JP2006033997A - Remote monitoring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate erroneous power outrage detection, cut battery drain, prevent a power outrage in equipment without fail, automatically switch to backup power supply, and perform recovery processing. <P>SOLUTION: A power supply backup means obtains control power Vdd from a commercial power source 1 through an AC-DC converter 2, and causes a battery change circuit 6 to switch to a primary battery 7 when a power outrage occurs. As the power supply backup means, the following members are provided: a voltage drop detection circuit 3 that detects any voltage drop in the commercial power source; an external-internal insulation circuit 4 that insulates and takes in the detection signal; and a battery control circuit 5 that is supplied with this voltage drop detection signal, and, when the secondary output of the AC-DC converter starts to drop, produces output for the battery change circuit to switch to battery power supply. The backup means is also used to perform processing corresponding to NMI interruption by a computer circuit and the detection of drop in secondary output. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  This apparatus relates to a remote monitoring system, and more particularly to a power backup system for a monitoring terminal (or monitoring circuit) provided at a monitoring position.

  As a remote monitoring system, for example, there is a system in which the state of various electric facilities is monitored by a local monitoring terminal, and monitoring information is transmitted to a central monitoring room computer or an abnormal occurrence is notified using a communication line. Specifically, the monitoring terminal monitors the leakage current flowing in the ground line of the electrical equipment in the distribution system, and notifies the monitoring room computer of an alarm when the leakage current is detected abnormally.

  In such a remote monitoring system, the monitoring terminal is often unmanned, and when a power failure occurs in the power supply of the monitoring terminal, the monitoring function is lost. , See Patent Document 1).

  A schematic configuration of the backup circuit of the control power supply is shown in FIG. The AC power of the commercial power supply (AC100V) 1 is converted to DC power that is voltage-controlled by an AC / DC converter 2 such as a switching power supply to obtain a voltage output Vdd (5V) of the control power supply. The backup circuit detects a power failure on the primary side of the AC input by the voltage drop detection circuit 3 and insulates and captures this power failure detection signal by an external-internal insulation circuit 4 such as a photocoupler. Outputs a power switching signal to the battery switching circuit 6. By this switching signal, the battery switching circuit 6 obtains an output of the voltage Vdd using the primary battery 7 as a power source instead of the output of the AC / DC converter 2.

When this power source is applied to the monitoring terminal, the computer circuit 8 receives the power failure detection output from the external-internal insulation circuit 4 as an interrupt (NMI) signal, and uses the primary battery 7 as a power source to monitor information to the central monitoring room computer. Notification of power failure. be able to.
Japanese Patent Application Laid-Open No. 8-328673

  As described above, the conventional power backup system switches to the battery power source when the primary voltage is lowered during a power failure, and returns the power source from the battery to the AC power source side when the primary voltage is restored.

  Here, there are many switching surges or the like in the AC power supply. In addition, the AC power supply often has an instantaneous interruption in which the voltage decreases for a very short time. Depending on the surge time and the instantaneous interruption time, the voltage drop detection circuit 3 may react erroneously. When the voltage drop detection circuit 3 reacts erroneously, it is switched to the battery power supply by detecting the voltage drop each time. In this case, battery consumption is accelerated, and the battery cannot be reduced in size. In addition, there is a problem that an erroneous power failure detection is erroneously notified to a host computer.

  As a countermeasure, it is conceivable that there is a time delay between the detection by the voltage drop detection circuit 3 and the switching control by the battery control circuit 5, but if the setting or design of this time delay becomes inappropriate, a power failure will actually occur. This causes a power failure of the computer circuit 8 and the like, resulting in a problem of erroneous processing and control of the computer circuit 8, and further loss of the function of the monitoring terminal.

  An object of the present invention is to provide a power backup capable of automatically switching to a backup power source and recovering the power by reliably preventing a power failure of a monitoring device while eliminating erroneous power failure detection due to a momentary interruption or the like and reducing battery consumption. To provide a method.

  In order to solve the above-mentioned problem, the present invention detects that the secondary output voltage of the AC / DC converter has started to decrease as a power failure, performs battery switching control based on this detection, and further includes a computer circuit. The processing data is saved by the above and a power failure notification is sent to the host computer, and has the following configuration.

(1) A power supply having an AC / DC converter for obtaining a control power supply from a commercial power supply and provided at a monitoring position, and switching to a battery power supply by a battery switching circuit in place of the output of the AC / DC converter in the event of a power failure of the commercial power supply In a remote monitoring system that communicates monitoring information between a monitoring terminal having backup means and the monitoring terminal and a host computer,
The power backup means includes
A voltage drop detection circuit for detecting a voltage drop of the commercial power supply;
An external-internal insulation circuit that insulates and captures the voltage drop detection signal detected by the voltage drop detection circuit;
Switching to the battery power source in the battery switching circuit when the voltage drop detection signal that is insulated and taken in by the external-internal insulation circuit is given and the secondary output of the AC / DC converter starts to drop. A battery control circuit for obtaining an output;
It is provided with.
(2) A power supply having an AC / DC converter for obtaining a control power supply from a commercial power supply and provided at a monitoring position, and switching to a battery power supply by a battery switching circuit in place of the output of the AC / DC converter in the event of a power failure of the commercial power supply In a remote monitoring system that communicates monitoring information between a monitoring terminal having backup means and the monitoring terminal and a host computer,
The power backup means includes
A voltage drop detection circuit for detecting a voltage drop of the commercial power supply;
An external-internal insulation circuit that insulates and captures the voltage drop detection signal detected by the voltage drop detection circuit;
A voltage drop detection signal insulated and captured by the external-internal insulation circuit is used as an NMI interrupt signal, processing data at that time is saved, and the battery immediately before the secondary voltage drop of the AC / DC converter starts. A computer circuit that generates a switching signal and then notifies the host computer of a power failure;
A battery control circuit which is insulated by the external-internal insulation circuit and is provided with a captured voltage drop detection signal and obtains a switching output to the battery power source in the battery switching circuit when a battery switching signal is generated from the computer circuit When,
It is provided with.

(3) A power supply having an AC / DC converter for obtaining a control power supply from a commercial power supply and provided at a monitoring position, and switching to a battery power supply by a battery switching circuit in place of the output of the AC / DC converter in the event of a power failure of the commercial power supply In a remote monitoring system that communicates monitoring information between a monitoring terminal having backup means and the monitoring terminal and a host computer,
The power backup means includes
A voltage drop detection circuit for detecting that the secondary side voltage of the AC / DC converter has started to drop;
A battery control circuit for obtaining a switching output to a battery power source in the battery switching circuit by a voltage drop detection signal detected by the voltage drop detection circuit;
The power failure detection signal generated from the battery control circuit is used as an NMI interrupt signal, the processing data at that time is saved and a power failure notification is sent to the host computer, and then a signal to turn off the battery power is generated in the battery control circuit. A computer circuit;
It is provided with.

  (4) In the above (1) or (2), when power recovery of the primary side voltage of the AC / DC converter is detected during power recovery, the battery switching circuit is switched to the commercial power source side, It is characterized by having means for processing power recovery notifications without a power outage.

  (5) In the above (3), when the power recovery of the secondary side voltage of the AC / DC converter is detected at the time of power recovery, the battery switching circuit is switched to the commercial power source side, and the host computer is uninterrupted. It is provided with means for processing power recovery notification.

  (6) In the above (1), (2) or (3), when the power recovery of the voltage on the primary side or the secondary side of the AC / DC converter is detected at the time of power recovery, the battery switching circuit is connected to the commercial power source. Or a means for turning off the battery switching circuit in order to shut down the computer circuit in accordance with the completion of the process at the time of a power failure when operating with a battery.

  As described above, the present invention has the following effects.

  In the first embodiment, it is possible to switch to a battery power source with a margin for stopping the secondary side by detecting the voltage drop detection of the commercial power source and the start of the primary side voltage drop of the AC / DC converter. .

  In the second embodiment, by detecting the voltage drop of the commercial power supply and performing software processing by interrupting the computer circuit, software processing by power failure detection activation, that is, power failure notification processing, DI erroneous detection lock due to power failure, DO erroneous output lock, etc. Software processing is possible for cooperation with external circuits. In addition, since it is software processing, processing can be performed in combination with the power failure detection processing.

  In the third embodiment, by detecting a voltage drop on the secondary side of the power supply circuit at the time of a power failure and switching the battery, the power supply primary side and the insulating circuit are unnecessary, and only the secondary side circuit performs computer processing due to the power failure. Is possible. Further, a small amount of electronic device for the power failure detection circuit is required, and the mounting area can be reduced.

  In the fourth embodiment, at the time of power recovery, power recovery can be detected by the voltage on the primary side of the power supply circuit, and power recovery control by hardware can be performed.

  In the fifth embodiment, power recovery can be controlled by hardware by detecting power recovery of the secondary side voltage of the power supply circuit at the time of power recovery.

  In the sixth embodiment, it is possible to detect power recovery of the primary voltage of the power supply circuit at the time of power recovery and perform power recovery control by software. As for the battery OFF process at the time, as a shutdown process after the necessary process after a power failure, it is easy to turn off the battery by the computer circuit itself and stop it.

  In the present embodiment, the hardware circuit configuration shown in FIG. 1 is used, a power failure is detected by a decrease in the primary voltage of the power supply circuit, and ON / OFF switching of the battery switching circuit 6 is performed on the secondary side (output) of the AC / DC converter. ) Use a voltage control method.

  8 differs from FIG. 8 in that the battery switching circuit 6 determines whether the output voltage of the AC / DC converter 2 is above a certain level in addition to the detection signal from the voltage drop detection circuit 3 at the input of the battery switching circuit 6. The point is to input the signal.

  The voltage drop detection on the primary side by the voltage drop detection circuit 3 detects a voltage drop using, for example, about 60 to 70V as an instantaneous interruption guarantee voltage. In addition to the AC / DC conversion function, the AC / DC converter 2 has a function of generating a battery switching signal (reset signal) as an output for determining whether or not the output voltage is at a specified voltage. The generation of the battery switching signal is realized, for example, by a simple comparator circuit having a comparison reference voltage slightly lower than a specified voltage.

  The battery control circuit 5 issues a battery switching command to the battery switching circuit 6 when the power failure detection signal is input and the battery switching signal is given (the output voltage of the AC / DC converter starts to decrease). put out.

  The backup operation according to the present embodiment will be described with reference to the time chart shown in FIG. When the commercial power supply 1 (AC 100 V) is applied (time t1), the rectified output of the AC / DC converter 2 rises to a certain voltage, and the output voltage (5 V) of the AC / DC converter 2 is a normal voltage. Get the output. Further, the AC / DC converter 2 restores the battery switching signal (not a voltage drop) by establishing the output voltage (5V).

  On the other hand, the power failure detection circuit 3 obtains an OFF output of the power failure detection signal with a certain time delay from the application time point of the commercial power source 1 (AC 100V) (time t2). Due to this output, the battery switching circuit 6 is in an OFF state, and the AC / DC converter 2 supplies power of the voltage Vdd (5 V).

  In this state, when a momentary interruption occurs in the commercial power source 1 (time t3), the power failure detection circuit 3 performs power failure detection only during that period, but the AC / DC converter 2 does not generate a battery switching signal. No switching is performed.

  On the other hand, when a power failure occurs in the commercial power supply 1 (time t4), a battery switching signal is generated when the voltage of the AC / DC converter 2 starts to decrease, and the battery control circuit 5 sends a switching signal to the battery switching circuit 6. And the output voltage Vdd is obtained using the primary battery 7 as a power source. When the power failure is resolved (when power is restored), it is the same as time t1 → t2.

  Therefore, according to the present embodiment, the battery switching is not performed immediately when the primary voltage is decreased, but is switched for the first time when the secondary side voltage of the AC / DC converter 2 starts to decrease. For this reason, battery switching due to a momentary interruption of the commercial power supply (instantaneous interruption within the time until the secondary voltage starts to drop) does not occur, and wasteful consumption of the primary battery 7 can be eliminated.

  In addition, since the battery switching is performed at the timing when the secondary side voltage of the AC / DC converter 2 starts to decrease, the battery switching can be surely performed without being too early or too late.

(Embodiment 2)
In the present embodiment, a backup method is performed in which a primary voltage drop in the power supply circuit is detected during a power failure, and the battery is switched by software processing using an interrupt to the computer circuit.

  This embodiment has the circuit configuration shown in FIG. 3 and the time chart shown in FIG. 3 differs from FIG. 1 in that the voltage drop detection signal is used as an NMI interrupt signal to the computer circuit 8 and a battery switching signal is generated by software by the computer circuit 8. Further, the computer circuit 8 restores the battery switching signal with a certain confirmation time when the voltage drop detection signal disappears (recovers power).

  When the NMI interrupt is generated, the computer circuit 8 holds data such as temporary saving of the processing data at that time, and generates a battery switching signal at a timing immediately before the secondary side voltage drop of the AC / DC converter 2 starts. Then, a power failure notification is made. The timing at this time is measured in advance by a test operation of an actual machine, or is set with a time margin.

  According to this embodiment, the power supply is switched to the battery 7 side through the battery control circuit 5 by NMI processing by the computer circuit 8. In this case, the computer circuit 8 can easily obtain the cooperation between the switching control that does not respond to the instantaneous interruption of the power supply and the notification processing by generating the battery switching signal output at an appropriate timing. That is, it is possible to perform software processing for cooperation with external circuits such as power failure notification processing, DI erroneous detection lock due to power failure, and DO erroneous output lock. In addition, it is not possible to notify the power failure accidentally when the commercial power supply is interrupted.

  An example of software processing by the computer circuit 8 is shown in FIG. (A) of the figure shows an ON switching flow to the battery power source. If a voltage drop is detected even after executing the NMI interrupt processing, the switching processing to the battery power source is performed. (B) shows an OFF switching flow, and the battery switching is turned OFF only when the voltage drop recovery is confirmed. (C) shows the H / W OFF flow. When there is a battery switching signal by system monitoring after the power is turned on, the battery power switching is turned off.

(Embodiment 3)
In the present embodiment, a backup method is adopted in which a drop in the voltage on the secondary side of the power supply circuit is detected during a power failure and the battery power is switched by software processing by a computer circuit.

  The present embodiment has the circuit configuration shown in FIG. 6, and the difference from the first embodiment in FIG. 1 is that the voltage drop detection circuit 3 does not monitor the primary voltage of the AC / DC converter 2 but its secondary side. When the power failure is detected in this monitoring, the battery control circuit 5 immediately controls the battery switching, and thereafter the computer circuit 8 notifies the power failure, and the battery power is turned off and controlled upon completion.

  In the backup operation according to the present embodiment, as shown in FIG. 7, the battery control circuit 5 recognizes the “H” → “L” state change of the detection signal of the voltage drop detection circuit 3, and the battery switching circuit 6 immediately recognizes this recognition. To start supplying the power source Vdd from the battery 7. In parallel with this, the battery control circuit 5 notifies the computer circuit 8 that a power failure is occurring. The computer circuit 8 performs a power failure notification process, and at this time, the battery control circuit 5 generates a cut signal (OFF signal) to the battery switching circuit 6 and stops the supply from the battery 7.

  The diode 9 provided at the output terminal of the AC / DC converter 2 is configured to collide with the output of the battery switching circuit 6 to prevent the voltage Vdd from wrapping around, and the voltage drop detection circuit 3 can detect a power failure / recovery. It is said.

  According to the present embodiment, in addition to the effects of the first and second embodiments described above, in order to detect a power failure / recovery on the secondary side of the AC / DC converter 2, the insulation between the commercial power source 1 and the internal circuit is achieved. Is unnecessary, and the external-internal insulation circuit 4 can be omitted to simplify the backup circuit configuration.

(Embodiment 4)
In the present embodiment, a power recovery of the voltage on the primary side of the power supply circuit is detected at the time of power recovery, and the system is automatically switched to the commercial power supply side by hardware.

  In the configuration shown in FIG. 1, the present embodiment detects a return voltage level (for example, 60 to 70 V) on the primary side of the AC / DC converter 2 and controls the battery switching circuit 6 with the battery control circuit 5. Turn off the primary battery.

  This OFF control can be performed by a computer circuit when applied to the configuration shown in FIG. In this case, the computer circuit can also cause the host computer to issue a power recovery notification.

(Embodiment 5)
In the present embodiment, a power recovery of the secondary side voltage of the power supply circuit is detected at the time of power recovery, and the system is automatically switched to the commercial power supply side by hardware and software.

  In the present embodiment, in the configuration shown in FIG. 6, the return voltage level (for example, 4.5 V) of the secondary side voltage (+5 V) of the AC / DC converter 2 is detected, and the battery control circuit 5 switches the battery. The circuit 6 is controlled to turn off the primary battery. At the same time, the computer circuit 8 is informed that the power has been restored.

(Embodiment 6)
In the present embodiment, a power recovery of the primary side voltage of the power supply circuit is detected at the time of power recovery, and the system automatically switches to the commercial power supply side by software.

  In the present embodiment, in the configuration shown in FIG. 3, the computer circuit 8 polls the primary side voltage drop state to detect power recovery, and turns off the battery through the battery switching circuit 6. In this case, the drop detection state can be monitored by monitoring the NMI state. The present embodiment can be applied to the configurations shown in FIGS.

The backup circuit diagram which shows Embodiment 1 of this invention. 3 is a time chart of the first embodiment. The backup circuit diagram which shows Embodiment 2 of this invention. 4 is a time chart of the second embodiment. 9 illustrates an example of software processing by the computer circuit 8 according to the second embodiment. The backup circuit diagram which shows Embodiment 3 of this invention. 10 is a time chart of the third embodiment. The conventional backup circuit diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Commercial power supply 2 AC / DC converter 3 Voltage drop detection circuit 4 External-internal insulation circuit 5 Battery control circuit 6 Battery switching circuit 7 Primary battery 8 Computer circuit 9 Diode

Claims (6)

A power backup means is provided at a monitoring position having an AC / DC converter that obtains a control power from a commercial power source, and is switched to a battery power by a battery switching circuit in place of the output of the AC / DC converter in the event of a power failure of the commercial power source. In a remote monitoring system that communicates monitoring information between the monitoring terminal provided and the monitoring terminal and the host computer,
The power backup means includes
A voltage drop detection circuit for detecting a voltage drop of the commercial power supply;
An external-internal insulation circuit that insulates and captures the voltage drop detection signal detected by the voltage drop detection circuit;
Switching to the battery power source in the battery switching circuit when the voltage drop detection signal that is insulated and taken in by the external-internal insulation circuit is given and the secondary output of the AC / DC converter starts to drop. A battery control circuit for obtaining an output;
A remote monitoring system characterized by comprising: A power backup means is provided at a monitoring position having an AC / DC converter that obtains a control power from a commercial power source, and is switched to a battery power by a battery switching circuit in place of the output of the AC / DC converter in the event of a power failure of the commercial power source. In a remote monitoring system that communicates monitoring information between the monitoring terminal provided and the monitoring terminal and the host computer,
The power backup means includes
A voltage drop detection circuit for detecting a voltage drop of the commercial power supply;
An external-internal insulation circuit that insulates and captures the voltage drop detection signal detected by the voltage drop detection circuit;
A voltage drop detection signal insulated and captured by the external-internal insulation circuit is used as an NMI interrupt signal, processing data at that time is saved, and the battery immediately before the secondary voltage drop of the AC / DC converter starts. A computer circuit that generates a switching signal and then notifies the host computer of a power failure;
A battery control circuit which is insulated by the external-internal insulation circuit and is provided with a captured voltage drop detection signal and obtains a switching output to the battery power source in the battery switching circuit when a battery switching signal is generated from the computer circuit When,
A remote monitoring system characterized by comprising: A power backup means is provided at a monitoring position having an AC / DC converter that obtains a control power from a commercial power source, and is switched to a battery power by a battery switching circuit in place of the output of the AC / DC converter in the event of a power failure of the commercial power source. In a remote monitoring system that communicates monitoring information between the monitoring terminal provided and the monitoring terminal and the host computer,
The power backup means includes
A voltage drop detection circuit for detecting that the secondary side voltage of the AC / DC converter has started to drop;
A battery control circuit for obtaining a switching output to a battery power source in the battery switching circuit by a voltage drop detection signal detected by the voltage drop detection circuit;
The power failure detection signal generated from the battery control circuit is used as an NMI interrupt signal, the processing data at that time is saved and a power failure notification is sent to the host computer, and then a signal to turn off the battery power is generated in the battery control circuit. A computer circuit;
A remote monitoring system characterized by comprising:   Means for switching the battery switching circuit to the commercial power source side when the power recovery of the primary side voltage of the AC / DC converter is detected at the time of power recovery, and causing the host computer to perform processing such as power recovery notification without power failure The remote monitoring system according to claim 1, further comprising a remote monitoring system.   Means for switching the battery switching circuit to the commercial power supply side when the power recovery of the secondary side voltage of the AC / DC converter is detected at the time of power recovery, and causing the host computer to perform processing such as power recovery notification without power failure The remote monitoring system according to claim 3, further comprising: Switch the battery switching circuit to the commercial power source when the power recovery of the primary or secondary side of the AC / DC converter is detected at the time of power recovery, or at the time of power failure when operating with batteries The remote monitoring system according to any one of claims 1 to 3, further comprising means for turning off a battery switching circuit in order to shut down the computer circuit upon completion of processing.

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