RU185322U1 - HYDROTURBINE ROTATION REGULATOR - Google Patents

Abstract

The utility model relates to the improvement of the electro-hydraulic speed controller of a turbine. The technical result consists in increasing the accuracy and quality of regulating the frequency of rotation of a hydraulic turbine, reducing the frequency and amplitude of oscillations of the regulating organs of a hydraulic turbine in steady-state modes of operation of a hydraulic unit, and increasing the periods of inclusion of oil pumps of an oil-pressure unit. A speed turbine speed controller is proposed, comprising a speed sensor, an acceleration sensor, an integrator, a control mechanism, the outputs of which are connected through an adder to an amplifier and an adaptation unit that provides a change in the gain of the error signal entering the amplifier, a correction unit, a distribution valve connected to a servomotor , a feedback sensor for the position of the servo motor rod, the output of which is connected to the adder. The integrator signal is combined on the adder with a frequency deviation signal, an acceleration signal, a control mechanism signal, and a constant static signal. The resulting signal from the adder, amplified by the amplifier and changed by the correction unit, actuates the distribution valve, controlling the servomotor of the valve system. The position of the servomotor of the valve system determines the flow rate of water through a hydraulic turbine, the speed of which is determined by the flow rate.

Description

The claimed utility model relates to speed controllers of hydraulic turbines. The utility model can be used in any type of hydraulic turbine control system.

A known speed controller of a hydraulic turbine (patent for utility model RU 51680 U1, IPC F03B 15/04, publ. 02.27.2006), comprising a speed sensor, acceleration sensor, integrator, control mechanism, the outputs of which are connected through an adder to an amplifier, a correction unit , a spool valve connected to the servomotor, a feedback sensor for the position of the servomotor rod, the output of which is connected to the adder.

The main disadvantage of the regulator is the decrease in the operation of the hydraulic unit, the accuracy of stabilization of the position of the servomotor of the regulating body of the turbine associated with the gradual wear and increase of leaks between the working cavities of the servomotor.

The task to which the claimed technical solution is directed is to create a hydraulic turbine speed controller that has significantly greater regulatory capabilities compared to the known one, which will allow the use of spool devices and servomotors with reduced technical characteristics compared to the specified ones, and at the same time ensure the stable operation of the control hydroturbine organs throughout its entire life cycle and reduce the frequency of inclusion of oil pumps of an oil-pressure plant.

The technical result consists in increasing the accuracy and quality of regulating the frequency of rotation of a hydraulic turbine, reducing the frequency and amplitude of fluctuations of the regulating organs of a hydraulic turbine, and increasing the life of an oil pressure unit.

To increase the efficiency of testing a regulator with characteristics of distribution spools and servomotors that differ from the set ones, the authors propose a control signal from the adder 9 of the known regulator [1] shown in FIG. 1, apply to adaptation block 11, calculate the required gain in it in accordance with the proposed algorithm and transfer it to amplifier 5.

The essence of the claimed technical solution lies in the fact that in the known controller shown in FIG. 1, comprising a speed sensor, acceleration sensor, integrator, control mechanism, the outputs of which are connected through an adder to an amplifier, a correction unit, a spool valve connected to a servomotor, a feedback sensor for the position of the servomotor rod, the output of which is connected to the adder, an adaptation unit is additionally introduced whose input is connected to the output of the adder, and the output to the amplifier.

In FIG. 1 shows the regulator in accordance with the claimed technical solution, where:

1 - speed sensor of a turbine;

2 - acceleration sensor;

3 - integrator;

4 - control mechanism;

5 - amplifier;

6 - distribution valve;

7 - a servomotor of the valve system;

8 - constant statism;

9 - adder;

10 - correction block;

11 - block adaptation.

Functionally, the adaptation unit 11 should be such that, depending on the control signal at the input of the unit, in combination with the actual characteristics of the distributor valve 6 and the servomotor 7, provide a given characteristic of the flow rate of the working fluid, i.e. such a characteristic, which provides the necessary ratio between the accuracy of the speed control, the frequency and amplitude of the oscillations of the regulating organs of the turbine.

In FIG. 2 presents graphs of determining the functional dependence of the correction block, where:

ΔS is the signal of deviation (mismatch) of the current position of the GT drive from the specified one, formed by the feedback adder 9.

- величина изменения коэффициента усиления, формирующаяся блоком адаптации 11 только в установившихся режимах работы гидроагрегата и изменяющаяся с некоторой заданной скоростью от 0 до максимального значения (

).

- the magnitude of the change in gain, formed by the adaptation unit 11 only in the steady-state modes of operation of the hydraulic unit and changing at a given speed from 0 to the maximum value (

)

To _y - the gain of the amplifier 5, dynamically changing by

The action of the adaptation unit provides:

- change in the gain (K _y ) of the amplifier 5 with a given speed to a predetermined maximum value when the signal | ΔS | from the outer boundary of the range (point ⎜ΔS3⎜) to the specified range (segment ⎜ΔS3⎜ - ⎜ΔS1⎜) with a time delay t _back (segments 3-5; 12-14 of Fig. 2);

- when the signal ΔS passes through a given range (segment отрезΔS3⎜ - ⎜ΔS1⎜), an abrupt change in the gain of amplifier 5 to the initial value Ku0 (segments 5-6; 8-9; 14-15 of Fig. 2);

- when the signal ⎜ΔS⎜ returns from the inner boundary of the range (point ⎜ΔS1⎜) to the specified range (segment ⎜ΔS3⎜ - ⎜ΔS1⎜) and the hysteresis point passes through (point ⎜ΔS2⎜), the amplifier gain is changed again at a given speed to a predetermined maximum value with a time delay t _ass (segments 6-8; 9-11 of Fig. 2);

- when the signal ⎜ΔS⎜ exits from the outside of the range (point ⎜ΔS3⎜) from the specified range (segment ⎜ΔS3⎜ - ⎜ΔS1⎜), an abrupt change in the gain of amplifier 5 to the initial value Ku0 (segment 11-12 of Fig. 2 )

The need for the introduction of the adaptation unit arose from the results of the industrial operation of speed controllers at the hydraulic units of the Chiryurt HPP-2, Zaramagskaya HPP and the Nam Na 2 HPP, with rotary-vane hydraulic turbines. Due to the increase in the amount of leakage between the cavities of the hydraulic turbine impeller servomotor during operation, it was not possible to achieve the required accuracy of stabilization of the position of the impeller blades, which is a function (combinatorial dependence) on the position of the servomotor of the guide apparatus and the acting pressure. To increase the accuracy of stabilization of the position of the impeller blades in the known controller shown in FIG. 1, there is only one way - this is an increase in the constantly acting gain of the error signal set in the amplifier 5, which led to a sharp increase in the oscillation frequency of the impeller servomotor 7, an increase in oil consumption through the distributor valve 6, frequent switching on of the oil pumps and strong heating of the oil .

Attempts to achieve the desired result, without the introduction of an adaptation unit, were unsuccessful. It was not possible to select the optimal value, permanent, gain, providing the required accuracy and quality of regulation,. In addition, a significant change in the gain of amplifier 5 led to the need to reconfigure all the coefficients of the PID regulator of the turbine and conduct full-scale tests.

The use of adaptation blocks 11 with algorithms that provide a change in the steady state operating mode of the hydraulic unit of the gain of the amplifier 5 depending on the size of the error signal for a given time, made it possible to obtain the necessary accuracy and quality of regulation of these hydraulic units with the same controller and servo coefficients that were originally determined when commissioning a hydraulic unit.

Claims (1)

A hydraulic turbine speed controller comprising a speed sensor, an acceleration sensor, an integrator, a control mechanism, the outputs of which are connected through an adder to an amplifier, a correction unit, a spool valve connected to a servomotor, a feedback valve for the position of the servomotor rod, the output of which is connected to the adder, characterized the fact that an adaptation block is additionally introduced into it, the input of which is connected to the output of the adder, and the output to the amplifier.

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