SU1113778A1 - Reserved automatic control system - Google Patents

Abstract

1. A BACK-UP AUTOMATIC CONTROL SYSTEM containing the main controller, the first information input of which is connected to the master output, the information output - with the first input of the OR element, and the control output - with the first input of the switch block, the first output of which is connected to the first input of the actuator , the second input is with the second output of the switch block, the second input of which is connected to the output of the setpoint, the output of the sensor is connected to the second information input of the main controller, the third input of the cut The first regulator and the input of the block of threshold elements, the output of which is connected to the second input of the OR element, the output of which is connected to the control input of the switch block, characterized in that. in order to improve the reliability of the system, it contains a control signal monitoring device, a backup regulator structure adjustment unit, a control output of the main regulator connected to the first input of a control signal control device, the second input of which is connected to the output of the setpoint controller, and an output to the third input -element OR, the input of the structure adjustment block of the backup regulator is connected to the second output of the backup regulator, and the output is connected to the third input of the switch block, the third output of which is connected to the fourth rtym entrance backup controller. (L 2. System pop.1, characterized in that the control signal control device contains a filter, a differentiating amplifier, an amplifier-inverter, an adder, the first and second threshold elements, the first input of the device connected in series through a filter and a differentiating amplifier with the input 00 of the first threshold element and through the adder with the input of the second threshold element, the second input of the device 00 through the amplifier-inverter is connected to the second input of the adder, the outputs of the threshold elements are connected to the output of the devices but.

Description

The invention relates to automation, in particular, to control systems with digital computing devices in the control circuit of complex objects and technical processes.

Automatic control systems are known with digital control computers that are backed up by regulators based on simpler and more reliable elements to ensure reliability. In the event of a computer failure, such systems provide, although with lower quality, control from the backup controller. The control signals of the computer are fed both to the actuator and to. the input of the backup regulator, and the input of the regulator is such a signal that, by its output, the signal is equal to the signal at the input of the actuator to ensure the transfer of control from the computer to the reserve controller without discontinuous disturbances l.

The disadvantage of the device is the additional computational load on the computer. In addition, in the event of an uncontrolled computer failure (for example, due to an error in the software), an invalid control signal could be generated leading to the output of the controlled parameter beyond acceptable values.

Closest to the present invention is an automatic control system comprising a sensor, a control computer, an analog reserve controller, a setting device, opening and closing contacts, a switch block, an analog controller control unit, an actuator and an actuator. A switch block is connected to a control computer and an analog controller. The feedback input of the analog controller is connected via the opening contacts to the output of the controlling computer, and through the closing contacts to the control unit of the analogue controller. The input of the actuator is connected via disconnecting contacts to the analog output of the control computer, and through the connecting contacts to the output

control unit analog controller. A sensor that converts the measured value of the parameter being controlled The current signal and the setpoint gauge are connected to the control computer and the analogue controller 2l,

In the known system, automatic switching from the control mode from the control computer to the analog controller occurs not only when the control computer fails, but also when the controlled parameter leaves the permissible limit values.

However, the control of the parameter and the formation of a signal according to its deviations are assigned to the computer, while the signal from its output is not controlled. Such a technical solution does not provide reliability in the event of a series of uncontrollable control failures and a computer associated with, for example, software errors. Uncontrolled failures in the control computer can lead to an unacceptable control action on the executive body or to the lack of control of the controlled parameter when the permissible limits are exceeded. The system can hardly be used to control potentially dangerous objects, such as nuclear power reactors, since it allows for a control signal that can bring the controlled parameter beyond the limits of regulated values and lead to catastrophic consequences.

The purpose of the invention is to increase the reliability of a system with a computing unit in a control loop by providing control of the magnitude and rate of change of the control signal, as well as switching to the backup regulator without sudden disturbances.

The goal is achieved by the fact that the primary controller, the first information input of which is connected to the master output, the information output - with the first input of the OR element, and the control output with the first input of the switch block, the first output of which is connected to the first entry of the executive body.

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the second input - with the second output of the switch block, the second input of which is connected to the output of the setpoint; the output of the sensor is connected to the second information input of the main controller, the third input of the backup regulator and the input of the threshold element block, the output of which is connected to the second input of the OR element, output which is connected to the control input of the switch block, a control signal monitoring device is introduced, a backup regulator structure adjustment block, the control output of the main regulator connected to the first input The control signal control device, the second input of which is connected to the output of the setpoint, and the output to the third input of the OR element, the input of the restructuring unit of the backup regulator is connected to the second output of the backup regulator, and the output to the third input of the switchgear, the third output of which connected to the fourth input of the backup controller.

The control signal control device contains a filter, a differentiating amplifier, an inverter amplifier, an adder, and the first and second threshold elements - the first input of the device is connected in series through a filter and a differentiating amplifier to the input of the first threshold element and through the adder to the second threshold element input. device through the amplifier-inverter is connected to the second input of the adder, the outputs of the threshold elements are connected to the output of the device.

Fig. 1 shows a functional block diagram of the proposed redundant automatic control system: Fig. 2 is a diagram of a control signal monitoring device; FIG. 3 shows a variant of the block diagram of a backup regulator with a structural adjustment block.

The redundant automatic control system (Fig. 1) contains a computing unit 1 (main controller), a backup controller 2. sensor 3j setpoint A, threshold element 5, element OR 6, switch unit 7, control signal monitoring device 8, adjustment unit 9 structures of reserve regulator. Switch block 7 contains

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inputs 10,11 and 12 and outputs 13,14 and 15, and reserve regulator 2 - outputs 16,17 and 18.

Block 8 contains a smoothing

filter 19, differentiating amplifier 20, threshold element 21, amplifier-inverter 22 adder 23 and threshold element 24, as well as an input 25 for connecting and an electrical circuit.

The controller 2 may contain an input signal limiter 26, an integrator 27, an amplifier 28, an actuator 29, and an adder 30.

The principle of operation is a system.

in the following.

In the control mode from the computational unit, when an unacceptable control signal appears at the output of the computational block, for example, with an unacceptable rate of change or unacceptable value, a control signal is transferred to the control signal monitoring device on the control signal monitoring device, and a rearrangement occurs structures of reserve regulator.

To perform these functions, the control signal monitor device contains a filter, a differentiating amplifier, an amplifier-inverter, an adder and threshold elements, and the control output signal of the computing unit, pass sequentially through the filter, the differential amplifier and the first threshold element are checked for the absence of an unacceptable speed changes, and the passage through the adder and the second threshold element - in the absence of an unacceptable value. The presence of the adder and the inverter amplifier connected to it, the input of which receives the master signal, allows the control signal to be changed depending on the magnitude of the master signal.

When controlling from the computing unit, the structure of the backup controller

is rebuilt in such a way that it does not have a significant effect on the control signal taken up by the computing unit, at the same time when switching to control mode from the backup regulator to

its output does not appear to jump the control signal. This can be accomplished, for example, by rebuilding the backup controller in control mode from the computing unit to the aperiodic link with such a constant time that the control signal generated by the computing unit passes through this link without significant distortion. Thus, the system blocks the passage to the executive body of unacceptable control signals arising for any failures of computations. unit, and the transition to the backup controller occurs without discontinuous disturbances, which significantly increases the reliability and safety of the control system. The system works as follows. When controlling the actuators from the computing unit 1, the control signal nocTvnaeT at the input 10 of the switch block, then (. Through closed contacts) to the output 13 of the switch block and through the reserve controller 2 to the output 17 to the executive bodies. In this case, backup regulator 2 is rebuilt into an aperiodic link with a small constant time and does not significantly affect the quality of control processes. The signal of the setpoint 4 is fed to the input of the computing unit and the input 11 of the switch unit 7; In this mode, it does not pass to output 14 (the contacts of the transducer block are open). The signal of sensor 3 enters the computing unit 1f back-up regulator 2 (feedbacks and to the threshold element 5. When the controlled parameter leaves the measured 3, the output signal of the threshold 5 appears at acceptable values. The block OR 6 outputs a signal to the switch block 7 to turn off the computing unit 1 and transfer to control from the backup regulator 2 if any of the three signals are present at its input: the output signal from the block of threshold elements 5, the signal from the computing unit 1 about its refusal, the signal from the device The control signal, generated by the computing unit 1, passes through the filter 19, smoothing the stepwise change of the signal of the digital-analog converter of the computing unit, to the differentiating amplifier 20, from the output of which, the threshold element 21 receives a signal proportional to the rate of change of the output control signal-. With an increase in the rate of change of the signal is acceptable, which may occur, for example, if the digital-to-analog converter malfunctions at the output of the computing unit 1, the threshold element is triggered, connects the electric circuit 25, and the output of the control device shows the signal The threshold element 24 is activated by connecting the electrical circuit 25, when the control signal is deviated beyond the allowable values. At the same time, the permissible value of the control signal is formed with the opposite sign of the inverter amplifier 22, the output of which is given by the preset signal 4. The gain of the inverter amplifier determines the degree of permissible excess of the control signal compared to the preset signal. In some modes of operation of the controlled object there is a limitation on the speed of movement of the executive body. To simplify the design of the backup regulator, this restriction applies to all modes of operation of the control object. To limit the speed of moving the actuator, the controller contains a sweep device consisting of an input signal limiter and an integrator 27. When the set position of the actuator is changed by setting device 4, not a jump signal, but a ramping or descending signal is applied to the input of amplifier 28 (depending on the sign of the signal at the input of the limiter 26). The sweep speed of the signal of the specified position of the actuator is determined by the magnitude of the input signal and the time constant of the integrator 27. Connecting the computing unit to control the actuator 29 allows optimization of technological processes, since the position and speed of movement of the actuator 29 are determined not only by the setting device 4, but and process parameters, the state of the controlled object and other conditions. For these purposes

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the output analog signal from the computing unit could be fed directly to the adder 30 instead of the signal from the output of the integrator 27. However, when transferring control from the computing unit 1 to the backup controller 2, a smooth transition is not provided, since at the time of switching the signal at the integrator 27 output may differ significantly from the signal from the output of the computing unit, which will lead to an abrupt change in the position of the executive body. In order to ensure a smooth transition of the control mode from the computing unit to the standby controller, the output signal of the computing unit is proposed to be applied to the input of the backup controller.

The structure adjustment unit 9 contains a capacitor, which is connected to the code 18 of the backup regulator and the input 12 of the switch block. In the control mode, the capacitor (block 9) is switched off by the switch block (opening 12 and output 15) from the computational block and, due to a decrease in capacity, the time constant decreases, and the integrator actually changes to an aperiodic link.

The backup regulator can be any electrohydraulic or electromechanical regulator, to the input of which electrical signals are applied. For example, the ARM-5 controller channel installed in the control system at nuclear power plants can be used as a backup controller. Connecting the computing unit in this

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case allows to optimize the management process.

The proposed control system in comparison with the known systems is protected from a large number of failures of the computing unit, including those arising due to errors in the software. The use of simple and reliable means of controlling the control signals of a computing unit, redundant controllers makes the system less dependent on the computing unit and allows building more reliable and cost-effective automatic control systems, including for nuclear reactors.

Compared with the base object, which is selected as a modern reactor control system of a high power nuclear power plant, the proposed system can perform additional functions such as the optimal distribution of the energy release field in the reactor. It is known that an increase in the thermal stability of reactors of a nuclear power plant with a capacity of 2 million kW only by 1% as a result of an improvement in the quality of control while maintaining the reliability of reactors gives an economic effect several times exceeding the cost of a BESM-6 computing machine.

Existing nuclear power plant reactor control systems cannot perform the functions of optimally allocating an energy release field due to the need to perform complex calculations by definition, controlling 1x of impacts.

Claims (2)

1. A RESERVED AUTOMATIC CONTROL SYSTEM, comprising a main controller, the first information input of which is connected to the output of the setter, the information output - with the first input of the OR element, and the control output - with the first input of the switch block, the first output of which is connected to the first input of the executive body, the second input - with the second output of the switch block, the second input of which is connected to the output of the master, the output of the sensor is connected to the second information input of the main controller, the third input of the backup the controller and the input of the block of threshold elements, the output of which is connected to the second input of the OR element, the output of which is connected to the control input of the switch block, characterized in that, in order to increase the reliability of the system, it contains a control signal control device, a unit for restructuring the structure of the backup regulator, controlling the output of the main controller is connected to the first input of the control signal control device, the second input of which is connected to the output of the setter, and the output with the third input is an OR element, the input is To restructure the backup controller, it is connected to the second output of the backup controller, and the output to the third input of the switch block, the third output of which is connected to the fourth input of the backup controller. 2. The system according to claim 1, with the fact that the control signal control device comprises a filter, a differentiating amplifier, an inverter amplifier, an adder, the first and second threshold elements, the first input of the device being connected in series through a filter and a differentiating amplifier with the input of the first threshold element and through an adder with the input of the second threshold element, the second input of the device through the amplifier-inverter is connected to the second input of the adder, the outputs of the threshold elements are connected to the output of the device. Π13778 1 1113778 2