JP2003164072A - Power failure compensation power unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To rapidly charge a secondary battery based on a charged ratio of the battery calculated by measuring a charging and discharging amounts of the battery, in a power failure compensation power unit equipped with a secondary battery as a NiCd battery or a Ni hydrogen battery, a charging circuit and a control circuit. <P>SOLUTION: There is provided a battery charging/discharging current measuring circuit that uses a V-F converter. The charging and discharging amounts are calculated by integrating measured charging and discharging currents. An SCO of the battery is calculated by the charging and discharging amounts. In charging the battery, the SCO control is made rapidly charge the battery until the SCO is restored 100%. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power failure compensating power supply device for electric equipment such as emergency lighting and information equipment which must be used even during a power failure.

[0002]

2. Description of the Related Art Conventionally, as a means for rapidly charging a secondary battery represented by a NiCd battery or a Ni hydrogen battery, the characteristics of the voltage drop and the temperature rise after full charge of these secondary batteries are utilized. , Drop voltage detection control (hereinafter referred to as-△ V detection control) that terminates charging by monitoring the battery terminal voltage during charging and detecting the drop voltage after the peak voltage, and monitor the battery temperature rise to an arbitrary temperature. Charging circuits have been used that use temperature control to terminate charging when reached. Also,
As means for rapidly charging the battery without performing the -ΔV control or temperature control, there is a method of measuring the power failure time in a power failure compensation power source, calculating the required charging time from this time, and performing the quick charging. It is described in the official gazette.

[0003]

When using -ΔV detection control or temperature control in a rapid charging circuit of a secondary battery represented by NiCd battery or Ni hydrogen battery, a voltage detection circuit for detecting battery voltage or battery temperature. And a temperature detection circuit, a sensor, etc. are required, and as the ambient temperature rises as a characteristic of these batteries, the voltage peak value at the time of charging decreases and the peak shape also becomes gentle. There is a problem that a circuit and a temperature detection circuit are required.
Further, since the battery deteriorates although it is slight each time -V detection or temperature rise occurs, there is a problem that the battery life becomes short when used in an environment where the frequency of power failure is high and the number of charge / discharge cycles is high. It was On the other hand, in the power failure compensation power supply, when calculating the required charging time based on the power failure time and performing rapid charging, the power consumption of the load connected to the power failure compensation power supply must be constant in order to calculate the appropriate charging time. Therefore, there is a problem that it cannot be applied to a power failure compensating power supply device connected to a load whose power consumption fluctuates depending on the operating rate and conditions of devices such as information devices.

[0004]

In order to solve the above problems, the present invention provides a charge / discharge current measuring circuit for a battery using a VF converter, and integrates the measured charge / discharge current to determine the charge / discharge amount. The SOC control of the battery is performed by calculating and calculating the SOC of the battery from these charge / discharge amounts, and performing rapid charging until the SOC returns to 100% during charging.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit example of a power failure compensating power supply device using the present invention. The positive electrode of the secondary battery 8 is connected to the battery charging power supply 2d of the power supply unit 2 via the quick charging switch SW1 and the current limiting resistor 5, and is connected to the load at the time of power failure from the discharging terminal 11 via the discharging switch SW2. . Here, in this example, DC output at the time of power failure is assumed, but AC output is also possible by providing an orthogonal conversion circuit (inverter) between the switch SW2 and the discharge terminal 11. Further, the switch SW1 is connected in parallel with the auxiliary charging current limiting resistor 6 and the backflow prevention diode 7, and the constant of the resistor 6 at this time is the maximum current in the auxiliary charging state in which the switch SW1 is OFF (current rate (full charging state). The current value at which the battery is completely discharged in 1 h is defined as 1 C), and the value is selected to be an arbitrary value of 0.1 C or less. In this embodiment, contact switches are used for SW1 and SW2 in order to reduce power loss at the time of ON, but when high speed at ON / OFF is required, semiconductor switches such as transistors are used. Good. On the other hand, the negative electrode side of the secondary battery is connected to the shunt resistor 9, and the voltage of the shunt resistor 9 is converted into a clock signal by the VF converter circuit 4 to charge / discharge the counter of the control microcomputer 3.
The charge / discharge amount of the battery is detected by counting with 3c (hereinafter referred to as CDC). Here, by using the V-F converter circuit 4 having the input / output characteristic in which the output clock frequency is proportional to the absolute value of the input voltage as shown in FIG. Since the frequency of the clock signal output from the V-F converter circuit 4 increases or decreases in proportion to the increase or decrease, the count speed of the CDC can also be proportional to the increase or decrease in the current of the charge / discharge column of the battery as a result. The CDC value can be made to correspond to the charge or discharge amount of the battery. The control microcomputer 3 is the above-mentioned C
In addition to the DC 3c, an initial charging timer 3a and an SOC counter (hereinafter referred to as SOCC) 3b are built in, and a commercial AC power source 1
The power failure detection signal from the power failure detection circuit 1 connected to 0 is input, and the switch SW is activated by these counters and control signals.
1 and SW2 are controlled respectively. In addition to the battery charging power source 2d, the power source unit 2 includes a control power source 2a that is a drive power source for this circuit. The control power source 2a receives an input from the commercial AC power source 10 as power for normal operation. Rectifier circuit 2b
The DC input is connected to the input from the battery as power for power failure via the diode 2c. Here, in order to use only the electric power from the rectifier circuit 2b during the normal operation, it is only necessary to set the output voltage of the rectifier circuit 2b higher than the maximum voltage of the battery.

Next, the control flow of the present invention will be described with reference to FIG. When the operation is started (S1), the CDC is cleared (S
2) Check the power failure detection signal and judge the power failure (S3). If it is not a power failure, the discharge switch SW2 is turned off (S4) to continue the undischarged state or to end the discharge. Next, it is determined whether or not the rapid charging is in progress (S5). If the rapid charging is in progress, the CDC is updated corresponding to the charge amount. Therefore, the value of the CDC is added to SOCC (S6), and the CDC is cleared ( S7): If the battery is not being rapidly charged, it is in the auxiliary charging state for recovering the leakage current of the battery. Therefore, S6 and S7 are not executed and SOCC is not updated. Next, SOC and SOC set in advance = 1
The counter value Nful corresponding to 00% is compared (S8),
If SOCC is Nful or more, SW1 is turned off (S9) to continue the replenishment state or end the rapid charging, and if SOCC is less than Nful, SW1 is turned on (S10) to continue rapid charging or Make a new input. The above is repeated from the power failure judgment (S3). On the other hand, if it is determined in the power outage determination (S3) that there is a power outage, SW1 is turned off.
By turning on F and SW2 (S11), if rapid charging is in progress, charging is stopped and discharging is started. At this time, the commercial AC power supply is cut off and the output of the battery charging power supply 2d also disappears, so that the auxiliary charging of the battery is also stopped. The CDC is updated corresponding to the discharge amount when the discharge is started, so the value of the CDC is subtracted from the SOCC (S12), and the CD
Clear C (S13). Next, the counter value Nem corresponding to SOCC and SOC = 0% preset.
p is compared (S14), and when SOCC is Nemp or less, SW2 is turned off (S15), discharging is ended and an alarm indicating that the battery is not charged is displayed (S16), and the operation is ended (S17). On the other hand, at S14, SOCC is Nemp.
If it is larger, the process is repeated from the power failure determination (S3). S
Since OCC and CDC are values corresponding to the amount of charge or discharge of the battery, not the time of charge or discharge, according to the above means, even when a device whose power consumption fluctuates is connected to the load during a power failure, after the power failure is restored. It is possible to perform appropriate rapid charging corresponding to the amount of discharge.

On the other hand, during actual operation, immediately after the power interruption power supply device equipped with this circuit is installed and immediately after the power is cut off for a long period of time due to construction, etc., the actual remaining battery level is affected by the self-discharge of the battery. And SOCC values may differ. As means for eliminating this difference, one means of initializing SOCC will be described with reference to the flowchart of FIG. When the power is turned on as a trigger, initialization is started (S21), and according to the circuit of FIG. 1, the auxiliary charge state is automatically set, and the initial charge timer is cleared and started (S22, S
23). Next, a power failure determination (S24) is performed, and if not a power failure, supplementary charging is automatically continued (S25), and the initial charge timer is compared with a preset arbitrary time Tend (S26).
If it is more than Tend, Nf corresponding to SOCC fully charged state
ul is set (S27), initialization is completed, and if less than Tend, power failure determination (S24) is repeated. Where Ten
d is the time during which the fully discharged battery can be fully charged during supplementary charging, and the current rate during supplementary charging is-△
It may be set to any value between 1/10 and 1 / 30C where V does not occur. In the power failure determination (S24), if there is a power failure, supplementary charging is automatically stopped (S29), the power supply of the device is shut off (S30), and the power supply is turned on again after the power failure is restored. By performing the above, it is possible to eliminate the difference from SOCC and to start the operation shown in the control flow of FIG. 2 regardless of the state of the remaining battery level.

[0008]

According to the present invention, a secondary battery represented by a NiCd or Ni hydrogen battery can be rapidly charged without performing -ΔV detection control or temperature control, and a highly accurate battery voltage detection circuit. And a temperature detection circuit are unnecessary. Also,
By controlling the quick charge by using the charge and discharge amounts instead of the discharge time, it is possible to apply to a device that supplies power to a load whose power consumption fluctuates.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a control flow showing an embodiment of the present invention.

FIG. 3 is a flowchart of initialization showing an embodiment of the present invention.

FIG. 4 is a characteristic diagram of a VF converter showing an embodiment of the present invention.

Continued front page    F term (reference) 2G016 CA01 CB12 CB22 CB32 CC02                       CC04 CC06 CC07 CC10 CC11                       CC12 CC17 CC18 CC21 CC23                       CC27 CD02 CD04 CD09 CD14                       CE00                 5G003 AA01 BA01 CA06 CC02 DA07                       DA12 DA18 EA05 GC05                 5H030 AS03 BB01 FF41

Claims (2)

[Claims] 1. In a power failure compensating power supply device equipped with a secondary battery represented by a NiCd battery or a Ni hydrogen battery, a charging circuit and a control circuit, the charging rate of the battery (hereinafter Called SOC, fully charged,
The charging circuit for the secondary battery is characterized in that a complete discharge state is represented by% values with 100% and 0% respectively, and rapid charging is performed based on this SOC. 2. A power failure compensating power supply device equipped with claim 1.