JP2013037436A - Controller for plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically operate operating procedures among operation variables where influences become minimum by considering interaction among the operation variables caused by a time factor of processes of a plant.SOLUTION: The controller for a plant includes a control logic database for storing operation variables to use for a plurality of logic operations, a control signal generation part for performing logic operation and generating a plurality of control signals to be given to the plant, and an operating procedure operation part for operating the operating procedures of operation variables. The operating procedure operation part obtains a delay time in logic operation before a result of logic operation of the first operation variable and a second operation variable are added with respect to operation variables associated with one another among a plurality of operation variables every operation variable and decides operating procedures of the plurality of operation variables. When it changes value of operation variables to use in the plurality of logic operation, the control signal generation part follows changed order of other operation variables associated with the operation variable according to operating procedures of the plurality of operation variables obtained by the operating procedure operation part.

Description

  The present invention relates to a plant control apparatus, and more particularly to a plant control apparatus that automatically calculates an operation procedure between operation variables.

  The plant control apparatus processes a measurement signal of a state quantity obtained from a plant that is a control target, calculates a control signal (operation signal) to be given to the plant, and transmits the control signal to the control target. In many cases, the control device inputs a plurality of measurement signals and outputs a plurality of control signals (operation signals) to the plant. The larger the plant, the larger the number of inputs and outputs. Often.

  The plant control device is implemented with an algorithm for calculating an operation signal so that the measurement signal of the state quantity of the plant satisfies the target value (hereinafter referred to as an operation variable). Therefore, an algorithm for calculating an operation signal for each operation variable is prepared in a control device with multiple inputs and multiple outputs. Such multi-input, multi-output control devices often include those that interact with each other in the input or output.

  As a control algorithm used for plant control, there is a PI (proportional / integral) control algorithm. In PI control, a value obtained by time-integrating the deviation is added to a value obtained by multiplying the deviation between the measurement signal of the state quantity of the plant and the operation variable by a proportional gain to derive an operation signal to be given to the plant. Since the control algorithm using PI control can describe the input / output relationship with a block diagram or the like, the causal relationship between the input and the output is easy to understand, and has a lot of application results.

  However, when the plant is operated under conditions that are not assumed in advance, such as a change in the operation state of the plant or a change in the environment, an operation such as changing the control logic may be required. Also, in recent years, not only stable and safe operation of the plant as in PI control, but also optimization of the operation state of the plant, such as energy saving, high efficiency of the plant, and reduction of emissions of harmful substances that affect the environment. There is an active movement to introduce control technology.

  Such control methods that adapt to plant operating conditions and environmental changes and optimize plant operating conditions include adaptive control and optimal control methods that automatically correct control algorithms and parameter values. There is.

  As a technique in view of the above, Patent Document 1 predicts a future value of the operation state of the plant, and optimizes a plurality of operation variables so that the operation state from the present to the future is optimal with respect to the control target. A technique for determining multivariate model predictive control is described.

JP 11-296204 A

  When the technology disclosed in Patent Document 1 is applied to a plant control device, the optimum operating variables can be determined in consideration of the future plant behavior by the optimization calculation of the prediction model. realizable. Moreover, with the technique disclosed in Patent Document 1, even when the manipulated variable reaches several tens, practicality can be ensured by devising the calculation cost of the prediction model.

  However, when the manipulated variable increases, the influence of the interaction between the manipulated variables cannot be ignored. That is, when constructing a basic control logic for controlling a plant, it becomes necessary to consider a plurality of operation variables. The interaction between manipulated variables is often governed by time factors such as lag time and dead time. When these influences are ignored, there is a possibility that a desired control effect cannot be obtained even though the plant is operated according to the operation variable obtained as a calculation result.

  The technique disclosed in Patent Document 1 does not have a configuration that takes into account the influence of the time factor inherent in the plant process, is strongly influenced by the time factor of the plant applied temporarily, and has a strong interdependence on the operating variables. However, there is a possibility that the target performance cannot be achieved for the control target for the reason described above although the desired performance can be achieved with respect to the time constraint for determining the manipulated variable.

  It is an object of the present invention to consider an interaction between operating variables caused by a time factor of a plant process in an adaptive and optimal control of a plant that considers a large number of operating variables, and to minimize the influence of the operating variables. Another object is to provide a plant control device that automatically calculates the operation procedure.

  From the above, in the present invention, in the plant control apparatus that takes in a plurality of measurement signals from the plant, executes a plurality of logic operations to match the measurement signals to the operation variables, and gives a plurality of control signals to the plant. The control device includes a control logic database that stores control logic data including operation variables used for a plurality of logic operations, a control signal generation unit that executes the logic operations and generates a plurality of control signals to be given to the plant, An operation procedure calculation unit for calculating an operation procedure is provided, and the operation procedure calculation unit performs a first operation on operation variables related to each other among a plurality of operation variables used for a plurality of logic operations stored in the control logic database. The delay time in the logic operation between the logic operation result of the variable and the second operation variable is taken into account The operation signal is determined for each operation variable, and the operation procedure of the plurality of operation variables is determined, and the control signal generation unit executes a plurality of logic operations to match the plurality of measurement signals with the operation variables, and outputs the plurality of control signals. When changing the size of an operation variable to be used for multiple logic operations while giving to the plant, the operation procedure for multiple operation variables obtained by the operation procedure calculation unit for the change order of other operation variables related to this operation variable Follow the instructions.

  In addition, multiple logic operations stored in the control logic database include PI control, with PI control integration time constants as parameters, and the operation procedure calculation unit uses integration time constants as delay times in logic calculations. To do.

  Further, the operation procedure calculation unit extracts control logic related to the operation variable, and determines the delay time from time factors such as delay time and dead time between the operation variables with respect to the control logic.

  From the above, in the present invention, in the plant control apparatus that takes in a plurality of measurement signals from the plant, executes a plurality of logic operations to match the measurement signals to the operation variables, and gives a plurality of control signals to the plant. The control device includes a control logic database that stores control logic data including operation variables used for a plurality of logic operations, a control signal generation unit that executes the logic operations and generates a plurality of control signals to be given to the plant, The operation procedure calculation unit includes an operation procedure calculation unit that calculates an operation procedure, and the operation procedure calculation unit performs a logic operation until the logic operation result of the first operation variable and the second operation variable are taken into account for the operation variables related to each other. Lag time in the form of a matrix representing the interrelationships between the manipulated variables, and the interrelationships between the manipulated variables are converted into directed graphs. The evaluation value of each operation variable is obtained from the directed graph, the operation procedure of the plurality of operation variables is determined according to the magnitude of the evaluation value, and the control signal generation unit includes a plurality of logics to match the plurality of measurement signals with the operation variable. When the operation is performed to give a plurality of control signals to the plant and the size of the operation variable used in the plurality of logic operations is changed, the change order of other operation variables related to the operation variable is changed to the operation procedure. The operation is performed according to the operation procedure of the plurality of operation variables obtained by the calculation unit.

  In addition, in order to obtain an evaluation value of each operation variable from the directed graph, a transition process between the nodes is executed according to the connection of the directed edge between the nodes provided for each operation variable, and the delay time information described in the directed edge is obtained. By adding according to the node transition, the evaluation value of each manipulated variable is calculated.

  Further, the operation procedure calculation unit assigns operation procedures in order from the smallest evaluation value of each operation variable obtained by the procedure.

  Further, the control device includes an image display device, and the image display device includes an operation variable for selecting operation variables related to each other from among a plurality of operation variables used for a plurality of logic operations stored in the control logic database. As the setting screen, a plurality of logic operation circuits and operation variables included in the circuits are displayed, and operation variables extracted from the displayed operation variables are displayed in a list.

In the plant control apparatus according to any one of claims 1 to 6,
In addition, the control device includes an image display device. The image display device executes the operation of the plant based on the result of determining the operation procedure in the operation procedure calculation unit for the selected operation variable and the operation procedure. The progress in progress is displayed as a calculation result display screen.

  Further, the control device includes an image display device, and a procedure calculation result display screen for displaying each operation variable in the calculation result list in ascending order of evaluation values is displayed on the image display device as a result calculated in the operation procedure calculation unit. The

  Further, the control device includes an image display device, and the image display device controls values before and after the change of each operation variable and values before and after the change of the non-control amount when the plant control by the control signal generation unit is executed. Displayed as a characteristic display screen.

  Further, as a measurement signal, at least one of the concentrations of nitrogen oxide, carbon monoxide, and hydrogen sulfide contained in the gas discharged from the thermal power plant, and the steam flow rate, steam temperature, and steam pressure of the plant is used. The control signal includes a signal for determining at least one of an air damper opening, an air flow rate, a fuel flow rate, a feed water flow rate, a turbine governor opening, and an exhaust gas recirculation flow rate.

  According to the present invention, it has a function of automatically calculating the procedure for operating the plant in consideration of the interdependence of the operation variables of the plant, and generates a control signal to operate the plant based on the calculated procedure, It is possible to realize a plant control device having a function of minimizing the influence due to the interdependency.

The block diagram which shows schematic structure of the plant control apparatus of this invention. Schematic which shows the structure of the thermal power plant made into a control object by a control apparatus. The enlarged view of the piping part relevant to the air heater installed in the boiler downstream. The figure which shows an example of a typical logic circuit. The flowchart which shows the processing content of the control apparatus 200. 5 is a flowchart showing a detailed operation of the operation procedure calculation unit 500. A diagram representing the interrelationships between manipulated variables in the form of a matrix. The figure which expressed the mutual relation between the operation variables with the directed graph. The flowchart which calculates the evaluation value of each operation variable from a directed graph. 9 is a diagram showing the processing flow of each part and information generated at this time. The figure which shows an example of an operation variable setting screen. The figure which shows an example of a calculation result display screen. The figure which shows an example of a procedure calculation result display screen. The figure which shows an example of a control characteristic display screen.

  Embodiments of a plant control apparatus according to the present invention will be described with reference to the drawings.

  First, a schematic configuration of the plant control apparatus of the present invention will be described with reference to FIG. As shown in FIG. 1, a plant 100 to be controlled is controlled by a control device 200. Here, an example in which the plant 100 is a thermal power plant will be described later with reference to FIGS. 2 and 3.

  If the internal structure of the control apparatus 200 of FIG. 1 is divided roughly according to a function, it will be comprised by the arithmetic unit M, database DB, and interface part IF.

  First, regarding the computing device M, it includes a correction signal computing unit 300, a control signal generating unit 400, and an operation procedure computing unit 500. Among these units, the control signal generation unit 400 is an existing control function configured by a control algorithm using PI control. The correction signal calculation unit 300 provides a correction signal that optimizes the operation variable used in the control signal generation unit 400. In addition, the operation procedure calculation unit 500 determines the procedure and timing for giving the correction signal.

  As the database DB, a measurement signal database DB1, an operation information database DB2, an operation procedure information database DB3, a control logic database DB4, and a control signal database DB5 are provided. For normal plant control by the control signal generator 400, the measurement signal database DB1, the control logic database DB4, and the control signal database DB5 are used. The calculation information database DB2 and the operation procedure information database DB3 are used by the correction signal calculation unit 300 and the operation procedure calculation unit 500.

  Further, an external input interface IF / I and an external output interface IF / O are provided as the interface unit IF.

  The control device 200 is connected to a maintenance tool 910, and an operator of the plant 100 can control the control device via an external input device 900 and an image display device (for example, a CRT display) 920 connected to the maintenance tool 910. 200 can be controlled.

  Hereinafter, the plant control device of the present invention configured as described above will be described. Before that, the configuration of a thermal power plant will be described as an example of the plant 100 to which the present invention can be applied.

  FIG. 2 is a schematic diagram showing a configuration of a thermal power plant 100a to be controlled by the control device 200 according to the present invention. First, the mechanism of power generation by the thermal power plant 100a will be briefly described.

  A thermal power plant 100a in FIG. 2 is a system that generates steam with a boiler 101 to drive a turbine 108 and obtains a desired amount of power with a generator 109 that is directly connected to the turbine. In order to realize this, water, fuel, and air supplied to the boiler 101 are appropriately controlled in response to a load request signal (power amount request signal), and the relationship between the temperature, flow rate, and pressure of the steam led to the turbine is desired. Therefore, the control device 200 is used for this purpose.

  First, for example, pulverized coal is supplied to the boiler 101 as fuel. The pulverized coal is obtained by finely pulverizing coal in the mill 110, and this pulverized coal is given as fuel from the pipe 134 through the plurality of burners 102.

  The boiler 101 is supplied with air for pulverized coal combustion. The air includes primary air for conveying pulverized coal and secondary air for adjusting combustion. The pulverized coal and primary air are led from the pipe 134 and the secondary air is led from the pipe 141 to the burner 102, respectively. Further, the boiler 101 is provided with an after-air port 103 through which air for two-stage combustion is introduced into the boiler 101. The air for two-stage combustion is guided from the pipe 142 to the after air port 103.

  In addition, water (water supply) is supplied to the boiler 101. The feed water is supplied to the heat exchanger 106 in the boiler via the feed water pump 105 and is superheated by the combustion gas flowing down the boiler 101 to become high-temperature and high-pressure steam.

  The high-temperature combustion gas generated by burning pulverized coal inside the boiler 101 flows downstream along the path inside the boiler 101 and is supplied to the heat exchanger 106 disposed inside the boiler 101. After generating steam by exchanging heat with the air, it becomes exhaust gas and flows into the air heater 104 installed on the downstream side of the boiler 101. The air supplied to the boiler 101 is heated by this air heater 104 and heated. To do. And the exhaust gas which passed this air heater 104 is discharged | emitted from the chimney to air | atmosphere after performing the exhaust gas process which is not shown in figure.

  The feed water circulating through the heat exchanger 106 of the boiler 101 is supplied to the heat exchanger 106 via the feed water pump 105 and is superheated by the combustion gas flowing down the boiler 101 in the heat exchanger 106 to become high-temperature and high-pressure steam. In this embodiment, the number of heat exchangers is one, but a plurality of heat exchangers may be arranged.

  The high-temperature and high-pressure steam generated in the heat exchanger 106 is guided to the steam turbine 108 via the turbine governor valve 107, and the steam turbine 108 is driven by the energy of the steam to generate power by the generator 109.

  As described above, the control device 200 appropriately controls the water, fuel, and air supplied to the boiler 101 in response to the load request signal, and changes the relationship among the temperature, flow rate, and pressure of the steam led to the turbine to a desired relationship. In order to fulfill the function to maintain, the state quantity of each part of a power plant is taken in. For this purpose, the thermal power plant 100a is provided with various measuring devices that detect state quantities indicating the operation state.

  Since the thermal power plant 100a corresponds to the plant 100 in FIG. 1, the measurement signal of the thermal power plant acquired from these measuring instruments is the measurement signal 1 from the plant 100 as shown in FIG. It is transmitted to the external input interface IF / I.

  As a measuring instrument, for example, as shown in a thermal power plant 100a in FIG. 2, a temperature measuring instrument 151 that measures the temperature of high-temperature and high-pressure steam supplied from the heat exchanger 106 to the steam turbine 108, and measures the pressure of the steam. A pressure measuring device 152 and a power generation output measuring device 153 that measures the amount of power generated by the generator 9 are shown.

  The feed water generated by cooling the steam by the condenser (not shown) of the steam turbine 108 is supplied to the heat exchanger 106 of the boiler 101 by the feed water pump 105. The flow rate of this feed water is measured by the flow meter 150. It is measured.

In addition, the state quantity relating to the concentration of components (nitrogen oxide (NOx), carbon monoxide (CO), hydrogen sulfide (H ₂ S), etc.) contained in the exhaust gas that is the combustion gas discharged from the boiler 101 The measurement signal is measured by a concentration measuring device 154 provided on the downstream side of the boiler 101. Although not shown in FIG. 2 as a measuring instrument, other state quantities such as the amount of pulverized coal fuel and air are measured by the measuring instrument and taken into the control device.

  As described above, the measurement data items of the thermal power plant 100a include the flow rate of fuel supplied to the boiler 101, which is the state quantity of the thermal power plant 100a measured by the respective measuring instruments, the flow rate of air supplied to the boiler 101, and the boiler. The feed water flow rate supplied to the heat exchanger 106 of the 101, the steam temperature generated in the heat exchanger 106 of the boiler 101 and supplied to the steam turbine 108, the feed water pressure of the feed water supplied to the heat exchanger 106 of the boiler 101, The gas temperature of the exhaust gas discharged from the boiler 101, the gas concentration of the exhaust gas, and the exhaust gas recirculation flow rate for recirculating a part of the exhaust gas discharged from the boiler 101 to the boiler 101 are included. The measurement data items are stored in the measurement signal database DB1 in the control device 200 of FIG.

  These measurement data items are measurement data items determined as a result of an operation by the control signal 13 calculated and output by the control signal generation unit 400 in the control device 200 shown in FIG. That is, the value of the measurement data item that is the plant state quantity is determined as a result of operating the operation end of each part of the plant based on the control signal 13.

  Next, the operation end of the plant will be described. Here, taking the air system supplied to the boiler 101 as an example, the operation end in this case will be described. Specifically, the path of air that is introduced into the boiler 101, that is, the path of primary air and secondary air that are introduced into the boiler 101 from the burner 102, and the interior of the boiler 101 from the after air port 103. The operation end used in the air path will be described with reference to FIG.

  In FIG. 2, the primary air is guided from the fan 120 to the pipe 130, and a pipe 132 that passes through the air heater 104 installed on the downstream side of the boiler 101 and a pipe that bypasses the air heater 104 without passing through the air. However, the pipe 133 is arranged downstream of the air heater 104 and is joined again to the mill 110 for producing pulverized coal installed on the upstream side of the burner 102.

  The primary air passing through the air heater 104 is heated by exchanging heat with the combustion gas flowing down the boiler 101. The primary air that bypasses the air heater 104 together with the heated primary air conveys the differential coal crushed in the mill 110 to the burner 102.

  The air introduced from the pipe 140 using the fan 121 is heated in the same manner by the air heater 104 and then branched into a secondary air pipe 141 and an after-air port pipe 142, respectively. To the burner 102 and the after-air port 103.

  FIG. 3 is an enlarged view of a piping portion related to the air heater 104 installed on the downstream side of the boiler 101 of the thermal power plant 100a shown in FIG. An example of the operation end of the boiler will be described with reference to this figure.

  In the thermal power plant control apparatus 200, as an example of controlling the flow rate of air sent from the fan 121 and introduced into the boiler 101 from the burner 102 and the after air port 103, the secondary air pipe 141 and the after air port are used. An air damper 162 and an air damper 163 serving as operation end devices are provided on the upstream side of the pipe 142, respectively, and the opening degree of the air damper 162 and the air damper 163 is adjusted by the control device 200 to be supplied to the inside of the boiler 101. The flow rate of air and after air can be controlled respectively.

  In addition, as an example of controlling the flow rate of air sent from the fan 120 and introduced into the boiler 101 together with the pulverized coal from the burner 102, an air damper serving as an operation end device is connected to the pipe 131 and the pipe 132 immediately before joining the pipe 133. 160 and an air damper 161 are provided, respectively, and the opening degree of the air damper 160 and the air damper 161 is adjusted by the control device 200 so that the flow rate of the air supplied into the boiler 101 can be controlled.

  In addition, since the said control apparatus 200 can also control another measurement data item, you may change the installation place of an operating end apparatus according to a control object.

  As shown in FIG. 3, the air heater 104 is provided with a pipe 130 for supplying air and a pipe 140. Of these, the pipe 140 is disposed through the air heater 104. The pipe 131 and the pipe 132 are branched from the middle, and the pipe 131 is arranged to bypass the air heater 104, and the pipe 132 is arranged to penetrate the air heater 104.

  The pipe 132 passes through the air heater 104 and then merges with the pipe 131 to become a pipe 133 and is led to the mill 110. From the mill 110, the pipe 133 and the pulverized coal together with air are led to the burner 102 of the boiler 101. It is installed.

  In addition, the pipe 140 passes through the air heater 104 and then branches into a pipe 141 and a pipe 142. Of these, the pipe 141 guides air to the burner 102 of the boiler 101, and the pipe 142 leads to the after-air port 103 of the boiler 101, respectively. It is arranged like this.

  Also, an air damper 160 and an air damper 161 for adjusting the amount of air flowing are installed in the pipe 131 and the pipe 132 immediately before joining the pipe 133, respectively, and the upstream part of the pipe 141 and the pipe 142 flows. An air damper 162 and an air damper 163 for adjusting the amount of air are respectively installed.

  Then, by operating these air dampers 160 to 163, the area through which air passes through the pipes 131, 132, 141, 142 can be changed, so that the boiler 101 passes through the pipes 131, 132, 141, 142. The flow rate of air supplied to the interior of each can be individually adjusted.

  In the above description, the operation end related to the air system of the boiler 101 has been described as an example, but there are many other operation ends. For example, there is a mill motor that rotates the mill 110 in the case of a fuel system, and a water supply amount control pump in the case of a water system. In addition to these, various valves on the piping of the water system, steam system, air system, or drain system, various auxiliary machines, and the like are the operation targets of the control device 200 as operation ends.

  The control signal 13 calculated by the control signal generator 400 of the control device 200 is output as the operation signal 14 for the thermal power plant 100a via the external output interface IF / O, and the pipes 131, 132, 141, 142 of the boiler 101 are output. The devices at the operation ends such as the air dampers 160, 161, 162, and 163 installed in each are operated.

  In this embodiment, devices such as the air dampers 160, 161, 162, and 163 are referred to as operation ends, and the control signal 13 calculated by the control device 200 necessary for operating the devices is transmitted from the control device 200. An output signal commanded to the operation end is referred to as an operation signal 14.

  Further, as the operation signal 14 calculated by the control signal generation unit 400 and output to the operation end, air that adjusts the flow rate of air installed in each of the pipes 131, 132, 141, and 142 that supplies air to the boiler 101 is used. The opening degree of the dampers 160 to 163, the rotational speed of the motor for the mill for adjusting the fuel flow rate of the pulverized coal supplied to the burner 102 of the boiler 101, and a part of the exhaust gas discharged from the boiler 101 are recirculated to the boiler 101. The opening degree of the exhaust gas damper for exhaust gas recirculation, the rotation speed of the motor for driving the feed water pump 105, the opening degree of the turbine governor valve 107 that determines the flow rate of steam guided to the turbine 108, and the like are included.

  The power plant control device 200 controls each part of the operation end to appropriately control the water, fuel and air supplied to the boiler 101 in response to the load request signal, and controls the temperature, flow rate and pressure of the steam led to the turbine. Control logic is provided to perform the function of maintaining the relationship in the desired relationship. This control logic is held in the control logic database DB4 of FIG. 1, and an example of this is shown in FIG.

  FIG. 4 shows an example of a typical logic circuit. In this example, there are four sets of logic circuits L1, L2, L3, and L4, and a situation in which they are related to each other will be described. This logic circuit is not for the above-mentioned power plant. For example, assuming that L1 is a load, L2 is fuel, L3 is water supply, and L4 is a logic circuit for air control, You can understand how the control logic is related and influencing each other.

  First, the logic circuits L1, L2, L3, and L4 are arithmetic elements such as an addition (subtraction) circuit ad, a multiplication circuit m, a division circuit di, a proportional integration circuit PI, a signal generation circuit SG, a function generation circuit FG, and an integration circuit. The process on the control logic transitions according to the connection of the directional branch (a signal flows in the direction of the arrow of the control signal line). Each arithmetic element includes delay time information until the execution is completed.

  The input / output of the logic circuits L1, L2, L3, and L4 will be described. First, IN is a measurement information input signal. This is a measurement signal input from the plant 200 in FIG. 1 and is often used as a feedback signal for the control system. The manipulated variables (A, B, C, D, E) are target setting signals for the control system. In addition, there are control commands (a, b, c, d, e, f) corresponding to plant operation signals. Here, the operation variables (A, B, C, D, E) are input variables to the control logic circuit for generating the control commands (a, b, c, d, e, f) and can be set. Value.

  For example, the control concept of the logic L1 will be briefly described. A deviation signal having the measurement signal IN1 as a control feedback signal with respect to the target signal A is obtained by the adder circuit ad1, and the control command b is obtained from the result of the proportional-plus-integral operation circuit PI. The operation end is created by the control command b. Prior to the proportional-plus-integral operation PI, the multiplication circuit X performs gain correction using the measurement signal IN2. Further, the other operation end is controlled by a signal (control command) a obtained by multiplying the result of the proportional-integral operation circuit PI and the signal from the signal generator SG by the multiplication circuit X.

  In the case of this example, the logic circuit L1 obtains control commands a and b by inputting the operation variable A, two types of measurement information input signals IN1 and IN2, and signals from the signal generation circuit SG. The logic circuit L2 receives the operation variables B and E and the control command b and obtains a control command c. The logic circuit L3 receives the operation variables D and E, the measurement information input signal IN3, and the control command c, and obtains a control command e. The logic circuit L4 receives the operation variable C, the measurement information input signal IN4, the control commands a and e, and obtains the control command f. Between the plurality of logic circuits L1, L2, L3, and L4 in FIG. 4, there is a logic circuit located upstream and a logic circuit located downstream from the above command and signal relationship. Can be understood.

  As is clear from this example, the control commands (a, b, c, d, e, f), which are the outputs of the respective logic circuits L, are respectively given to the operation ends at various locations in the plant to execute control. At the same time, it is used as a part of the input of another logic circuit L. Manipulated variables (A, B, C, D, E) may also be used in different logic circuits.

  As is clear from the above description, the control device 200 of FIG. 1 inputs the measurement signal 1 from the plant 100 and gives the operation signal 14 in the normal operation state. This function is executed by the control signal generator 400. The control signal generation unit 400 uses the measurement data 3 accumulated in the measurement signal database DB1 and the control logic data 11 stored in the control logic database DB4, for example, as shown in FIG. Thus, the control signal 13 is generated. The control signal 13 generated by the control signal generator 400 is stored in the control signal database DB5.

  The logic circuit of FIG. 4 is not that of the power plant, but it has been described above that, for example, L1 is a load, L2 is a fuel, L3 is a water supply, and L4 is a logic circuit for controlling air. Under this assumption, for example, the manipulated variable A can be considered as a load request signal, B as a fuel request signal, D as a water supply request signal, and C as an air request signal. These manipulated variables are so-called target setting signals. In the example of a thermal power plant, when the load request signal is changed, other target setting signals (fuel request signal B, water supply request signal D, air request signal C) are also generated. It is necessary to change while balancing. In this change operation, it is necessary to determine the time-series magnitude of each target setting signal, the order of change, and the timing.

  In the control device 200 of FIG. 1, the correction signal calculation unit 300 determines the time-series magnitude of the operation variable, and the operation procedure calculation unit 500 determines the order and timing for changing the operation variable. The determination result is reflected in the control in the control signal generator 400.

  Hereinafter, functions of the correction signal calculation unit 300, the control signal generation unit 400, and the operation procedure calculation unit 500 will be briefly described.

  First, the control signal generation unit 400 generates the control signal 13 using the control logic data 11 stored in the control logic database DB4 and the measurement data 3 so that the measurement signal 1 has a desired value. In the control logic database DB4, as described with reference to FIG. 4, control circuits and control parameters for calculating the control logic data 11 and 12 are stored. The control circuit for calculating the control logic data 11 and 12 uses PI (proportional / integral) control known as a conventional technique.

  The control signal generation unit 400 basically operates as described above. In this case, the correction signal calculation unit 300 and the operation procedure calculation unit 500 are set so that the control signal provided by the control signal generation unit 400 has an optimum value. It is adjusted by. For this purpose, the control signal generator 400 further receives the correction signal calculation data 6 stored in the calculation information database DB2 and the operation procedure information 8 stored in the operation procedure information database DB3.

  Among these, the operation procedure information 8 is an operation procedure and timing to be considered when the control signal generation unit 400 generates the control signal 13, and is determined by the operation procedure calculation unit 500. In the operation procedure calculation unit 500, the measurement data 3 stored in the measurement signal database DB1, the control logic data 12 stored in the control logic database DB4, and the operation variables to be considered during plant control stored in the operation procedure information database DB3. This is determined using the operation procedure calculation information data 9 including the conditions. The operation procedure information data 10 as the calculation result is stored in the operation procedure information database DB3. The function of the operation procedure calculation unit 500 is the core of the present invention and will be described in detail separately.

  The correction signal calculation data 4 is for correcting the magnitude of the control signal 13 generated by the control signal generation unit 400 and is determined by the correction signal calculation unit 300. The correction signal calculation unit 300 includes measurement data 3 stored in the measurement signal database DB1, correction signal calculation information 5 stored in the calculation information database DB2, and operation procedure information 7 stored in the operation procedure information database DB3. Entered. And the correction signal calculation data 4 are produced | generated as a calculation result here. The correction signal calculation data 4 is stored in the calculation information database DB2. A part of the measurement data 3 stored in the measurement signal database DB1 is input to the control signal generation unit 400 and the operation procedure calculation unit 500, and is used for calculation in these.

  The correction signal calculation unit 300 is basically a function for determining the magnitude of the operation variable of the logic circuit of FIG. 4. In the case of the present invention, this internal configuration can be realized by a conventionally known method. For example, the magnitude of the manipulated variable can be determined according to the idea described in Japanese Patent No. 4627553. For example, in the case of thermal power plant control, when the load request signal is changed, how much the target signals of fuel, water supply, and air amount, which are other operation variables (target setting signals), should be changed. Alternatively, the correction signal calculation unit 300 obtains the optimum size. This can be optimized by learning past experiences and the like. In the present invention, the correction signal calculation unit 300 can be realized by applying these known techniques, and thus detailed description thereof is omitted.

  The operation procedure information data 10 stored in the operation procedure information database DB3 from the operation procedure calculation unit 500 includes input information (operation variables) that can be operated on the control logic set by the operator of the plant 100 via the maintenance tool 910. ) Is included.

  In addition, the control signal generation unit 400 considers the past operation history from the operation procedure information data 10, extracts operation variable information to be considered at the time of the current control signal generation, and generates the control signal 13 based on the extracted information. .

  With this configuration, the control device 200 generates the control signal 13 according to the operation procedure information data 8 determined in consideration of the control logic information stored in the control logic database DB4. By providing this mechanism, it is possible to execute control in consideration of the influence of mutual interference between manipulated variables and control commands, and the control performance can be improved.

  The control device 200 is generally configured as described above, and executes control of the plant 100. This control is executed under the supervision of an operator of the plant 100, and a maintenance tool 910 is connected to the control device 200 for that purpose.

  An operator of the plant 100 is provided in the control device 200 by using an external input device 900 composed of a keyboard 901 and a mouse 902, a maintenance tool 910 that can transmit and receive data to and from the control device 200, and an image display device 920. You can access information stored in various databases. For this purpose, the control device 200 has an input unit or an output unit (not shown) for exchanging the input / output data information 90 with the maintenance tool 910.

  By using these devices, an operator of the plant 100 can set conditions used in the correction signal calculation unit 300, the control signal generation unit 400, and the operation procedure calculation unit 500 of the control device 200 and confirm the obtained calculation results. Necessary information can be entered.

  The maintenance tool 910 includes an external input interface 911, a data transmission / reception processing unit 912, and an external output interface 913, and can transmit / receive data to / from the control device 200 via the data transmission / reception processing unit 912.

  The maintenance tool input signal 91 generated by the external input device 900 is taken into the maintenance tool 910 via the external input interface 911. The data transmission / reception processing unit 912 of the maintenance tool 910 acquires the input / output data information 90 from the control device 200 according to the information of the maintenance tool input signal 92.

  In addition, the data transmission / reception processing unit 912 sets and obtains conditions used in the correction signal calculation unit 300, the control signal generation unit 400, and the operation procedure calculation unit 500 of the control device 200 of the control device 200 according to the information of the maintenance tool input signal 92. Input / output data information 90 necessary for confirming the calculated result is output.

  The data transmission / reception processing unit 912 transmits a maintenance tool output signal 93 obtained as a result of processing the input / output data information 90 to the external output interface 913. The maintenance tool output signal 94 transmitted from the external output interface 913 is displayed on the image display device 920.

  In the control device 200, the measurement signal database DB1, the calculation information database DB2, the operation procedure information database DB3, the control logic database DB4, and the control signal database DB5 are arranged inside the control device 200. Alternatively, a part thereof can be arranged outside the control device 200.

  Hereinafter, a control procedure showing the processing contents of the control device 200 of FIG. 1 will be described with reference to the flowchart of FIG. The flowchart shown in FIG. 5 is executed by combining steps S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, and S20. Hereinafter, each step will be described.

  First, after the operation of the control device 200 is started, in step S10 in which the execution conditions of the control device are set, various parameter conditions used when the correction signal calculation unit 300, the control signal generation unit 400, and the operation procedure calculation unit 500 are executed. Set.

  Next, in step S <b> 11 for setting an operation variable, the control device 200 sets an operation variable for which the operation condition is to be changed for the plant 100. This operation variable can be arbitrarily selected from operation items (CRT operations) defined in the control logic according to the control purpose. The operation variable is a target signal of the control system as described in the logic circuit of FIG. 4, and (A, B, C, D, E) corresponds to this in the example of FIG. For example, in the case of a thermal power plant, when attention is paid to a load request signal as a control purpose from among many operation variables, target setting signals for fuel, water supply, and air to be controlled in balance with this are set. This means that it should be extracted as an operation variable whose condition is to be changed.

  Next, in step S12 for calculating the operation procedure, when the operation procedure calculation unit 500 is operated to control the plant 100, the order of changing the operation variables set in step S11 is calculated, and the operation procedure information database DB3 is calculated. Save to. In other words, these target signals are operated with their magnitude changed at an appropriate timing in the control process, but need to be changed in relation to each other, so the timing of the change becomes important. For example, when changing the target signal of water supply in a boiler case, it is necessary to change the fuel and air to stabilize the whole, but because there is a delay time mutually, other operating variables are changed. It is necessary to consider the order and timing. The detailed function and operation of the operation procedure calculation unit 500 will be described later.

  Next, in step S13 of acquiring measurement signal data, the measurement signal data 1 is acquired through the external input interface IF / I installed in the control device 200 and stored in the measurement signal database DB1.

  Next, in step S14 for calculating a correction signal, the correction signal calculation unit 300 is operated to generate an operation correction signal for the operation variable corresponding to the current operation based on the operation procedure information calculated in step S12. To do. This operation correction signal is a control signal for only the corresponding operation variable. That is, in step S12, the order and timing of changing other operation variables are considered, but here, the magnitude of the control signal 13 in the transient control state is further corrected.

  Next, in step S15, the operation correction signal calculation result 4 obtained in step S14 is stored in the calculation information database DB2.

  Next, in step S16 for generating a control signal, the control signal generator 400 of the control device 200 is operated, and the correction signal calculation data 6 stored in the calculation information database DB2, the operation procedure information database DB3, and the control logic database DB4. The control signal 13 is generated using the operation procedure information 8 and the control logic data 11. The generated control signal 13 is used for plant control and is stored in the control signal database DB5.

  The next step S17 for determining the execution of control is a branch determination. If the operation of the plant cannot be executed from the operation state of the plant 100 at this time, the process proceeds to step S18, and if not, the process proceeds to step S19.

  In step S18 for controlling the plant, the generated control signal 13 is output as the control signal 14 through the external output interface IF / O installed in the control device 200 to control the plant.

  The next step S19 is also branch determination. In accordance with the operation procedure calculated in step S12, the process proceeds to step S20 if the control of the plant 100 relating to the series of operation variables has been completed, otherwise the process proceeds to step S13.

  Finally, step S20 for determining the end of a series of processing operations is a branch determination. If a signal for ending the operation of the control device 200 of the present invention is input through the external input device 900, the process proceeds to a step for ending the process, and if not, the process returns to step S11.

  With the above operation, in the operation of the control device 200 of the present invention, based on the execution conditions set by the operator of the plant 100, a series of operations ranging from operation data acquisition, operation procedure calculation, correction signal calculation, control signal generation and control execution. Processing can be acquired and executed autonomously.

  Next, the detailed operation of the operation procedure calculation unit 500 in the control device 200 will be described with reference to the flowchart in FIG. 6 and conceptual diagrams in FIGS. 4, 7, and 8.

  FIG. 6 is a flowchart showing the operation of the operation procedure calculation unit 500, and shows in detail the operation of step S12 in the overall flowchart shown in FIG. The flowchart in FIG. 6 is executed by combining steps S121, S122, S123, S124, and S125. Hereinafter, each step will be described.

  After starting the operation of the operation procedure calculation unit 500, first, in step S121, the control logic information stored in the control logic database DB4 is extracted and read in consideration of the operation variable set in step S11 of FIG.

  The control logic information is composed of a logic circuit for generating a control signal 13 necessary for the control device 200 to control the plant, with measurement information from the plant as an input, and its setting parameter information. As shown, a plurality of arithmetic elements are connected by directed branches.

  Here, the logic circuit for generating the control signal 13 is, for example, the circuit of FIG. 4, and the setting parameters are arithmetic elements forming the logic circuit and various constants thereof. For example, the use of manipulated variables, measurement signals, and proportional constants, integral gains, integral time constants if the arithmetic element is a proportional-integral circuit, or gain or input (output) signals if it is a function generator This also includes ranges.

  Since FIG. 4 has already been described, detailed description will not be made. However, as shown in this example, in the plant control, control commands (a, b, c, d, e, A plurality of manipulated variables (A, B, C, D, E) which are the target signals are related to the calculation of f). The combination increases as the number of manipulated variables (A, B, C, D, E) increases. In addition, an operation variable that exists on the downstream side of the logic transition has a greater influence due to a change in another upstream operation variable. For this reason, when all the operation variables (A, B, C, D, E) are changed at once, there is a possibility that control to a desired operation condition cannot be performed by this interaction.

  In the present invention, these relationships are organized focusing on the manipulated variables. Specifically, next, in step S122 for extracting the control signal correlation matrix, the interrelationships among the manipulated variables (A, B, C, D, E) are shown in FIG. It is expressed in the form of the matrix shown in. FIG. 7 defines how the operation variables A, B, C, D, and E shown in the example of FIG. 4 are interrelated in the logic circuits L1, L2, L3, and L4.

  For example, let us focus on the operation variable B. The operation variable B is one input of the multiplication circuit m in the logic circuit L2, but the control command b which is the other input of the multiplication circuit m is determined by the operation variable A in the logic circuit L1.

  For this reason, when focusing on the output of the multiplication circuit m, the operation of the operation variable B is affected by the operation result of the operation variable A. Similarly, focusing on the output of the multiplication circuit m, the operation of the operation variable A is affected by the result of the operation of the operation variable B. From this, it can be said that the operation of the operation variable B and the operation of the operation variable A are in an interactive relationship with each other. Hereinafter, focusing on the downstream operation variable, this will be referred to as “the operation of the operation variable B has an interaction relationship that is influenced by the operation result of the operation variable A”.

  In this way, when there is an interaction relationship between the manipulated variables, it is next considered to quantitatively grasp this interaction relationship. Here, a quantitative grasp is made focusing on the time delay between the manipulated variables. Specifically, for example, the control command b is derived in the logic circuit L1 from the operation of the operation variable A, and the process up to that time is followed by the multiplication operation of the control command b and the operation variable B in the logic circuit L2. There is an elapsed delay time.

  In the above processing, the logic operation result of the first operation variable and the second operation variable are added to the operation variables related to each other among the plurality of operation variables used for the plurality of logic operations stored in the control logic database. The delay time in the logic operation until it is performed is obtained for each manipulated variable.

  The delay time at this time is predominantly the delay caused by the proportional integration circuit PI of the logic circuit L1. From the above, when the interaction relationship between the operation variable B and the operation variable A is quantified in consideration of the delay time and expressed in a matrix, 600 is described in B row A column as shown in FIG. Here, the described numerical value corresponds to the delay time (integration time constant) of the proportional integration circuit PI of the logic circuit L1.

  A similar interaction relationship is confirmed for the downstream manipulated variable C and the upstream manipulated variable A. The operation variable C is input as one input to the addition circuit ad5 in the logic circuit L4. A control command a which is one of the other inputs of the adder circuit ad5 is determined by the operation variable A in the logic circuit L1. From this, focusing on the output of the adder circuit ad5, it can be said that the operation of the operation variable C is in an interaction relationship that is affected by the result of the operation of the operation variable A.

  In addition, a delay time that has elapsed in the processing up to that time until the control instruction a is derived in the logic circuit L1 from the operation of the operation variable A and then the addition calculation of the control instruction a and the operation variable C is performed in the logic circuit L4. Exists. The delay time at this time is predominantly the delay caused by the proportional integration circuit PI of the logic circuit L1. From the above, when the interaction relationship between the operation variable C and the operation variable A is quantified in consideration of the delay time and expressed in a matrix, 600 is described in C row A column as shown in FIG.

  A similar interaction relationship will be confirmed for the upstream manipulated variable B and the latest downstream manipulated variable E. The operation variable E is input as one input to the adder circuit ad2 in the logic circuit L2, and the other input of the adder circuit ad2 is determined by the operation variable B in the logic circuit L2. Therefore, the operation of the operation variable E is in an interaction relationship that is affected by the operation result of the operation variable B. In this case, from the operation of the operation variable B to the addition operation with the operation variable E in the logic circuit L2, only the function generator FG exists and there is almost no delay time. From the above, when the interaction relationship of the manipulated variable E with respect to the manipulated variable B is expressed in a matrix in consideration of the delay time, 0 is written in E row B column as shown in FIG.

  A similar interaction relationship is confirmed with respect to the downstream manipulated variable C and the latest upstream manipulated variable D. The operation variable C is input as one input to the addition circuit ad5 in the logic circuit L4, and one of the other inputs of the addition circuit ad5 is determined by the operation variable D in the logic circuit L3. Therefore, the operation of the operation variable C is in an interaction relationship that is affected by the operation result of the operation variable D. In this case, the function generator FG and the integration circuit I exist from the operation of the operation variable D in the logic circuit L3 to the addition operation with the operation variable C in the logic circuit L4. There are 300. From the above, when the interaction relationship of the operation variable C with respect to the operation variable D is expressed in a matrix in consideration of the delay time, 300 is described in C row and D column as shown in FIG.

  When the upstream operation variable and the downstream operation variable are confirmed according to the same procedure as described above, the remaining combination is only the relationship between the operation variable D and the operation variable E. And since the operation variable E is used in the logic circuit L2 and the logic circuit L3, the relationship between the operation variable D and the operation variable E is upstream and downstream. There is almost no delay time in the relationship of the logic circuit L3 in which the operation variable E is located downstream, and on the contrary, a slight delay time 10 occurs in the relationship from the logic circuit L2 in which the operation variable E is located in the upstream to the logic circuit L3.

  As a result of extracting the interrelationships between the operation variables from the logic circuits L1, L2, L3, and L4 for all the operation variables having the latest upstream and downstream relationships, the correlation matrix shown in FIG. 7 is finally extracted. The In addition, since the matrix of FIG. 7 expresses between the operation variables in the most recent upstream / downstream relationship, there is no corresponding information in other portions.

  Next, in step S123 in which the evaluation by the graph calculation is executed, a directed graph showing the interrelationship between the operation variables is generated based on the control signal correlation matrix of FIG. 7 created in step S122, and the calculation evaluation is executed.

  FIG. 8 shows a directed graph generated based on the correlation matrix of FIG. 7, and has a structure in which nodes N representing each operation variable are connected by a directed branch 30. The connection of the directional branch 30 exists between manipulated variables whose correlation is defined in the correlation matrix.

  For example, in the example of FIG. 7, between the operation variable A and the operation variable B, the downstream operation variable B has a correlation with a delay time 600 with respect to the upstream operation variable A. If this is expressed in FIG. 8, the directed branch 30AB is connected from the node NA representing the operation variable A to the node NB representing the operation variable B. In addition, 600 is described as delay time information on the directed branch 30AB.

  In the example of FIG. 7, between the operation variable B and the operation variable E, the downstream operation variable E has a correlation with a delay time 0 with respect to the upstream operation variable B. If this is expressed in FIG. 8, the directed branch 30BE is connected to the node NE indicating the operation variable E from the node NB indicating the operation variable B. Further, 0 is written as delay time information on the directed branch 30BE.

  In the example of FIG. 7, between the operation variable A and the operation variable C, the downstream operation variable C has a correlation with a delay time 600 with respect to the upstream operation variable A. If this is expressed in FIG. 8, the directional branch 30AC is connected from the node NA representing the operation variable A to the node NC indicating the operation variable C. Further, 600 is described as delay time information on the directed branch 30AC.

  Further, in the example of FIG. 7, between the operation variable C and the operation variable D, the downstream operation variable C has a correlation with a delay time 300 with respect to the upstream operation variable D. If this is expressed in FIG. 8, the directional branch 30DC is connected from the node ND meaning the operation variable D to the node NC indicating the operation variable C. In addition, 300 is described as delay time information on the directed branch 30DC.

  In the example of FIG. 7, there is a correlation between the operation variable E and the operation variable D that is upstream and downstream of each other. If this is expressed in FIG. 8, the directional branch 30DE is connected from the node ND meaning the operation variable D to the node NE indicating the operation variable E, and 0 is set as delay time information on the directional branch 30DE. be written. Further, in this case, the directional branch 30ED is connected from the node NE to the node ND, and 10 is described as delay time information on the directional branch 30ED.

  An evaluation value of each operation variable (A, B, C, D, E) is calculated with respect to the directed graph of FIG. 8 generated by the above procedure. This detailed procedure will be described later using the flowchart of FIG. To do.

  Next, in step S124 for determining the operation procedure, the operation procedure is determined in order from the smallest evaluation value based on the evaluation value of each operation variable calculated in step S123.

  Finally, in step S125, the determined operation procedure information is stored in the operation procedure information database DB3, and the operation proceeds to the step of ending the operation of the operation procedure calculation unit 500.

  Next, a detailed operation for evaluating the directed graph of FIG. 8 in the operation of the operation procedure calculation unit 500 will be described with reference to the flowchart of FIG. FIG. 9 corresponds to step S123 in which the evaluation by the directed graph calculation in the flowchart of FIG. 6 is executed.

  The flowchart shown in FIG. 9 is executed by combining steps S1231, S1232, S1233, S1234, S1235, S1236, and S1237.

  In step S1231, in which the execution start nodes (nodes NA, NB, NC, ND, and NR in FIG. 8) are designated after the directed graph computation algorithm is started, a node that is the starting point for starting the graph computation is arbitrarily designated. Here, it is assumed that the node NA is selected first.

  Next, in step S1232, which initializes the node transition variable, the node transition variable representing the node number currently in the processing target is initialized to the start node NA. Also, the evaluation value of each operation variable (A, B, C, D, E) is initialized to zero.

  The next step S1233 for determining whether or not there is a transition destination node is a branch. If there is no connection from the current processing target node to a node that has not changed, the process proceeds to step S1234; otherwise, the process proceeds to step S1236.

  The next step S1234 for determining whether or not there is a connection source node is a branch. If there is a connection source node for the current processing target node, the process proceeds to step S1235, and if not, the process proceeds to a step of terminating the directed graph calculation algorithm.

  In the next step S1235, the transition is returned to an arbitrary node among the nodes connected to the current node, and the process is returned to step S1233.

  On the other hand, in step S1236 for executing node transition, a transition is made to an arbitrary node among nodes that are connected from the current processing target node and have not transitioned in the past.

  In the next step S1237 for calculating the evaluation value of each manipulated variable, the delay time information described in the transitioned directional branch is read, and the result obtained by adding the provisional value of the evaluation value at the transition source node to the transition destination node. Obtained as a provisional value of the evaluation value at the node.

  FIG. 10 shows the processing flow of each part of FIG. 9 and the information generated at this time when the example of FIG. 8 is evaluated by applying it to the processing flow of FIG. FIG. 10 shows the number indicating the number of processing rounds, the determination route of the processing step at that time, the transition destination node determined in processing step S1236, the node determined in processing step S1237, and the evaluation value assigned thereto. The reference node in the tour is described. In the determination route of the processing step, only the last number of the step is described for convenience of description. Therefore, “3” means step S1233. In addition, the transition destination node determined in the processing step S1236 means a new node to be determined in the next round in another sense.

  In the first round, it is assumed that the current node is NA. In this case, in step S1233, it is determined whether or not there is a connection from the current processing target node to a node that has not changed, but in this case, there is (exists), so processing step S1236. Move on. Here, although the nodes NB and NC are targets, the node NB is first selected, and the NB is stored as a connection destination node in step S1236. Next, the process proceeds to processing step S1237, and NB = 600 is stored as the evaluation value at this time. This NB = 600 means an evaluation value up to the node NB when the reference node is NA.

  In the second round, the current node is the connection destination NB, and the reference node is NA. In this case, in step S1233, since there is a connection from the current processing target node to a node that has not changed, the process proceeds to processing step S1236. Here, the node NE is selected, and NE is stored as a connection destination node in step S1236. Next, the process proceeds to processing step S1237, and NE = 600 is stored as the evaluation value at this time. In this case, as the evaluation value of the node NE, 600 is stored by adding 0 in the second round to the first round 600 as the total evaluation value from the node NA.

  In the third round, the current node is the NE of the connection destination. In this case, in step S1233, since there is a connection from the current processing target node to a node that has not changed, the process proceeds to processing step S1236. Here, the node ND is selected, and ND is stored as the connection destination node in step S1236. Next, the process proceeds to processing step S1237, and ND = 610 is stored as the evaluation value at this time. In this case, as the evaluation value of the node ND, as the total evaluation value from the node NA, 10 in the third round is added to 600 in the second round, and 610 is stored.

  In the fifth round, the current node is the NC as the connection destination. In this case, in step S1233, since there is no connection from the current processing target node NC to a node that has not changed, the process proceeds to processing step S1234. Here, if there is a connection source node for the current processing target node NC, the process proceeds to step S1235. In this case, since the connection source node is NA, the process proceeds to step S1235. Here, the transition is returned to an arbitrary node among the nodes connected to the current node NC, and the process returns to step S1233, so that the transition is returned to the connection source node NA with respect to the current node NC. In FIG. 10, the column in step S1236 of the fifth round describes the connection source node NA in the meaning of the new node to be judged in the next round (in the reason that the NA is determined by the judgment in step S1236). Absent). Since step S1237 does not pass, the evaluation value is not counted.

  In the sixth round, the current node is set to NA again. In this case, in step S1233, since there is an NC as a node that has not changed from the current processing target node, the process proceeds to processing step S1236, and the NC is stored as a connection destination node. Next, the process proceeds to processing step S1237, and NC = 600 is stored as the evaluation value at this time.

  In the seventh round, the current node is set to NC again. In this case, in step S1233, since there is no connection from the current processing target node to a node that has not changed, the process proceeds to processing step S1234. In S1234, since there are no unconnected nodes including the connection source with respect to the NC, the processing is terminated.

  In the flow of FIG. 9, the evaluation value is obtained as a result of tracing NA from both the connection destination and the connection source, using NA as a reference node. In this determination, the relationship between the nodes ND and NE cannot be traced. However, for example, by performing the search again using ND as a reference node as another node, it is possible to similarly obtain evaluation values for all options. is there.

  By executing the above algorithm, the evaluation value of the manipulated variable is finally calculated at each node. In the example of FIG. 10, the evaluation values of the respective operation variables are finally NA: 0, NB: 600, NC: 910, ND: 610, E: 600, and A, B, E, D, and C are operation procedures in which the influence of the interaction between the operation variables is minimized.

  As is clear from the series of descriptions above, the operation procedure calculation unit 500 of the control device 200 automatically calculates the operation procedure of the operation variable based on the temporal interaction relationship extracted from the control logic. As a result, control is performed with minimal influence of mutual interference between manipulated variables, which is a problem in multivariate control, and a more desirable control effect can be obtained.

  The operation when the operation procedure of the operation variable obtained by the operation procedure calculation unit 500 in this way is applied to the control signal generation unit 400 will be briefly described. For example, in the logic circuit of FIG. 4, when the value of the most upstream manipulated variable A is changed, the manipulated variable B and the manipulated variable E are changed after a time delay determined by the evaluation value 600. Further, the operation variable D is changed after a time delay determined by the evaluation value 610. The operation variable C is changed after a time delay determined by the evaluation value 600 and 910. The operation procedure calculation unit 500 determines only this order and timing. The correction signal calculation unit 300 determines the specific value of the correction value.

  Next, the maintenance tool 910 that transmits / receives data to / from the control device 200 in the plant control device will be described. In particular, a screen displayed on the image display device 920 that displays the maintenance tool output signal 94 transmitted from the external output interface 913 will be described with reference to FIGS. 11, 12, 13, and 14. These drawings are specific examples of a screen displayed on the image display device 920. The operator performs various settings and operations using these display screens.

  FIG. 11 is an operation variable setting screen. This is an example of the specification of the screen 80 used in step S11 for setting the operation variable in the flowchart of FIG. 5 showing the operation procedure of the plant control apparatus.

  The operation variable setting screen 80 is largely displayed in two. One of them is a control logic selection screen used in the operation procedure calculation unit 500 in the plant control apparatus. The control logic selection screen includes a logic diagram display screen 600 displayed in the logic circuit format of FIG. 4 and a list display screen 601 for selecting and selecting the logic circuit by a logic number. Here, the logic circuit is displayed by designating the logic number, and it is confirmed that the logic circuit includes the operation variable desired to be changed.

  The second operation variable setting screen is an operation variable setting / extraction screen for extracting an operation variable desired to be changed from operation variables included in the logic circuit. The operation variable list 602 displays all operation variables included in the logic circuit, and the selected operation variable list 603 displays some selected operation variables. Buttons 604 and 605 are used to select operation variables from these screens. The selection result is determined by the end button 606.

  With the setting screen 80 shown in FIG. 11, it is possible to set a control logic drawing used in the operation procedure calculation unit 500, an operation variable used in the correction signal calculation unit 300 and the operation procedure calculation unit 500.

  Specific processing using the screen will be described. With the screen shown in FIG. 11 displayed on the image display device 920, the operator operates the mouse 902 of the external input device 900 to move the focus to the numeric box on the screen, and uses the keyboard 901 to enter the numeric value. You can enter. Further, by operating the mouse 902 and clicking a button on the screen, the button can be selected (pressed).

  In the screen of FIG. 11, first, the control logic data stored in the control logic database DB4 is displayed on the logic diagram display screen 600. A list of logic data stored in the control logic database DB4 is displayed on the list display screen 601. By selecting an arbitrary logic number by operating the mouse 902, the display of the logic diagram display screen 600 can be switched. . In addition, in the control logic data corresponding to the selected control logic number, the operation variable that is the target of the plant operation variable is displayed in the operation variable list 602.

  Next, from among the operation variables displayed in the operation variable list 602, an operation variable to be used for generating a correction signal is selected by operating the mouse 902, and a button 604 is selected to add to the selected operation variable list 603. Can do. Similarly, the selected operation variable can be arbitrarily selected by operating the mouse 902 and can be deleted from the selection operation variable list 603 by selecting the button 605.

  From this screen, it is possible to extract only the operation variables related to each other among the plurality of operation variables in the plurality of control logic circuits. Here, the interrelated operational variables are in a relationship that requires balanced control, such as fuel, water supply, and air target signals for load request signals in the case of a thermal power plant. Say something.

  When the button 606 is selected after completing the above execution condition selection, the operation variable setting screen is terminated and the process proceeds to execution of step S12 in FIG.

  FIG. 12 shows the result of determining the operation procedure in the operation procedure calculation unit 500 for the operation variable selected on the operation variable setting screen of FIG. 11 and the progress of the operation of the plant based on the operation procedure. 6 is a calculation result display screen displayed on the image display device 920 when displaying.

  The operator can select (push) a button by operating the mouse 902 of the external input device 900 and clicking a button on the screen while the screen of FIG. 12 is displayed on the image display device 920. it can.

  In the screen of FIG. 12, the operation procedure of the operation variable calculated by the operation procedure calculation unit 500 is displayed in the operation procedure list 610. A unit 611 of each operation variable value and a list 612 of current operation progress statuses are also displayed side by side in the list 610. In the operation progress status list 612, the symbol “▼” means that the operation has been completed, and the symbol “」 ”means that the operation has not been performed.

  For the operation variable currently being operated, the operation content is displayed in the display dialog 613. For example, a display in the form of “current operation is changing (operation variable xx) from (value yy) to (value zz)” is performed. Further, by selecting the buttons 614 and 615 on the screen of FIG. 12, the operation procedure calculation result display screen of FIG. 13 and the operation characteristic display screen of FIG. 14 can be activated and displayed, respectively.

  The screen display of FIG. 12 makes it possible to check the operation procedure calculated by the operation procedure calculation unit 500 of the present invention and to check the progress of the operation on the current plant 100.

  FIG. 13 is a procedure calculation result display screen for displaying the calculation result of the algorithm in the operation procedure calculation of the operation procedure calculation unit 500. The screen 80 displayed on the image display device 920 when the button 614 in FIG. 2 is selected. It is an example.

  In the procedure calculation result display screen of FIG. 13, each operation variable 621 is displayed in the calculation result list 620 in ascending order of the evaluation value 622 as a result calculated by the operation procedure calculation unit 500. In addition, the directed graph used when calculating the operation procedure is displayed on the graph display screen 623. Here, by using the mouse 902 to match the cursor 622 with an arbitrary operation variable 625 displayed in the list 620, the nodes and directional branches executed when calculating the evaluation value of the selected operation variable are indicated by bold lines. Highlighted. In the figure, the display of “3 D ****** 610” is highlighted. Thereby, the plant operator can confirm the basis for deriving the operation procedure by the operation procedure calculation unit 500. Further, by selecting the button 624, the procedure calculation result display screen of FIG. 13 can be terminated.

  FIG. 14 is a control characteristic display screen displayed on the image display device 920 when checking the control characteristic for the plant 100 when the correction signal calculation unit 300 generates and controls the correction signal according to the calculated operation procedure. .

  In a state where the control characteristic display screen shown in FIG. 14 is displayed on the image display device 920, an arbitrary operation variable displayed in the operation variable list 630 on the screen is selected by operating the mouse 902 of the external input device 900. Thus, the cursor 636 can be moved. In this list, in addition to each operation variable 631, operation condition values 632 and 633 before and after the operation, and values 634 and 635 before and after the operation of the controlled amount of the plant 200 by the control device 100 of the present invention are displayed. Is done.

  In the example of the control characteristics shown in the figure, when the operation variable A ****** is changed from 100 before operation to 90, the controlled variable a changes (changes) from 1000 to 1200. When B *** is changed from 100 before operation to 85, the controlled variable a changes (changes) from 60 to 35, and the operation variable D *** currently being selected. When ** is changed from 100 to 70 before operation, the controlled amount a is changed (changed) from 360 to 500.

  Further, the operation characteristic graph corresponding to the operation variable is displayed on the graph display unit 637 in a state where the cursor is selected as an arbitrary operation variable (D *** in the illustrated example). The graph display unit 637 displays the operation characteristics of the selected operation variable D *** (horizontal axis) with respect to the controlled variable a (vertical axis) as a one-dimensional graph, and the operation before the operation is displayed on the same graph. Variable values (indicated by ■ in the graph), actual values after operation (indicated by ○), and predicted operation values during simultaneous operation (indicated by ●) are plotted.

  Here, the operation predicted value at the time of simultaneous operation is the condition value of the selected operation variable when all operation variables are operated simultaneously without using the operation procedure calculated by the operation procedure calculation unit 500 of the present invention. This means a set of controlled quantities at that time, and this is calculated by the correction signal calculation unit 300.

  From the above graph, the control effect when the plant 100 is operated according to the operation procedure calculation result of the present invention can be confirmed, and the control effect when the operation procedure calculation result of the present invention is not used can be compared, The control effect with respect to the plant 100 by the control apparatus of this invention can be confirmed on a screen.

  Note that by selecting the button 638, the screen displayed in FIG. 14 can be terminated.

  Above, description about the screen displayed on the image display apparatus 920 in the control apparatus of a plant is complete | finished.

  As described above, the case where the plant control device 200 of the present invention is applied to a thermal power plant has been described as an example. However, according to the present invention, even when the mutual interference between operating variables is very strong, Since the operation procedure that minimizes the influence of the action is automatically calculated and controlled accordingly, a more desirable control effect can be obtained. In addition, since the operator can intervene at each stage of the operation procedure determination work, and the progress and result can be confirmed, the reliability can be improved.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. In addition, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor.

  Information such as programs, tables, files, measurement information, and calculation information for realizing each function is stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD. Can be put in. Therefore, each process and each configuration can realize each function as a processing unit, a processing unit, a program module, and the like.

  Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. Actually, it may be considered that almost all the components are connected to each other.

  The present invention is applicable to control devices for various plants.

1, 2: Measurement signal 3: Measurement data 13: Control signal 14: Operation signal 100: Plant to be controlled 101: Boiler 102: Burner 103: After air port 104: Air heater 105: Feed water pump 106: Heat exchanger 108: Turbine 109 : Generator 110: Mill 120, 121: Fan 130-134: Piping 140-142: Piping 150: Water supply measuring device 151: Temperature measuring device 152: Pressure measuring device 153: Power generation output measuring device 154: Concentration measuring device 161-163 : Air damper 200: Control device 300: Correction signal calculation unit 400: Control signal generation unit 500: Operation procedure calculation unit 900: External input device 910: Maintenance tool 920: Image display device M: Calculation device M DB: Database IF: Interface unit DB1: Measurement No. database DB2: operation information database DB3: operation procedure information database DB4: control logic database DB 5: control signal database IF / I: External input interface IF / O: external output interface

Claims (11)

In a plant control device that takes in a plurality of measurement signals from a plant, executes a plurality of logic operations to match the measurement signals with the operation variables, and gives a plurality of control signals to the plant,
The control device includes a control logic database that stores control logic data including operation variables used for the plurality of logic operations, a control signal generation unit that executes the logic operations and generates a plurality of control signals to be given to the plant, An operation procedure calculation unit for calculating the operation procedure of the operation variable is provided.
The operation procedure calculation unit includes a logic operation result of a first operation variable and a second operation for operation variables related to each other among a plurality of operation variables used for a plurality of logic operations stored in the control logic database. Obtain the delay time in the logic operation until the variable is taken into account for each operation variable, determine the operation procedure of the plurality of operation variables,
The control signal generation unit executes a plurality of logic operations to match the plurality of measurement signals with the operation variables, gives a plurality of control signals to the plant, and uses a plurality of operation variables to be used in the plurality of logic operations. A plant control apparatus characterized in that, when a change is made, a change order of other operation variables related to the operation variable is executed according to an operation procedure of a plurality of operation variables obtained by the operation procedure calculation unit. The plant control apparatus according to claim 1,
The plurality of logic operations stored in the control logic database includes PI control, and includes an integration time constant of PI control as a parameter, and the operation procedure calculation unit uses the integration time constant as a delay time in the logic operation. A plant control device characterized by being used. The plant control apparatus according to claim 1,
The operation procedure calculation unit has a function of extracting a control logic related to an operation variable and determining the delay time from a time factor such as a delay time and a dead time between the operation variables with respect to the control logic. Control device. In a plant control device that takes in a plurality of measurement signals from a plant, executes a plurality of logic operations to match the measurement signals with the operation variables, and gives a plurality of control signals to the plant,
The control device includes a control logic database that stores control logic data including operation variables used for the plurality of logic operations, a control signal generation unit that executes the logic operations and generates a plurality of control signals to be given to the plant, An operation procedure calculation unit for calculating the operation procedure of the operation variable is provided.
The operation procedure calculation unit calculates a delay time in the logic calculation between the operation variables related to each other until the logic calculation result of the first operation variable and the second operation variable are added. Understand the relationship in the form of a matrix, convert the interrelationships between the manipulated variables into a directed graph, obtain the evaluation value of each manipulated variable from the directed graph, and determine the operation procedure for multiple manipulated variables according to the size of the evaluated value. ,
The control signal generation unit executes a plurality of logic operations to match the plurality of measurement signals with the operation variables, gives a plurality of control signals to the plant, and uses a plurality of operation variables to be used in the plurality of logic operations. A plant control apparatus characterized in that, when a change is made, a change order of other operation variables related to the operation variable is executed according to an operation procedure of a plurality of operation variables obtained by the operation procedure calculation unit. In the plant control apparatus according to claim 4,
In order to obtain an evaluation value of each operation variable from the directed graph, a transition process between the nodes is executed according to the connection of the directed edge between the nodes provided for each operation variable, and the delay time information described in the directed edge is obtained. A plant control device that calculates an evaluation value of each operation variable by adding according to node transition. In the plant control apparatus according to claim 4 or 5,
The plant control apparatus, wherein the operation procedure calculation unit assigns operation procedures in order from the smallest evaluation value of each operation variable obtained by the procedure. In the plant control apparatus according to any one of claims 1 to 6,
The control device includes an image display device,
In the image display device, as an operation variable setting screen for selecting operation variables related to each other among a plurality of operation variables used for a plurality of logic operations stored in the control logic database,
A plant control apparatus, wherein a plurality of logic operation circuits and operation variables included in the circuits are displayed, and operation variables extracted from the displayed operation variables are displayed in a list. In the plant control apparatus according to any one of claims 1 to 6,
The control device includes an image display device,
The image display device displays, as a calculation result display screen, the result of determining the operation procedure in the operation procedure calculation unit for the selected operation variable and the progress of the operation of the plant based on the operation procedure. The plant control apparatus characterized by the above-mentioned. In the plant control apparatus according to any one of claims 1 to 6,
The control device includes an image display device,
The plant control apparatus, wherein the image display device displays a procedure calculation result display screen for displaying each operation variable in the calculation result list in ascending order of evaluation values as a result calculated by the operation procedure calculation unit. In the plant control apparatus according to any one of claims 1 to 6,
The control device includes an image display device,
In the image display device, when the plant control is performed by the control signal generation unit, values before and after the change of each operation variable and values before and after the change of the non-control amount are displayed as a control characteristic display screen. A plant control device. In the plant control apparatus according to any one of claims 1 to 10,
The plant is a thermal power plant,
A signal representing at least one of the concentrations of nitrogen oxide, carbon monoxide, and hydrogen sulfide contained in the gas discharged from the thermal power plant, and the steam flow rate, steam temperature, and steam pressure of the plant as the measurement signal Including
A plant control apparatus comprising: a signal for determining at least one of an opening degree of an air damper, an air flow rate, a fuel flow rate, a feed water flow rate, a turbine governor opening degree, and an exhaust gas recirculation flow rate as a control signal.

Images