RU2668231C1 - System for controlling instability of the internal plasma disruption in the real time mode in tokamak type plants - Google Patents

Abstract

FIELD: control systems.SUBSTANCE: invention relates to a system for controlling the instability of internal plasma disruption in real time mode in Tokamak plants. System contains operator's automated workstation 13, connected to the microwave plasma heating complex 6, vacuum chamber 1 with plasma radiation monitoring sensors 2 installed therein for detecting a period of sawtooth oscillations of the instability of the internal plasma disruption, connected to sawtooth oscillation controller 3, the signal from which is transmitted to the microwave power contribution control circuit, while regulator 3 is made in the form of a hardware-software complex comprising parameter setting unit 7, the outputs of which are connected to visualization and data processing unit 8 and control algorithm block 9, the outputs of which are connected to measurement results and calculated control actions buffering block 12 and control signals generation and output block 11, the output of which is connected to the microwave power contribution control circuit, consisting of magnetic control system 4 and plasma cord position control coils 5, while control algorithm block 9 is connected through diagnostic channel block 10 to the plasma X-ray monitoring sensors.EFFECT: technical result is the ability to control fast processes in the tokamak plasma in real time by means of a plug-in module built into the plasma control system.1 cl, 4 dwg

Description

The invention relates to control techniques in the field of plasma physics and research, but controlled thermonuclear fusion (TCF) and can be used to obtain stable operating conditions with high energy content to create a cost-effective and safe thermonuclear reactor based on a tokamak-type installation. The invention is used in the construction of control systems for fast processes in tokamak plasma in real time and is an embedded module in the plasma control system.

To create a cost-effective and safe fusion reactor based on a tokamak-type installation, it is necessary to ensure stable operating conditions with a high energy content. Realization of such regimes is impeded by instabilities developing in the tokamak plasma. The greatest influence on energy retention in the central regions of the plasma column is exerted by instability of the internal breakdown and neoclassical tearing modes. The development of these modes is associated with unfavorable profiles of current density and plasma pressure. Using local effects on these profiles using electron-cyclotron resonance (ECR) heating and ECR current generation can allow monitoring of these instabilities.

Known devices for controlling plasma parameters in installations such as tokamak, see, for example, Patent of Ukraine No. 14414, op. April 25, 1997. The device contains a tokamak vacuum system, a memory unit of a given concentration, a control unit, a memory unit, the device implements control via a program channel and a feedback channel using a proportional-integral-differential law.

The prior art automated control system for the instability of internal plasma disruption in real time assembled on the basis of the complexes included in the Tokamak TCV (Paley JI et al 2009 Nucl. Fusion 49 085017). The instability of the internal plasma breakdown is controlled by modifying the current density and plasma pressure profiles using local exposure to microwave heating. The control system contains a tokamak vacuum system with installed plasma X-ray sensors connected to the diagnostic input of the D-tAcq regulator, the output of which is connected to the controller responsible for the rotation of the poloidal mirrors of the microwave heating complex, which heats the tokamak plasma according to the instructions of the automatic worker operator places (AWP). The microwave power input zone is controlled by real-time changes in the poloidal angle of the gyrotron mirrors of the microwave heating complex. The disadvantage of the system is that for the operational control of the system involved sophisticated precision technology, such as vacuum drives gyrotron mirrors.

The technical result of the invention is to obtain stable operating modes with a high energy content by controlling the instability period of the internal breakdown in real time by changing the spatial position of the contribution zone of the microwave power by changing the currents in the winding control the position of the plasma cord, which will simplify the control system.

To achieve this result, a real-time system for controlling the instability of internal plasma breakdown in Tokamak-type installations is proposed, containing an operator's automated workstation (AWS) connected to a microwave plasma heating complex, a vacuum chamber with installed sensors for monitoring x-ray plasma for recording the period of sawtooth oscillations of the instability of the internal plasma breakdown connected to the sawtooth oscillator regulator, the signal from which is transmitted to the circuit control the position of the contribution of microwave power, while the controller is made in the form of a hardware-software complex (AIC) containing a parameter setting unit, the outputs of which are connected to a visualization and data processing unit and a control algorithm block, the outputs of which are connected to a buffer unit for measuring and calculated results control actions and the block generating and issuing control signals, the output of which is connected to the control loop position of the contribution of microwave power. consisting of a magnetic control system and windings for controlling the position of the plasma cord, while the block of control algorithms is connected through the block of diagnostic channels to sensors for monitoring the x-ray radiation of the plasma.

The essence of the invention lies in the fact that the control of the instability period of the internal plasma breakdown is carried out due to the ability to change the position of the contribution of the microwave power of the gyrotron complex by changing the currents in the winding control the position of the plasma cord, which is a fundamentally different approach to solving control issues.

In FIG. 1 shows a block diagram of a real-time internal disruption control system for tokamak-type installations, where

1. The tokamak vacuum chamber

2. X-ray sensors

3. Regulator sawtooth oscillations "APK T-Control"

4. Magnetic tokamak control system

5. The winding control position of the plasma tokamak cord

6. A complex of microwave heating tokamak 13. AWP operator tokamak

In FIG. 2 shows a block diagram of the controller "APK T-Control", where

7. The parameter setting unit, including the plasma discharge scenario control module, the PID controller control and configuration module, the user algorithm setting and implementation module

8. The unit of visualization and data processing, providing navigation through the database of plasma discharge scenarios, processing and visualization of control parameters

9. A block of control algorithms that provide the implementation of the control scenario logic, preliminary processing and analysis of feedback channel signals, calculation of control actions, calculation of dynamic corrections

10. Block of diagnostic channels receiving a signal from x-ray monitoring sensors

11. The block generating and issuing control signals, issuing a control signal to the magnetic plasma control system

12. A block for buffering measurement results and calculated control actions, performing archival functions for storing calculation results.

Consider the composition of the system and the principle of the system on the example of Tokamak-10. An indicator of the development of disruption instability is periodic fluctuations in the temperature and plasma density, the so-called sawtooth oscillations, which are clearly visible on the signals of the X-ray radiation control sensors 2 (Fig. 3), made on Toka aka T-10 as a multi-wire gas detector mounted on the flange of the vacuum chamber I tokamak T-10. The signal from the detector enters the block of diagnostic channels 10 of the controller "APK T-Control" 3, which is a hardware-software complex (APC), which includes blocks 7-12. whose work will be considered below. Regulator 3 analyzes and processes the signal in real time in the block of control algorithms and, through the block for generating and issuing control signals 11, transmits a program of actions for winding control of the movement of the plasma cord 5 through the T-10 magnetic tokamak control system (4. Separately, through the tokamak operator's workstation 13, a start signal is supplied to the microwave heating complex 6. By shifting the plasma cord, the contribution zone of the microwave power is adjusted and, as a result, the period of instability of the internal breakdown is regulated.

Consider the operation of the controller “AKP T-Control" 3.

The regulator "APK T-Control" is a device in the tokamak feedback circuit.

The purpose of the T-Control is to maintain the set value of the ramp period relative to the current value. The set value of the sawtooth period is called the set point, and the difference between the set value and the measured one is called the residual or mismatch.

The following algorithm for detecting the period of sawtooth oscillations is implemented:

1. The initial diagnostic signal from the X-ray sensors 2 falls into the control algorithm block 9. There it is smoothed by the moving average method and then by the simple average method. The received signal is differentiated. Emission-specific values are discarded. The result of differentiation is subjected to additional processing:

- Grouping and combining single-valued values

- Integration and rejection of negative values.

- Discarding values not exceeding the “noise” threshold.

2. Next, in the same block 9, the duration of the current saw period is calculated and compared with the minimum and maximum possible values set by the user in block 7.

3. In the case of saw detection, the average value of the saw period for a given number of previous received periods is calculated.

4. If the saw is not detected, zeroing the value of the average saw period.

5. If the average saw period is not zeroed in the same block 9, the difference between the average value of the saw period and the current value of the saw period is calculated.

6. The obtained value for changing the saw period is used in the adaptive algorithm for dynamically controlling the displacement of the plasma cord, taking into account changes in the period of sawtooth oscillations.

In FIG. 4 shows the sequence of conversion of the diagnostic signal from x-ray sensors in the process of calculating the sawtooth period:

- Pila.S - Diagnostic signal used to detect sawtooth oscillations coming to the block of diagnostic channels 10

- Pila.S-2 signal after preliminary processing in the block of control algorithms (9).

- Differencial - the result of differentiation in the block of control algorithms 9.

- Pila.С - the result of grouping “single-sign emissions” as a result of differentiation of the control algorithm block 9.

- Pilf.P - the amplitude of this signal corresponds to the period of the saw at the moment, and zero values of the amplitude correspond to the borders of the sawtooth oscillation.

The Pila.C signal allows you to use the following characteristics to determine the sawtooth wave:

- Minimum saw period

- Maximum saw period

- Minimum amplitude of a saw

- Maximum amplitude of a saw

As a result of the above-described procedure for detecting sawtooth oscillations, the period of the last oscillation in real time is determined. Having the dynamics of changing the period of the sawtooth oscillations at the current time, the calculation of the dynamic correction for the program of horizontal displacement of the plasma cord based on the analysis of the signal of the sawtooth oscillations is implemented.

The calculated dynamic correction is summed up with the value of the program for horizontal displacement of the plasma cord corresponding to a given moment of time and the obtained value is used in the controller “AIC T - Control” to set the required position of the plasma cord at a given time and transfer it to the control loop of the position of the contribution of the microwave power consisting of magnetic control system 4 and windings for controlling the position of the plasma cord 5.

The calculation of the dynamic correction is performed by the formula:

D = Cr * Dy + Kd * (Dy-DyPrev) / Dx + Ki * Integral

Where:

- Integral: = Integral + Dy * Dx;

- Dy - change the period of the last saw. (Relative to the previous saw or relative to the specified saw period. In the first case, the program will try to increase or decrease the saw period - depending on the given sign, in the second case, the program will try to keep the specified saw period.)

- DyPrev - change the period of the penultimate saw.

- Dx - the sum of the periods of the last and penultimate saw.

- Kp - proportional coefficient

- Ki - integral coefficient

- Kd- - differential coefficient

Additionally, depending on the given strategy, the dynamic correction may be added to the previous achieved correction value.

To set the parameters for applying the dynamic correction in the plasma-cord displacement program, a configuration file of the following form is used:

The implemented algorithms for detecting the sawtooth oscillation period and calculating the dynamic offset correction (depending on the change in the saw period) are simple enough to use in real time and have significant development potential towards the addition of adaptability.

The controller “APK T-Control” runs under the control of the specialized 16-bit disk operating system PTS-DOS 2000, compatible with MS DOS version 6.22 and higher.

The software implements the following main modes:

1) Monitoring (registration of diagnostic channels for saving and subsequent mathematical processing and analysis).

2) Static control of object parameters by issuing specified programs to control channels.

3) Dynamic control of object parameters using feedback signals and built-in control algorithms (including custom ones) according to specified parameter change programs. For multi-channel multi-parameter control, adjustable parameters can be set both by start / end values and rate of change, and by arrays of set values for each moment in time in the form of editable text and through a graphical user interface. Regulator coefficients can be set individually for each given time interval of the scenario.

Physically, the APK-T-Control regulator includes:

- The T-Control system unit with digital-to-analog modules for communication with the control object

- A set of peripheral equipment

- Operator workstation

All units are made of standard electronic components.

The real-time control system for instability of internal plasma disruption in Tokamak-type installations can improve the quality and expand the capabilities of the Tokamak control system. at the same time, it is integrated into the overall control system of a separate module and does not require a fundamental change in the entire system.

Claims (1)

A real-time control system for the instability of internal plasma breakdown in Tokamak-type installations, containing an AMR operator workstation connected to a microwave plasma heating complex, a vacuum chamber with installed sensors for controlling x-ray plasma radiation to record the period of sawtooth oscillations of the instability of the internal plasma breakdown connected to the sawtooth regulator, the signal from which is transmitted to the loop for controlling the position of the contribution of the microwave power the controller being made in the form of a hardware-software complex containing a parameter setting unit, the outputs of which are connected to a visualization and data processing unit and a control algorithm block, the outputs of which are connected to a buffering unit of measurement results and calculated control actions and a control generation and output unit signals, the output of which is connected to the control loop for the position of the contribution of the microwave power, consisting of a magnetic control system and windings for controlling the position of the plasma cord RA, while the block of control algorithms is connected through the block of diagnostic channels with sensors for monitoring the x-ray radiation of the plasma.

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