JPH04131779A - Battery abnormality detection device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a device for detecting an abnormality in a battery that is charged with a DC power source that outputs DC at a desired voltage through on/off operations of switching elements.

(Prior Art) FIG. 3 is a circuit diagram showing a conventional example of detecting an abnormality in a battery used in an uninterruptible FTA device.

In FIG. 3, AC power from AC power s2 is converted into DC power by a main rectifier 3, and then this DC power is turned on and off by a chopper transistor 4 as a switching element. Direct current power at a desired voltage can be obtained by controlling the current rate. Here, 5 is a freewheel diode.

The DC power taken out from the chopper transistor 4 passes through a smoothing circuit made up of a DC reactor 6 and a smoothing capacitor 7, whereby pulsations are removed and a smooth DC tRiff power is obtained. This smoothed DC power is supplied to a load 10 via a blocking diode 8, and a battery 9 is charged.

If the AC power supply 2 experiences a power outage or the chopper transistor 4 fails, the battery 9 releases its stored energy, allowing the load 10 to continue operating without a power outage.

In this way, the battery 9 plays an important role in the uninterruptible tfA device.
When using a chopper transistor 4 or the like shown in Figure 3 to charge the battery, the current pulsations will increase heat generation in the battery 9 and shorten its lifespan, so a smoothing circuit with a sufficiently large capacity should be used. The current pulsation is suppressed to a certain value or less. At the same time, the voltage of the battery 9 is introduced to the comparator 11, and the voltage setting device 1
The DC voltage is compared with the value set in step 2, and the presence or absence of an abnormality in the battery 9 is detected from this DC voltage. This is battery 9
This is because the internal resistance changes as the material deteriorates.

[Problems to be Solved by the Invention] However, when detecting an abnormality in the battery 9 using DC voltage using the conventional circuit shown in FIG. be.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to detect an abnormality at an early stage in a battery that is charged with a DC power source that outputs a desired voltage through the on/off operation of a switching element.

[Means for Solving the Problems] In order to achieve the above object, the abnormality detection device of the present invention includes a DC power supply that outputs DC of a desired voltage by turning on and off switching elements, and a DC power supply that is charged by the DC power supply. and a smoothing circuit composed of a DC reactor and a smoothing capacitor located between the DC power supply and the battery, a bypass contact that bypasses a part of the DC reactor and the smoothing capacitor; , comprising a DC cut-off capacitor that cuts the DC component, and AC voltage detection means that detects the voltage drop of the battery via the DC cut-off capacitor;
Alternatively, instead of this AC voltage detection means, a rectifier that rectifies the voltage drop of the battery obtained via the DC cut-off capacitor, and a comparator that compares the DC voltage output from the rectifier with a predetermined value are provided. do.

(Function) This invention focuses on the fact that at the beginning of battery deterioration, changes in AC internal impedance become large. , the battery is charged with a current that contains a large amount of pulsation, and the voltage drop at the second stage is extracted as AC through a DC cut-off capacitor, and the degree of deterioration can be detected at an early stage based on changes in the internal impedance of the battery. This is what we are trying to detect.

〔Example〕

FIG. 1 is a circuit diagram showing the first embodiment of the present invention, in which the circuit of the first embodiment includes an AC current fA2, a main rectifier 3, a chopper transistor 4, a freewheel diode 5, a DC reactor 6, and a smoothing capacitor 7. , blocking diode 8, battery 9, and load 10 are the same as those in the conventional circuit already described in FIG. 3, so their explanation will be omitted.

In the first embodiment circuit shown in FIG. 1, a part of the DC reactor 6 is left and the remaining DC reactor 6, smoothing capacitor 7, and blocking diode 8 are bypassed so that the impedance of the circuit does not become extremely small. A bypass contact 21 is provided.

When the bypass contact 21 is closed during operation of the uninterruptible power supply, the battery 9 is charged with the current containing a large amount of pulsation output from the chopper transistor 4, so even if the battery 9 is in the early stage of deterioration, Since the AC internal impedance of the battery 9 is changing, the degree of deterioration can be detected early by extracting the voltage drop via the DC cutoff capacitor 22 and measuring it with the voltmeter 23.

FIG. 2 is a circuit diagram showing a second embodiment of the present invention, which includes an AC power supply 2, a main rectifier 3, a chopper transistor 4, and a freewheel diode.
1''-5, DC reactor 6, smoothing capacitor 7, blocking diode 8, battery 9, and load 10, their names, uses, and functions are the same as those of the conventional circuit described in FIG. is omitted.

The second embodiment circuit shown in FIG. 2 also has a bypass that leaves a part of the DC reactor and bypasses the remaining DC reactor 6, smoothing capacitor 7, and blocking diode 8, similar to the first embodiment circuit described above. A contact 21 is provided, and the bypass contact 21 is closed to allow a current containing a large amount of pulsation to flow through the haft relay 9. The voltage drop at this time is taken out via the DC cut-off capacitor 22, and the resistor 25
The rectifier 26 converts the DC current into direct current and supplies it to the comparator 27.

The comparator 27 quickly detects a change in the AC internal impedance of the battery 9 by comparing the voltage converted to DC with the value set by the voltage setting device 28.

(Effects of the Invention) According to the present invention, a battery is charged with a current containing a large amount of pulsation by bypassing the smoothing circuit, and changes in the AC internal impedance of the battery are detected through a DC cutoff capacitor. By detecting the amount of voltage drop, it is possible to quickly detect abnormalities in the early stages of battery deterioration.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram showing the first embodiment of the present invention;
FIG. 3 is a circuit diagram showing a second embodiment of the present invention, and FIG. 3 is a circuit diagram showing a conventional example for detecting an abnormality in a battery used in an uninterruptible power supply. 2... DC power supply, 3... Main rectifier, 4... Chopper transistor, 5... Freewheel diode,
6... DC reactor, 7... Smoothing capacitor, 8
...Blocking diode, 9...Battery, 10...
・Load, 1127... Comparator, 12.28...
・Voltage setting device, 21... Bypass contact, 22... DC cut-off capacitor, 23... Voltmeter, 25...
・Resistance, 26... Rectifier. -Meiゝ1 -~Nei,?

Claims (1)

[Claims] 1) A DC power supply that outputs DC at a desired voltage by turning on and off switching elements, a battery that is charged by the DC power supply, and a DC reactor located between the DC power supply and the battery. A device equipped with a smoothing circuit configured with a smoothing capacitor, a bypass contact that bypasses a part of the DC reactor and the smoothing capacitor, a DC cut-off capacitor that cuts a DC component, and the DC cut-off capacitor. An abnormality detection device for a battery, comprising: AC voltage detection means for detecting a voltage drop in the battery via the AC voltage detection means. 2) It consists of a DC power supply that outputs DC at a desired voltage by turning on and off switching elements, a battery that is charged by this DC power supply, and a DC reactor and a smoothing capacitor located between the DC power supply and the battery. A device comprising a smoothing circuit, a bypass contact that bypasses a part of the DC reactor and the smoothing capacitor, a DC cutoff capacitor that cuts a DC component, and the battery obtained through the DC cutoff capacitor. 1. A battery abnormality detection device comprising: a rectifier that rectifies a voltage drop; and a comparator that compares a DC voltage output from the rectifier with a predetermined value.