JPH06100641B2 - Battery deterioration detection circuit for uninterruptible power supply - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention detects a deterioration of a battery in an uninterruptible power supply device including a power supply circuit for outputting DC power and a battery connected in parallel on the output side, The present invention relates to a circuit for displaying.

(Prior Art) When an optical fiber cable is used for a subscriber line that connects a communication terminal device and a telephone station, power cannot be supplied by the fiber cable, so that an uninterruptible power supply is required on the terminal device side. This power source normally operates by receiving commercial power, and when a power failure occurs, a battery mounted in the power source generally supplies power to a load.

Secondary batteries such as sealed lead-acid batteries and nickel-cadmium batteries are usually used as batteries, but the current battery life is several years or less.

In addition, it is not preferable to use a deteriorated battery because the time during which power can be supplied during a power failure is shortened. Therefore,
It is necessary to detect the decrease in capacity and replace the battery before the battery life is completely exhausted.

For such an application, a deterioration detection circuit which has been devised by the present inventors and applied as a patent application No. 59751 in 1982 has been considered. This conventional method is a method of measuring the open circuit voltage of the battery by disconnecting the power supply circuit and the battery for a certain period of time or a method of discharging the battery for a short time after disconnecting both and measuring the amount of decrease in the battery voltage. Also detected that the voltage was lower than the specified value.
However, the voltage of the battery has a large variation due to the history of battery charging, such as when the battery is being discharged, for example immediately after the power failure is recovered. It has the drawback of being limited to

In addition, voltage measurement during short-time discharge requires at least several seconds until the judgment result becomes clear after inputting the deterioration judgment command because the discharge time requires several seconds or more, until the deterioration judgment result is obtained. It had an inconvenient aspect that the time was long.

(Object of the Invention) The present invention has been proposed in order to improve the above-mentioned drawbacks, and is intended to judge the deterioration by the magnitude of the inrush current at the initial stage of charging by utilizing the relationship between the internal resistance of the battery and the deterioration. The purpose of this is to replace the battery before it deteriorates completely to reach the end of its service life, to secure the time during which power can be supplied during a power outage, and to reduce the variation in deterioration of the battery to be replaced. Is to raise.

(Structure of the invention) In order to achieve the above object, the present invention has a power supply circuit that outputs DC power, and a battery connected in parallel to the output side of the power supply circuit. In an uninterruptible power supply device that supplies electric power to a load connected in parallel to a battery, connected between the battery and the power supply circuit and becomes non-conductive or conductive when a predetermined signal or a predetermined operation is applied. A switch element, a circuit for transmitting a signal that makes the switch element non-conductive for a first constant period, and a charging current that flows into the battery only for a second predetermined period immediately after the switch element becomes conductive. Of the uninterruptible power supply device for detecting the charging current and detecting that the charging current does not become larger than a predetermined value during the second constant period. Invention of deterioration detection circuit This is the purpose.

Furthermore, the present invention has a power supply circuit that outputs DC power and a battery connected in parallel to the output side of the power supply circuit, and supplies power from the power supply circuit and the battery to a load connected in parallel to the battery. In the uninterruptible power supply to be supplied, a circuit for controlling the output voltage of the power supply circuit to rise by a certain constant voltage value for a predetermined constant period, and the charging current for only the constant period is detected, and the charging current is A battery deterioration detection circuit for an uninterruptible power supply, which is provided with a circuit for detecting that the value does not become larger than a predetermined value and displaying the detected value, is the gist of the invention.

Next, an embodiment of the present invention will be described with reference to the accompanying drawings. It is needless to say that the embodiment is merely an example, and various modifications and improvements can be made without departing from the spirit of the present invention.

FIG. 1 shows an embodiment of the present invention, in which 1 is a power supply device, 2 is a battery, 3A and 3B are device output terminals, 4 is a first switch element, 5 is a switch drive signal input circuit, and 6 is A timer circuit, 7 is a current detection element, 8 is a current detection circuit, and 9 is a display circuit. FIG. 1 shows the configuration of a floating charging type uninterruptible power supply in which power is supplied to a battery and a load through a first switch element 4 which is conducted by a DC output of a power supply device 1.

Among such uninterruptible power supplies, lead-acid batteries and small sealed lead-acid batteries (hereinafter abbreviated as lead-acid batteries) are often used. The state in which the output capacity does not recover to a certain extent or more even when recovery charging is performed on this lead battery is called deterioration. The main causes of deterioration of lead batteries are "sulfuration", which causes white PbSo ₄ to form on the electrode plate when it is left for a long time after over-discharging, resulting in a decrease in capacity. There is a "lattice corrosion" that causes corrosion and decreases the capacity.

In general, floating charging causes a larger current than the charging current required to compensate for self-discharge in the battery, so the battery becomes overcharged, causes lattice corrosion and deteriorates, and due to a long power failure, etc. It can be said that most of the deterioration of the battery occurs when the battery is over-discharged and left for a long period of time to cause sulfation to cause deterioration.

In each of these states, the electrical resistance between the active material in the lead electrode and the electrode grid is equivalently large. In general, immediately after returning an open battery to floating charging, or after the power is restored due to a power failure and the power is restored to floating charging, the battery or active material that has not deteriorated In a battery with a small electric resistance between the electrode grids, an extremely large charging current flows rapidly. But,
Due to the above deterioration, in a battery in which the electric resistance between the active material in the portion where the charging reaction occurs and the electrode grid is large, the charging current tends to be relatively small.

As shown in Fig. 2, after releasing the deteriorated battery,
A characteristic A of the charging current immediately after returning to the floating charging and a characteristic B of the charging current in the same state in a normal battery are shown. In the case of a deteriorated battery, since the electric resistance is large, the charging current is smaller than that of a normal battery. Further, the charging currents of both the characteristics A and B gradually decrease as the charging of the battery progresses with the passage of time.

This phenomenon also appears when the battery is opened or discharged, and then returned to the charged state, or when the floating charge pressure is increased from the normal floating state.

Therefore, in the present invention, the magnitude of the charging current when the state of charge of the battery is changed is detected, and when this current is sufficiently large,
When the battery is normal or smaller than a certain constant current value, it is determined that the battery is deteriorated and an attempt is made to display it.

Therefore, according to the present invention, by opening the first switch 4, after disconnecting the battery from the floating charge state,
It returns to the floating charge state again, the magnitude of the charging current at this time is detected, and if this current is sufficiently large, the battery is normal, and if it is less than a certain current value, it is judged that the battery has deteriorated and it is displayed. It is a thing. In FIG. 1, when it is desired to confirm whether or not the battery has deteriorated, a predetermined external signal or a predetermined operation for making the switch element 4 non-conductive from the switch drive signal input circuit 5 is added to the switch element 4. , Disconnect the power supply 1 and the battery 2,
The battery 2 is discharged while supplying power to the load 3, and after a lapse of a certain time T ₀ defined by the timer circuit 6, the switch element 4 is returned to the conducting state again, and the battery is returned to the floating charging state. At the same time, the timer circuit 6 is activated again,
At the same time, the current detection circuit 8 is operated for another fixed period to monitor whether the charging current is higher than a fixed value.

To clarify the operation of the circuit shown in FIG. 1 more specifically, FIG. 3 shows the voltage and current waveforms of the respective portions of FIG. v _g is the drive signal voltage of the switch element 4, v _t is the signal voltage for starting the timer circuit 6 and operating the current detection circuit, and i ₁ and i ₂ are the current of the power supply device 1 and the battery 2, respectively. The charging current.

When a signal is input from the switch drive signal input circuit 5,
A voltage v _g is applied to the switch element 4, i ₁ becomes 0, and i ₂ becomes a discharge current having a polarity opposite to that at the time of charging.

Further, when the voltage v _t is applied and the timer circuit is operated at the same time, and when a predetermined time T ₀ has passed, a signal is sent from the timer circuit to make the switch element 4 conductive again, and at this time, A signal is sent to the detection circuit 8 to perform the detection operation, and after a predetermined time T _{1 has} elapsed, a signal is sent from the timer circuit to terminate the detection operation. If the charging current flowing into the battery during this time T ₁ is smaller than the predetermined current value,
A signal is sent from the detection circuit 8 to the display circuit 9 to judge that the battery has deteriorated, and display is performed.

It is possible to judge the deteriorated battery by such operation, and it is possible to replace the battery before it reaches the end of its life, and it is possible to always keep the power supply time of the battery above a certain level and replace the battery. However, since it can be performed while appropriately determining the state of each battery, it is also economical. Further, when the deterioration of the battery is detected, by holding this display, the person who operates the device can be prompted to replace the battery. The display hold function may be performed by the display circuit 9 or the detection circuit 8 in FIG. 1, and the hold release is performed by mechanically detecting that the battery has been replaced. You can do it.

Further, once battery deterioration is detected, discharging the battery again for deterioration determination may shorten the life of the battery. In order to prevent this, it is sufficient to prevent the discharge of the battery by not sending a signal for making the switch element non-conductive while the display is held. Therefore, a control loop shown by a broken line in FIG. 1 may be added, and during this period, control may be performed so that the switch drive signal is invalid even if input.

The above is a configuration example in which the switch element 4 is turned off to discharge the battery and then return to the charged state. However, by connecting the switch element to the battery in series and turning off the switch element. It is also possible to put the battery in the open state, return it to the charged state again, detect the charging current at this time, and similarly determine the deterioration.

FIG. 4 is a circuit diagram showing an embodiment when the present invention is applied to an uninterruptible power supply for a telephone, and 5A is a telephone. Other reference numerals are the same as those in FIG. By making the switch element 4 non-conductive each time the handset of the telephone 6A is detached from the telephone body, it is possible to perform the capacity reduction determination. That is, every time the handset of the telephone 6A is picked up, the switch element 4 becomes non-conductive, and after a certain period of time irrelevant to the telephone call time, the switch element 4 becomes conductive again and returns to the original floating charge state. The operation of discriminating the battery that has been discharged is performed.

Also, in the case of floating charging, the battery is almost overcharged, but by frequently discharging a short time every time the handset is picked up, the overcharged state of the battery is relieved and Since the charging status of the cells can be made uniform,
It also has the effect of extending battery life.

FIG. 5 shows another embodiment of the present invention, in which the circuit of FIG.
The AND circuit 10 is added. According to this configuration, A
Only when a switch drive signal is input from the switch drive signal input circuit 5 while the output voltage of the power supply device 1 is input to the ND circuit 10, the switch element 4 is made non-conductive and battery deterioration determination is performed. It was done.

Therefore, according to this embodiment, the switching element is opened / closed only when the voltage is output from the power supply 1, and the switch is opened / closed when the power supply 1 is not output due to a power failure or the like. Absent. Therefore, timer circuit 6
It is sufficient to supply power from the power supply device 1 to the circuit necessary for opening and closing the switch, and it is not necessary to supply power from the battery, so that there is an advantage that the consumption of the battery can be reduced.

Although the AND circuit is used in this embodiment, the NAN
The same configuration can be achieved by using another logic circuit such as a D circuit.

FIG. 6 shows another embodiment of the present invention.
As shown in the figure, the charging circuit of the battery 2 is changed without adding a switching element.
Also, the timer circuit 6 sends a signal to the power supply circuit 1 to increase the output voltage v ₁ of the power supply circuit ₁ by a predetermined voltage in a predetermined period T ₂ , and detects the charging current during this T _2. is there. As described above, even immediately after the charging voltage is increased, the normal battery and the deteriorated battery show the same tendency of the charging current as shown in FIG. 2, which can be used for the battery deterioration detection. FIG. 7 shows the operation waveform of each part of the configuration of FIG. Where v _t starts the timer and
The signal voltage for operating the current detection circuit, v ₁ is the output voltage of the power supply circuit, and i ₂ is the charging current. According to the configuration of FIG. 6, as compared with FIG. 1, the switch element can be omitted, and the timing of the time setting by the timer is only one.
The circuit can be simplified.

FIG. 8 shows a specific configuration example for increasing the output voltage of the power supply circuit 1 in FIG. 6 by a predetermined voltage value.

FIG. 8 shows an example of a configuration using a switching power supply. AC power is input from the AC input terminals 11A and 11B, converted to DC by the rectifier 12, converted to high frequency AC by the transformer 13 and the switching transistor 14, and then rectified. It is rectified by the circuit 15 and smoothed by the filter 16. The constant voltage control of the output voltage is performed by detecting the output voltage and feeding it back to the base of the transistor 14 via the control drive circuit 17. Signal input circuit to power supply
When a signal is input from 5B, the switch element 20 switches the reference voltage composed of the zener diodes 18 and 19 of the operational amplifier of the circuit 17 for comparison with the output voltage, and the switch 20 is normally turned on. Then, the reference voltage is set low, and when a signal is input from the signal input circuit 5B, the switch 20 is turned off and the reference voltage is increased. As a result, a signal is sent from the control drive circuit 17 and the power supply circuit is controlled so that the output voltage rises. Further, at the same time when a signal is input from 5B, the timer circuit 6 is operated to send a signal to the detection circuit 8 to detect the current and monitor whether the charging current becomes larger than a certain value. It should be noted that, instead of using the switch element 4 described in the present invention, the same effect can be obtained by using a method of controlling the start / stop of the power supply circuit 1 to cause the change of the charging voltage.

Further, the lengths of T ₀ and T ₁ in FIG. 3 are determined by the relationship with the charging current detection level, and it is also possible to set T ₀ = T ₁ by setting the detection level. There is an effect that the time setting by can be made single and the configuration can be further simplified.

(Effects of the Invention) As described above, according to the present invention, deterioration of a battery can be detected and displayed accurately in a short time, and the battery can be replaced. The time during which power can be supplied can be maintained at a certain level or higher, and the reliability of the device supplied by the uninterruptible power supply can be significantly improved.

Further, it is not necessary to periodically replace the battery, and it is sufficient to replace the battery according to the condition of each battery, so that the economical efficiency is improved.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is a principle diagram showing the characteristics of the battery 2 of FIG. 1, and FIG. 3 is an operation waveform of each part of the circuit of FIG. 1, FIGS. 6 and 6 are circuit diagrams of one embodiment of the present invention, FIG. 7 is an operation waveform of each portion of the circuit of FIG. 6, and FIG. 8 is a circuit diagram showing a concrete configuration example of the power supply circuit of FIG. . 1 ... Power supply device, 2 ... Battery, 3A, 3B ... Output terminal, 4
...... Switch element, 5,5B ...... Switch drive signal input circuit, 5A ...... Telephone, 6 ...... Switch element drive timer circuit, 7 ...... Current detection element, 8 ...... Detection circuit, 9 ...... Display circuit, 10 …… AND circuit, 11A, 11B …… AC input terminal, 12
...... Rectifier circuit, 13 ...... Transformer, 14 …… Switching transistor, 15 …… Rectifier circuit, 16 …… Filter, 17 ……
Control drive circuit, 18, 19 ... Reference voltage source, 20 ... Switch circuit

Claims (6)

[Claims] 1. A power supply circuit for outputting DC power, and a battery connected in parallel on the output side of the power supply circuit. Power is supplied from the power supply circuit and the battery to a load connected in parallel to the battery. In the uninterruptible power supply for supplying, a switch element which is connected between the battery and the power supply circuit and becomes non-conductive or conductive when a predetermined signal or a predetermined operation is applied, and a first constant period, A circuit that sends out a signal that makes the switch element non-conductive, and immediately after the switch element becomes conductive,
A circuit for detecting a charging current flowing into the battery only during a second predetermined period, detecting that the charging current does not exceed a predetermined value during the second constant period, and displaying the detected current. A battery deterioration detection circuit for an uninterruptible power supply, characterized by being equipped with. 2. A power supply circuit for outputting DC power, and a battery connected in parallel to the output side of the power supply circuit. Power is supplied from the power supply circuit and the battery to a load connected in parallel to the battery. In a telephone having an uninterruptible power supply for supplying, provided with a switch element which is connected between the battery and the power supply circuit and becomes non-conducting or conducting when a predetermined signal or a predetermined operation is applied, When you remove the handset,
The battery deterioration detection circuit of the uninterruptible power supply according to claim 1, wherein the switch element is made non-conductive. 3. A power supply circuit for outputting DC power, and a battery connected in parallel on the output side of the power supply circuit, and supplying power from the power supply circuit and the battery to a load connected in parallel to the battery. In the uninterruptible power supply for supplying, a switch element which is connected between the battery and the power supply circuit and becomes non-conductive or conductive when a predetermined signal or a predetermined operation is applied, and a first constant period, A circuit that sends out a signal that makes the switch element non-conductive, and immediately after the switch element becomes conductive,
A circuit for detecting a charging current flowing into the battery only for a second predetermined period of time, detecting that the charging current does not become larger than a predetermined value for the second constant period of time, and displaying this. And a logic circuit for inputting the output voltage of the power supply circuit and a predetermined signal or operation for making the switch element non-conductive, and the predetermined voltage is input to the logic circuit from the power supply circuit. The battery deterioration detection circuit for an uninterruptible power supply according to claim 1, wherein the switch element is made non-conductive only when the predetermined signal is input to the logic circuit. 4. A power supply circuit for outputting DC power, and a battery connected in parallel to the output side of the power supply circuit, wherein power is supplied from the power supply circuit and the battery to a load connected in parallel to the battery. In the uninterruptible power supply for supplying, a switch element which is connected between the battery and the power supply circuit and becomes non-conductive or conductive when a predetermined signal or a predetermined operation is applied, and a first constant period, A circuit that sends out a signal that makes the switch element non-conductive, and immediately after the switch element becomes conductive,
A circuit for detecting a charging current flowing into the battery only for a second predetermined period of time, detecting that the charging current does not become larger than a predetermined value for the second constant period of time, and displaying this. The uninterruptible power supply according to claim 1, further comprising: a display function added to the display circuit for canceling the display when the battery is replaced. Device battery deterioration detection circuit. 5. A power supply circuit for outputting DC power, and a battery connected in parallel on the output side of the power supply circuit. Power is supplied from the power supply circuit and the battery to a load connected in parallel to the battery. In the uninterruptible power supply for supplying, a switch element which is connected between the battery and the power supply circuit and becomes non-conductive or conductive when a predetermined signal or a predetermined operation is applied, and a first constant period, A circuit that sends out a signal that makes the switch element non-conductive, and immediately after the switch element becomes conductive,
A circuit for detecting a charging current flowing into the battery only during a second predetermined period, detecting that the charging current does not exceed a predetermined value during the second constant period, and displaying the detected current. And detecting that the charging current of the battery does not become larger than a predetermined current value and not displaying the switch element in a non-conducting period while displaying this. A battery deterioration detection circuit of the uninterruptible power supply according to the first range. 6. A power supply circuit for outputting DC power, and a battery connected in parallel to the output side of the power supply circuit, and supplying power from the power supply circuit and the battery to a load connected in parallel to the battery. In the uninterruptible power supply to be supplied, a circuit for controlling the output voltage of the power supply circuit to rise by a certain constant voltage value for a predetermined constant period, and the charging current for only the constant period is detected, and the charging current is A battery deterioration detection circuit for an uninterruptible power supply, comprising: a circuit that detects that the value does not become larger than a predetermined value and displays this.