JP2017122587A - Storage battery degradation level measurement method and device using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a degradation level measurement device capable of easily measuring internal resistance components which are minute change, and a degradation level measurement method using the device.SOLUTION: The storage battery degradation level measurement device includes a control unit 6 that measures degradation level the storage battery 1. The storage battery degradation level measurement device includes a capacitor 3 having a voltage resistance larger than a rated voltage of the storage battery; a first switching part 4a which includes the storage battery 1 and the capacitor 3 connected in series to each other to form a closed loop; a measurement section 5 that measures a voltage across both ends of the first switching part 4a; and a current source 2 that flows a current to the storage battery 1. The control unit 6 estimates degradation level of the storage battery 1 by executing a switching operation of the first switching part 4a to flow a current from the current source 2 to the storage battery 1 using a voltage value measured by the measurement section 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for measuring the degree of deterioration of a storage battery and an apparatus for measuring the degree of deterioration using the method.

  Conventionally, as shown in Patent Document 1, a storage battery deterioration determination device that measures an internal resistance component of a storage battery by measuring only an AC voltage excluding the DC voltage of the storage battery has been disclosed.

JP-A-11-118891

  When a storage battery (secondary battery) continues to be used for many years, the internal resistance component increases and deteriorates. This internal resistance component shows only a small change compared to the output voltage of the storage battery, although it is a change that should be emphasized as an index for measuring the degree of deterioration of the storage battery. Because of this, it was difficult to measure the amount of change by measuring with AC.

  Therefore, the present invention can easily measure the internal resistance component showing a minute change regardless of the DC voltage / AC voltage, and uses the degradation degree measuring method and the same method for calculating the magnitude of the internal resistance component as the degradation degree. An object of the present invention is to provide a degradation degree measuring apparatus.

  In order to solve the above problems, a storage battery deterioration degree measuring method of the present invention is a storage battery deterioration degree measuring method for measuring an internal resistance component of a chargeable / dischargeable storage battery, and has a withstand voltage equal to or higher than the rated voltage of the storage battery. A first step of connecting a capacitor, the storage battery, and an open / close unit in series to close the open / close unit to form a closed loop; and a second step of determining whether the potentials of the storage battery and the capacitor are equal A third step of opening the open / close unit to open the closed loop after the potentials of the storage battery and the capacitor are equal, and measuring an internal resistance component from a current source provided outside the closed loop to the storage battery And measuring the voltage value at both ends of the opening / closing part while passing the current for measuring the internal resistance component, and from the obtained voltage value, the power storage Calculating the internal resistance component resulting from deterioration, characterized in that it comprises a fifth step of estimating the internal resistance component as the deterioration degree of the battery.

  The storage battery deterioration degree measuring device having a control unit that measures the internal resistance component of a chargeable / dischargeable storage battery includes a capacitor having a withstand voltage equal to or higher than a rated voltage of the storage battery, and the storage battery and the capacitor connected in series. An open / close unit that can be opened and closed; a measurement unit that measures a voltage at both ends of the open / close unit; and a current source that supplies current to the storage battery, and the control unit closes the open / close unit, If the potential of the storage battery and the capacitor are equal, the switching unit is opened to allow current to flow from the current source to the storage battery, and the internal resistance component caused by the deterioration of the storage battery is calculated from the voltage value measured by the measurement unit The deterioration degree of the storage battery is estimated based on the internal resistance component.

With the above configuration, the deterioration degree of the storage battery can be measured using a simple circuit regardless of the DC voltage / AC voltage.

The circuit block diagram of the storage battery degradation degree measuring apparatus which shows embodiment of this invention The flowchart figure of the control part which a storage battery degradation degree apparatus same as the above has. Circuit block diagram of a system example using the above storage battery deterioration degree measuring device The graph showing the voltage value in each of (a) measurement part (b) capacitor | condenser (c) storage battery of embodiment same as the above

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention calculates an internal resistance component caused by deterioration of a storage battery, and obtains the magnitude of the internal resistance component as a degree of deterioration.

  FIG. 1 is a circuit diagram of a storage battery deterioration degree measuring apparatus according to this embodiment.

  The storage battery deterioration degree measuring device includes a storage battery 1, a current source 2, a capacitor 3, a first opening / closing part 4a, a second opening / closing part 4b, a measuring part 5, and a control part 6. The

  The chargeable / dischargeable storage battery 1 deteriorates as the ideal power supply Video indicating the ideal voltage value reflecting the dischargeable storage amount and the charging and discharging of the storage battery 1 are repeated, and the internal resistance component R generated by the deterioration. It can be regarded as an equivalent circuit by series connection. The internal resistance component R gradually increases with a small value while the storage battery 1 repeats charging and discharging. The internal resistance component R is an important index that can indicate the degree of deterioration of the storage battery 1 with a small value, and can be regarded as a variable resistance value that changes with a small value.

  The current source 2 applies a charging current (symbol i1) to the storage battery 1 and may be a DC power source or an AC power source. In this embodiment, the DC power supplied from an external power source (symbol 15 in FIG. 3) is used. As a bidirectional DC / DC converter circuit having a storage operation for converting to a DC voltage level suitable for application to the storage battery 1 and a discharge operation for supplying DC power from the storage battery 1 to an external power source (reference numeral 15 in FIG. 3) Illustrated.

  The capacitor 3 is a storage element having a withstand voltage equal to or higher than the rated voltage value of the storage battery 1, and when the internal resistance component R is zero, in other words, the ideal voltage value when the ideal voltage value is the maximum value is applied. However, the ability to store electricity without damage is required. Since the capacitor 3 does not have to be damaged even if any ideal voltage value of the storage battery 1 is applied, a general-purpose electrolytic capacitor element that is extremely inexpensive and easy to handle may be employed. The storage battery 1 includes an internal resistance component R. When the rated voltage of the storage battery 1 is 45 V, for example, the rated voltage of the capacitor 3 is 60 V. If the rated voltage of the capacitor 3 is larger than the rated voltage of the storage battery 1, The size of the storage battery 1 and the capacitor 3 is not limited to this.

  The first switching part 4a is a switching element having a physical or electrical switching contact for connecting a series circuit of the storage battery 1 and the capacitor 3 to form a closed loop or opening the closed circuit. And relays.

  The second switching unit 4b is a switching having a physical or electrical switching contact for connecting a series circuit of the storage battery 1 and the current source 2 to form a closed loop or opening the closed circuit. It may be an element, a relay, etc., and may be opened and closed without cooperation with the first opening / closing part 4a. However, as long as it does not contradict the control sequence described in FIG. May be opened and closed.

  The measuring unit 5 measures the potential difference between both ends of the switching contact of the first switching unit 4a and outputs it digitally, and an AD converter may be used.

  The control unit 6 calculates the digital voltage value output from the measurement unit 5 obtained as a result of the control for opening / closing the switching contact of the first switching unit 4a and the control for opening / closing the switching contact of the second switching unit 4b. The deterioration level of the storage battery 1 is estimated from the magnitude of the internal resistance component R based on the voltage detection unit (reference numeral 7 in FIG. 3) to be read and the digital voltage value read by the voltage detection section (reference numeral 7 in FIG. 3). It has at least a deterioration judgment unit (reference numeral 10 in FIG. 3).

  The storage battery degradation degree measuring apparatus configured as described above forms a first closed loop that passes through the storage battery 1 and the capacitor 3 when the first opening / closing part 4a is closed, and the storage battery 1 when the second opening / closing part 4b is closed. A second closed loop is formed through the current source 2.

  Moreover, although the storage battery 1 of FIG. 1 is represented by one, what was connected two or more may be sufficient. At this time, the capacitor 3 may be connected to one of the plurality of connected storage batteries 1 having a voltage larger than the whole voltage, or the same as the storage battery 1 connected to a storage battery having a voltage larger than the rated voltage per storage battery. It may be connected for several minutes.

  Hereinafter, the operation method of this embodiment will be described. FIG. 2 is a flowchart of the control unit 6 showing the operation method of the present embodiment.

  First, when the storage battery 1 is turned on (step S0-1), the storage battery 1 is either charged from the current source 2 or discharged to the current source. This is called normal operation, and it can be considered that the deterioration has started (step S0-2).

  Next, the normal operation in step S0-2 is performed until an external input instruction for shifting to the operation mode as a deterioration degree measuring apparatus using the deterioration degree measuring method for the storage battery 1 is given to the control unit 6. If the external input instruction is given to the control unit 6 (No in step S0-3) (Yes in step S0-3), the control unit 6 closes the first opening / closing unit 4a on the capacitor 3 side ( Step S1). At this time, the external input instruction in step S0-3 means a control signal from an external observation circuit or the like (not shown) to the control unit 6, and is measured by a current sensor (not shown) provided in the second closed loop. When a suspicious event such as a decrease in the value of the discharge current emitted from the storage battery 1 is observed, an external input instruction for instructing to estimate the deterioration degree of the storage battery 1 is received from an external observation circuit. Etc., to the control unit 6.

  As a result, the discharge current i2 from the storage battery 1 flows toward the capacitor 3, the power is stored in the capacitor 3, and a voltage is generated in the capacitor 3. When the storage battery 1 and the capacitor 3 become equal voltage Vop, that is, when the current i2 stops flowing from the storage battery 1 (step S2), the first opening / closing part 4a is opened (step S3). At this time, the voltage value sensed by the measurement unit 5 is zero (V). Note that the controller 6 determines that a predetermined time has elapsed until the transfer of power from the current source 2 to the storage battery 1 is completed, or the current i2 flowing in the closed loop between the storage battery 1 and the capacitor 3 is a current not shown. When the sensor no longer senses, the control unit 6 itself is permitted to move from step S2 to step S3.

  Subsequently, the control unit 6 closes the second opening / closing unit 4b on the current source 2 side. Then, since the current i1 flows from the current source 2 toward the storage battery 1, the measurement unit 5 measures the voltage value at both ends of the switching contact of the first switching unit 4a while the current i1 is flowing, and performs sampling. Therefore, the digital signal is taken in as a voltage value Vbit generated by the internal resistance component R of the storage battery 1 (step S4).

  The control unit 6 calculates the internal resistance component R generated by the deterioration from the voltage value Vbit, and has a threshold relating to the deterioration degree, the magnitude of which is the deterioration degree. Compared with the set threshold value, If the calculated threshold value is a larger value (step S5), it indicates that the internal resistance component R of the storage battery 1 has increased, so a notification signal to prompt the maintenance of the storage battery 1 or replacement with a new one is about to be issued. And output to the outside (step S6). Note that the control unit 6 outputs the value of the internal resistance component R to the outside without having a threshold regarding the internal resistance component R so that the transition of the increase in the internal resistance component R is externally determined. In this case, the process of deterioration of the storage battery 1 can be notified in time series. In the above description, in step S5, the threshold value relating to the deterioration degree is provided, but instead, the measured value of the internal resistance component R is deteriorated by the predetermined function prepared in the control unit 6 in advance. You may make it convert into degree.

  By performing the above-described series of operations, the control unit 6 calculates the internal resistance component R of the storage battery 1 using the voltage value Vbit output to the measurement unit 5 and the current i1 flowing from the current source 2, and calculates The degree of deterioration of the storage battery 1 can be measured using the magnitude of the internal resistance component R thus made as the degree of deterioration.

  Hereinafter, an example in which the apparatus or method of the present invention is used in a power supply apparatus will be described.

  FIG. 3 shows a power supply system A using a solar cell 11 for home or non-home that includes the control unit 6 for measuring the deterioration degree of the storage battery according to the present invention.

  The power supply system A includes a converter control unit 13, a unidirectional DC / DC converter 14, a second bidirectional DC / DC converter 15, a bidirectional AC / DC converter 16, and a system control unit 100. The power supply system A is connected to the unidirectional DC / DC converter 14, the second bidirectional DC / DC converter 15, the bidirectional AC / DC converter 16, and the second bidirectional DC / DC converter 15. At least one of the first bidirectional DC / DC converter 2 which is an example of the current source 2 generates power generated by control from the system control unit 100 via a breaker 18 connected to a commercial power supply 12 which is a system power supply. Power is supplied to equipment and household load equipment.

  3 is a function for measuring the internal resistance component R described above with reference to FIGS. 1 and 2 (voltage detection unit 7) and a function for estimating the degree of deterioration of the storage battery 1 (degradation determination unit 10). Are concentrated in the system control unit 100 and transferred. The main role of the control unit 6 in FIG. 3 is specialized in performing opening / closing control on the first opening / closing unit 4a and the second opening / closing unit 4b in response to a command from the system control unit 100.

The electric power supplied from the solar cell 11 is accumulated in the storage battery 1 by the converter control unit 13 through the second bidirectional DC / DC converter 15 via the intermediate potential that is the output of the unidirectional DC / DC converter 14. . At this time, the second bidirectional DC / DC converter 15 becomes the current source 2. In addition, a bidirectional AC / DC converter 16 is connected to the commercial power supply 12 so as to perform system linkage, and the bidirectional AC / DC converter 16 passes through a power supply path independent of the unidirectional DC / DC converter 14. Thus, power can be supplied to the second bidirectional DC / DC converter 15. The unidirectional DC / DC converter 14, the second bidirectional DC / DC converter 15, and the bidirectional AC / DC converter 16 may all be known ones based on a full bridge circuit having a power semiconductor element as a base circuit. The operation control is performed by the converter control unit 13. The first bidirectional DC / DC converter 2 mentioned as an example of the current source 2 is originally a circuit to be controlled by the control unit 6, but both the control unit 6 and the converter control unit 13. In order to prevent the time deviation of each control timing from expanding, the converter control unit 13 may perform operation control without being controlled by the control unit 6.

  Here, the control unit 6 includes a voltage detection unit 7 and a current detection unit 8. When the first opening / closing part 4a is closed, a current i2 flows from the storage battery 1 to the capacitor 3. When it is determined by the voltage detection unit 7 or the current detection unit 8 that the storage battery 1 and the capacitor 3 have the same voltage, that is, the current i2 does not flow, the first opening / closing unit 4a is opened.

  Subsequently, the second opening / closing part 4 b is closed, and a current i <b> 1 is supplied from the second bidirectional DC / DC converter 15. At this time, the voltage value Vbit measured by the measuring unit 5 is a voltage generated by the internal resistance component R. Using the measured voltage value Vbit and the current i1 flowing from the second bidirectional DC / DC converter 15, the internal resistance component R of the storage battery 1 is calculated, and the calculated internal resistance component R is calculated by the control unit 6. It is calculated as the degree of deterioration by the deterioration determining unit 10 having it.

  At this time, if the degree of deterioration exceeds a preset threshold value, a notification signal that prompts replacement of the storage battery is issued. This notification signal is preferably displayed on an electronic device in the house, for example, an interphone or a television through a communication device. For example, the control unit 6 issues a notification signal that prompts the user to replace the storage battery 1 via a user interface 17 typified by an interphone of a residential unit or a smartphone that can be transferred from the interphone.

  The control unit 6 includes a temperature detection unit 9. The temperature detection unit 9 measures the surface temperature of the storage battery 1 using a storage battery heat generation measuring element 9-1 such as a thermistor or a thermocouple, and if the heat generation exceeds a certain value, the storage battery 1 is abnormal for some reason. A signal for stopping the first bidirectional DC / DC converter is issued via the deterioration determination unit 10 in order to stop the power supply of the storage battery 1 assuming that the battery is generating heat.

  Further, power supply by the commercial power source 12 may be used as the current source 2. At this time, the power supplied from the commercial power supply 12 is supplied to the bidirectional AC / DC converter 16, and the current component supplied from the commercial power supply 12 passes through an intermediate potential that is the output of the bidirectional AC / DC converter 16 to It is stored in the storage battery 1 through the two bidirectional DC / DC converters 15.

  FIG. 4 is a graph of voltage values at the time of current application in each of (a) measuring unit 5, (b) capacitor 3, and (c) storage battery 1 from above. The horizontal axis indicates the elapsed time when the current is applied, and the vertical axis indicates the voltage value detected by each.

  When the current i2 is flowing from the storage battery 1 (period A), if the voltage charged in the storage battery 1 is Vop, the voltage value in the measurement unit 5 is zero, the voltage value in the capacitor 3 gradually increases to Vop, A voltage value Vop in the storage battery 1 is detected. When the capacitor 3 reaches the voltage value Vop of the storage battery 1, that is, when the current i2 stops flowing, the current i1 flows from the current source 2 (period B). At this time, the voltage value Vbit generated by the internal resistance component R in the measuring unit 5, the voltage value Vop that remains accumulated because no current flows through the capacitor 3, the voltage value charged in the storage battery 1 and the internal voltage A voltage value Vop + Vbit generated by the resistance component R is detected.

  By using the measuring method using the present storage battery degradation degree device, it is possible to measure only the voltage value caused by the deterioration by removing the rated voltage of the storage battery 1 with an easy circuit regardless of the DC voltage / AC voltage.

As shown in the graph of FIG. 4, the measurement unit 5 can assign only the voltage value Vbit due to the internal resistance component R to the AD converter in full scale. Therefore, a simple circuit and an AD converter with a small number of bits can be provided. Even if it is used, highly accurate measurement is possible, and even minute changes can be detected.

  By using a voltage value of the capacitor 3 that is larger than the rated voltage of the storage battery 1, the degree of deterioration can be measured regardless of the amount of charge of the storage battery 1.

  Moreover, it is preferable that the 1st opening / closing part 4a is connected to the measurement part 5 which has an AD converter via an amplifier circuit at both ends. At this time, by setting the amplification factor of the amplifier circuit to the maximum voltage of the AD converter, the amount of change can be detected in the maximum range of the AD converter, so that the measurement accuracy can be further improved. .

DESCRIPTION OF SYMBOLS 1 Storage battery 2 Current source 3 Capacitor 4a First opening / closing part 4b Second opening / closing part 5 Measuring part 6 Control part R Internal resistance component

Claims (2)

A storage battery deterioration measuring method for measuring an internal resistance component of a chargeable / dischargeable storage battery,
A first step of forming a closed loop by connecting the capacitor having a withstand voltage equal to or higher than the rated voltage of the storage battery, the storage battery and the open / close unit in series to close the open / close unit;
A second step of determining whether or not the potentials of the storage battery and the capacitor are equal;
A third step of opening the open / close portion and opening the closed loop after the potentials of the storage battery and the capacitor are equal;
A fourth step of flowing a current for measuring an internal resistance component from a current source provided outside the closed loop to the storage battery;
While the current for measuring the internal resistance component is flowing, the voltage value at both ends of the switching unit is measured, and the internal resistance component generated by the deterioration of the storage battery is calculated from the obtained voltage value, and the internal resistance component is calculated. And a fifth step of estimating the degree of deterioration of the storage battery. A storage battery deterioration measuring device having a control unit for measuring the internal resistance component of a chargeable / dischargeable storage battery,
A capacitor having a withstand voltage equal to or higher than the rated voltage of the storage battery;
An open / close portion that connects the storage battery and the capacitor in series to form a closed loop; and
A measuring unit for measuring a voltage at both ends of the switching unit;
A current source for passing current to the storage battery,
The controller is
After closing the opening / closing part, if the potential of the storage battery and the capacitor becomes equal, the opening / closing part is opened to allow a current to flow from the current source to the storage battery,
A storage battery deterioration degree measuring apparatus that calculates an internal resistance component caused by deterioration of the storage battery from a voltage value measured by the measurement unit and estimates the deterioration degree of the storage battery based on the internal resistance component.

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