JPH06311668A - Uninterruptible power-supply device - Google Patents

Abstract

PURPOSE:To provide an uninterruptible power supply device wherein, when a load capacity is large, the discharge capability of a battery is drawn out sufficiently, the backup time is ensured to the full and the battery is not discharged excessively even in a light load. CONSTITUTION:The title device is provided with a voltage detection means 1h which detects the terminal voltage of a battery 1g and with a voltage comparison means 1i which compares the terminal voltage of the battery with a prescribed voltage which has been set to be larger than the discharge finish voltage of the battery and which generates a first control signal A when the terminal voltage of the battery becomes the prescribed voltage of lower. In addition, the title device is provided with a timer management means 1e which counts the time elapsed since the start of the supply of a backup power supply from the battery and which generates a second control signal 13 when the time elapsed becomes the preset prescribed time or higher and with a backup-power- supply stop means 1b which stops the supply of the backup power supply when the first or second control signal is received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is connected to a device (hereinafter, referred to as "computer device or the like") that operates by an external power source, such as a computer device or a communication device, and when the power source has a trouble, that device is used instead of the power source. The present invention relates to an uninterruptible power supply device that supplies power.

[0002]

2. Description of the Related Art In recent years, an uninterruptible power supply unit is connected in order to protect data being processed when a computer unit or the like is in an abnormal state due to a trouble of an external power source such as a power failure or a voltage change.

A conventional uninterruptible power supply detects an abnormality at the time of a power supply trouble, and a computer such as a lead battery built in the uninterruptible power supply replaces the power supply until the voltage drops to a predetermined constant voltage. By supplying power to the device or the like, it has been possible to prevent the computer device or the like from stopping during data processing and from losing data being processed.

[0004]

However, in the above-described conventional uninterruptible power supply device, the discharge voltage of the battery is not constant due to the discharge current, and in order to prevent overdischarge as the discharge current becomes smaller, the cutoff voltage is It needs to be set high. Therefore, a means for varying the set voltage for comparing and detecting the battery terminal voltage according to the discharge current value is required, and there is a problem that the configuration becomes complicated and the device becomes expensive.

Further, if the discharge end voltage is set to a high value in accordance with the case where the discharge current is small, when the load capacity of the uninterruptible power supply is large and the discharge current is large, the discharge time of the battery can be compared with the time that can be originally taken out. There is a problem that the backup time becomes short because the discharge capacity becomes short and the discharge capacity cannot be sufficiently drawn out.

Therefore, the present invention has been made by paying attention to such a conventional problem. When the load capacity is large,
It is an object of the present invention to provide an excellent uninterruptible power supply device in which the discharge capacity of the battery is sufficiently drawn to maximize the backup time and the battery is not over-discharged even under a light load.

[0007]

In order to achieve the above object, according to the present invention, a device which receives power from an external power source and operates is operated without supplying a backup power source from a battery to the device when the external power source is abnormal. In the power failure power supply device, a voltage detection unit that detects a terminal voltage of the battery is compared with a terminal voltage of the battery and a predetermined voltage that is set higher than a discharge end voltage of the battery, and the battery terminal voltage is the predetermined voltage. When the voltage becomes equal to or lower than the voltage, the voltage comparing means for generating the first control signal and the elapsed time from the start of the supply of the backup power from the battery are counted, and the elapsed time becomes equal to or more than the preset predetermined time. Timer management means for generating a second control signal when it becomes negative, and for the backup power supply when it receives the first or second control signal. Characterized by comprising a backup power supply stopping means for stopping the supply, the.

[0008]

Therefore, according to the present invention, the terminal voltage of the battery, that is, the output voltage is detected, and the terminal voltage of the battery is compared with the predetermined voltage set higher than the discharge end voltage of the battery, and at the same time the start of the backup operation by the battery is detected. When the backup power supply time is measured and the elapsed time is compared with the set time which is the backup supply limit time, if the above battery voltage is lower than the comparison voltage or the backup supply time exceeds the comparison limit time. If this happens, stop the backup operation of the UPS.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the uninterruptible power supply according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an uninterruptible power supply according to the present invention. In FIG. 1, an uninterruptible power supply 1 supplies power to a load device (computer device or the like) 2 from a commercial power supply P which is an external power supply or a built-in battery 1g. This uninterruptible power supply system 1 has the following components. That is, a charging unit 1a that charges the battery 1g from the commercial power source P, a battery cutoff unit (backup power supply stopping means) 1b that cuts off the current of the backup power supply from the battery 1g according to a control signal described later,
The inverter unit 1c that generates a power supply voltage to the load device 2 by the power supply from the battery 1g, the output switching unit 1d that switches between the commercial power source P connected to the contact point 1d1 and the inverter unit 1c connected to the contact point 1d2, and the commercial power source P The power supply abnormality of the output switching unit 1d and the inverter unit 1
a power failure detecting section (power supply monitoring means) 1f for controlling c, a timer managing section for starting operation upon receiving a detection signal indicating an abnormal state from the power failure detecting section 1f, and for turning off the battery cutoff section 1b at a preset time. (Timer management means) 1e, voltage detection section (voltage detection means) 1h for detecting battery voltage,
It has a voltage comparison section (voltage comparison means) 1i which compares the output of the voltage detection section 1h with a preset voltage and turns off the battery cutoff section 1b when the detected voltage becomes equal to or lower than a set value. The signal lines of the first and second control signals A and B input from the timer management unit 1e and the voltage comparison unit 1i to the battery cutoff unit 1b have a wired OR configuration or the like, and the battery cutoff unit 1b. Is turned off regardless of which control signal is received.

Next, the backup process performed by the uninterruptible power supply system 1 shown in FIG. 1 when a power supply trouble occurs will be described with reference to FIG.

FIG. 2 is a flow chart showing the operation of the backup process when the uninterruptible power supply system of FIG. First, in a normal state, power is supplied from the commercial power supply P to the load device 2 via the contact 1d1 of the output switching unit 1d, and at the same time, the battery 1g is in a charging operation state by the charging unit 1a. . Further, the inverter unit 1c is in a stopped state due to the signal from the power failure detection unit 1f, and the load device 2 is in commercial power supply operation (step S1).

In the power failure detection unit 1f, the commercial power source P is monitored, and it is determined whether or not power failure such as power failure or voltage change has occurred (step S2).
When a power trouble occurs, the power failure detection unit 1f outputs a detection signal indicating an abnormal state, and the output switching unit 1d
Is switched to the contact 1d2 side, and at the same time, the inverter unit 1c
to start. Then, the backup operation from the inverter unit 1c starts, and the power supply of the backup power supply from the battery 1g to the load device 2 starts (step S3). At the same time, the timer management unit 1e is activated by a signal from the power failure detection unit 1f, and timer counting is started (step S
4). That is, the timer management unit 1e measures the elapsed time from the start of the backup power supply.

After the backup operation is started, that is, after the operation of the inverter section 1c of the load device 2 is started, the terminal voltage of the battery 1g is measured by the voltage detection section 1h and the preset voltage is set by the voltage comparison section 1i. Are compared (step S5). If the detected voltage is equal to or lower than the set voltage, immediately issue the first control signal A for turning off the battery shutoff unit 1b to stop the current from the battery 1g to the inverter unit 1c and stop the backup operation. (Step S9).

On the other hand, when the detected voltage of the battery 1g is higher than the set voltage, the time-out of the timer management section 1e is checked (step S6).
That is, if the elapsed time from the start of the backup operation has not reached the set time, the power failure detection unit 1f detects the power recovery of the commercial power supply P (power failure status) whether it is continuing (step S7). If the power is continuously lost, the process proceeds to step S5. If the commercial power supply P is restored and the power is restored, the backup operation is stopped, the output switching unit 1d is switched to the commercial power supply P side, and the normal commercial power supply operation is performed. (Step S8), the process proceeds to step S1.

If the time-out has occurred in step S6, that is, if the elapsed time from the start of the backup operation has exceeded the set time, the second control signal B for immediately turning off the battery cutoff unit 1b is issued, The current from the battery 1g to the inverter unit 1c is stopped to stop the backup operation (step S9).

FIG. 3 is a diagram showing the relationship between the discharge characteristics of the battery 1g, the set voltage value and the timer set time, showing the case where there are three unit batteries (cells) and the case where there are six unit batteries. is there. In FIG. 3, the characteristic curve e1,
e2 and e3 show the discharge characteristics of the battery 1g, the discharge characteristics e1 have a large discharge current, the discharge characteristics e3 have a small discharge current, and the discharge characteristics e2 have a discharge current between them. The points c1, c2, and c3 are discharge characteristics e1 and e, respectively.
2, the discharge end voltage on e3, and if discharged below this voltage, over discharge occurs and the life of the battery 1g is shortened.
The characteristic curve d is a characteristic curve of the discharge end voltage obtained by connecting the discharge end voltages c1, c2, and c3.

In FIG. 3, a horizontal axis b'is a set voltage value set in a conventional uninterruptible power supply device having no timer management unit, and is a voltage value which does not cause overdischarge even at a light load (that is, discharge end). (Value higher than the voltage c3). Therefore, for example, in the case of the discharge characteristic of the characteristic curve e1, the backup operation is stopped at the point of c1 ′, so that the discharge current that can be taken out is as described in the section “Problems to be solved by the invention”. It is large, that is, even though the battery 1g has a discharging capacity, the discharging capacity cannot be sufficiently taken out, and the dischargeable time becomes short.

Therefore, in the present embodiment, the set voltage b lower than the conventional set voltage b'is set, and the timer set time a is set to stop the backup operation when the discharge time reaches the timer set time a. Then, the discharge is stopped. With such a configuration, in the case of the discharge characteristic of the characteristic curve e1, the backup operation time is extended to the point of c1, and the operation range of the backup operation is as shown in FIG.
In the range shown by hatching, it is possible to prevent over-discharging when the load is light, and to secure a long discharge time when the discharge current is large. Therefore, the discharge capacity of the battery 1g can be taken out sufficiently. In this case, regarding the point c0 in FIG. 3, when the set voltage b is used as a reference, the maximum timer setting time a is the time of the point c0, and when the timer set time a is used as a reference, the set voltage is set. The minimum value of b is the voltage value at the point c0. That is, the point c0 needs to be set to a value larger than the value of the characteristic curve d of the discharge end voltage.

In the uninterruptible power supply, it is required to secure a longer backup time when the load capacity is large. Therefore, the uninterruptible power supply of the present invention shown in the above-mentioned embodiment has an excellent effect. Become.

In the above embodiment, the timer setting time is fixed, but as another embodiment, a user can set the time by changing the program or providing a time setting means such as a DIP switch. Also good.

As another embodiment, the timer set time can be freely controlled according to the capacity of the load current.

[0023]

As is apparent from the above embodiments, the present invention provides the first control signal when the battery terminal voltage becomes equal to or lower than the predetermined voltage with respect to the predetermined voltage set to a low value, or the backup power source. When a second control signal is received when the elapsed time from the start of supply exceeds a predetermined time,
By stopping the backup power supply, when the load capacity is large, the discharge capacity of the battery is fully drawn to maximize the backup time, and the battery does not become over-discharged even at a light load, so the battery life is extended. It has the effect of never becoming shorter.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an uninterruptible power supply according to the present invention.

FIG. 2 is a flowchart showing an operation of backup processing when a power source trouble occurs in the uninterruptible power supply device in FIG.

FIG. 3 is a diagram showing a relationship between a discharge characteristic of a battery and a set voltage value and a timer set time in the present invention.

[Explanation of symbols]

 1 uninterruptible power supply device 2 load device (computer device etc.) 1b battery cutoff unit (backup power supply stopping unit) 1c inverter unit 1d output switching unit 1e timer management unit (timer management unit) 1f power failure detection unit (power supply monitoring unit) 1g battery 1h Voltage detection section (voltage detection means) 1i Voltage comparison section (voltage comparison means) P Commercial power supply (external power supply)

Claims (1)

[Claims] 1. An uninterruptible power supply for supplying a backup power supply from a battery to a device that operates by receiving power supply from an external power supply when the external power supply is abnormal, and detects a terminal voltage of the battery. The voltage detection means compares the terminal voltage of the battery with a predetermined voltage set higher than the discharge end voltage of the battery, and when the battery terminal voltage becomes equal to or lower than the predetermined voltage, the first
And a voltage comparing means for generating a control signal of the second control signal, and counting the elapsed time from the start of the backup power supply from the battery, and when the elapsed time is equal to or longer than a preset predetermined time, the second control signal An uninterruptible power supply device comprising: a timer management unit that generates a backup power supply; and a backup power supply stop unit that stops the supply of the backup power supply when receiving the first or second control signal.