JP2011103071A - Multiplexing control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a more compact multiplexing control device while securing high reliability and a high operation rate. <P>SOLUTION: The triple-system multiplexing control device including three process control arithmetic parts calculating and outputting three-system process control signals to the same controlled target includes three priority selection parts each selecting one of two-system arithmetic results inputted to a priority-system port and a standby-system port from the process control arithmetic parts, and relaying it to a process signal input/output unit for a triple system. The process control arithmetic part includes a mutual diagnostic function by comparison between a self-diagnostic function and arithmetic results of the other two systems, and performs instruction to change over an input source of a selection result relayed by the priority selection part where the arithmetic result of the system detected with an abnormality is inputted to the priority-system port to the standby-system port side from the priority-system port side. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a multiplexing control apparatus that includes a plurality of process control arithmetic units and performs control multiplexed by these.

  In general, multiplexing control is used in a system that requires high reliability for process control, such as a power plant. In multiplexing control, arithmetic processing for control of one controlled device is performed in parallel by a plurality of process control arithmetic units, and from each control signal obtained by parallel processing by the plurality of arithmetic units, For example, for analog output, intermediate value priority, low value priority, high value priority, and for digital output, signal selection is performed by majority decision, AND selection, OR selection, etc., and the selection result is output to the controlled device as a control signal. Like to do.

  In addition, when an abnormal control signal is output due to a failure in some systems, the controlled process is not stopped by disconnecting the abnormal system and performing a degenerate operation. I am doing so. Therefore, in the conventional multiplexing control device, a method of changing the selection logic of the output signal at the same time as disconnecting the abnormal system according to the diagnosis result by self-diagnosis or mutual diagnosis has been adopted.

  For example, in the prior art (prior art 1) described in Patent Document 1, each of the output signal selection circuits provided for each controlled object is configured so that a plurality of selection logics can be executed. The selection logic to be executed is changed according to the pattern of the diagnosis result. However, in the prior art 1, since each output signal selection circuit becomes complicated, the amount of hardware increases as the number of controlled objects increases, and there is a disadvantage that the apparatus becomes large.

  On the other hand, in the prior art (prior art 2) described in Patent Document 2, it is possible to use a standard process signal input / output card by providing an output signal selection function in software executed by the process control operation unit. As a result, the device was made compact. However, in the prior art 2, since the process signal input / output card portion is a single system, the input / output system has a disadvantage that high reliability is not achieved by a redundant configuration.

JP 61-52701 A JP 2003-177801 A

  The present invention has been made to solve the above-described disadvantages of the prior art, and it is an object of the present invention to provide a more compact multiplexing control device while ensuring high reliability and operating rate. .

In order to solve the above-described problem, a multiplexing control apparatus according to the present invention provides a triple-system signal selection circuit that outputs three process control signals for the same controlled object output from three process control operation systems. There are three priority selection units that relay to the process signal input / output unit, each of which receives two different process control signals and relays them to the process signal input / output unit, causing a fault in one system In this case, the process control signal from the other normal system is relayed in place of the process control signal from the failed system. As a result, even when a failure occurs in one or two of the three process control operation systems, two or more normal process control signals are relayed to the process signal input / output unit. According to the control system, from the triple system to the single system degenerate operation can be realized by using the process signal input / output unit including the triple system signal selection circuit.
Specifically, the multiplexing control apparatus of the present invention includes three process control operation units that each execute the same operation processing in parallel and calculate and output three system process control signals for the same controlled object. And three analog or digital process control signals are input in parallel, and in the case of an analog process control signal, an intermediate value thereof, and in the case of a digital process control signal, a majority value thereof is input. A triple multiplexing control device comprising a process signal input / output unit for outputting to a controlled object, wherein two processing results are input from the process control arithmetic unit to a priority system port and a standby system port. 3 priority selection units that select one of the process control signals and relay to the process signal input / output unit as a process control signal of the selection result The process control signal of the calculation result of each system output from the process control calculation unit is input to the priority port for the two different sets of priority selection units, and the other is input to the standby port. The process control calculation unit includes a self-diagnosis function for diagnosing the presence or absence of abnormality in the own system, and process control of the calculation results of the other two systems acquired from the other two process control calculation units via the data transmission means. Comparing a signal with a process control signal of a calculation result obtained by itself, a mutual diagnosis function for detecting an abnormal system, and a calculation result of a system in which an abnormality is detected by the self-diagnosis function or the mutual diagnosis function Process control of the selection result to be relayed to the process signal input / output unit for the priority selection unit in which the process control signal is input to the priority system port Characterized in that an instruction to switch to standby port side No. of input source from the priority system port side.

  According to the present invention, it is possible to provide a more compact multiplexing control device while ensuring high reliability and availability.

It is a block diagram which shows the structural example of the multiplexing control apparatus which concerns on this invention. It is explanatory drawing about the selection instruction | indication signal which instruct | indicates operation | movement of a priority selection part. It is explanatory drawing which shows the flow of a signal when all the systems are normal. It is explanatory drawing which shows the flow of a signal when one system is abnormal. It is explanatory drawing which shows the flow of a signal when two systems are abnormal. It is a flowchart which shows operation | movement of a process control calculating part. It is a block diagram which shows the example of application to a nuclear power plant.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments for carrying out a multiplexing control apparatus according to the invention will be described in detail with reference to the drawings as appropriate.
FIG. 1 is a block diagram showing a configuration example of a multiplexing control apparatus according to the present invention. As shown in FIG. 1, the multiplexing control apparatus 1 includes three process control arithmetic units 11A, 11B, and 11C and three priority selection units 12A and 12B that are communicably connected to each other via a data transmission unit 18. , 12C, and a process signal input / output unit 13 for inputting / outputting signals used for controlling the controlled object 2.

  The process signal input / output unit 13 is an analog output circuit 14 for a triple system, a digital output circuit 15, an analog input circuit 16, a digital input circuit 17, and a data bus 19 for transmitting / receiving data to / from these circuits. Consists of The analog output circuit 14 receives three systems of analog process control signals output from the process control arithmetic units 11A to 11C, selects an intermediate value thereof, and outputs the intermediate value to the controlled object 2. The digital output circuit 15 inputs the three systems of digital (in this example, binary) process control signals output from the process control arithmetic units 11A to 11C, and calculates the majority of the input three systems of process control signals. Select and output to controlled object 2. The analog input circuit 16 and the digital input circuit 17 distribute the input from an analog sensor such as a transmitter or a digital sensor such as a limit switch to the process control arithmetic units 11A to 11C through the data bus 19 as a process input signal (not shown). To do. There may be a plurality of output circuits 14 and 15 and input circuits 16 and 17.

  The three process control calculation units 11A, 11B, and 11C each input a process input signal for control of the same controlled object 2 from the process signal input / output unit 13 and execute the same control calculation process. As a result, the process control signals p1, p2, and p3 are calculated and output. The process control signals p1, p2, and p3, which are output as computation results, are input to the priority system port and the standby system port of two different priority selection units 12, respectively. For example, the process control signal p1 is input to two locations, that is, the priority system port of the priority selection unit 12A and the standby system port of the priority selection unit 12C, and the process control signal p2 is input to the priority system port of the priority selection unit 12B, It is input to two places with the standby system port of the priority selection unit 12A.

  The priority selection units 12A, 12B, and 12C select one of the two process result process control signals input to each of the priority system port and the standby system port, and select the process control signals q1 and q2 as the selection results. , Q3 to the process signal input / output unit 13. In the following, the process control operation unit 11 that is the output source to the priority system port is referred to as the “priority system side operation unit”, and the process control operation unit 11 that is the output source to the standby system port is referred to as “ This is called a “standby system side arithmetic unit”. Each priority selection unit 12A, 12B, 12C, in a normal state where no failure has occurred in the priority system side arithmetic unit, is a process control signal p1, p2, which is a calculation result input from the priority system side arithmetic unit to the priority system port. p3 is selected and relayed. When a failure occurs in the priority system side arithmetic unit, the process control signals p2, p3, and p1 of the operation result input from the standby system side arithmetic unit to the standby system port are selected and relayed.

  Whether the priority selection unit 12A, 12B, or 12C selects the process control signal of the calculation result on the priority system port side or the standby system port side is determined by both the priority system side calculation unit and the standby system side calculation unit. Are commanded by binary selection instruction signals c1, c2 and c3 generated from the two state signals output from, respectively. Here, when the selection instruction signal is at the H level, the priority system port side is selected, and when the selection instruction signal is at the L level, the standby system port side is selected. If the L level is output, as shown in the example of FIG. 1, the signal lines of the two state signals output from the priority system side arithmetic unit and the standby system side arithmetic unit are connected and wired OR is performed. Thus, the selection instruction signal can be generated.

  FIG. 2 shows two state signals output from the priority system side arithmetic unit and the standby system side arithmetic unit, and a selection instruction signal ci (i) obtained by wired-ORing them. = 1, 2, 3) is an explanatory diagram showing a correspondence relationship. As shown in FIG. 2B, the selection instruction signal ci (i = 1, 2, 3) obtained by wired-ORing these two state signals is the state signal from the priority system side arithmetic unit and the standby system. It is a value obtained by logical product with the state signal from the side arithmetic unit. Further, as shown in FIG. 2A, the status signal from the priority system side arithmetic unit is sent when the process control arithmetic unit 11 is operating normally and the self-diagnosis result is determined to be normal (self Diagnosis normal) H level is output, and when the self-diagnosis result is determined to be abnormal (local system abnormality) or when the process control operation unit 11 is stopped (priority system is stopped), L level is output The On the other hand, the status signal from the standby system side arithmetic unit is determined that the result of the self-diagnosis of the standby system side arithmetic unit is abnormal when the priority system side arithmetic unit is determined to be normal by mutual diagnosis (normal diagnosis is normal). When the standby system side arithmetic unit is stopped (when the standby system is stopped), the H level is output, and when the priority system side arithmetic unit is determined to be abnormal by mutual diagnosis ( Mutual diagnosis error) L level is output.

  That is, if the priority system side arithmetic unit diagnoses itself as normal and the priority system side arithmetic unit is not diagnosed as abnormal by mutual diagnosis by the other two process control arithmetic units 11, the selection instruction signal ci is The process control signal on the priority system port side is selected at the H level, and in other cases, the selection instruction signal ci is set to “L level” and the process control signal on the standby system port side is selected.

Hereinafter, the operation of the multiplexing control apparatus 1 will be described in detail with reference to FIGS. 3 to 5.
FIG. 3 is an explanatory diagram showing an operation when each of the triple systems configured by the three process control arithmetic units is normal (when the entire system is normal). As shown in FIG. 3, in this case, since the state signals output from the process control arithmetic units 11A to 11C are all at the H level, the selection instruction signals c1, c2, and c3 are all at the H level. From each of the priority selection units 12A to 12C, the process control signal resulting from the calculation input to the priority system port becomes the process control signal resulting from the selection (q1 = p1, q2 = p2, q3 = p3), and the analog output circuit 14 or Relayed to the digital output circuit 15. As a result, the analog output circuit 14 outputs an intermediate value of the process control signals {p1, p2, p3} of the three calculation results output from the three process control calculation units 11A, 11B, and 11C, respectively. 15 determines the output signal based on the normal triple selection logic of outputting the majority value of the three process control signals {p1, p2, p3}.

  FIG. 4 is an explanatory diagram showing an operation when a system constituted by the process control operation unit 11A in the triple system (hereinafter, this system is referred to as “A system”) is abnormal (when the A system is abnormal). It is. The abnormality of each system discovered by self-diagnosis or mutual diagnosis is also transmitted to the process control arithmetic unit 11 of another system via the data transmission means 18. Then, the process control operation unit 11B that discovers or transmits the abnormality in the A system changes the status signal for the priority selection unit 12A to L level, thereby setting the selection instruction signal c1 to L level. As a result, the priority selection unit 12A switches the input source of the process control signal to be relayed from the priority system port side to the standby system port side, and outputs the process control signal p2 (q1 = p2). The priority selection units 12B and 12C output process control signals p2 and p3 input to the priority ports, respectively (q2 = p2, q3 = p3). Therefore, the analog output circuit 14 outputs p2 as an intermediate value of the process control signals {p2, p2, p3} of the three selection results output from the three priority selection units 12A, 12B, and 12C, respectively. 15 also outputs p2 as the majority value of the three process control signals {p2, p2, p3}. As described above, the control by the other two normal systems can be continued without depending on the output from the A system in which the abnormality is detected.

  FIG. 5 shows the operation when the system configured by the process control operation unit 11B in addition to the A system (hereinafter, this system is referred to as “B system”) also becomes abnormal (when the A system & B system is abnormal). FIG. In the state where one system is abnormal, the mutual diagnosis function does not work, so the abnormality of the second system is discovered by self-diagnosis, and the process control operation unit 11 of the other system is detected via the data transmission means 18. It is transmitted that the two systems of the A system and the B system are abnormal. Then, the process control operation unit 11C to which the abnormality of the other two systems has been transmitted changes the status signal for the priority selection unit 12B to L level, thereby setting the selection instruction signal c2 to L level. As a result, the priority selection unit 12B switches the input source of the process control signal to be relayed from the priority system port side to the standby system port side, and outputs the process control signal p3 (q2 = p3). The priority selectors 12A and 12C output process control signals p2 and p3 input to the standby port and the priority port, respectively (q1 = p2, q3 = p3). Therefore, the analog output circuit 14 outputs p3 as an intermediate value of the process control signals {p2, p3, p3} of the three selection results output from the three priority selection units 12A, 12B, and 12C, respectively. 15 also outputs p3 as the majority value of the three process control signals {p2, p3, p3}. Thus, control can be continued only with one normal system without depending on outputs from the A system and the B system in which an abnormality is detected.

  FIG. 6 is a flowchart showing the operation of the process control calculation unit. Hereinafter, the operation of the process control calculation unit will be described in detail with reference to this flowchart.

  When the process control calculation unit 11 is activated, first, in step S1, a self-diagnosis for detecting an abnormality occurring in its own system is executed. In self-diagnosis, abnormalities are detected by performing hardware and software operation checks, input signal upper and lower limit checks, calculation result upper and lower limit checks, and the like.

Subsequently, in step S2, the self-diagnosis result is determined. If the diagnosis result is determined to be "abnormal"("abnormal" in step S2), a standby system selection instruction is executed in step S3. The process returns to step S1. In this standby system selection instruction, by setting the status signal to the priority selection unit, which is the priority system side arithmetic unit itself, to L level, the input source of the priority selection unit is switched to the standby system port side. An abnormality of the own system is transmitted to the process control calculation unit 11 of the system.
When an operation for stopping the process control calculation unit 11 is performed for maintenance or the like (“stop operation” in step S2), the operation of the process control calculation unit 11 is terminated.

  If the diagnosis result is determined to be “normal” (“normal” in step S2), first, a priority system selection instruction is executed in step S4. In this priority system selection instruction, the priority system side port can be selected as the input source of the priority selection unit by setting the status signal to the priority selection unit that is the priority system side arithmetic unit to H level. And However, as described with reference to FIG. 2, in order for the input on the priority system port side to actually become effective, the status signal from the standby system side arithmetic unit must also be at the H level.

  Subsequently, in step S5, a process control signal is executed and a process control signal to be output is obtained. In step S6, an operation result of another system is acquired, and in step S7, a mutual diagnosis is executed. In the mutual diagnosis, among the calculation results of the three process control calculation units 11, the calculation result of one system has a certain deviation or more than the calculation result of the other two systems, or the binary logical value is different. If so, diagnose that one system is abnormal. For example, if the calculation results of the A system, B system, and C system are -5, +5, and +5, respectively, the A system is diagnosed as abnormal, and the calculation results of the A system, B system, and C system are ON, If it is OFF or ON, the B system is diagnosed as abnormal.

Next, in step S8, the result of the mutual diagnosis is determined, and if the own system is determined to be abnormal ("Self system abnormality" in step S8), the same as the case where the self diagnosis determines that there is an abnormality. After executing the standby system selection instruction in step S3, the process returns to step S1.
If it is determined that the other system corresponding to the priority system side arithmetic unit of the priority selection unit that uses itself as the standby system side arithmetic unit is abnormal (“other system abnormality in standby system” in step S8), the process proceeds to step S9. Then, after the other system standby system selection instruction is executed, the process returns to step S1. In this other system standby system selection instruction, by setting the status signal to the priority selection unit which uses itself as the standby system side operation unit to L level, the input source of the priority selection unit is switched to the standby system port side.

  If it is determined that the diagnosis result is neither “own system abnormality” nor “standby system other system abnormality” (“normal or other” in step S8), a priority system selection instruction for another system is issued in step S10. After execution, the process returns to step S1. In this other system priority system selection instruction, by setting the status signal to the priority selection unit that uses itself as the standby system side operation unit to H level, the priority system port side selection is made as the input source of the priority selection unit. Make it possible.

In the above description, the case where the selection instruction signal is generated by the wired OR of the state signals output from both the priority system side arithmetic unit and the standby system side arithmetic unit has been described. When the abnormality is detected by self-diagnosis of the priority system side arithmetic unit, it is transmitted to the standby system side arithmetic unit, and the standby system side arithmetic unit sends it to the standby system port side. May be instructed to switch. Alternatively, a relay circuit that operates according to the results of self-diagnosis and mutual diagnosis by each process control arithmetic unit may be provided, and the selection instruction signal may be generated by the output of this relay circuit.
The analog output circuit outputs an intermediate value of the three process control signals, but may output an average value of the three.

  As described above, according to the multiplexing control apparatus of the present invention, even when a failure occurs in one or two of the triple process control operation systems, output to the controlled object 3 is performed. Since two or more normal process control signals are relayed to the process signal input / output unit for the heavy system, the standard process signal input / output unit for the triple system is used to change from the triple system to the single system. It can realize up to degenerate operation. Therefore, it is possible to provide a more compact multiplexing control device while ensuring high reliability and operating rate.

  FIG. 7 is a block diagram showing an application example of the multiplexing control device according to the present invention to a nuclear power plant that is a suitable application target. The nuclear power plant P shown in FIG. 7 is a boiling water reactor plant, and high reliability and availability are required. Therefore, the multiplexing control device according to the present invention is connected to the reactor water supply flow rate control device 1a. This is applied to the reactor recirculation flow rate control device 1b.

  The reactor water supply flow rate control device 1a controls the water supply flow rate by operating the water supply pump 2a based on the water level signal in order to keep the water level of the reactor 3 appropriate. On the other hand, the nuclear reactor recirculation flow rate control device 1b appropriately controls the recirculation pump 2b that adjusts the flow rate of circulating water circulating in the nuclear reactor 3 based on the reactor output. These two control devices 1a and 1b are particularly important control systems in the nuclear power plant P, and extremely high reliability is required. At the same time, high operating rate and cost reduction by downsizing are strongly demanded. The multiplexing control device according to the present invention is particularly suitable for taking advantage of the features of high reliability, high availability, and compactness.

DESCRIPTION OF SYMBOLS 1 Multiplexing control apparatus 11, 11A, 11B, 11C Process control calculating part 12, 12A, 12B, 12C Priority selection part 13 Process signal input / output unit 14 Analog output circuit 15 Digital output circuit 16 Analog input circuit 17 Digital output circuit 18 Data Transmission means 19 Data bus 1a Reactor feed water flow control device 1b Reactor recirculation flow control device 2a Feed water pump 2b Recirculation pump 3 Reactor 4 Turbine 5 Generator 6 Condenser P Nuclear power plant c1, c2, c3 Selection instruction Signals p1, p2, p3 Process control signal resulting from operation q1, q2, q3 Process control signal resulting from selection

Claims (6)

Three process control arithmetic units each for executing the same arithmetic processing in parallel and calculating and outputting three system process control signals for the same controlled object;
Three systems of analog or digital process control signals are input in parallel, and in the case of analog process control signals, the intermediate values thereof, and in the case of digital process control signals, the majority value of them is selected as the controlled object. A triplex multiplexing control device comprising a process signal input / output unit for outputting to
The process signal input / output unit is selected as a process control signal of a selection result by selecting one of the two system calculation result process control signals input from the process control calculation unit to the priority port and the standby port. With three priority selection sections to relay to
The process control signal of the calculation result of each system output from the process control calculation unit is input to the priority port and the other to the standby port for the two different sets of priority selection units,
The process control operation unit is
A self-diagnosis function for diagnosing the presence or absence of abnormalities in the own system;
By comparing the process control signals of the other two systems of operation results obtained from the other two process control operation units via the data transmission means with the process control signals of the operation results obtained by itself, the abnormal system can be identified. With mutual diagnostic function to detect,
The selection result relayed to the process signal input / output unit for the priority selection unit in which the process control signal of the calculation result of the system in which the abnormality is detected by the self-diagnosis function or the mutual diagnosis function is input to the priority system port. A multiplexing control apparatus, wherein a selection instruction is given to switch an input source of a process control signal from a priority system port side to a standby system port side. The selection instruction is made by a process control arithmetic unit that detects an abnormality of its own system by the self-diagnosis function or a process control arithmetic unit that detects an abnormality of another system by the mutual diagnosis function. The multiplexing control device described. The signal for the selection instruction is output by a process control arithmetic unit that detects an abnormality of the own system by the self-diagnosis function and a process control arithmetic unit that detects an abnormality of another system by the mutual diagnosis function. 3. The multiplexing control device according to claim 2, wherein the multiplexing control device is generated by performing a wired-OR operation on the status signal. 3. The multiplexing according to claim 2, wherein the selection instruction signal is generated by a relay circuit that operates according to a self-diagnosis result and a mutual diagnosis result output from each of the process control arithmetic units. Control device. Three process control arithmetic units each for executing the same arithmetic processing in parallel and calculating and outputting three system process control signals for the same controlled object;
Three systems of analog or digital process control signals are input in parallel, and in the case of analog process control signals, the intermediate values thereof, and in the case of digital process control signals, the majority value of them is selected as the controlled object. A triplex multiplexing control device comprising a process signal input / output unit for outputting to
The process signal input / output unit is selected as a process control signal of a selection result by selecting one of the two system calculation result process control signals input from the process control calculation unit to the priority port and the standby port. With three priority selection sections to relay to
The process control signal of the calculation result of each system output from the process control calculation unit is input to the priority port and the other to the standby port for the two different sets of priority selection units,
The process control operation unit is
A self-diagnosis function for diagnosing the presence or absence of abnormality in the own system, and / or
By comparing the process control signals of the other two systems of operation results obtained from the other two process control operation units via the data transmission means with the process control signals of the operation results obtained by itself, the abnormal system can be identified. It has a mutual diagnosis function to detect,
When an abnormality is detected in one system, the process control signal of the calculation result of the other two systems is relayed to the process signal input / output unit. When an abnormality is detected in two systems, the calculation result of the other one system is A multiplexing control apparatus, wherein a process control signal is duplicated and relayed to the process signal input / output unit to continue control of the controlled object. A nuclear power plant comprising the multiplexing control device according to any one of claims 1 to 5.

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