JPS5839301A - Signal selection system - Google Patents

Abstract

PURPOSE:To perform stable plant control by diagnosing plural detection signals invariably in the signal selection of a plant process variable for the plant control, and performing switching to a normal signal when a signal in use becomes abnormal. CONSTITUTION:Output signals of detection parts 1, 2, 3, and 4 are sent to a signal switching part 5, and also supplied to a switching diagnosis part 7. The diagnosis part 7 diagnoses plural detection signals invariably and, if a signal in use becomes abnormal, sends a switching command for selecting the best normal signal to the switching part 5. Thus, the labor of operators is reduced, the activity of a plant is improved, and stable plate control is exercised.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal selection method for increasing the reliability of detection signals of plant process quantities in plant control (for example, power generation plants).

Conventionally, there was a system as shown in Fig. 1. In Fig. 0, (1) to (4) are process detection sections, (6) is a process detection section (1) to 1 phantom signal switching section, ( 6) indicates a switch that issues a switching command to the switching unit flit.

Next, the operation will be explained.

For example, four detection signals (1) to (4) are connected to the signal switching section (
6), and the operator selects an appropriate detection signal using a changeover switch (61) based on the operating state of the plant.

Line signals from the detection unit are often the cause of plant disturbances.

Previously, when the plant status became abnormal, the operator noticed it and selected a normal signal using a changeover switch.

In many cases, it is not enough to take measures after the plant condition becomes abnormal, resulting in a plant trip, that is, a plant shutdown. There is also great psychological pressure on the operators.

This invention was made in order to eliminate the drawbacks of the conventional ones as mentioned above, and +! The purpose is to provide a signal switching system with a diagnostic function instead of a switching switch operated by a staff member.

With this function, it is possible to automatically switch from an abnormality detection signal to a normal detection signal before the plant enters an abnormal state, thereby enabling stable control of the plant. This in turn leads to an improvement in the pumping rate of the plant.

An embodiment of this invention will be described. In FIG. 2, (1) to (4) are a plurality of detection units, and (6) is a signal switching unit.

(7) is a switching diagnostic section which has a diagnostic function, compares a plurality of signals with each other, selects the most suitable signal, and outputs a switching signal to the key switching section t6).

The plurality of detection signals are connected to the signal switching section (6) and also input to the switching diagnosis section (7).

The cut hakama diagnosis section (7) constantly diagnoses multiple detection signals.

If the currently used signal becomes abnormal, a switching command is sent to the signal switching unit to select the most normal signal.

Here, in order to specifically explain the switching diagnosis section ()), an example will be described with reference to FIG. FIG. 3 is presented in flowchart form to clarify the functions.

The switching diagnosis section ( ) 1 can be realized by a predefined computer, a microprocessor, or an analog arithmetic circuit. Various methods for determining 0 can be considered depending on the target plant. If the selection method is based on the average value, it is also possible to select the second highest signal.

Does the scope of application also apply? [Applicable not only to plants but also to general industrial facilities.]

As described above, according to the present invention, multiple detection signals are constantly diagnosed, and if the signal currently in use becomes abnormal, it is possible to send a highly reliable detection signal to the controller by switching to a normal signal. As a result, stable plant control can be achieved. Therefore, it is possible to improve the operating rate of the plant.

1lll again! It also saves labor during transfers.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional signal one selection method. FIG. 2 is a block diagram showing one embodiment of the present invention. FIG. 3 is a flowchart illustrating a functional example of the switching diagnostic section of the present invention. In the figure, (]) to (4) are detection signals, (51 is a switching unit, (71 is a switching diagnosis unit), and the same reference numerals in the figure indicate the same or corresponding parts. Agent Makoto Kuzuno - Figure 1, Figure 2 Figure 3 pIS roars

Claims (1)

[Claims] In a device that detects process copying and sends it as an input signal to one sidecar, the switching diagnosis section obtains multiple input signals and automatically selects the optimal signal from these multiple input signals for control. A signal selection method characterized by outputting to a # device.