of the measurement storage battery by obtaining the difference between the difference curve and the difference curve area determined by the difference in the phase difference curve.

  According to another storage battery deterioration judgment method of the present invention, the impedance of each frequency is measured by supplying and discharging an alternating current whose frequency is changed to the storage battery, and the actual resistance component and reactance component of the impedance for each measured frequency. Are plotted on a Smith chart to create an impedance locus, and deterioration of the storage battery is judged based on the impedance locus.

  In this case, preferably, the impedance trajectory is created for the measurement storage battery and the reference storage battery, and the deterioration of the measurement storage battery is determined by comparing the impedance trajectories of the measurement storage battery and the reference storage battery.

  In the above storage battery deterioration determination method, it is preferable to change the alternating current within a frequency range of 0.1 to 1 kHz.

  The storage battery degradation determination device of the present invention includes a frequency control unit that changes the frequency of an alternating current, a current supply unit that supplies and discharges an alternating current whose frequency is changed by the frequency control unit to the storage battery, and a change caused by the discharge. An impedance measurement unit that measures the impedance of the storage battery, a phase difference detection unit that detects a phase difference of the impedance by synchronously detecting a reference signal from the frequency control unit and a measurement signal from the impedance measurement unit, and A deterioration determination unit that determines deterioration of the storage battery using the phase difference of the phase difference detection unit as an index.

  In this case, the deterioration determination unit is determined by the phase difference curve calculation unit that calculates a phase difference curve in which the phase difference of the impedance is plotted with respect to the frequency, and the phase difference curve within a predetermined frequency range. It is preferably formed by a determination unit that determines deterioration based on the phase difference area.

  Further, the phase difference detection unit detects a phase difference of the impedance with respect to the measurement storage battery and the reference storage battery, and the phase difference curve calculation unit creates the phase difference curve with respect to the measurement storage battery and the reference storage battery, and the determination The unit calculates the difference between the phase difference curve of the reference storage battery and the phase difference curve of the measurement storage battery within a predetermined frequency range, and the deterioration of the measurement storage battery based on the difference curve area determined by the difference of this phase difference curve Is preferably determined.

  Another storage battery degradation determination device of the present invention includes a frequency control unit that changes the frequency of an alternating current, a current supply unit that supplies and discharges an alternating current whose frequency is changed by the frequency control unit, and the discharge An impedance measuring unit that measures the impedance of the storage battery that varies depending on the impedance, an impedance locus calculating unit that calculates an impedance locus by plotting the actual resistance component and reactance component of the impedance measured by the impedance measuring unit on a Smith chart, and the impedance A deterioration determination unit that determines deterioration of the storage battery based on the impedance locus determined by the locus calculation unit.

  In this case, it is preferable that the impedance locus calculating unit plots the actual resistance component and the reactance component of the measurement storage battery and the reference storage battery on the Smith chart and calculates the impedance locus for the measurement storage battery and the reference storage battery.

  In the above storage battery deterioration determination device, it is preferable that the frequency controller changes the alternating current in a frequency range of 0.1 to 1 kHz.

  According to the storage battery degradation determination method of the present invention, since the impedance of the storage battery is measured within a wide frequency range, it is possible to easily determine the degradation of the storage battery. Moreover, since the deterioration of the storage battery is evaluated by integrating the phase difference curve, or the deterioration of the storage battery is evaluated by calculating the locus area from the impedance locus, the quantitative accuracy of the deterioration degree is improved. Thereby, deterioration judgment of a storage battery can be performed with high accuracy.

  According to the storage battery deterioration determination device of the present invention, the above deterioration determination can be suitably performed.

It is a graph which shows the phase difference at the time of discharging a storage battery with a fixed frequency. It is a graph which shows the impedance according to the change of a frequency. It is a graph which shows the phase of the impedance according to the change of a frequency. It is a graph which shows a phase difference curve. It is a block diagram which shows the deterioration determination apparatus of a storage battery. It is a block diagram which shows the deterioration determination apparatus of another storage battery. It is a front view which shows a Smith coordinate. It is a front view which shows the impedance locus | trajectory plotted on the Smith chart. It is a front view explaining the case where a locus area is calculated from an impedance locus.

  The inventors measured an actual resistance component and a reactance component at a constant frequency (1 kHz) when an alternating current was supplied to a lead storage battery and discharged. FIG. 1 is a graph showing the measurement results. The characteristic curve A is a lead storage battery having a CCA value of 270, the characteristic curve B is charged and regenerated, and the lead storage battery having a CCA value of 230 is deteriorated. This is a lead storage battery having a CCA value of 170. The CCA value is a cold cranking ampere, and the larger the CCA value, the higher the engine start performance.

  Arrow lines A1, B1, and C1 in FIG. 1 indicate the phase difference (phase angle) between the voltage and current at the initial stage of discharge of the characteristic curves A, B, and C, respectively. The phase difference of the arrow line A1 is the largest and the phase difference of the arrow line C1 is the smallest, indicating that the phase difference corresponds to the magnitude of the CCA value. That is, the phase difference of the storage battery corresponds to the CCA value, and the deterioration of the lead storage battery is less as the phase difference is larger (that is, as the CCA value is larger). From this, it can be understood that the phase difference at the time of discharging can be used as an index of deterioration of the lead storage battery. The present invention has been made based on such knowledge.

  According to one embodiment of the present invention, the storage battery deterioration determination method measures the impedance of each frequency by supplying an alternating current whose frequency is changed to the storage battery and discharging it, and detects the phase difference of the impedance from the measured value. A phase difference curve in which the phase difference is plotted with respect to the frequency is created, and deterioration of the storage battery is determined based on a phase difference area determined by the phase difference curve within a predetermined frequency range. Here, a secondary battery such as a lead storage battery is a target for the storage battery.

  Such deterioration judgment method does not set the alternating current applied to the storage battery to a fixed frequency, but applies an alternating current having a wide range of frequencies to the storage battery and discharges it. There is a feature in the point to get. In addition, for a wide range of frequencies generated by the application of alternating current, the phase difference of the impedance of each frequency is detected, a phase difference curve is created based on this phase difference, and based on the created phase difference curve It is characterized in that the deterioration of the storage battery is judged.

  In this deterioration judgment, the phase difference of the impedance is detected for the measurement storage battery and the reference storage battery, and after the phase difference curve is created for the measurement storage battery and the reference storage battery, the phase difference curve of the reference storage battery and the phase difference of the measurement storage battery are determined. It is preferable to determine the deterioration of the storage battery by obtaining the difference between the curves within a predetermined frequency range and comparing the difference curve area determined by the difference between the phase difference curves.

  FIG. 2 is a graph plotting the impedance of each frequency obtained by supplying an alternating current of a wide range of frequencies to the storage battery (lead storage battery) to discharge the storage battery, and the characteristic curve M has a CCA value of 275. The storage battery, characteristic curve N is the impedance to the storage battery with a CCA value of 215. As shown in the figure, the impedance changes in a wide frequency range of 0.1 Hz to 1 kHz. In this embodiment, the deterioration of the storage battery is determined based on the impedance change in this wide frequency range. FIG. 3 is a graph in which the phase with respect to the frequency is plotted based on FIG. 2. The characteristic curve D shows the storage battery D with the CCA value 275 and the characteristic curve E shows the storage battery E with the CCA value 215. The horizontal axis in FIG. 3 is the frequency axis and is displayed on the logarithmic axis.

  In FIG. 3, a storage battery D having a large CCD value can be used as a reference storage battery for determining deterioration, and a storage battery E having a small CCD value can be used as a measurement storage battery that requires chemical determination. From these characteristic curves D and E, the phase difference between voltage and current at each frequency is calculated. The characteristic curve F is a plot of values obtained by performing a calculation by subtracting the phase difference of the storage battery E from the calculated phase difference of the storage battery D. Therefore, the characteristic curve F is a phase difference curve in which the difference in phase difference of the measurement storage battery E relative to the phase difference of the reference storage battery D is plotted against the frequency. The difference value of the phase difference curve F is the right axis of FIG. 3, and the unit is rad.

  After creating the phase difference curve F, the phase difference area determined by the phase difference curve F is calculated within the measured frequency range (in the range of about 0.1 to 1 kHz in FIG. 3). The calculated phase difference area represents the degree to which the measurement storage battery E has deteriorated with respect to the reference storage battery D. For this reason, the deterioration of the measurement storage battery E can be determined based on the calculated phase difference area.

  The calculation of the phase difference area is performed by integrating the area of the phase difference curve F with respect to the frequency axis (horizontal axis) within a frequency range of about 0.1 to 1 kHz. This calculation need not be performed within the above frequency range, but can be performed within an appropriate frequency range. That is, it is possible to select and perform a frequency range that is easy to calculate and in which the difference can be a clear numerical value. In this embodiment, it is preferable to calculate within a frequency range of 100 to 2000 Hz as will be described later.

  4 is a graph in which the horizontal axis in the graph of FIG. 3 is converted from a logarithmic axis to a normal real axis and the characteristic curve F of FIG. 3 is plotted. The characteristic curve F of FIG. Become. This characteristic curve G is the same as the characteristic curve F, and becomes a phase difference curve G obtained by subtracting the phase difference of the storage battery E from the phase difference of the storage battery D in FIG.

  After creating the phase difference curve G, the phase difference area is calculated within the frequency range where the phase difference can be clearly calculated from the graph of FIG. In FIG. 4, the frequency range of about 100 to 2000 Hz is clear, and the phase difference area within this range is calculated by integration. Then, the deterioration of the storage battery is determined based on the calculated phase difference area. That is, since the phase difference area is calculated by integrating the value obtained by subtracting the phase difference from the phase difference of the storage battery D to the storage battery E, the calculated phase difference area is deteriorated by the measurement storage battery E with respect to the reference storage battery E. The deterioration state of the characteristic storage battery E can be grasped by the size of the phase difference area.

  According to such a deterioration judgment of the storage battery, the impedance of the storage battery is not measured only with a specific fixed frequency, but the impedance of the storage battery is measured within a wide frequency range. The integrated value of the phase difference area is larger than that in FIG. For this reason, it is possible to easily determine the deterioration of the storage battery. Further, since the deterioration of the storage battery is evaluated by integrating the phase difference curve, the quantitative accuracy of the degree of deterioration is improved. Thereby, deterioration judgment of a storage battery can be performed with high accuracy.

  In this embodiment, the deterioration of the storage battery is determined based on the difference between the phase difference of the reference storage battery D and the phase difference of the measurement storage battery E. However, the present invention is not limited to this. The deterioration may be determined by setting and comparing with this threshold value. The determination in this case is to create a phase difference curve from the characteristic curve E in FIG. 2, calculate the phase difference area based on the phase difference curve within a predetermined frequency range, and compare the calculated phase difference area with a threshold value. Can be performed.

  FIG. 5 shows a deterioration determination apparatus 1 used for deterioration determination of this embodiment. Reference numeral 2 denotes a storage battery to be measured. Since the storage battery 2 holds a voltage therein, the deterioration determination device 1 has a structure in which impedance is measured by an AC four-terminal method. The degradation determination device 1 is for determining degradation by connecting two input / output terminals to each of the terminals 3 and 3 of the storage battery 2, and includes a frequency control unit 5, a current supply unit 6, and impedance measurement. Unit 7, phase difference detection unit 8, and deterioration determination unit 9.

  The frequency control unit 5 changes the frequency of the alternating current supplied to the storage battery 2, and a sweep oscillation circuit 11 is used. The sweep oscillation circuit 11 is a circuit that continuously changes the frequency from a low frequency to a high frequency. The frequency changed by the sweep oscillation circuit 11 is supplied to the current supply unit 6.

  The current supply unit 6 supplies an alternating current having a changed frequency to the storage battery 2, and the storage battery 2 is discharged by the supply of the alternating current. The current supply unit 6 includes a sweep waveform amplitude control circuit 12 connected to the sweep oscillation circuit 11 and an output amplifier 13 connected to the circuit 12, and the output amplifier 13 is connected to one terminal 3 of the storage battery 2. The sweep waveform amplitude control circuit 12 is connected to a rectifying / smoothing / integrating circuit 15 connected to the current-voltage conversion circuit 14.

  The impedance measuring unit 7 measures the impedance of the storage battery 2 that changes due to discharge at each frequency. As the impedance measuring unit 7, a voltage differential amplifier 17 connected to the other terminal 3 of the storage battery 2 is used.

  The phase difference detection unit 8 receives the measurement signal from the voltage differential amplifier 17 and the reference signal from the sweep oscillation circuit 11, thereby synchronously detecting these signals and the synchronously detected detection signal. And a phase difference detection circuit 19 for detecting a phase difference based on the above. By the synchronous detection by the synchronous detector 18, the phase difference φ is output to the phase difference detection circuit 19 as a value of cos φ, for example, and the phase difference detection circuit 19 detects the phase difference based on this. Thereby, the phase difference detector 8 detects the phase difference of each frequency from the impedance of each frequency.

  The deterioration determination unit 9 determines deterioration of the storage battery 2 using the phase difference of each frequency detected by the phase difference detection unit 8 as an index. The deterioration determination unit 9 is formed by a phase difference curve calculation unit 21 and a determination unit 22. The phase difference curve calculation unit 21 is a calculation unit that calculates a phase difference curve (characteristic curve F or G) in which the phase difference of the impedance is plotted against the frequency. The determination unit 22 calculates a phase difference area determined by the phase difference curve calculated by the phase difference curve calculation unit 21 within a predetermined frequency range, and determines deterioration of the storage battery 2 based on the calculated phase difference area. This determination is made by comparison with the phase difference area of the reference storage battery D as described above, or by comparison with a predetermined threshold value set in advance.

  Next, another embodiment of the present invention will be described. The deterioration judgment method of this embodiment measures the impedance of each frequency by supplying an alternating current whose frequency has been changed to the storage battery and discharging it, and calculates the actual resistance component and reactance component of the impedance for each measured frequency. An impedance locus is created by plotting on a chart, and deterioration of the storage battery is determined based on the impedance locus.

  The deterioration judgment method of this embodiment does not use an alternating current applied to the storage battery as a fixed frequency in the same manner as in the above embodiment, but applies and discharges an alternating current of a wide range of frequencies to the storage battery, thereby widening the frequency. Impedance is measured over a range. In addition, this embodiment is characterized in that the impedance obtained by the discharge is plotted on a Smith chart and an impedance locus is created to determine deterioration.

  In determining the deterioration of the storage battery, it is preferable to create an impedance locus for the measurement storage battery and the reference storage battery and determine the deterioration of the storage battery based on the impedance locus of the measurement storage battery and the reference storage battery.

  FIG. 6 shows a deterioration determination device 1A used in this embodiment. 5 is different from the deterioration determination device 1 in FIG. 5 in that an impedance locus calculation unit 31 is connected to the voltage differential amplifier 17 constituting the impedance measurement unit 7, and a deterioration determination unit 32 is connected to the impedance locus calculation unit 31. The frequency control unit 5 and the current supply unit 6 are the same as those of the deterioration determination device 1 in FIG. Therefore, in the deterioration determination apparatus 1A, the AC current whose frequency has changed in a wide range is supplied to the storage battery 2 to be discharged, and the impedance that changes due to the discharge is measured corresponding to each frequency. Same as 1. The frequency range of the alternating current to be supplied can be appropriately selected within the range of 0.1 to 1 kHz.

  The impedance locus calculation unit 31 plots the actual resistance component and reactance component of the impedance measured by the impedance measurement unit 7 on a Smith chart to calculate the impedance locus. The deterioration determination unit 32 determines the deterioration of the storage battery 2 based on the impedance locus.

  FIG. 7 shows Smith coordinates. When the impedance is expressed as Rs + jRx, the actual resistance component of the impedance is plotted on the Rs coordinate. The Rs coordinate is zero at the left end and infinite at the right end. A circle Rx in FIG. 7 is a constant resistance circle having a constant actual resistance component, and a numerical value Rx of the reactance component is plotted. These plots create an impedance locus on the Smith chart.

  FIG. 8 shows the impedance locus created on the Smith chart, where locus H is the impedance locus due to the discharge of the storage battery with the CCA value 270, and locus K is the impedance locus due to the discharge of the storage battery with the CCA value 175. In this embodiment, a storage battery with a large CCA value (CCA value 270) can be used as a reference storage battery for determination of deterioration, and a storage battery with a small CCA value (CCA value 175) can be used as a measurement storage battery that requires determination of deterioration.

  As a result of the examination by comparing the impedance trajectory of the Smith chart and the CCA value of the storage battery, the present inventors have confirmed that the impedance trajectory tends to converge inward as the CCA value decreases, that is, as the deterioration progresses. . In FIG. 8, the impedance trajectory K (measurement storage battery) converges inward with respect to the impedance trajectory H of the reference storage battery, and deterioration of the measurement storage battery can be determined based on the degree of convergence to the inside.

  According to the deterioration determination of such an embodiment, the impedance of the storage battery is measured within a wide frequency range, and this impedance is plotted on a Smith chart to create an impedance locus. Deterioration can be easily determined. Moreover, since the deterioration of the storage battery is evaluated from the degree of convergence of the impedance locus, the quantitative accuracy of the degree of deterioration is improved. Therefore, the deterioration determination of the storage battery can be performed with high accuracy.

  In this embodiment, it is possible to determine the deterioration of the storage battery based on the locus area determined by the impedance locus in addition to the impedance locus on the Smith chart. FIG. 9 shows a case where the locus area is determined by the impedance locus H, K. The trajectory area can be calculated by integrating the area surrounded by a line connecting the start point and the end point plotted on the Smith chart by determining the frequency range used for measurement.

  The area P in FIG. 9 is the locus area of the impedance locus H, and the area Q is the locus area of the impedance locus K. As described above, since the impedance trajectory converges as the deterioration progresses, the magnitudes of the trajectory areas P and Q correspond to the magnitude of the CCA value, that is, the degree of progress of the degradation. Therefore, the deterioration determination unit 32 can compare the two trajectory areas P and Q to determine the degree of deterioration of the measured storage battery (storage battery with CCA value 175) with respect to the reference storage battery (storage battery with CCA value 270). As described above, the deterioration of the storage battery can be easily determined by the deterioration determination based on the locus area of the impedance locus. In this case, since the deterioration of the storage battery is evaluated by the numerical value of the locus area, the quantitative accuracy of the degree of deterioration is improved.

In this embodiment, the deterioration of the storage battery is determined based on the difference between the impedance locus of the reference storage battery and the impedance locus of the measurement storage battery. However, the present invention is not limited to this. However, the deterioration may be determined by comparison with this threshold value. The determination in this case can be made by calculating the impedance locus of the measurement storage battery within a predetermined frequency range and comparing the impedance locus with a threshold value.
The

DESCRIPTION OF SYMBOLS 1, 1A Degradation judgment apparatus 2 Storage battery 5 Frequency control part 6 Current supply part 7 Impedance measurement part 8 Phase difference detection part 9, 32 Degradation judgment part 21 Phase difference curve calculation part 22 Determination part 31 Impedance locus calculation part F, G Phase difference Curve H, K Impedance locus P, Q locus area

Claims (11)

  A phase difference curve in which the impedance of each frequency is measured by supplying an alternating current having a changed frequency to the storage battery and discharged, the phase difference of the impedance is detected from the measured value, and the phase difference is plotted against the frequency And determining deterioration of the storage battery based on the phase difference area determined by the phase difference curve within a predetermined frequency range. A method for judging deterioration of a storage battery according to claim 1,
After detecting the phase difference of the impedance with respect to the measurement storage battery and the reference storage battery, and creating the phase difference curve with respect to the measurement storage battery and the reference storage battery, between the phase difference curve of the reference storage battery and the phase difference curve of the measurement storage battery A deterioration determination method for a storage battery, wherein the deterioration of the measurement storage battery is determined by comparing the difference curve area determined by the difference of the phase difference curve.   Measure the impedance of each frequency by supplying alternating current of varying frequency to the storage battery and discharging it, and plot the actual resistance component and reactance component of the impedance for each measured frequency on a Smith chart to create an impedance locus And determining a deterioration of the storage battery based on the impedance trajectory. A method for judging deterioration of a storage battery according to claim 3,
A method for determining deterioration of a storage battery, wherein the impedance locus is created for a measurement storage battery and a reference storage battery, and the deterioration of the measurement storage battery is determined by comparing impedance traces of the measurement storage battery and the reference storage battery.   The deterioration determination method for a lead storage battery according to any one of claims 1 to 4, wherein the alternating current is changed in a frequency range of 0.1 to 1 kHz. A frequency controller that changes the frequency of the alternating current;
A current supply unit for supplying and discharging an alternating current whose frequency is changed by the frequency control unit to the storage battery;
An impedance measuring unit that measures the impedance of the storage battery that changes due to the discharge;
A phase difference detection unit for detecting a phase difference of impedance by synchronously detecting a reference signal from the frequency control unit and a measurement signal from the impedance measurement unit;
A deterioration determination unit for a storage battery, comprising: a deterioration determination unit that determines deterioration of the storage battery using the phase difference of the phase difference detection unit as an index. A storage battery deterioration determination device according to claim 6,
The deterioration determining unit includes a phase difference curve calculating unit that calculates a phase difference curve in which the phase difference of the impedance is plotted with respect to the frequency, and a phase difference area determined by the phase difference curve within a predetermined frequency range. And a determination unit for determining deterioration based on the battery. A storage battery deterioration determination device according to claim 7,
The phase difference detection unit detects the phase difference of the impedance for the measurement storage battery and the reference storage battery, the phase difference curve calculation unit creates the phase difference curve for the measurement storage battery and the reference storage battery, and the determination unit The difference between the phase difference curve of the reference storage battery and the phase difference curve of the measurement storage battery is determined within a predetermined frequency range, and the deterioration of the measurement storage battery is judged based on the difference curve area determined by the difference of the phase difference curve An apparatus for judging deterioration of a storage battery. A frequency controller that changes the frequency of the alternating current;
A current supply unit for supplying and discharging an alternating current whose frequency is changed by the frequency control unit to the storage battery;
An impedance measuring unit that measures the impedance of the storage battery that changes due to the discharge;
An impedance trajectory calculating unit that calculates an impedance trajectory by plotting the actual resistance component and reactance component of the impedance measured by the impedance measuring unit on a Smith chart;
A deterioration determination device for a storage battery, comprising: a deterioration determination unit that determines deterioration of the storage battery based on the impedance locus determined by the impedance locus calculation unit. A deterioration determination device for a storage battery according to claim 9,
The impedance trajectory calculating unit plots the actual resistance component and reactance component of the measurement storage battery and the reference storage battery on the Smith chart and calculates the impedance trajectory for the measurement storage battery and the reference storage battery. Judgment device.   The deterioration determination device for a lead storage battery according to any one of claims 6 to 10, wherein the frequency control unit changes the alternating current in a frequency range of 0.1 to 1 kHz.

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