JPS61231601A - Hierarchy type high reliable attaining device - Google Patents

Abstract

PURPOSE:To reduce the arithmetic operating time while reducing number of components of the hardware by connecting directly each level of a hierarchy type controller to a terminal device also so as to apply apparent high hierarchy. CONSTITUTION:The titled device consists of a controller A of a high-order level, a controller B being the subsequent level and a controller of the lowest order, in total the three hierarchies. Further, a terminal device R comprising an input circuit RI, an output circuit RO and transmitters RTA-RTC is connected to the process at the field. Thus, a triple system is formed apparently without increasing number of controllers. Thus a signal from the terminal device R is fetched simultaneously to the controllers A-C respectively, then the operating and arithmetic time of the arithmetic devices of the levels A-C is the sm between the own operating and arithmetic times TA-TC and respective transmission times T1-T3 and the time is decreased remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a control device for a thermal or nuclear power plant, and particularly to a hierarchical high reliability device suitable for achieving high reliability at a low cost.

[Background of the invention]

In a thermal or nuclear power plant, improving the operating rate of the plant is essential for reducing power generation costs. In particular, it is necessary to prevent as much as possible the plant from being stopped and the operating rate from decreasing due to a defect in the control device's hardware or system.

In general, there are two ways to improve operating efficiency: selecting hardware parts and using high-quality parts to improve reliability, and making the system multiplexed and redundant to improve it systematically. .

Since there is a limit to improving reliability at the component level, high reliability cannot be achieved unless system-wide improvements are made. In order to improve the system, manual backup method, double timing method, triple method, etc. are generally adopted. However, although the reliability improves as the multiplexing increases, the cost increases accordingly, making it uneconomical.

The circumstances surrounding this will be explained using the conventional example shown in FIGS. 5 and 6. FIG. 5 is a block diagram of a water supply control system multiplexed according to the prior art in a nuclear power plant, and FIG. 6 is a diagram showing the execution time in the conventional example shown in FIG. The A level instructs the B level control device to control plant automation and the like using the process computer. The B-level control device is a feed water control device, and performs three-element control based on the reactor water level and process signals such as the main steam flow rate and the feed water flow rate. The water supply control device is the control device C closest to the control target.
The calculation results are sent to the C level, and the control device at the C level gives a control signal to the final control target. In these various three-layer control configurations, a general method for systematically improving reliability is to make each control device double or triple.

In FIG. 5, the blocks slightly visible on the upper left of blocks A, B, and C indicate that each block is duplicated.

However, the more multiplexed, the higher the cost, which is not economical. Furthermore, the more hierarchical the structure, the longer the time required for transmission, which slows down the calculation speed. Particularly in digital calculation methods, the sampling period is the biggest factor in determining whether or not control is possible.

Generally, if the sampling period is one or more orders of magnitude shorter than the response time of the object to be controlled, control almost equivalent to that of an analog arithmetic device is possible. Therefore, shortening the sampling period is important in terms of control system configuration, and also serves as a basis for determining applicability.

be. At the C level, the calculation time Tc required by the calculation device C
is added to the time T1 required for transmission, and the calculation time is:
tc=Tc+T+. However, at B level, C
Calculation time tc spent at level + own calculation time 1. and the transmission time T2 are added. (Here, the transmission time T is evaluated as being different, but if the transmission device is the same, the same value Tl may be used.) The calculation time at the B level is t n =Tn +Tc +TI +T2. Furthermore, if we go back to A level, t* = TA + Ta
+Tc +T 1 + T 2 + T 3,
This will significantly delay calculation time.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hierarchical control device that reduces the number of hardware components, shortens calculation time, and improves reliability.

[Summary of the invention]

In order to achieve the above object, the present invention connects each level of a hierarchical control device directly to a terminal device, and while maintaining the hierarchical structure, apparently increases the number of hardware components and reduces the number of hardware components. It is characterized by reducing the control calculation time to the same level as that for the first layer, and increasing reliability.

[Embodiments of the invention]

Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 is a block diagram showing an embodiment of a hierarchical high reliability device according to the present invention. This embodiment is an example of a three-layer configuration, and includes a control device at an upper level, a control device B at a lower level, and a control device C at the lowest level. A terminal device R is connected to the process in the field. Inside the terminal device, there are 8 input circuits that input process signals from the site, an output circuit RO1 that controls the control target at the site, and transmission devices R and T that connect to three-layer control devices by signal multiplex transmission. It consists of people, RTm, and RTc.

On-site process signals pressure plant status.

It is determined by flow rate, water level, temperature, opening/closing status, etc.

For example, in the case of the pressure of a nuclear reactor, a signal from a pressure transmitter such as a semiconductor detection method is input to the input circuit RI.

These process signals are multiplexed and transmitted by the input circuit RI, and are sent to the transmission device hole T A - by three interface buses.
Connect to RT c. Transmission devices RT A to R, Tc are transmission devices AT to CT inside control devices A to C, respectively.
connected to transmit signals.

do.

FIG. 2 is a diagram showing the computation time in the three-layer configuration according to the embodiment of FIG. 1. The signal from the terminal device R is sent to the control device A.
-C at the same time, the calculation time of the A-C level arithmetic device is the own calculation time T A -T c and each transmission time T1. By adding T2°T3, the time becomes significantly shorter. It is also told here.

If the sending device is the same, all calculations are done using Tl.

The configuration shown in FIG. 1 has an apparent triple system configuration without increasing the number of control devices. That is, the control device C
If the system stops for some reason, it will be backed up by control device B or A, and even if control devices B and C stop, control device A will back up, which is a triplex configuration.

3 and 4 are circuit diagrams of the input circuit RI and output circuits R and O of the terminal device hole in FIG. 1.

Figure 3 shows an analog circuit powered by four people. The 0th to 3rd input signals are sent to the timing/internal address generation circuit R.
, for IT, from input acquisition section RICHO to RICH3
are sequentially input to the multiplexer RIMPX via the multiplexer RIMPX. Then, the output is amplified through the amplifier RIAMP, and A
The signal is converted into a digital serial signal by the /D converter RIAD. Digital serial signals are stored in memories IMA to IMc. That is, the analog signal is converted into a digital signal and stored in the memory at regular intervals. The memory will be increased three times from A to C. Information on the memory can be connected to a transmission device via a bus using an address access control RIADA, an input data buffer PIDA, and status data buffers R and ISA.

FIG. 4 shows an output circuit with four analog outputs.

Three digital signals from the transmission device are input to the output circuit section via the bus. A.

B and C are output signals corresponding to the control devices A, B, and C of the hierarchical section, respectively. When dealing with transmission equipment,
The signals are sequentially taken in by the output scanning control ROC via the address access control ROADA, the output data buffer RODA, the operation data buffer BOXA, and the status data buffer RO8A, and the signals are transmitted to the determination circuit ROJ.

The determination circuit ROJ outputs a signal of C to the D/A converter ROD when the control device C is normal, depending on the state of the control devices A-C. If control device C is abnormal, B is selected, and if B is also abnormal, A is selected. The output of the D/A converter becomes four analog outputs via the output multiplexer ROMPX.

As explained above, according to one embodiment of the present invention, a multiplexed configuration can be realized without increasing the number of control devices, high-speed calculations can be performed with the shortest calculation time, and the effects of improving reliability and economic efficiency are significant. .

Although the above embodiment of the present invention has three hierarchies, the same applies to multiple hierarchies, and the same holds true even when each hierarchy has a plurality of arithmetic units.

Furthermore, the number of points for the input circuit and output circuit was 4 points,
Needless to say, any number of points is fine.

〔Effect of the invention〕

According to the present invention, it is possible to obtain a hierarchical high-reliability device that reduces the number of hardware parts, shortens the control calculation time, and has high reliability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a hierarchical high reliability device according to the present invention, FIG. 2 is a diagram showing calculation time in the embodiment of FIG. 1, and FIG. 3 is an input circuit of the embodiment of FIG. 1. FIG. 4 is a diagram showing an example of the output circuit of the embodiment shown in FIG. 1. FIG. The figure is a diagram showing the computation time in the conventional example shown in FIG. Person ~ C... Control device, R... Terminal device, AT ~ CT
...Transmission device, RTA-RTc...Transmission device, RI
...Input circuit, RO...Output circuit.

Claims (1)

[Claims] 1. In a hierarchical control device in which a higher-level control device monitors a lower-level control device that controls a controlled object, the control device at each level is also directly connected to a terminal device placed near the controlled object, and connections between each level are established. So, while maintaining the hierarchy,
A hierarchical high reliability device characterized by multiplexing between each level.