JP2014149165A - Dc power supply apparatus, degradation determination method of storage battery in dc power supply apparatus, storage battery degradation determination apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage battery degradation determination method for a DC power supply apparatus connected to an external load and a storage battery, which does not require a long time actual discharging.SOLUTION: DC power supply apparatus 10 comprises: a current measuring unit 41 measuring charge/discharge current Ib and outputting a charge/discharge current value S41 at a certain time interval; a voltage measurement unit 42 measuring a charge/discharge terminal voltage Vb and outputting a charge/discharge terminal voltage value S42 at a certain time interval; and a storage battery degradation determination unit 30 that detects a timing for switching from a discharge state to a charge state caused with accompanying a change in output voltage Vout, from the charge/discharge current value S41 and the charge/discharge terminal voltage value S42, and that determines degradation of a storage battery 60 on the basis of the charge/discharge current value S41 and the charge/discharge terminal voltage value S42 before and after the timing. This does not require a long time actual discharge, and allows degradation determination of the storage battery 60 by simple control.

Description

  The present invention relates to a DC power supply apparatus having a storage battery deterioration determination function, a storage battery deterioration determination method in the DC power supply apparatus, and a storage battery deterioration determination apparatus.

  Conventionally, for example, in Patent Document 1 below, the voltage between terminals of a storage battery is measured periodically, the measurement result is stored, and it is detected that there is a predetermined fluctuation in the discharge current. A storage battery management device that detects the presence or absence of abnormality of a storage battery based on the measured voltage between terminals is described.

  In Patent Document 2 below, the charge / discharge terminal voltage of the storage battery when the storage battery discharges with the set discharge current or the change thereof, or the charge / discharge terminal voltage of the storage battery when discharged with the set discharge current is disclosed. A degradation determination circuit that determines the characteristics of a storage battery from the time it reaches a specified voltage is described.

  Patent Document 3 listed below describes an internal impedance detection device that can detect the internal impedance of a secondary battery with high accuracy.

  Further, Patent Document 4 below discloses a storage battery that determines that the life of the storage battery is near when the rate of decrease in the charge / discharge terminal voltage of the storage battery is equal to or greater than a predetermined value and the rate of increase in internal impedance is equal to or greater than a predetermined value. The life diagnosis method is described.

JP 2007-271583 A Japanese Patent No. 4759542 WO2006 / 022073 JP 2002-350521 A

  However, in the conventional storage battery diagnosis method, long-time actual discharge is required to diagnose the deterioration state of the storage battery. In addition, when the battery is discharged while controlling the output voltage of the power supply unit so that the discharge current is constant, it is possible to determine the deterioration of the storage battery without depending on the storage battery capacity and the discharge current. In order to adjust the output voltage of the power supply unit so that the discharge current becomes constant following this, a circuit for detecting the fluctuation of the discharge current and adjusting the output voltage is required in the power supply unit. Is complicated. Furthermore, in the case of the method of measuring the internal impedance, a separate measurement circuit is required.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a DC power supply device that does not require long-time actual discharge and enables determination of storage battery deterioration by simple control, a storage battery deterioration determination method in the DC power supply device, and a storage battery deterioration determination device. That is.

  The direct current power supply device according to the first aspect of the present invention measures a power supply unit that supplies an output voltage and an output current to an external load and a storage battery having a charge / discharge terminal, and a charge / discharge current that flows from the power supply unit to the storage battery. A current measuring unit that outputs a charge / discharge current value at regular time intervals, and a voltage that measures a charge / discharge terminal voltage, which is a voltage of the charge / discharge terminal, and outputs a charge / discharge terminal voltage value at each regular time interval From the state of discharge from the storage battery to the external load, which occurs with a change in the output voltage, from the charging unit and the charging / discharging terminal voltage value input at every predetermined time interval, the power source Storage battery deterioration in which deterioration of the storage battery is determined based on the charge / discharge current value and the charge / discharge terminal voltage value before and after the timing is detected. Characterized by comprising a tough, the.

  A storage battery deterioration determination method according to a second aspect of the present invention is a storage battery deterioration determination method using the DC power supply device, wherein the output voltage of the power supply unit is set lower than a rated output voltage value, and the storage battery is discharged. In a state, at every fixed time interval, while continuing to measure and store the measurement value of the charge / discharge terminal voltage and the charge / discharge current, reset the output voltage of the power supply unit to a rated output voltage value, Detecting a timing at which a difference value between values before and after the certain time interval of the charging / discharging terminal voltage value and the charging / discharging current value measured every certain time interval is switched from negative to positive, and immediately before the timing The process of setting the charge / discharge terminal voltage value and the charge / discharge current value to the discharge voltage value and the discharge current value, respectively, and the difference value of the charge / discharge terminal voltage value measured at each predetermined time interval is zero and the constant time The timing at which the difference value of the charging / discharging current measured at every interval is switched from positive to zero or negative is detected, and the charging / discharging terminal voltage value and the charging / discharging current value immediately before the timing are respectively determined as the charging voltage value and And a process of obtaining a charge current value, a process of obtaining an internal resistance value of the storage battery from the discharge voltage value and the discharge current value, and the charge voltage value and the charge current value.

  A storage battery deterioration determination device according to a third aspect of the present invention is characterized in that a current measurement unit, a voltage measurement unit, and a storage battery deterioration determination unit in the DC power supply device are independent from the DC power supply device.

  According to the DC power supply device, the storage battery deterioration determination method, and the storage battery deterioration determination device of the present invention, the storage battery includes a power supply unit, a current measurement unit, a voltage measurement unit, and a storage battery deterioration determination unit. The deterioration determination unit detects the timing of switching from the discharge state to the charge state caused by the change in the output voltage of the power supply unit based on the charge / discharge current value and the charge / discharge terminal voltage value input at regular time intervals, The deterioration of the storage battery is determined based on the charge / discharge current value and the charge / discharge terminal voltage value before and after this timing. As a result, it is possible to determine the deterioration of the storage battery by simple control without requiring long-time actual discharge.

FIG. 1 is a block diagram showing an outline of the configuration of a DC power supply device 10 in Embodiment 1 of the present invention. FIG. 2 is a circuit diagram showing an example of the power supply unit 20 in FIG. FIG. 3 is a circuit diagram showing an example of the voltage detection circuit 25 in FIG. FIG. 4 is a circuit diagram showing an example of the reference voltage circuit 24 in FIG. FIG. 5 is a diagram showing an equivalent circuit during charging / discharging of the storage battery 60 in FIG. FIG. 6 is a waveform diagram showing temporal changes in the charge / discharge current Ib and the charge / discharge terminal voltage Vb in FIG. FIG. 7 is a diagram for explaining the charge / discharge current value S41 and the charge / discharge terminal voltage value S42 in FIG. FIG. 8 is a flowchart of the calculation process of the internal resistance value of the storage battery 60 of the first embodiment. FIG. 9 is a diagram showing an individual measurement circuit for storage battery cells in the storage battery 60 in FIG. FIG. 10 is a block diagram showing a schematic configuration of a DC power supply device 10A according to the second embodiment of the present invention. FIG. 11 is a block diagram showing an outline of the configuration of a DC power supply device 10B according to the third embodiment of the present invention. FIG. 12 is a block diagram showing an outline of the configuration of the storage battery deterioration diagnosis device 70 according to the fourth embodiment of the present invention.

  Modes for carrying out the present invention will become apparent from the following description of the preferred embodiments when read in light of the accompanying drawings. However, the drawings are only for explanation and do not limit the scope of the present invention.

(Configuration of Example 1)
FIG. 1 is a block diagram showing an outline of a configuration of a DC power supply device 10 according to the first embodiment of the present invention.

  When the input voltage Vin is input, the DC power supply device 10 has a function of outputting an output voltage Vout and supplying a DC current to the load device 50 and the storage battery 60 as external loads. The DC power supply device 10 includes a power supply unit 20 as a power supply unit that outputs an output voltage Vout when an input voltage Vin is input, a current measurement unit 41, a voltage measurement unit 42, and a storage battery deterioration determination unit 30. doing.

  The current measuring unit 41 measures the charging current flowing from the power supply unit 20 to the storage battery 60 and the discharging current flowing from the storage battery 60 to the load device 50, and outputs a charging / discharging current value S41 at regular time intervals (for example, 10 ms). Is. The voltage measuring unit 42 measures the charge / discharge terminal voltage Vb, which is the voltage at the charge / discharge terminal of the storage battery 60, and outputs the charge / discharge terminal voltage value S42 at regular time intervals.

  The storage battery deterioration determination unit 30 changes the output voltage Vout of the power supply unit 20 from the charge / discharge current value S41 and the charge / discharge terminal voltage value S42 input from the current measurement unit 41 and the voltage measurement unit 42 at regular time intervals, respectively. The timing for switching from the discharge state from the storage battery 60 to the load device 50 to the charge state from the power supply unit 20 to the storage battery 60 is detected, and the charge / discharge current value S41 and the charge / discharge terminal voltage value S42 before and after this timing are detected. Based on this, the deterioration of the storage battery 60 is determined.

  The storage battery deterioration determination unit 30 includes an analog / digital (hereinafter referred to as “A / D”) conversion unit 31, a storage unit 32, a calculation unit 33, a comparison unit 34, a notification unit 35, and a voltage command signal generation unit. 36.

  The A / D converter 31 converts the analog charge / discharge current value S41 and the charge / discharge terminal voltage value S42 into digital values. The memory | storage part 32 memorize | stores temporarily the charging / discharging electric current value S41 and charging / discharging terminal voltage value S42 which were converted into the digital value.

  The calculating part 33 calculates | requires the difference value for every fixed time interval of each charging / discharging electric current value S41 converted into the digital value, and charging / discharging terminal voltage value S42, and from a discharge state from the change of the positive / negative sign in these difference values. The timing to switch to the charging state is detected, the internal resistance value r of the storage battery 60 is calculated from the charge / discharge current value S41 and the charge / discharge terminal voltage value S42 before and after this timing, and the initial value of the internal resistance value of the storage battery 60 is further calculated. The increase value Δr from r0 to the internal resistance value r is calculated.

  The comparison unit 34 compares the increase value Δr calculated by the calculation unit 33 with a threshold value, and determines that the storage battery 60 has deteriorated when the increase value Δr becomes equal to or greater than the threshold value. The notification unit 35 notifies the user of the deterioration of the storage battery 60 when the comparison unit 34 determines that the storage battery 60 has deteriorated. Further, the voltage command signal generation unit 36 provides the voltage command signal S30 from the storage battery deterioration determination unit 30 to the output voltage adjustment circuit 23 in the power supply unit 20.

FIG. 2 is a circuit diagram showing an example of the power supply unit 20 in FIG.
The power supply unit 20 includes a central processing unit (hereinafter referred to as “CPU”) 21 that controls the power supply unit 20, an output voltage adjustment circuit 23 connected to the CPU 21, a transformer T1, and a drive signal Vdrv. It includes a switching element SW1 that performs on / off operation, diodes D1, D2, and D3, an inductor L1, and a polar capacitor C1. The power supply unit 20 is connected to the storage battery deterioration determination unit 30 by the internal bus 10a. The bus 10a connects the CPU 21 of the power supply unit 20 and the storage battery deterioration determination unit 30 so that they can communicate with each other.

  The output voltage adjustment circuit 23 is a circuit that controls the output voltage Vout of the power supply unit 20 to be constant. The output voltage adjustment circuit 23 is a voltage detection circuit 25 that detects the output voltage Vout output from the power supply unit 20 and outputs the detection voltage Vdet, and a reference that is a voltage switching unit that switches the reference voltage Vref by the output voltage switching signal Vsel. A voltage circuit 24, an error amplification circuit 26 that amplifies the voltage difference between the detection voltage Vdet and the reference voltage Vref and outputs an error voltage Vdif, and a drive that outputs a drive signal Vdrv to the switching element SW1 based on the error voltage Vdif And a signal forming circuit 27. The output voltage adjustment circuit 23 is a circuit that feeds back a difference between the output voltage Vout and the reference voltage Vref and controls the output voltage Vout to be constant.

  The input terminals Vinp and Vinm of the power supply unit 20 are connected in series to the primary winding of the transformer T1 and the switching element SW1 through an element group (not shown). The secondary winding of the transformer T1 is connected to a rectification output circuit that rectifies the AC output of the transformer T1.

  The rectified output circuit includes diodes D1, D2, and D3, an inductor L1, and a polar capacitor C1. Output terminals Voutp and Voutm of the power supply unit 20 are connected to the output side of the rectification output circuit.

  The diode D1 of the rectification output circuit is connected to the secondary winding of the transformer T1 in the forward direction. The cathode terminal of the diode D1 is connected to the cathode terminal of the diode D2, and the anode terminal of the diode D2 is connected to the ground GND. The cathode terminal of the diode D1 is connected to the positive electrode side of the polar capacitor C1 via the inductor L1, and further connected to the output terminal Voutp via the diode D3 connected in the forward direction. The ground GND of the rectification output circuit is connected to the output terminal Voutm.

  The anode terminal and the cathode terminal of the diode D3 and the ground GND of the rectification output circuit are connected to the voltage detection circuit 25. The node ND-D3A is an anode terminal of the diode D3. Node ND-D3C is a cathode terminal of diode D3.

  The voltage detection circuit 25 measures the voltage Va of the anode terminal (= ND−D3A) and the voltage Vc of the cathode terminal (= ND−D3C) of the diode D3, thereby obtaining the output voltage Vout output from the power supply unit 20. A corresponding detection voltage Vdet is output.

  The error amplification circuit 26 is a circuit that amplifies the voltage difference between the reference voltage Vref and the detection voltage Vdet and outputs an error voltage Vdif. The error amplifier circuit 26 includes an operational amplifier circuit (hereinafter referred to as “op-amp”) AMP1 and resistors R1 and R2. The detection voltage Vdet is input to the non-inverting input terminal of the operational amplifier AMP1, and the reference voltage Vref is input to the inverting input terminal via the resistor R1. Further, a resistor R2 is connected between the inverting input terminal and the output terminal of the operational amplifier AMP1.

FIG. 3 is a circuit diagram showing an example of the voltage detection circuit 25 in FIG.
The voltage detection circuit 25 is a circuit that detects the output voltage Vout output from the power supply unit 20 and outputs a detection voltage Vdet corresponding to the detection result. The voltage detection circuit 25 includes resistors R10, R11, R12, R13, R14, and R15, and diodes D10 and D11. The voltage detection circuit 25 is connected to the node ND-D3A (= the anode terminal of the diode D3), the node ND-D3C (= the cathode terminal), and the ground GND. The anode voltage Va is input from the node ND-D3A, and the cathode voltage Vc is input from the node ND-D3C. An error amplification circuit 26 is connected to the output terminal of the voltage detection circuit 25.

  The node ND-D3A is connected to the ground GND through a diode D10 connected in the forward direction and resistors R10 and R15 connected in series. The diode D10 has a characteristic in which the forward voltage drop is equal to or very close to that of the diode D3. The node ND-D3C is connected to the ground GND via resistors R11, R12, R13, and R14 connected in series. Furthermore, a diode D11 is connected in the forward direction between the resistors R11 and R12 and between the resistors R10 and R15. The detection voltage Vdet is output from between the resistors R13 and R14. The detection voltage Vdet is a voltage corresponding to the output voltage Vout output from the power supply unit 20 and is input to the error amplification circuit 26.

FIG. 4 is a circuit diagram showing the reference voltage circuit 24 in FIG.
The reference voltage circuit 24 is a circuit that outputs a reference voltage Vref. The reference voltage circuit 24 includes resistors R20, R21, R22, R23 and a photocoupler PC1. The reference voltage circuit 24 is connected to the output terminal of the output voltage switching signal Vsel from the CPU 21 and is supplied with a constant voltage Vcc from a power source (not shown). An error amplification circuit 26 is connected to the output side of the reference voltage circuit 24.

  The output terminal of the output voltage switching signal Vsel from the CPU 21 is connected to the ground GND2 via the resistor R20 and the light emitting element of the photocoupler PC1 connected in series. The light receiving element of the photocoupler PC1 has a resistor R23 connected in parallel and connected to the ground GND, and is pulled up to a constant voltage Vcc by resistors R21 and R22 connected in series. The reference voltage Vref is output from between the resistors R21 and R22 and is input to the error amplifying circuit 26.

(Operation of Example 1)
(I) Operation of the power supply unit 20, (II) Principle of calculation of the internal resistance value of the storage battery 60, (III) Details of calculation processing of the internal resistance value of the storage battery 60, and (IV) Deterioration determination of the storage battery 60 The process will be described separately.

(I) Operation of Power Supply Unit 20 The operation of the power supply unit 20 will be described with reference to FIG.

  An input voltage Vin is applied to the power supply unit 20 between the input terminals Vinp and Vinm. When the switching element SW1 is turned on, a direct current flows to the primary winding of the transformer T1 via an element group (not shown), is discharged to the rectification output circuit via the secondary winding of the transformer T1, and further power is supplied to the load device 50. Supplied.

  In the power supply unit 20, a diode D3 is connected to the output terminal Voutp in order to prevent backflow from the output terminal Voutp to the inside. The voltage detection circuit 25 detects a detection voltage Vdet corresponding to the output voltage Vout from the anode voltage Va of the diode D3 and the cathode voltage Vc of the diode D3. The error amplifying circuit 26 amplifies the difference between the detection voltage Vdet and the reference voltage Vref and outputs it as an error voltage Vdif. The drive signal forming circuit 27 outputs the drive signal Vdrv so that the error voltage Vdif becomes constant, and performs feedback control so that the output voltage Vout becomes constant. Further, by switching the output voltage switching signal Vsel, the reference voltage Vref applied to the error amplifying circuit 26 is switched to switch between the rated voltage value Vo and the standby voltage value Vs as the output voltage Vout. The rated voltage value Vo is a voltage for driving the load device 50. The standby voltage value Vs is a voltage value that is lower than the rated voltage value Vo and higher than the lower limit voltage value VL that can drive the load device 50.

  The voltage detection circuit 25 illustrated in FIG. 3 is a circuit that detects a detection voltage Vdet indicating the output voltage Vout of the power supply unit 20. In the power supply unit 20 of the first embodiment, a diode D3 that is a rectifier is connected to the output terminal Voutp in order to prevent backflow from the output terminal Voutp to the inside. The cathode terminal of the diode D3 is a node ND-D3C. The anode terminal of the diode D3 is a node ND-D3A.

  The node ND-D3A is connected to the ground GND via the diode D3 and the resistors R10 and R15. A voltage obtained by subtracting a voltage that falls by the diode D3 (= a voltage that falls by the diode D10) from the anode voltage Va is divided by resistors R10 and R15. Furthermore, a diode D11 is connected in the forward direction between the resistors R11 and R12 and between the resistors R10 and R15.

  When the cathode voltage Vc is lower than or equal to the voltage obtained by subtracting the decrease due to the diode D10 from the anode voltage Va, the voltage obtained by dividing the cathode voltage Vc by the resistors R11, R12, R13, and R14 is the detection voltage Vdet. Is output. When the cathode voltage Vc is higher than the voltage obtained by subtracting the decrease due to the diode D10 from the anode voltage Va, the voltage obtained by subtracting the decrease due to the diode D10 from the anode voltage Va is further divided by the resistors R10, R12, R13, and R14. The pressed voltage is output as the detection voltage Vdet.

The reference voltage circuit 24 shown in FIG. 4 is a circuit that outputs different reference voltages Vref in accordance with the output voltage switching signal Vsel.
When the output voltage switching signal Vsel is at a low level (hereinafter referred to as “L level”), the light emitting element of the photocoupler PC1 does not emit light, and the light receiving element of the photocoupler PC1 is off. Therefore, the reference voltage Vref is a value obtained by dividing the constant voltage Vcc by the resistors R21 to R23.
Vref = {Vcc × (R22 + R23) / (R21 + R22 + R23)}

When the output voltage switching signal Vsel is at a high level (hereinafter referred to as “H level”), the light emitting element of the photocoupler PC1 emits light, and the light receiving element of the photocoupler PC1 is turned on and becomes conductive. When the impedance of the light receiving element of the photocoupler PC1 is a value close to 0, the reference voltage Vref is a value obtained by dividing the constant voltage Vcc by the resistors R21 and R22.
Vref = {Vcc × (R22) / (R21 + R22)}

  In the first embodiment, an analog circuit and a photocoupler are used. However, a CPU having a digital / analog converter (hereinafter referred to as “D / A converter”) is provided in the power supply unit 20, and the CPU outputs an output voltage. A reference voltage Vref corresponding to the switching signal Vsel may be output.

(II) Principle of Calculation of Internal Resistance Value of Storage Battery 60 FIGS. 5A and 5B are diagrams showing an equivalent circuit during charging / discharging of the storage battery 60 in FIG. 1, and FIG. It is a wave form diagram which shows the time change of charging / discharging electric current Ib and charging / discharging terminal voltage Vb.

  FIG. 6 shows the charge / discharge current Ib and the charge / discharge terminal voltage Vb of the storage battery 60 when transitioning between the charge state shown in FIG. 5 (a) and the discharge state shown in FIG. 5 (b). The waveform is shown.

FIG. 5A is an equivalent circuit during charging, and the output voltage Vout of the power supply unit 20 is set to the rated voltage value Vo. In this case, the output current Iout flowing from the power supply unit 20 is split into a load current I _L and the charge-discharge current Ib flowing through the battery 60 to be supplied to the load device 50 at the node N, the load current I _L and the charge and discharge The current Ib merges at the node M and flows into the power supply unit 20. Here, assuming that the storage battery 60 has an internal resistance value r and an internal electromotive force E connected in series, Kirchoff's law is applied to the equivalent circuit of FIG.
_{Iout = Ib + I L ··· (} 1)
Vb = Ib × r + E (2)
= (Iout-I _L ) × r + E (3)
It becomes.

Referring to FIG. 6, the output current Iout in the charging period Tc, charge-discharge current Ib and a load current _{I L,} satisfies the equation (1) relationship.

On the other hand, FIG. 5B is an equivalent circuit during discharge, and the output voltage Vout of the power supply unit 20 is set to be less than the rated voltage value Vo (Vout <Vo). Here, when the output voltage Vout of the power supply unit 20 is set to be lower than the rated voltage value Vo, the case where the input voltage Vin is not supplied to the power supply unit 20 due to a power failure or the like is included. In this case, since the output voltage Vout of the power supply unit 20 is a voltage lower than the discharge terminal voltage Vb of the storage battery 60, the output current Iout = 0, and becomes the discharge current Ib = load current _{I L.} Here, when Kirchhoff's law is applied to the equivalent circuit of FIG.
Ib ₌ I L ··· (4)
Vb = −Ib × r + E (5)
= − (I _L −Iout) × r + E (6)
It becomes.

Referring to FIG. 6, the output current Iout = 0 in the discharge period Td, the charge-discharge current Ib and a load current _{I L,} satisfies the equation (4) relationship.

  In FIG. 6, during the discharge period Td corresponding to the equivalent circuit of FIG. 5B, the charge / discharge terminal voltage Vb is a discharge voltage Vdis having a value smaller than the rated voltage value Vo, and the charge / discharge current Ib is a negative discharge current Idis. It becomes. On the other hand, in the charging period Tc corresponding to the equivalent circuit of FIG. 5A, the charging / discharging terminal voltage Vb becomes substantially equal to the rated voltage value Vo, and the waveform of the charging / discharging current Ib changes from the discharging period Td to the charging period Tc. Immediately after the change, the charging current rapidly rises to Ichg and then decreases gently.

When the discharge voltage value Vdis, the discharge current value Idis, the charge voltage value Vchg, and the charge current value Ichg in FIG. 6 are used, the internal electromotive force E of the storage battery 60 immediately before switching from the discharge state to the charge state and immediately after the start of charging is approximately Since it can be assumed that they are equal, assuming that E in the equations (2) and (5) is equal, the internal resistance value r of the storage battery 60 in FIGS. 5A and 5B is given by the following equation.
r = (Vchg−Vdis) / (Ichg−Idis) (7)

  Therefore, from the charge / discharge current value S41 and the charge / discharge terminal voltage value S42 input from the current measurement unit 41 and the voltage measurement unit 42 in the DC power supply device 10 shown in FIG. If the current value Idis, the charging voltage value Vchg, and the charging current value Ichg can be calculated, the internal resistance value r of the storage battery 60 can be calculated by the equation (7).

FIG. 7 is a diagram for explaining the charge / discharge current value S41 and the charge / discharge terminal voltage value S42 in FIG.
FIG. 7 shows the charge / discharge current value S41 (◯) and the charge / discharge terminal voltage value S42 (●) output at regular time intervals (Δt). For example, the temporal change dIb / dt ≦ 0 of the charge / discharge current value S41 is the charge / discharge current value Ib = Ichg, and the charge / discharge current value Ib = Idis immediately before the timing of switching from the discharge state to the charge state. . Similarly, the charge / discharge terminal voltage value Vb = Vdis immediately before the timing of switching from the discharge state to the charge state, and the charge / discharge terminal voltage value Vb immediately before the charge change / discharge terminal voltage value S42 becomes dVb / dt = 0. = Vchg.

(III) Details of Calculation Process of Internal Resistance Value of Storage Battery 60 FIG. 8 is a flowchart of the calculation process of the internal resistance value of the storage battery 60 in Embodiment 1 of the present invention.

  The calculation process of the internal resistance value r of the storage battery 60 of the first embodiment will be described along the flowchart of FIG. 8 with reference to FIGS.

  In the flowchart of FIG. 8, step ST1 is a process for setting the output voltage Vout of the power supply unit 20 to be less than the rated voltage value Vo and setting the discharge state, and steps ST2 to ST9 detect the timing when the discharge state is switched to the charge state. In this process, the charging / discharging terminal voltage value S42 and the charging / discharging current value S41 immediately before this timing are changed to the discharging voltage value Vdis and the discharging current value Idis, respectively, and after steps ST10 to ST18 are switched from the discharging state to the charging state. The timing at which the charging / discharging terminal voltage value S42 is zero and the temporal change of the charging / discharging current value S41 is zero or negative is detected, and the charging / discharging terminal voltage value S42 and the charging / discharging current value S41 immediately before this timing are respectively charged. A process for obtaining a voltage value Vchg and a charging current value Ichg, and further comprising a step T19 is the above-described (7), is a process of calculating the internal resistance r of the battery 60.

  When the processing of the storage battery deterioration determination unit 30 in FIG. 1 is started, the process proceeds to step ST1, and in step ST1, the voltage command value generation unit 36 outputs the voltage command signal S30 to the power supply unit 20, and The output voltage Vout is set below the rated voltage value Vo, and the process proceeds to step ST2. When the output voltage Vout of the power supply unit 20 is set to be less than the rated voltage value Vo, the equivalent circuit shown in FIG. 5B is discharged. Note that the output voltage Vout may be set to be lower than the rated voltage value Vo by the CPU 21 shown in FIG.

  In step ST2, the charge / discharge current value S41 and the charge / discharge terminal voltage value S42 that are input at regular time intervals are stored in the storage unit 32, and the process proceeds to step ST3. In step ST3, the voltage command value generation unit 36 outputs the voltage command signal S30 to the power supply unit 20, resets the output voltage Vout of the power supply unit 20 to the rated voltage value Vo, and proceeds to step ST4.

In step ST4, charge / discharge is performed from the latest value Vb (n) of the charge / discharge terminal voltage value S42 input at regular time intervals, the previous value Vb (n-1), and the predetermined time interval Δt. The temporal change dVb / dt of the terminal voltage value S42 is calculated by the following equation.
dVb / dt = {Vb (n) −Vb (n−1)} / Δt (8)

Similarly, the charge / discharge current value is calculated from the latest value Ib (n), the previous value Ib (n-1) of the charge / discharge current value S41 input at regular time intervals, and the constant time interval Δt. The temporal change dIb / dt in S41 is calculated by the following equation.
dIb / dt = {Ib (n) −Ib (n−1)} / Δt (9)

  In step ST <b> 4, the calculation unit 33 calculates the expressions (8) and (9) to calculate the temporal changes dVb / dt and dIb / dt of the charge / discharge terminal voltage value S <b> 42 and the charge / discharge current value S <b> 41. Then, the process proceeds to step ST5.

  In step ST5, the operation unit 33 determines whether or not the value of the temporal change dIb / dt of the charge / discharge current value S41 is positive, and the value of the temporal change dIb / dt of the charge / discharge current value S41 is zero or negative. If (N), the process proceeds to step ST6. In step ST6, n = n + 1 is set, and the process returns to step ST4. In step ST5, the processes of steps ST4 and ST5 are repeated until the value of the temporal change dIb / dt of the charge / discharge current value S41 becomes positive (Y). In step ST5, if the value of the temporal change dIb / dt of the charge / discharge current value S41 is positive (Y), the process proceeds to step ST7.

  In step ST7, the operation unit 33 determines whether or not the value of the temporal change dVb / dt of the charge / discharge terminal voltage value S42 is positive, and the value of the temporal change dVb / dt of the charge / discharge terminal voltage value S42 is zero. Or if negative (N), it will progress to step ST8. In step ST8, n = n + 1 is set, and the process returns to step ST4. In step ST7, the processes of steps ST4 to ST7 are repeated until the temporal change dVb / dt of the charge / discharge terminal voltage value S42 becomes positive (Y). In Step ST7, if the value of the temporal change dVb / dt of the charge / discharge terminal voltage value S42 is positive (Y), the process proceeds to Step ST9.

  In step ST9, as the discharge voltage value Vdis and the discharge current value Idis immediately before the change from the discharge state to the charge state, the previous charge / discharge terminal voltage value Vb (n-1) and charge / discharge current value Ib (n- Substitute 1) and proceed to step ST10.

  In step ST10, n = n + 1 is set, and the process proceeds to step ST11. In step ST11, similarly to step ST4, the arithmetic unit 33 performs the calculations of equations (8) and (9) to calculate the charge / discharge terminal voltage value S42. The temporal change dVb / dt and the temporal change dIb / dt of the charge / discharge current value S41 are calculated, and the process proceeds to step ST12.

  In step ST12, the calculation unit 33 determines whether the temporal change dIb / dt of the charge / discharge current value S41 is zero or negative, and the temporal change dIb / dt of the charge / discharge current value S41 is positive. If (N), the process proceeds to step ST13. In step ST13, n = n + 1 is set, and the process returns to step ST11. In step ST12, the processes of steps ST11 to ST13 are performed until the value of the temporal change dIb / dt of the charge / discharge current value S41 becomes zero or negative (Y). Repeatedly, if the value of the temporal change dIb / dt of the charge / discharge current value S41 is zero or negative (Y) in step ST12, the process proceeds to step ST14.

  In step ST14, the operation unit 33 determines whether or not the value of the temporal change dVb / dt of the charge / discharge terminal voltage value S42 is zero, and the value of the temporal change dVb / dt of the charge / discharge terminal voltage value S42 is zero. Otherwise (N), the process proceeds to step ST15. In step ST15, n = n + 1 is set, and the process returns to step ST11. In step ST14, the processes of steps ST11 to ST15 are repeated until the value of the temporal change dVb / dt of the charge / discharge terminal voltage value S42 becomes zero (Y). In Step ST14, if the value of the temporal change dVb / dt of the charge / discharge terminal voltage value S42 is zero (Y), the process proceeds to Step ST16.

  In step ST16, the operation unit 33 determines whether or not the charge / discharge current value Ib (n) is positive. If the charge / discharge current value Ib (n) is not positive (N), the process proceeds to step ST17. In step ST17, n = n + 1 is set, and the process returns to step ST1. In step ST16, the processes of steps ST1 to ST17 are repeated until the charge / discharge current value Ib (n) becomes positive (Y). If the current value Ib (n) is positive (Y), the process proceeds to step ST18.

  In step ST18, as the charging voltage value Vchg and the charging current value Ichg immediately before the charging current changes from the discharging state to the charging state, the charging / discharging terminal voltage value Vb (n-1) and the charging / discharging terminal voltage value Vch (n-1) and charging The discharge current value Ib (n-1) is substituted, and the process proceeds to step ST19. In step ST19, the discharge voltage value Vdis and the discharge current value Idis substituted in step ST9, the charge voltage value Vchg substituted in step ST18, and The charging current value Ichg is substituted into the equation (7), the internal resistance value r of the storage battery 60 is calculated, and the calculation process of the internal resistance value r of the storage battery 60 is finished. The calculated internal resistance value r of the storage battery 60 is stored in the storage unit 32.

(IV) Processing for Determining Deterioration of Storage Battery 60 In FIG. 1, the calculation unit 33 in the storage battery degradation determination unit 30 is an initial value of the internal resistance value of the storage battery 60 from the internal resistance value r of the storage battery 60 stored in the storage unit 32. By subtracting the value r ₀ , an increase value Δr of the internal resistance value of the storage battery 60 is calculated, and this increase value Δr is output to the comparison unit 34.

The comparison unit 34 compares the input increase value Δr with a threshold value, and when the increase value Δr is equal to or greater than the threshold value, determines that the storage battery 60 has deteriorated and outputs a notification signal S34 to the notification unit 35. Here, the threshold value to be compared with the increase value Δr is the load voltage V _L input to the load device 50 when the output voltage Vout of the power supply unit 20 decreases and current is supplied from the storage battery 60 to the load device 50. The value is calculated from the internal resistance value r of the storage battery 60 that may be lower than the operation guarantee voltage of the load device 50.

  When the notification signal S34 is input, the notification unit 35 notifies the user that the storage battery 60 has deteriorated by a display screen (not shown), a warning lamp, a buzzer, or the like.

(Effect of Example 1)
According to the DC power supply device 10 of the first embodiment, the power supply unit 20, the current measurement unit 41, the voltage measurement unit 42, and the storage battery deterioration determination unit 30 are provided, and the current measurement unit 41 and the voltage measurement unit 42 are constant. Based on the charge / discharge current value S41 and the charge / discharge terminal voltage value S42 input at each time interval, the timing for switching from the discharge state to the charge state is detected, and the charge / discharge current value S41 and the charge / discharge terminal voltage before and after this timing are detected. Since the internal resistance value r of the storage battery 60 is calculated from the value S42 and it is determined that the storage battery 60 has deteriorated when the change in the internal resistance value r is greater than or equal to the threshold value, the following (1) to (4) There is an effect like this.

  (1) There is no need to actually discharge the storage battery 60 for a long time, and there is no risk of energy loss or a reduction in backup time after deterioration diagnosis.

  (2) Since it is possible to determine the deterioration of the storage battery 60 without disconnecting the storage battery 60 from the load device 50, the load device 50 is backed up by the storage battery 60 even if the power supply unit 20 is stopped during the deterioration determination of the storage battery 60. Therefore, the load device 50 does not stop.

(3) regardless of the capacity of the storage battery 60 and the load current I _L, it is possible to make an accurate determination of the deterioration of the battery 60.

  (4) It is not necessary to separately provide a circuit for detecting the fluctuation of the discharge current value Idis and adjusting the output voltage Vout in the power supply unit 20, and the control for diagnosing the deterioration of the storage battery 60 can be simplified.

(Modification of Example 1)
FIG. 9 is a diagram showing an individual measurement circuit for storage battery cells in the storage battery 60 in FIG. 1.

FIG. 9 shows an example in which the storage battery 60 in FIG. 1 is configured by connecting a series connection of storage battery cells 60 _{11 to} 60 _{1n and} a series connection of storage battery cells 60 _{21 to} 60 _2n in parallel. .

The storage battery 60 in FIG. 1 and FIG. 8 calculates the internal resistance value r as a lump battery in which storage battery cells are assembled, but the combined internal resistance value Σr1 of the series connection of the storage battery cells 60 _{11 to} 60 _1n is
Σr1 = r11 + r12 +... + R1n (10)
And the internal resistance value Σr2 of the combined series connection of the storage battery cells 60 _{21 to} 60 _2n is
Σr2 = r21 + r22 +... + R2n (11)
It becomes. Since the internal resistance value r as a lump of the storage battery 60 is a parallel connection of Σr1 and Σr2,
r = 1 / (1 / Σr1 + 1 / Σr2) (12)
It becomes.

  Even if one of the storage battery cells constituting the storage battery 60 is deteriorated, it is difficult to identify the deteriorated storage battery cell by the method of calculating the internal resistance value r as a lump of the storage battery 60.

In contrast, for each battery cell, a plurality of current measurement section 41a, 41b and the voltage measuring unit _{42 11, ···, 42 1n,} 42 21, individual measuring circuit of the battery cell in which a · · · _{42 2n} is This is shown in FIG.

  According to the individual measurement circuit for storage battery cells according to the modification, even if the number of series and / or parallel storage battery cells increases, the internal resistance values r11, r12,..., R1n, r21, r22,. .. Since r2n can be calculated, deterioration of the storage battery 60 can be quickly detected at the level of the storage battery cell.

(Configuration and operation of embodiment 2)
FIG. 10 is a block diagram showing an outline of the configuration of the DC power supply device 10A according to the second embodiment of the present invention. Elements common to those in FIG. 1 showing the first embodiment are denoted by common reference numerals. .

  The DC power supply device 10A of the second embodiment includes a power supply unit 20, a voltage measurement unit 42, a load device 50, and a storage battery 60 that are the same as those of the first embodiment, and a current measurement unit 41A and a storage battery deterioration determination unit 30A that are different from the first embodiment. And is constituted by. The current measuring unit 41A includes a first current measuring unit 41c and a second current measuring unit 41d.

The first current measurement unit 41c measures the output current Iout flowing from the power supply unit 20 to the load device 50 and the storage battery 60 and outputs an output current value S41c at regular time intervals. The second current measurement unit 41d and a load current I _L that flows from the power supply unit 20 or the storage battery 60 to the load device 50 measures and outputs a load current value S41d every predetermined time interval.

  The storage battery deterioration determination unit 30A detects the timing of switching from the discharge state to the charge state from the output current value S41c, the load current value S41d, and the charge / discharge terminal voltage value S42 that are input at regular time intervals, and before and after this timing. The deterioration of the storage battery 60 is determined based on the output current value S41c, the load current value S41d, and the charge / discharge terminal voltage value S42.

From the output current value S41c and the load current value S41d input at regular time intervals in the calculation unit 33A in the storage battery deterioration determination unit 30A, Ib = Iout−I _L and (4) from the above-described equation (1). The value of the charge / discharge current Ib is calculated as Ib = I _L −Iout by the equation, and the value of the charge / discharge current Ib and the charge / discharge terminal voltage value S 42 input from the voltage measurement unit 42 at regular time intervals are calculated. Based on the flowchart shown in FIG. 8, the calculation process of the internal resistance value r of the storage battery 60 is performed, and the storage battery 60 is deteriorated when the calculated increase value Δr of the internal resistance value r is equal to or greater than the threshold value. It is determined. Other operations are the same as those in the first embodiment.

(Effect of Example 2)
DC power supply apparatus 10A of the second embodiment, a second current measuring unit 41d for outputting a load current value S41d every predetermined time intervals by measuring the load current I _L that flows from the power supply unit 20 to the load device 50 Yes. Therefore, in addition to the effects of Embodiment 1, it is possible to estimate the charge and discharge terminal voltage Vb at the time of discharge of the storage battery 60 from the load current I _L which flows to the load device 50 is how much decreased, when the storage battery discharging, the load Based on the actual load current _IL , it is possible to determine whether the device 50 is likely to drop below the guaranteed operating voltage.

(Configuration and operation of Embodiment 3)
FIG. 11 is a block diagram showing an outline of the configuration of the DC power supply device 10B according to the third embodiment of the present invention. Elements common to those in FIG. 10 illustrating the second embodiment are denoted by common reference numerals. .

  The DC power supply device 10B according to the third embodiment includes a storage battery deterioration determination unit 30A, a current measurement unit 41A, a voltage measurement unit 42, a load device 50, and a storage battery 60 that are the same as those of the second embodiment. Unit 20A.

  The power supply unit 20A in the DC power supply device 10B according to the third embodiment includes a plurality of power supply units 20-1, 20-2,..., 20-n, and each power supply unit 20A (= 20-1, 20). −2,..., 20-n) is input with a control signal S30A for performing each operation instruction or standby instruction from the storage battery deterioration determination unit 30A. Other configurations are the same as those of the second embodiment.

  The number of the power supply units 20A in FIG. 11 to be operated is determined by the control signal S30A for performing the operation instruction or the standby instruction, and becomes the range of the output current Iout corresponding to the operation number. For example, when the range of the output current Iout per power supply unit 20A is 0 to 100A and the number of operating units determined by the control signal 30A is 5, the range of the output current Iout is 400A to 500A. Since the operation for determining the deterioration of the storage battery 60 in the DC power supply device 10B of the third embodiment is the same as that of the second embodiment, a description thereof will be omitted.

(Effect of Example 3)
The DC power supply device 10B according to the third embodiment includes a plurality of power supply units 20-1, 20-2,..., 20-n that can be controlled in an operation or standby state, and operates according to the load current value S41d. The number is controlled. As a result, in addition to the effects of the first and second embodiments, a part of the current flowing from the storage battery 60 to the load device 50 when discharging the storage battery 60 is discharged while being supplemented by the output current Iout from each power supply unit 20A. The internal resistance value r of the storage battery 60 can be estimated while limiting the current value Idis.

(Configuration and operation of embodiment 4)
FIG. 12 is a block diagram showing an outline of the configuration of the storage battery deterioration diagnosis device 70 according to the fourth embodiment of the present invention. Elements common to the elements in FIG. Yes.

  In the storage battery deterioration diagnosis device 70 of the fourth embodiment, the storage battery deterioration determination unit 30, the current measurement unit 41, and the voltage measurement unit 42 in the DC power supply device 10 of the first embodiment are separated from the DC power supply device 10C and made independent. It is a configuration. The operation of the storage battery deterioration diagnosis device 70 according to the fourth embodiment of the present invention is the same as the operation of the storage battery deterioration determination unit 30 in the DC power supply device 10 according to the first embodiment.

(Effect of Example 4)
The storage battery deterioration diagnosis device 70 of the fourth embodiment has a configuration in which a portion having a deterioration determination function of the storage battery 60 is made independent from the DC power supply device 10C. Thus, the present invention can also be applied to DC power supply apparatuses other than the configuration described with reference to FIGS.

(Modification)
This invention is not limited to the said Examples 1-4, A various utilization form and a modification are possible. For example, the following forms (1) to (4) are available as usage forms and modifications.

  (1) In the description of the first to third embodiments, the voltage measuring unit 42 has been described as measuring the charge / discharge terminal voltage Vb, but the voltage measuring unit 42 measures the output voltage Vout of the power supply units 20 and 20A. It is also good. This is because the charge / discharge terminal voltage Vb changes in conjunction with the output voltage Vout of the power supply units 20 and 20A except when the DC power supply devices 10, 10A and 10B are stopped.

  (2) Although the reference voltage circuit 24 in the output voltage adjustment circuit 23 in the power supply unit 20 of the first embodiment has been described as receiving the output voltage switching signal Vsel from the CPU 21 and outputting the reference voltage Vref, the reference voltage circuit 24 is described. The CPU 21 may directly generate and output the reference voltage Vref without providing the reference voltage.

(3) for individual measurement circuit of the storage battery cells ₆₀ 11 _{to 60 2n,} for the convenience of description, has been described as a modification of the first embodiment, the individual measurement circuit of the storage battery cells ₆₀ 11 _{to 60 2n} may in Example 1 It is not limited. The individual measurement circuits of the storage battery cells 60 _{11 to} 60 _2n are also applicable to Examples 3 to 4.

  (4) In the description of Examples 1 to 4, the current measurement unit 41 and the voltage measurement unit 42 have been described as measuring the charge / discharge current and the charge / discharge terminal voltage at regular time intervals (for example, 10 ms). The time interval for measuring the current and the charge / discharge terminal voltage is not limited to a certain time. For example, the time interval for measuring when the change width of the charge / discharge current and the charge / discharge terminal voltage is large may be narrowed. If the time interval measured when the charge / discharge current and the change width of the charge / discharge terminal voltage are large is narrowed, the timing for switching from the discharge state to the charge state can be accurately detected.

10, 10A, 10B, 10C DC power supply device 20, 20A power supply unit 23 output voltage adjustment circuit 30, 30A storage battery degradation determination unit 41, 41a, 41b, 41c, 41d current measurement unit 42 voltage measurement unit 50 load device 60 storage battery 70 storage battery Degradation judgment device

Claims (11)

A power supply for supplying output voltage and output current to an external load and a storage battery having a charge / discharge terminal;
A current measuring unit that measures a charge / discharge current flowing from the power supply unit to the storage battery and outputs a charge / discharge current value at predetermined time intervals; and
A voltage measuring unit that measures a charge / discharge terminal voltage, which is a voltage of the charge / discharge terminal, and outputs a charge / discharge terminal voltage value at each predetermined time interval; and
From the charging / discharging current value and the charging / discharging terminal voltage value that are input at every certain time interval, from the discharge state from the storage battery to the external load that occurs with the change of the output voltage, from the power supply unit to the storage battery Detecting the timing of switching to the state of charge to the storage battery, and determining the deterioration of the storage battery based on the charge / discharge current value and the charge / discharge terminal voltage value before and after the timing; and
A DC power supply device comprising: The storage battery deterioration determination unit
The charging / discharging current value at a timing when the difference value between the charging / discharging current value and the charging / discharging terminal voltage value input before and after the certain time interval changes from negative to positive. The internal resistance value of the storage battery is calculated from the charge / discharge terminal voltage value, the charge / discharge current value and the charge / discharge terminal voltage value at the timing of changing from positive to zero or negative, and based on the internal resistance value The direct current power supply device according to claim 1, wherein deterioration of the storage battery is determined. The deterioration determination of the storage battery in the storage battery deterioration determination unit,
By comparing the internal resistance value increased value obtained by subtracting the initial value of the internal resistance value of the storage battery from the internal resistance value and a threshold value, the storage battery deteriorated when the increased value is equal to or greater than the threshold value. The DC power supply device according to claim 2, wherein The deterioration determination of the storage battery in the storage battery deterioration determination unit,
A voltage drop when the storage battery is in a discharged state is estimated from the internal resistance value and the rated current of the external load or an actual value of the load current, and the voltage drop is less than the operation guarantee voltage of the external load. The DC power supply device according to claim 2, wherein the storage battery is determined to have deteriorated when there is a risk of becoming. The storage battery is configured by connecting a plurality of storage battery cells in series and / or in parallel,
The storage battery deterioration determination unit
5. The DC power supply according to claim 1, wherein deterioration of the storage battery is determined based on a cell charge / discharge current value and a cell charge / discharge terminal voltage measured for each of the plurality of storage battery cells. apparatus. The current measuring unit is
A first current measurement unit that measures the output current flowing from the power supply unit to the external load and the storage battery and outputs an output current value at each predetermined time interval; and
A second current measuring unit that measures a load current flowing from the power supply unit to the external load and outputs a load current value at each predetermined time interval; and
The storage battery deterioration determination unit
From the output current value, the load current value, and the charge / discharge terminal voltage value that are input at every predetermined time interval, a discharge state from the storage battery to the external load that occurs with a change in the output voltage of the power supply unit From the power supply unit, the timing of switching to the charged state of the storage battery is detected, and the deterioration of the storage battery is determined based on the output current value, the load current value, and the charge / discharge terminal voltage value before and after the timing. The DC power supply device according to claim 1, wherein: The power supply unit is configured by connecting a plurality of power supply units in parallel,
The storage battery deterioration determination unit further includes:
According to the load current value, an operation instruction or a standby instruction is given to each of the plurality of power supply units,
The DC power supply device according to claim 6, wherein the plurality of power supply units are controlled to be in an operation state or a standby state in accordance with the operation instruction or the standby instruction. The storage battery deterioration determination unit further includes:
The voltage command signal for changing the output voltage is output to the power supply unit so as to switch from a discharge state from the storage battery to the external load to a charge state from the power supply unit to the storage battery. The DC power supply device according to any one of 1 to 7. The storage battery deterioration determination unit further includes:
The DC power supply device according to any one of claims 1 to 8, further comprising notification means for notifying deterioration of the storage battery. A storage battery deterioration determination method for determining deterioration of the storage battery connected to the DC power supply device using the DC power supply device according to any one of claims 1 to 9,
The output voltage of the power supply unit is set lower than a rated output voltage value, the storage battery is set in a discharge state, and the charge / discharge terminal voltage and the charge / discharge current are measured and stored at regular intervals. Continuing and resetting the output voltage of the power supply unit to a rated output voltage value, before and after the fixed time interval of the charge / discharge terminal voltage value and the charge / discharge current value measured at the fixed time interval Detecting a timing at which the difference value of the value is switched from negative to positive, and setting the charge / discharge terminal voltage value and the charge / discharge current value immediately before the timing to a discharge voltage value and a discharge current value, respectively;
Detects a timing at which the difference value of the charge / discharge terminal voltage value measured at each fixed time interval is zero and the difference value of the charge / discharge current measured at the fixed time interval switches from positive to zero or negative And the process which makes the charging / discharging terminal voltage value and the charging / discharging current value immediately before the timing a charging voltage value and a charging current value, respectively,
A process for obtaining an internal resistance value of the storage battery from the discharge voltage value and the discharge current value, and the charge voltage value and the charge current value;
A method for determining deterioration of a storage battery, comprising: From a DC power supply device having a power supply unit that supplies output voltage and output current to an external load and a storage battery having a charge / discharge terminal, the charge / discharge current value flowing through the storage battery is measured and the charge / discharge current value is determined at regular time intervals. An output current measurement unit;
A voltage measuring unit that measures a charge / discharge terminal voltage of the charge / discharge terminal and outputs a charge / discharge terminal voltage value at each predetermined time interval; and
The charging / discharging current value and the charging / discharging terminal voltage value are inputted at every predetermined time interval, and the storage battery that is generated along with the change of the output voltage based on the charging / discharging current value and the charging / discharging terminal voltage value. The timing of switching from the discharge state to the external load to the charge state to the storage battery from the DC power supply device is detected, and based on the charge / discharge current value and the charge / discharge terminal voltage value before and after the timing, the storage battery A storage battery deterioration determination unit for determining deterioration;
A storage battery deterioration determination device comprising:

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