RU2399787C1 - Adaptive control method of rotor speed of adjustable-blade propeller turbine - Google Patents

Abstract

FIELD: power industry. ^ SUBSTANCE: essence of invention consists in qualification at each step of the control process of parametres of adaptive control and correction of gate-blade relationship by means of the trained model parametres which have been found at the previous step of control; the above model consists of mathematical models of control object, combinatory and adaptive control. Rotor speed of turbine, vibration level, degree of opening the guide vane, location of blades of impeller is found by means of error signal between measured values and values of control parametres, which are predicted with the model by recurrence algorithm of optimum control by minimising the functional of general operation by means of maximum principle. Specified parametres of adaptive control and updated gate-blade relationship provides optimum control of hydroturbine at minimum vibration level of allowable deviations specified with factory characteristics. ^ EFFECT: optimum control of hydroturbine rotor rotation speed with specified quick action and accuracy, and taking into account the influence of disturbing actions, at minimum vibration, increasing repair intervals and increasing service life of hydroturbine as a whole owing to reducing vibration level. ^ 1 dwg

Description

The invention relates to methods for adaptively controlling the rotational speed of a rotor of hydroturbines of hydroelectric power plants (HES) and can be used in hydropower to create automated digital systems for optimal control of hydropower units with a rotary vane hydraulic turbine.

A known method of controlling the rotor speed of a rotary-vane hydraulic turbine, which consists in changing the degree of opening of the guide apparatus and the position of the blades of the turbine impeller by forming and applying control actions to the control drives of the guide apparatus and impeller blades (electrical panel EGR-MP-2-1- 220-220 / 50-1-0-OZUHL4. Operating Instructions 2266999 RE of OJSC Leningrad Metal Plant 2003).

In the known method, the control action on the control drive of the guide apparatus is formed using a controller with constant parameters, which are set in advance during commissioning using a linear model of a hydraulic turbine.

The control action on the drive wheel of the turbine impeller blades is formed using a combinator according to a predetermined combinatorial dependence, the same for all hydroturbines of the same type installed at a multi-unit hydroelectric power station. The combinatorial dependence is determined by the results of experimental studies of the layout of a rotary-blade turbine and is specified during field tests of the head sample under operating conditions at this hydroelectric station. This method of controlling the rotor speed of a hydraulic turbine is used in existing systems for automatic control of hydraulic units of hydroelectric power plants in Russia.

But at the same time, this method does not take into account the fact that each turbine has individual distinctive features that affect the choice of optimal control actions. These distinguishing features include:

- non-linear dependence of the rotor speed of the turbine on the control actions and the pressure of the water;

- significant differences in the sizes of water paths of various hydraulic units, even if they are within the tolerance of building codes specified in relative units;

- differences in the gaps between the impeller vanes and the chamber;

- the presence of discrepancies between the calculated and actual values of the degree of opening of the guide apparatus and the position of the impeller blades;

- differences in the profile and size of the impeller blades.

Therefore, each hydraulic turbine maintains a given rotor speed with large values of static and dynamic control errors.

As a prototype, a method of adaptive correction of the combinatorial dependence of a rotary-blade turbine is adopted (patent for invention RU 2302551 C2, IPC F03B 15/00, published July 10, 2007, bull. No. 19).

In this method, first, there is a discrepancy between the optimal turbine control parameters obtained from the combinatorial dependence, and then the combinatorial dependence is taken out of operation, the direction of correction is determined and the optimal parameters are searched for, in which the increase in water flow with a change in the position of the impeller blades would be equal to the increase in flow water when changing the opening of the guide vane, for which test impulse effects are formed, producing them simultaneously, but in opposite formulations, grouping them in pairs, and stepwise feeding them to the drive drives of the impeller and guide vanes, measuring the increment of the electric power of the unit, while a positive increase in electric power is used as a sign for selecting a correcting pair of pulses, and the correction is continued until the moment when the unit power increment will become equal to zero, while the control parameters are accumulated in the memory unit for their subsequent use as optimal when niya unit mode, the corresponding pressure and power.

The prototype has the following disadvantages.

The optimal parameters of the combinatorial dependence are determined in a special mode of operation of the turbine with the combinatorial dependence taken out of operation, in which trial impulse actions are supplied to the control drives.

In addition, in the process of correction of combinatorial dependence, control impulses are supplied with test impulse actions, first aimed at increasing and then decreasing control actions (or vice versa), due to which there is an increased level of vibration and wear of the moving parts of the turbine and control drives, corrections of combinatorial dependence do not take into account the level of vibration of the turbine, which leads to a decrease in the period of operation of the turbine between repairs and the period of operation of the turbine as a whole.

The invention solves the problem of automated optimal control of the rotor speed of a rotary-vane hydraulic turbine with a given speed with minimal vibration, taking into account the permissible deviations provided by the factory characteristics.

The technical result is the optimal control of the rotor speed of the turbine with the given speed and accuracy and taking into account the influence of disturbing influences, with minimal vibration, and as a result - increase of the overhaul intervals and increase the service life of the turbine as a whole by reducing the level of vibration.

The technical result achieved is achieved in a method for adaptively controlling the rotor speed of a rotary vane hydraulic turbine, which consists in generating actions on the control drives of the impeller blades and the guide apparatus using a combinatorial dependence, in changing the position of the impeller blades and opening the guide apparatus by applying actions to the control drives with impeller blades and a guiding apparatus for the given parameters of turbine regulation, in the cor the combinatorial dependence on the presence of a mismatch between the required and measured control parameters, first, at the first step, control actions are formed in the adaptive controller with the initially configured parameters and the combinator and fed to the control drives of the impeller blades and the guiding apparatus, as well as to the training model of the hydraulic turbine consisting of mathematical models of the control object, combinator and adaptive controller, then the position of the blades is changed and the degree of opening of the guide vane for the given parameters of regulation of the turbine, namely: the rotational speed of the rotor of the turbine, the level of vibration and pressure of water, then measure the position of the blades of the impeller, the degree of opening of the guide vane, the speed of rotation of the rotor of the turbine, the level of vibration and pressure of water and determine the mismatch signal between the measured and the required values of the control parameters, which is used in the adaptive controller, simultaneously measured values of the parameter The regulation signals are fed into the training model of the hydraulic turbine, using the training model, the predicted values of the regulation parameters are calculated according to the control actions and the error signal between the predicted and measured values of the regulation parameters is determined, then using this error signal the recurrence algorithm of optimal control minimizes the functional of generalized work using of the maximum principle, the updated values of the parameters of the trained model are found, which are used to correction of combinatorial dependence, as well as custom parameters of the adaptive controller in the next step of the control process.

The essence of the invention is to clarify at each step the process of controlling the parameters of the adaptive controller and correcting the combinatorial dependence using the parameters of the learning model found in the previous step of the control process, consisting of mathematical models of the control object, combinator and adaptive controller. The parameters of the model being trained, namely: the speed of rotation of the rotor of the turbine, the vibration level, the degree of opening of the guide apparatus, the position of the impeller blades, are found using the mismatch signal between the measured and predicted model values of the control parameters according to the recurrent optimal control algorithm by minimizing the functional of generalized work using principle of maximum. The adjusted parameters of the adaptive controller and the corrected combinatorial dependence provide optimal control of the turbine with a minimum level of vibration, taking into account the permissible deviations provided by the factory characteristics, which allows to increase the overhaul intervals and the life of the turbine as a whole.

The drawing shows a block diagram of an adaptive control system for the rotor speed of a rotary vane hydraulic turbine, explaining the principle of operation of the control method, consisting of an adaptive controller 1 with adjustable parameters for generating a control action on the control drive of the guide apparatus 2, combinator 3 for forming a control action on the drive control of the blades of the impeller 4 according to combinatorial dependence, the control drive of the guide apparatus 2, the control blade Static preparation wheels 4, 5 hydroturbine, a measuring unit 6 for measurement control parameters hydroturbine 5, 7 trained model for calculating the adaptive controller parameter values 1 and correction combinatorial function.

The method is as follows. All control time is divided into separate intervals - time quantization steps. At the first step, in adaptive controller 1 with initially set parameters, a control action is generated and applied to the control drive of the guiding apparatus 2 - Uy (t). Then, using a combinatorial dependence predetermined (for example, obtained during testing of the head sample of the batch), a control action is generated and applied to the control drive of the impeller blades 4 - Uφ (t). Formed control actions are also served in the trained model 7 of the turbine 5.

After that, the values of the position of the impeller blades, the degree of opening of the guide vane, the level of vibration, the rotational speed of the rotor of the turbine 5, the pressure of the water are measured. The measured values of these control parameters are influenced by external uncontrolled disturbances, denoted as w (t). After that, the measured values of the control parameters are supplied to the adaptive controller 1, which also serves the required values of the control parameters specified in the form of reference paths. Next, a mismatch signal is found between the measured and required values of the control parameters, which are used in adaptive controller 1.

The adaptive controller 1 is adjusted using the trained model 7 of the turbine 5. In the trained model 7 with the initial parameters, where the control actions are applied, the predicted values of the parameters of the hydraulic turbine 5 are calculated, such as: the position of the impeller blades, the opening of the vanes of the guide vane, the vibration level, speed rotation of the rotor of the hydraulic turbine 5. After that, a mismatch signal between the predicted and measured parameters is found. Further, this mismatch signal is used to find the refined parameters of the trained model 7 in a recurrent optimal control algorithm in which the functional of generalized work is minimized (Krasovsky A.A. Optimal Algorithms in Identification Problems with an Adaptive Model // Autom. 1975, No. 12, p. 75-82 .):

using the maximum principle (Fomin V.N., Fradkov A.L., Yakubovich V.A. Adaptive control of dynamic objects. M .: Nauka, 1981, 384 pp.), taking into account the equations of the trained model 7 and the constraints provided by the factory characteristics

where N (t) is the rotational speed of the rotor of the turbine 5;

n _CR (t) is the predicted rotational speed of the rotor of the turbine 5;

y (t) is the degree of opening of the guide vane;

y _ol (t) is the predicted degree of opening of the guide vane;

φ (t) is the position of the impeller blades;

φ _CR (t) is the predicted position of the impeller blades;

z (t) is the vibration level;

z _ol (t) is the predicted vibration level;

w (t) is the vector of disturbing influences;

σ _N , σ _φ , σ _y , σ _z , σ _w are normalizing factors;

α is the regularization parameter 0 <α <1.

The refined values of the parameters of the trained model 7, which take into account external disturbances, provide optimal control of the turbine 5, with minimal vibration. Next, the parameters of the trained mathematical model 7 are used as adaptive parameters of the adaptive controller 1 and with the help of them they correct the combinatorial dependence, which is used in combinator 3.

After that, the control process is transferred to the next step and repeated.

Due to this, the proposed method allows to provide optimal control of the rotor speed of the turbine with the given speed and accuracy, to take into account the influence of disturbing influences, to reduce the level of vibration of the turbine taking into account the permissible deviations provided by the factory characteristics.

Claims (1)

A method of adaptive control of the rotor speed of a rotary vane hydraulic turbine, which consists in generating effects on the control drives of the impeller blades and the guiding apparatus using combinatorial dependence, in changing the position of the impeller blades and opening the guide apparatus by applying actions to the control drives of the impeller blades and guides the apparatus for the given parameters of regulation of the turbine, in the correction of combinatorial dependence on the presence of mismatch between the required and measured control parameters, characterized in that at the first step, control actions are formed in an adaptive controller with initially set parameters and a combinator and fed to the control drives of the impeller blades and the guide apparatus, as well as to the training model of a hydraulic turbine, consisting of mathematical models of the control object, combinator and adaptive controller, then change the position of the impeller blades and the degree of opening of the guide arata at given control parameters of the turbine, namely the rotor speed of the turbine, vibration level and pressure of the water, then measure the position of the impeller blades, the degree of opening of the guide apparatus, the rotational speed of the turbine, vibration and pressure of the water and determine the error signal between the measured and the required values of the regulation parameters, which is used in the adaptive controller, simultaneously the measured values of the regulation parameters are fed to the learner Hydroturbine del, using the trained model, calculate the predicted values of the control parameters from the control actions and determine the mismatch signal between the predicted and measured values of the control parameters, then using this mismatch signal using the recurrent optimal control algorithm, minimizing the functional of the generalized work using the maximum principle, find the adjusted values parameters of the trained model, which are used to correct combinatorial dependence, as well as adjustable parameters in the adaptive control process of the next step.

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