JPH0583879A - Method and apparatus for charging storage battery - Google Patents

Abstract

PURPOSE:To decrease the corrosion of an electrode and to extend the life of a battery by conducting floating charging appropriately. CONSTITUTION:Floating charging is conducted intermittently by repeating the charging period and the non-charging period alternately. A controlling and rectifying circuit 3 rectifies the output of an a.c. power supply 1 and conducts recovery charging or floating charging of a storage battery 2 according to a charging command signal. A charging control circuit 4 determines which of recovery charging or floating charging should be done, and outputs a charging command signal to the controlling and rectifying circuit 3. A floating charging control circuit 9 controls on and off of a switch circuit 8 so that floating charging may be conducted intermittently by repetition of the charging period and the non-charging period during the period until the nest recovery charging gets started after the finish of recovery charging is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a storage battery charging method and a charging device, in which floating charging is always performed and recovery charging is performed in a predetermined charging mode after discharging to a load.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a charging device which has been generally used to charge a storage battery provided for supplying power to a load. In the figure, 1 is an AC power supply, 2 is a storage battery,
Reference numeral 3 is a control rectification circuit for charging provided between the AC power supply 1 and the storage battery 2, and 4 is a charge control circuit for controlling the charging operation of the control rectification circuit 3. Reference numeral 5 is a current detection line for inputting charging current information to the charging control circuit 4 from the output side of the control rectification circuit 3 through a current transformer, and 6 is information on the storage battery voltage from the anode end side of the storage battery 2 to the charging control circuit 4. The voltage detection line 10 for inputting is the output terminal to the load.

The above charging device operates as shown in the charging characteristic curve of FIG. That is, the recovery charge of the storage battery 2 starts after the discharge is completed. In the initial period a of the recovery charging period, the storage battery voltage V is lowered and a large current is likely to flow. Therefore, the charging control circuit 4 controls the constant current charging control by the feedback signal from the current detection line 5. The rectifier circuit 3 is controlled. Then, during the period of b in the figure in which the battery voltage gradually rises and the charging current Ic falls below the predetermined current, the charging control circuit 4 is controlled by the feedback signal from the voltage detection line 6 so as to perform constant voltage charging control. Control the circuit 3. After that, the charging current IC gradually decreases, and when the storage battery 2 is fully charged, the battery voltage becomes a constant voltage as in the period c in the figure, and the recovery charging is completed.
After that, in the period of d in the figure, the storage battery 2 is floating-charged by the floating charging voltage that only supplements the self-discharge. Although the voltages in the periods c and d are stepwise in FIG. 7, the voltages in the periods c and d may be the same in actual operation. In FIG. 7, ID is the discharge current. If the storage battery 2 is an uninterruptible power supply and is used to drive an inverter when a commercial power supply fails, the discharge time of about several tens of minutes is often observed throughout the year, and the floating charge period of d in FIG. 7 continues in most cases. It will be.

[0004]

Electrode corrosion is the main cause of shortening the life of a storage battery having a very long floating charging time, such as a sealed lead storage battery used in an uninterruptible power supply.
It has been found that electrode corrosion progresses as the floating charging time increases. An object of the present invention is to provide a charging method and a charging device for a storage battery, which can reduce corrosion of electrodes and prolong battery life by appropriately performing floating charging.

[0005]

In order to solve the above-mentioned problems, a method of charging a storage battery according to the present invention is a storage battery in which floating charging is always performed and recovery charging is performed in a predetermined charging mode after discharging to a load. In this charging method, the charging period and the charging suspension period are alternately repeated to perform floating charging intermittently.
In addition, the charging device of the present invention that performs the above charging method rectifies the output of the AC power supply 1 and recovers or floats the storage battery 2 that is charged according to the charging command signal, as seen in the drawings of the embodiment. The control rectifier circuit 3 for charging, the charge control circuit 4 for determining whether to perform the recovery charge or the floating charge and outputting a charge command signal to the control rectifier circuit 3, and the next recovery charge when the end of the recovery charge is detected. Until the start
A floating charge control circuit 9 for controlling the floating charge of the storage battery 2 to alternately repeat the charging period and the charging suspension period is provided. When the storage battery 2 is a battery used for an uninterruptible power supply, the main part of the charging device is configured as follows. The floating charge control circuit 9 sets the switch circuit 8 provided between the control rectification circuit 3 and the storage battery 2, and brings the switch circuit 8 into a conductive state when receiving a drive signal, and cuts off the switch circuit 8 when receiving a stop signal. A switch opening / closing drive circuit 9d, a recovery charge end detection circuit 9a that outputs a recovery charge end signal when detecting the end of the recovery charge, and stops the output of the recovery charge signal when a reset signal is input,
When the recovery charge end signal is received, the stop signal and the drive signal are alternately and repeatedly output to the switch opening / closing drive circuit 9d at preset time intervals, and when the reset signal is received, the timer 9b that returns to the start state and the AC When a power failure of the power source 1 is detected, the recovery charge end detection circuit 9a
And a power failure detection circuit 9c that outputs the reset signal to the timer 9b and outputs the drive signal to the switch opening / closing drive circuit 9d. Further, the charge control circuit 4 controls constant current charging control circuit 4a that controls the control rectification circuit 3 to perform constant current charging when a control signal is input, and constant voltage charging when a control signal is input. A constant voltage charging control circuit 4b for controlling the control rectification circuit 3 to be performed, and either a recovery charging mode or a floating charging mode is selected according to the charging condition of the storage battery 2, and each charging mode is selected. And a charging mode selection circuit 4c which outputs a corresponding control signal. Then, the charge mode selection circuit 4c selects the floating charge mode when the recovery charge end detection circuit 9a detects the end of the recovery charge, and selects the recovery charge mode when the power failure detection circuit 9c outputs the reset signal.

[0006]

In the charging method of the present invention, the floating charging is intermittently performed by alternately repeating the charging period and the charging suspension period. Therefore, as compared with the case where the floating charging is performed for a long time, the electrode corrosion of the storage battery 2 is prevented. Progress is delayed. Thereby, the life of the storage battery 2 can be extended. Further, in the charging device according to the second aspect, the above charging method is satisfactorily implemented. Further, in the charging device according to the third and fourth aspects, the above charging method is extremely favorably performed on the storage battery 2 used in the uninterruptible power supply.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is an AC power supply, 2 is a storage battery, 3 is a control rectifier circuit, 4 is a charge control circuit, 5 is a current detection line, 6 is a voltage detection line, and 10 is an output terminal to a load. It is the same as the charging device of FIG. 7 is a power failure detection line connected to the output side of the AC power supply 1, 8 is a switch circuit arranged between the output side of the control rectifier circuit 3 and the storage battery 2, and 9 is a voltage detection line 6 and a power failure detection line. The floating charge control circuit functions to control the charge control circuit 4 and the switch circuit 8 by using a signal as an input. In this embodiment, the storage battery 2 is used as a backup power source for the uninterruptible power supply.

In this embodiment, the load is supplied from the storage battery 2 when the AC power supply 1 fails. In addition, the floating charge control circuit 9 which detects a power failure by the input from the power failure detection line 7 acts to close the switch circuit 8. When the AC power supply 1 is restored, the storage battery 2 stops discharging and the AC power supply 1
Recovery charging is performed through the control rectifier circuit 3 and the switch circuit 8. FIG. 2 shows a charging characteristic curve of the charging device of this embodiment. Since a large charging current I C easily flows in the initial period a of the recovery charging, the charging control circuit 4 receives the feedback signal from the current detection line 5. Operates to control the control rectifier circuit 3 to perform constant current charging. Then, the charge control circuit 4 operates by the feedback signal from the voltage detection line 6 from the period b in which the battery voltage V gradually rises and the charging current is lower than the predetermined current to control the control rectification circuit 3 to perform constant voltage charging. To perform. After that, the charging current gradually decreases, and when fully charged, the battery voltage becomes a constant voltage and the recovery charging is completed. The charging operation so far is the same as that of the charging device of FIG.

The end of the recovery charge is detected in the floating charge control circuit 9 by the input signal from the voltage detection line 6, and the recovery charge end signal is sent from the circuit 9 to the charge control circuit 4. The charge control circuit 4 controls the control rectifier circuit 3 by the input of the recovery charge end signal, and starts the floating charge of the storage battery 2 with the floating charge voltage that compensates for the self-discharge. On the other hand, the floating charge control circuit 9 which detects the end of the recovery charge and the absence of power supply from the storage battery 2 by the input signal from the power failure detection line 7 performs a timer operation to perform the charge period d1 in FIG. And the next period d
During 2, the switch circuit 8 is turned off. The switch circuit 8 is repeatedly opened and closed so as to be turned on during the next period d3 and turned off during the next period d4, so that floating charging is controlled intermittently.

Since the opening / closing time of the switch circuit 8 is set by adjusting the timer function of the floating charge control circuit 9, the floating charge can be intermittently performed in an arbitrary open / close period depending on the load condition of the storage battery 2. .. For example, it is assumed that the capacity is lowered due to self-discharge of the storage battery 2, and that the lower limit for satisfying the load condition is 95%. Considering a device in which the battery capacity drops to 95% in about 30 days, and the battery can be charged from 95% to 100% in about 1 day,
The off period and the on period of the switch circuit 8 may be set to 30 days and 1 day, respectively. By intermittently performing the floating charge in this manner, the floating charge time is reduced to 1/30 of that of the conventional case, the electrode corrosion of the storage battery is reduced, and the battery life is extended.

3 and 4 show different application examples of the charging device of this embodiment to an uninterruptible power supply, respectively.
In the apparatus of FIG. 3, the same parts as those of the apparatus shown in FIG. 1 are designated by the same reference numerals. Reference numeral 11 is a charging device including the control rectification circuit 3, charging control circuit 4, detection lines 5, 6, 7 and floating charging control circuit 9 of FIG. 1, and 12 is an AC that converts AC from the AC power supply 1 into DC. / DC converter, 13
Is a storage battery 2 that flows through the diode 14 when the direct current from the AC / DC converter 12 or the AC power source 1 fails.
This is an inverter that converts the direct current from AC to AC and supplies it from the output terminal 15 to the load. FIG. 4 is an application example in which the converter 12 of FIG. Next, a specific configuration example in which the charging device of the present invention is applied to a power failure power supply device will be described with reference to FIG. In FIG. 5, the same parts as in FIG.
The same reference numerals as those shown in FIG. 1 are attached. The charge control circuit 4 includes a constant current charge control circuit 4a and a constant voltage charge control circuit 4b for controlling the control rectification circuit 3, a charge mode selection circuit 4c for controlling both of these control circuits, a current detection unit 4d, and a voltage. It is composed of the detection means 4e. The detection signals from the current detection means 4d and the voltage detection means 4e coupled to the output side of the control rectification circuit 3 are input to the charging mode selection circuit 4c. The floating charge control circuit 9 includes a recovery charge end detection circuit 9a that controls the charge mode selection circuit 4c, a timer 9b that is started by the output of the detection circuit 9a, and a power failure detection circuit that detects a power failure of the AC power supply 1. 9c, a switch opening / closing drive circuit 9d driven by the output signals from the timer 9b and the power failure detection circuit 9c, and a switch circuit 8 opened / closed by the output of the switch opening / closing drive circuit 9d.

Next, the operation of the charging device shown in FIG. 5 will be described. If the storage battery 2 is a battery used as a backup power supply of the uninterruptible power supply, when the AC power supply 1 fails, the DC power of the storage battery 2 is supplied from the output terminal 10 to the load. in this case,
Reset signal R and drive signal O from the power failure detection circuit 9c
A signal corresponding to N is output, and the charging mode selection circuit 4
c, the recovery charge end detection circuit 9a, and the timer 9b are reset by the input of the reset signal R, and the switch opening / closing drive circuit 9d operates by the input of the drive signal ON to close the switch circuit 8. As described above, the storage battery 2 is in the charging standby state. Then, when the AC power supply 1 is restored, the storage battery 2 stops discharging, and the AC power supply 1 charges the storage battery 2 through the control rectifier circuit 3 and the switch circuit 8.
In this charging, the recovery charge is selected based on the input signals from the current detection means 4d and the voltage detection means 4e and the recovery charge end detection circuit 9a output from the charge mode selection circuit 4c according to the charge state of the storage battery 2. Mode or floating charge mode. Storage battery 2
When the discharge of the battery is progressing, the recovery charge mode is selected, and the control rectifier circuit 3 is first controlled via the constant current charge control circuit 4a by the control signal according to the recovery charge mode to recover the charge characteristic curve of FIG. During the initial period of charging, constant current charging of a is performed. Then, in the period b in which the charging current is lower than the predetermined current, the control rectifying circuit 3 is operated via the constant voltage charging control circuit 4b.
When the battery is fully charged, the battery voltage becomes a constant voltage and the recovery charging is completed. The recovery charge end detection circuit 9a detects the end of the recovery charge based on the input signal from the voltage detection means 4e. The recovery charge end detection circuit 9a includes the charge mode selection circuit 4c and the timer 9b.
The recovery charge end signal is output to. As a result, the charging mode selection circuit 4c selects the floating charging mode and controls the control rectification circuit 3 by the control signal according to this mode.
The floating charging is started during the period d1. On the other hand, when the timer 9b receives the recovery charge end signal, it starts a predetermined series of timer operations and outputs the stop signal OF after the elapse of the charge period d1 of a predetermined time length. When the stop signal OF is received, the switch opening / closing drive circuit 9d operates to open the switch circuit 8 and suspend the floating charging. The timer 9b continues to operate, and the drive signal is turned on at the end of the charging suspension period d2 when a predetermined time has elapsed after the stop signal OF was output.
Is output. Upon receiving this, the switch opening / closing drive circuit 9d
Closes the switch circuit 8 and the floating charge is restarted. When the charging period d3, which is relatively short after the charging suspension period d2, elapses, the stop signal O is again output from the timer circuit 9b.
F is output, the switch circuit 8d is opened by the switch opening / closing drive circuit 9d, and the charging pause period d4 starts. After that, the same operation as described above is repeated, and a relatively long charging suspension and a relatively short charging are alternately repeated, so that the storage battery 2 is intermittently floating-charged.

Next, when the AC power supply 1 fails, the storage battery 2 starts discharging. Then, the output signal from the power failure detection circuit 9c becomes the reset signal R, and the charging mode selection circuit 4c,
The recovery charge end detection circuit 9a and the timer 9b are respectively reset, and the switch open / close drive circuit 9d operates by the drive signal ON output from the power failure detection circuit 9c to close the switch circuit 8. As a result, even if a power failure occurs during the suspension period of floating charging, the charging system of the storage battery 2 is prepared.

In the above embodiment, the switch circuit 8 is provided independently, but the function of the switch circuit 8 may be provided to the control rectifying element in the control rectifying circuit 3.

[0015]

As described above, according to the charging method of the present invention, the floating charging of the storage battery is performed intermittently by alternately repeating the charging period and the charging suspension period, so that the floating charging can be performed for a long time. Compared with the case of continuously performing over the period, the progress of electrode corrosion of the storage battery can be sent, and the life of the storage battery can be extended. According to the charging device of the second aspect, the charging method of the present invention can be satisfactorily implemented. Further, according to the charging device of the third and fourth aspects, the charging method of the present invention can be extremely favorably carried out on the storage battery used for the uninterruptible power supply.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a storage battery charging device of the present invention.

FIG. 2 is a charging characteristic curve diagram showing an embodiment of a method for charging a storage battery of the present invention.

FIG. 3 is a block diagram showing a different application example of the present invention to an uninterruptible power supply.

FIG. 4 is a block diagram showing a different application example of the charging device of the present invention to an uninterruptible power supply device.

FIG. 5 is a block diagram showing a specific configuration example of an embodiment of the charging device of the present invention.

FIG. 6 is a block diagram showing a configuration of a conventional storage battery charging device.

FIG. 7 is a charging characteristic curve diagram of an example of a conventional charging method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... AC power supply, 2 ... Storage battery, 3 ... Control rectification circuit, 4 ... Charge control circuit, 4a ... Constant current charge control circuit, 4b ... Constant voltage charge control circuit, 4c ... Charge mode selection circuit, 4d ... Current detection means, 4e ... Voltage detecting means, 8 ... Switch circuit, 9
... Floating charge control circuit, 9a ... Recovery charge end detection circuit, 9
b ... timer, 9c ... power failure detection circuit, 9d ... switch opening / closing drive circuit.

Claims (4)

[Claims] 1. A method of charging a storage battery, wherein charging is always performed by floating charging and recovery charging is performed in a predetermined charging mode after discharging to a load, wherein the floating charging is performed by alternately repeating a charging period and a charging suspension period. A method of charging a storage battery, which is characterized in that it is carried out intermittently. 2. A charging device for a storage battery, which normally performs floating charging and performs recovery charging in a predetermined charging mode after discharging to a load, which rectifies the output of an AC power supply and charges a storage battery to be charged. Control rectifier circuit for performing recovery charge or floating charge according to the above, a charge control circuit for determining whether to perform recovery charge or floating charge, and outputting the charge command signal to the control rectifier circuit, and for ending the recovery charge. A storage battery characterized by comprising a floating charge control circuit for controlling the floating charge of the storage battery so as to alternately repeat a charging period and a charging suspension period until the next recovery charging is started when detected. Charging device. 3. The storage battery is a storage battery used in an uninterruptible power supply, and the floating charging control circuit receives a drive signal when a switch circuit is provided between the control rectification circuit and the storage battery. The switch circuit is made conductive,
When a stop signal is received, a switch open / close drive circuit that shuts off the switch circuit, and a recovery charge end signal is output when the end of recovery charge is detected, and output of the recovery charge signal is stopped when a reset signal is input. A recovery charge end detection circuit, and a timer that, when receiving the recovery charge end signal, outputs the stop signal and the drive signal intermittently and repeatedly to the switch opening / closing drive circuit, and returns to the start state when receiving the reset signal, The power failure detection circuit configured to output the reset signal to the recovery charge end detection circuit and the timer and to output the drive signal to the switch opening / closing drive circuit when a power failure of the AC power supply is detected. Storage battery charger. 4. The constant charge charging control circuit, which controls the controlled rectifier circuit to perform constant current charging when a control signal is input, and constant voltage charging when the control signal is input, A constant voltage charging control circuit for controlling the control rectification circuit so as to perform a recovery charging mode or a floating charging mode according to the charging condition of the storage battery, and selects the charging mode according to each charging mode. And a charge mode selection circuit that outputs a control signal, wherein the charge mode selection circuit selects a floating charge mode when the recovery charge end detection circuit detects the end of recovery charge, and the power failure detection circuit outputs a reset signal. The storage battery charging device according to claim 3, wherein the recovery charging mode is selected when output.