JPS6032430B2 - Storage battery charging device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a storage battery charging device that uniformly charges a storage battery that has been continuously floatingly charged over a long period of time at regular intervals of 3 to 6 months.

In general, power supplies used in emergency lights, instrumentation equipment, communication equipment, signaling equipment, etc. normally supply stable DC power, which is obtained by rectifying AC power with a charger, to the load, and also supply stable DC power to the load during power outages. The structure is such that the battery is supplied to a storage battery that serves as an auxiliary power source, and the storage battery is charged in a floating manner.

When the AC power supply fails, DC power is supplied from the storage battery to the load, and when the AC power supply recovers from the power failure, DC power from the charger is supplied to the load, and is also supplied to the storage battery to recover and charge the storage battery. , floating charge the storage battery.
Therefore, if there is no power outage of the AC power source, the storage battery continues to be floatingly charged, and the charged state of the storage battery is maintained. However, even if the AC power supply does not have a power outage, the storage battery may discharge for a short time due to fluctuations in the AC power supply, or self-discharge may occur in each cell of the storage battery, resulting in continuous floating charging for a long period of time. However, variations occur in the terminal voltage of each cell of the storage battery, which causes variations in the discharge capacity, resulting in the inconvenience that the discharge capacity cannot reach the capacity at uniform charging. Furthermore, cells with reduced capacity are more likely to be over-discharged and damaged during a power outage of AC power. The present invention takes into account the above-mentioned conventional problems, and when a storage battery is continuously charged in a floating manner for a long period of time,
The storage battery is charged regularly and equally at intervals of 3 to 6 months. Next, this invention will be described in detail with reference to the drawings showing one embodiment thereof.

In FIG. 1, 1 is a commercial AC power supply, and 2 is a charger for rectifying the commercial AC of the commercial AC power supply 1, which is composed of a rectifier including a transformer, a thyristor, and the like.

3 is a load to which DC power from the charger 2 is supplied, 4 is a storage battery that is charged by the DC power from the charger 2, and 5 and 6 are a charging diode and a shunt connected in series between the charger 2 and the storage battery 4. The detector 6 detects the charging current flowing through the charging diode 5 and converts it into a voltage.

7 is a charging diode 5 and a charging diode 5 in the opposite direction.
A discharging diode is connected in parallel to the series circuit of the detector 6 and the controller 8 is a control device consisting of the part surrounded by a broken line, and the controller 8 controls the charger 2 according to the amount of discharging current and the amount of charging current.
control.

Charging command signal CS and discharging command signal E output from the charger 2 during charging and discharging, respectively.
1 is an input terminal for a preset signal PS of the rate of change of charging current with respect to time output from a preset device (not shown); 12 is a detector 6 driven by input of a charge command signal CS; A charging voltage amplifier 13 is a voltage-to-frequency converter, which converts the output voltage of the charging voltage amplifier 12 into a pulse having a frequency proportional to the output voltage.

Reference numeral 14 denotes a matching circuit which integrates the output pulses of the voltage-frequency converter 13 during a fixed sampling time and outputs the integrated value when it matches the preset signal PS.

15 is a first timer that starts time counting based on the output signal of the matching circuit 14, and outputs an output when the time is up after a set time has elapsed.

Reference numeral 16 denotes a second timer which is reset by the discharge command signal ES and counts a long-term set period of 3 to 6 months, and outputs an output when the time is up.

17 is an equal charging command device that changes the output setting of the charger 2 to equal charging based on the output signal of the second timer 6, and 18 is a third timer that starts time counting based on the output signal of the second timer 16. , output when time is up.

Reference numeral 19 denotes an OR circuit which outputs an output signal from either the first timer 15 or the third timer 18 and changes the charger 2 from equal charging to floating charging.

Next, the operation of the above embodiment will be explained.

Now, when the commercial AC power supply 1 is normal, the DC power obtained by rectifying the commercial AC of the commercial AC power supply 1 by the charger 2 is supplied to the load 3 and is also supplied to the storage battery via the charging diode 5 and the detector 6. 4, and the storage battery 4 is floatingly charged. At this time, the discharge command signal ES is sent from the charger 2.
is not output, the second timer 16 continues to count the floating charging time.
When the commercial AC power supply 1 is out of power, DC power is supplied from the storage battery 4 to the load 3 via the discharging diode 7, the storage battery 4 is discharged, and its terminal voltage decreases. At the same time, the second timer 16 is reset by the discharge command signal ES from the charger 2. Next, when the commercial AC power supply 1 recovers from the power outage, it receives a power outage recovery signal and the DC power of the charger 2 is supplied to the load 3 and the charging diode 5 and It is supplied to the storage battery 4 via the detector 6, and the storage battery 4 is recovered and charged.

At this time, the discharging command signal ES from the charger 2 disappears, and the second timer 16 starts time counting. At the same time, the charging command signal CS output from the charger 2
The charging voltage amplifier 12 is driven, and the output voltage of the detector 6 which detects the charging current and converts it into voltage is amplified by the amplifier 12 and then in the voltage-frequency converter 13.
It is converted into a pulse with a frequency proportional to the output voltage of the amplifier 12, and then input to the matching circuit 14. Then, in the coincidence circuit 14, the output pulses of the voltage-to-frequency converter 13 at any sampling time of 1 to 30 minutes are integrated. In other words, as shown in FIG. 2 illustrating the relationship between charging time and charging current, the amount of charging current at sampling time ΔT is integrated, and when this integrated value matches the preset signal SP, it is output from the matching circuit 14. Ru. Here, the preset signal PS is a current amount of 1/2 to 1/4 of the integrated current amount at the sampling time ΔT during constant current charging at the initial stage of charging, which is shown as A in FIG. It is set to match the integrated current amount at the sampling time ΔT of the pole inversion point. Therefore, matching circuit 1
4 outputs when a turning point is detected, and the first timer 15 starts time counting by the output signal of this matching circuit 14, and recovery charging is performed for 1 to 6 hours while the first timer 15 is counting time. The output signal from the time-up of the first timer 15 is input to the charger 2 via the OR circuit 19, and the charger 2 is switched from recovery charging to floating charging. Note that the second timer 16 and the coincidence circuit 14 are each reset by the output of the OR circuit 19. Next, when the storage battery 4 is continuously and floatingly charged for a long period of 3 to 6 months, the second timer 16 times out and outputs a signal.

In response to the output signal of the second timer 16, the third timer 18 starts time counting and the equal charge command device 17 operates, and the output of the equal charge command device 17 forces the output setting of the charger 2. It is changed to high and switches from floating charge to equal charge. Then, when equal charging starts, this charging current is detected by the detector 6, converted to voltage, and outputted from the charger 2, similar to when the AC power supply 1 is recovered from a power outage. Hour command signal CS
As a result, the amplifier 12 operates to amplify the output voltage of the detector 6, and the output voltage of the amplifier 12 is converted into a pulse with a frequency proportional to the output voltage. Pulses are integrated during the sampling time, and when the integrated value matches a preset signal set in advance, the signal is output from the matching circuit 14 and the first timer 15 counts the time.
A signal is output when the time is up. On the other hand, the third timer 8 is set between 12 and 2 unique times, and the third timer 8 is
When the timer 18 times up, the third timer 18
A signal is output from. Then, the output signal of the first timer 15 or the third timer 18, whichever is earlier, is applied to the charger 2 via the OR circuit 19, and the charger 2 is shifted from equal charging operation to floating charging operation. . In the above embodiment, a current shunt was used as the detector 6, but a DC current transformer may also be used.In this case, when converting the detected current to a voltage, if the voltage is several volts, a voltage amplifier 12 becomes unnecessary.

Further, the preset signal PS of the preset device is set to 1/2 to 1/4 of the integrated current amount during the sampling time during constant current charging at the initial stage of charging, as in the embodiment. moreover,
In the above embodiment, an antiparallel circuit of two diodes 5 and 7 was provided to detect only the charging current, but only the detector 6 was provided between the charger 2 and the storage battery 4, and the It is also possible to operate the detector 6 with a command signal and detect only the charging current. As described above, the storage battery charging device of the present invention includes a detector that detects the charging current during recovery charging after discharge of the storage battery and converts it into a voltage, and an output voltage of the detector that is proportional to the output voltage. A voltage-to-frequency converter that converts into pulses with a frequency of A first timer that starts time counting when the integrated value reaches 1/2 to 1/4 of the integrated value, and outputs a signal to change the charger from recovery charging to floating charging when the time is up; The discharging command signal input from the charger and the signal from the first timer are 3
a second timer that times up when there is no input for a long period of ~6 months; an equal charging command device that changes the charger from floating charging to equal charging according to an output signal when the second timer times out; By including a third timer that starts time counting based on the output signal of the second timer and outputs a signal that changes the charger from equal charging to floating charging when the time is up, the storage battery can be
If floating charging is continued for a long period of up to 6 months, the charger is forced to shift from floating charging to equal charging and the storage battery is charged evenly, resulting in variations in capacity between each cell of the storage battery. do not have.

Further, there is provided a means for operating a first timer when the charging current per hour during equal charging reaches a predetermined value, and switching to floating charging when the first timer times out, and a means for setting a 12 to 2 unique period. Since the charger is switched from equal charging to floating charging according to the earlier signal of both means, highly reliable equal charging can be performed. Furthermore, since the turning point is detected when the change in charging current reaches a certain value, it is possible to detect the turning point more reliably than when detecting the turning point based on the terminal voltage of a storage battery, which does not change much. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the storage battery charging device of the present invention, and FIG. 2 is a diagram showing the relationship between charging time and charging current. 2...Charger, 4...Storage battery, 6...Detector, 13.
...Voltage-frequency converter, 15...First timer, 1
6... Second timer, 17... Equal charging command device,
18...Third timer. Figure 1 Figure 2

Claims (1)

[Claims] 1. A detector that detects the charging current during recovery charging after discharge of the storage battery and converts it into a voltage, and a voltage that converts the output voltage of the detector into a pulse with a frequency proportional to the output voltage.
The output pulses of the frequency converter and the voltage-frequency converter are integrated over an arbitrary sampling time of 1 to 30 minutes, and the integrated value is 1/2 to 1/2 of the integrated value integrated over the sampling time during constant current charging at the initial stage of charging. A first timer that starts time counting when the value reaches 1/4 and outputs a signal to change the charger from recovery charging to floating charging when the time is up; and a discharging command signal that is input from the charger during discharging. and a second timer that times up when the signal from the first timer is not input for a long period of 3 to 6 months, and an output signal when the second timer times up to equalize the charger from floating charging. The charger includes an equalizing charging command device for changing to charging, and a third timer that starts time counting based on the output signal of the second timer and outputs a signal for changing the charger from equalizing charging to floating charging when the timer expires. A storage battery charging device featuring: