JPH03203519A - Automatic synchronous switching system for demand meter - Google Patents

Abstract

PURPOSE:To reduce the number of setting term and to simplity the operation by continuously confirming existence of an external synchronizing input signal in a specific time signal at an incorporated timer section and automatically switching the synchronizing system. CONSTITUTION:When both a specific time 32 and an external synchronizing signal pulse 36 are H, a switching signal goes H. since an external synchronizing signal 37 is detected during next specific time 33, duration of the switching signal at H level is updated. Since no external synchronizing signal is detected during a specific time 34, the switching signal goes to L level at the time point of a specific time signal (T1) and switching is made to a clock time fixed synchronizing system. In other words, since the operation is switched at every T1 time, switching is made to the external synchronizing system upon detection of next external synchronizing signal.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to receiving a metering pulse and a 30-minute demand time period pulse from an electric power company through a pulse detector, or receiving only a metering pulse and detecting the demand power within the 30-minute demand time period. This invention relates to an automatic synchronous switching method in a power demand measuring device that calculates the power consumption and provides data necessary for power management.

Conventional technology Conventionally, there are two cases in which the 30-minute demand time limit is supplied by the electric power company as a synchronized time signal, and when it is not supplied. Therefore, in the latter case, the clock (internal The synchronization time was set at a fixed time every 30 minutes (timer synchronization section).

In the following description, the former method will be referred to as an external synchronization method, and the latter method will be referred to as a fixed clock time synchronization method.

Next, a conventional switching method for the above two synchronization methods will be explained.

One conventional method is to initially set the synchronization method to one of the synchronization methods in the synchronization method setting section using a setting key, and after setting, the synchronization method is not switched.

FIG. 3 shows a conventional embodiment, in which setting data is written to the synchronization method setting section 14 by setting the synchronization method to either one using the setting key 16 of the operation section, and the external synchronization signal is Means has been taken to select either the input section 12 or the internal timer synchronization section 13 to determine the synchronization method.

Problems to be Solved by the Invention Conventional power demand measuring devices have the following problems.

■ The conventional method requires a setting operation section and is cumbersome to set.

■ When set to the external synchronization method, if there is a failure in the signal circuit of the external synchronization signal, it will not be possible to shut off the power demand at any time. Therefore, the present invention reduces the number of setting items as much as possible and makes the operability simple. The purpose is to automatically switch the synchronization method with improved reliability by preventing erroneous measurements such as those caused by the above-mentioned causes.

Means for Solving the Problems The present invention comprises an external synchronization signal input section, a built-in timer section, an external synchronization input determination section, a synchronization signal switching section, and a clock time fixed synchronization section.
The presence or absence of an external synchronization input signal is constantly checked by the determination section, and as a result, the synchronization signal switching section automatically switches the synchronization method. The button is pressed when the clock time fixed synchronization method is set, and the external synchronization input determination section determines whether or not there is an external synchronization signal within a specific time, and if an external synchronization signal is detected, the determination section converts the detected signal into a synchronization signal. The signal is output to the switching section, and the switching section automatically switches the synchronization method from the clock time fixed synchronization section to the external synchronization method. In addition, the clock time synchronization section is set and continues measurement when the external synchronization input determination section does not detect an external synchronization signal within a specific time.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention,
23 is a built-in timer unit that outputs a specific time signal T1 that gives a specific time; 24 has two functions for the specific time signal T1 and an external synchronization signal DO, and determines the presence or absence of the external synchronization signal Do within a specific time. This is an external synchronization input determination section, and when the external synchronization signal DO is detected within a specific time, the switching signal is set to rH. 26 is a synchronization method switching unit;
For example, when the switching signal is "rH" as described above, the system switches to the external synchronization method. The synchronization method switching unit 26 sets the clock time synchronization method in the initial state and switches the synchronization method depending on the state of the button switching signal. Also, within a specific time, the external synchronization signal Do
is not detected, the switching signal becomes I''LJ, and the synchronization method switching section 25 switches to the clock time fixed synchronization method at the time of the specific time signal T1.The above operation is repeated every T1, so The synchronization method is switched depending on the state of the external synchronization signal.

21 is a pulse input section, 22 is an external synchronization signal input section, 26
is an internal timer section which performs various arithmetic operations within the demand time period using the metering pulse and the synchronization signal.

Next, the operation will be explained with reference to the timing chart of FIG.

32 to 35 indicate specific time To, 36.37 indicates external synchronization signal pulse, and 38 indicates "H" time of switching signal, and the horizontal direction indicates time.

As shown in FIG. 2, when the specific time To32 and the external synchronization signal pulse 36 are both rH, the switching signal becomes rH. At the next specific time TO33, the external synchronization signal DQ
37 is detected, the FHJ time of the switching signal is updated. Then, at specific time TQ34, external synchronization signal Do
Since this is not detected, the switching signal becomes "L" at the time of the specific time signal T1, and the clock time is switched to the fixed clock time synchronization method. As described above, since the above operation is repeated every T1, when the next external synchronization signal Do is detected, the system switches to the external synchronization method.

As described above, depending on the state of the external synchronization input determination section 24,
The synchronization method is automatically switched in the synchronization signal switching section 26.

Effect of the invention As described above, according to the present invention, the following effects can be obtained.

(1) When setting the external synchronization method, even if the external synchronization signal cannot be received for some reason such as a failure of the external synchronization signal circuit, it will automatically switch to the clock time fixed synchronization method, so subsequent measurements will be reliable. It becomes something sexual.

(2) A synchronization method setting section is not required, and the troublesome setting operation is eliminated. Furthermore, it is possible to prevent erroneous measurements due to erroneous settings such as forgetting settings.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an automatic synchronous switching method of a power demand measuring device according to an embodiment of the present invention, FIG. 2 is a timing chart of the same, and FIG. 3 is a block diagram of a conventional example. 11.21... Pulse input section, 12, 22.
...External synchronization signal input section, 13.26...
Internal timer synchronization section, 16.27...Measurement/calculation section, 14...Synchronization method setting section, 15...
Setting key manual section, 23...Built-in timer section, 24
......External synchronization input determination section, 26...Synchronization method switching section, 32-36...Specific time, 36
．． 37...External synchronization pulse, 38...
External synchronization method setting period.

Claims (1)

[Claims] Give the pulse input signal and demand time signal to the measurement/calculation section,
A power demand measuring device that calculates the demand power within a demand time limit is equipped with both an external synchronization signal input section and an internal timer synchronization section as the demand time limit, and uses the external synchronization signal input section and the built-in timer section as input sources. an external synchronization input determination section that reads both signals and determines the presence or absence of an external synchronization signal within a specific time; and a synchronization signal switching section that switches between the internal timer synchronization section and the external synchronization signal input section based on the result of the external synchronization input determination section. An automatic synchronization switching method for a power demand measuring device, characterized in that the synchronization method is automatically switched between an external synchronization method and a clock time fixed synchronization method depending on the presence or absence of an external synchronization signal within a specific time.