JPH0427885A - Internal impedance measuring device for lead-acid storage battery - Google Patents

Abstract

PURPOSE:To obtain an internal impedance measuring device for a lead-acid storage battery free from erroneous operations by setting the output voltage of alternating current path at a proper voltage automatically corresponding to the voltage of a battery being measured. CONSTITUTION:A voltage detection controller 2 automatically detects the voltage of a lead-acid storage battery 3 being measured and outputs control signals corresponding to the voltage. In the controller 2 is memorized in advance the relation between the battery voltage and proper impression voltage so that it outputs control signals indicating a proper impression voltage for every input of detected voltage. When alternating current is being given to the battery 3, the controller 2 does not function for detection. A variable voltage direct current source 4 outputs slightly higher direct current voltage than the voltage of battery 3 to an alternating current path 5 according to the control signals output from the controller 2. The current path 5 having an inverter circuit 4 capable of frequency control converts the direct current voltage to an alternating current voltage with a determined frequency and outputs proper alternating current voltage corresponding to the voltage of the battery 3. An alternating current voltage detecter 6 detects the alternating current voltage caused between measuring electrodes of the battery 3. An anode and a cathode are usually used for the measuring electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an internal impedance measuring device for lead-acid batteries.

[Prior Art] Conventionally, the lifespan of a lead-acid battery (reduction in electrolyte and deterioration of the anode grid) has been determined from changes in internal impedance of the battery. As a method for measuring the internal impedance of a lead-acid battery, a measuring method called an alternating current method is often used. In this AC method, an AC measurement current is passed between an anode and a cathode of a battery to be measured, and internal impedance is measured from an AC voltage component between predetermined measurement electrodes. The frequency of the alternating current used in this case is IK when the reduction in the electrolyte is to be measured.
A relatively high frequency of about Hz is used, and when deterioration of the anode grid is to be measured, a low frequency of 100 Hx or less is used.

[Problems to be Solved by the Invention] When using such a low-frequency measurement current, it is difficult to conduct current to the battery under test due to capacitor or transformer coupling, so the battery under test and the alternating current carrying part must be coupled with direct current. Must be. In this case, the power supply voltage of the AC current-carrying section must be appropriately higher than the voltage of the battery to be measured. Therefore, in a measuring device that can measure both a single cell and a battery pack made of a combination of multiple cells, a power source that outputs a voltage value corresponding to the voltage of the battery pack with a higher voltage is used. When such a measuring device is used to measure a low-voltage battery such as a single cell, the applied voltage is higher than necessary (which increases the power consumption and the amount of heat generated by the control element for energizing the measurement current). It is possible to manually change the power supply voltage according to the voltage of the various batteries being measured, but the voltage switching operation is troublesome and
There is a problem that it is easy to make mistakes in operation.

An object of the present invention is to provide an internal impedance measuring device for a lead-acid battery that solves the above problems by automatically setting the output voltage of an AC current carrying part to an appropriate voltage value in accordance with the voltage of the battery to be measured. Our goal is to provide the following.

[Means for Solving the Problems] In order to solve the above problems, the internal impedance measuring device of the present invention has an internal impedance measurement device that uses AC between the anode and cathode of the lead-acid battery 3, as shown in the embodiment shown in the drawings. A measurement current is applied to the lead-acid battery 3 from the AC voltage component between predetermined measurement electrodes.
A device for measuring the internal impedance of a lead-acid battery 3 includes a voltage detection control unit 2 that detects the voltage of a lead-acid battery 3 and outputs a control signal according to the detected voltage, and a voltage detection control unit 2 that detects the voltage of a lead-acid battery 3 and outputs a control signal according to the detected voltage, and an appropriate a variable voltage DC power supply 4 that outputs a DC voltage of a certain height, and an AC current conducting section 5 that converts the output voltage of the DC power supply 4 into an AC voltage and passes an AC measurement current to the lead acid battery 3. There is. A known method may be used to measure and display the internal impedance.

E Effect In the internal impedance measuring device with the above configuration,
When measuring batteries with various different voltages, from single cells to assembled batteries, there is no need to manually switch the measurement power supply voltage (it can be done automatically. Therefore, the measurement operation is easy, There is no risk of malfunction.

Further, the power consumption during measurement of a low-voltage battery such as a unit cell, the amount of heat generated by the control element for supplying the measurement current, etc., do not increase, and the control element and the heat sink can be made smaller.

"Example code" The present invention will be described in detail below with reference to the drawings.

In the drawings, reference numeral 1 denotes a power source, 2 a voltage detection control unit that operates by being supplied with power from the power supply, and 3 a lead-acid battery to be measured whose voltage is detected by the voltage detection control unit. 4 is a variable voltage DC power supply whose output voltage is controlled based on the voltage detected by the voltage detection control unit 2; 5 is a lead-acid battery to be measured by converting the output voltage of this DC power supply into an AC voltage and applying the required AC measurement current to the AC voltage; 3
This is an alternating current energizing section that energizes the. 6 is an AC voltage detection unit that detects the AC voltage between predetermined measurement electrodes of the lead-acid battery 3 to be measured, and 7 is an internal impedance that displays the internal impedance of the lead-acid battery 3 to be measured based on the detection output of this AC voltage detection unit. This is the display section.

In the above embodiment, the voltage detection control unit 2 automatically detects the voltage of the lead acid battery 3 to be measured and outputs a control signal according to the detected voltage. The voltage detection control section 2 stores the relationship between the battery voltage and the appropriate applied voltage in advance as data, and outputs a control signal indicating the appropriate applied voltage every time the detected voltage is input. Note that, of course, when the battery 3 is being supplied with alternating current, the voltage detection control section 2 does not perform the detection operation. The variable voltage DC power supply 4 outputs a DC voltage slightly higher than the voltage of the lead acid battery 3 to the AC current supply unit 5 based on the control signal output from the voltage detection control unit 2 . Automatic control of the DC voltage can be performed using, for example, a chopper circuit. The AC current supply section 5 includes an inverter circuit that can control the frequency, converts the DC voltage into an AC voltage of a predetermined frequency, and outputs an AC voltage of an appropriate value corresponding to the voltage of the battery 3. The AC voltage detection section 6 detects the AC voltage generated between the measurement electrodes of the battery to be measured 3. As the measurement electrodes, an anode and a cathode can usually be used, but it is of course possible to arrange a dedicated measurement electrode inside the battery.

As described above, the internal impedance of a single cell to an assembled battery consisting of a combination of a plurality of cells can be easily measured.

[Effects of the Invention] As described above, according to the internal impedance measuring device for a lead-acid battery according to the present invention, the voltage of the battery to be measured can be detected by the voltage detection control section and the output voltage of the variable voltage DC power source can be switched. By switching the AC voltage output from the AC current carrying part to an appropriate voltage value corresponding to the voltage of the battery being measured, it is possible to measure the internal impedance of batteries with various different voltages, from single cells to assembled batteries. In this case, the necessary switching of the measurement power supply voltage can be carried out automatically without manual operation, making the measurement operation easier and eliminating the possibility of erroneous operation.

Also, when measuring low voltage batteries such as single cells,
Since the measurement power supply voltage can be automatically lowered, power consumption during measurement and heat generation of the measurement current control element do not increase more than necessary, and the control element and heat dissipation member can be made smaller, making measurement easier. The device can be made smaller.

[Brief explanation of the drawing]

The drawing is a block diagram showing an overview of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Power supply, 2... Voltage detection control part, 3... Lead-acid battery to be measured, 4... Voltage variable DC power supply, 5... AC current carrying part, 6... AC voltage detection Part, 7...Internal impedance display part. Procedural amendment (dispatch) September 4, 1990 Director General of the Patent Office Satoshi Uematsu 1, Indication of the case Patent application No. 2-132477 2゜3゜4゜Name of invention Correction of internal impedance measuring device for lead-acid batteries Relationship with the patent applicant (120) Shin-Kobe Electric Co., Ltd.

Claims (1)

[Scope of Claims] An apparatus for passing an alternating current measurement current between an anode and a cathode of a lead acid battery (3) and measuring the internal impedance of the lead acid battery (3) from an alternating current voltage component between predetermined measurement electrodes, comprising: a voltage detection control unit (2) that detects the voltage of the lead acid battery (3) and outputs a control signal according to the detected voltage; a variable voltage DC power supply (4) that outputs a DC voltage of a certain value; and an AC current that converts the output voltage of the DC power supply (4) into an AC voltage and passes the AC measurement current to the lead acid battery (3). An internal impedance measuring device for a lead-acid battery, comprising a current-carrying section (5).