RU1822908C - Method of control of hydraulic unit - Google Patents

Abstract

The invention relates to the field of electric power industry. A computing device 9 is located inside the GRAM system 10. The measuring transducer 6 is located in an aggregate controller 4. The position of the servomotor 5 is determined indirectly. The generator 1 is brought to a predetermined power using the controller 4. The guide apparatus 3 of the turbine 2 is driven by a servomotor 5. This embodiment of the method will improve the speed of control processes. 2 s.p. f-ly, 4 ill.

Description

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The invention relates to electrical engineering (electric power industry) and can be used in digital systems for group control of units of hydroelectric power plants (HES) and in digital electrohydraulic controllers (EGR) of frequency and power of hydraulic units.

The aim of the invention is to increase the speed of control processes, for which a control signal is formed so that the mismatch between the set and actual power of the unit occurs in one control cycle.

This is achieved by first determining the dependence of the position of the servomotor (F) on the effective pressure (P) and the electric power of the unit (P), and the formation of the control signal is carried out by measuring the effective pressure using a measuring transducer, determining the actual position of the servomotor and according to the dependence F (H, P) - the required, corresponding to the given generator power, comparing the latter and determining the duration and sign of the specified signal.

These differences were not revealed during the study, in addition to the prototype, other sources of information in the considered and other areas of technology.

This method takes advantage of the fact that for any hydraulic unit there is an unambiguous monotonic function

F f (H, P) (1)

where F is the opening of the turbine (the position of the main servomotor;

N - effective pressure:

P is the electric power of the generator.

In rotary vane turbines, opening should be understood as a pair of combinatorial positions of regulatory bodies.

Function (1) can be obtained from the universal model characteristics of the turbine, taking into account losses in the generator. This function can be clarified during operation of the unit.

The control computing device must store in its memory a certain array of nodal points of function (1) and, by two-dimensional interpolation, calculate the required value of F from the given P and measured N.

From the point of view of simplifying the computational process, it is advisable to use auxiliary

variable R H 2. This allows to reduce the array of points of the function and increase the accuracy of interpolation.

In Fig. 1, a function F (R, P) is constructed for a hydraulic unit of the Bureyskaya HPP. Here, the changes in the pressure loss in the plant’s water conduits from the flow rate, as well as the dependence of the generator efficiency on the load are taken into account. The dashed line marks the nominal head.

If the actual (current) position of the servomotor Рф is determined and using the function (1) the required (new) value FT is calculated, then the algebraic sign of the increment

F FT - Russian Federation (2)

determine the sign of the control action

(more or less), and the duration of its application

t G | L f | , (3)

where T is the coefficient determining the MIM displacement rate (in relative units, the time of the shift).

An example implementation of the method is shown in figure 2, where 1 is a synchronous generator (SG), 2 is a turbine (T), 3 is a guide apparatus

5 (ON), 4 - frequency and power regulator (RFM), 5 - servomotor of the directing apparatus (SM), 6 - measuring transducer of movement (IPP), 7 measuring transducer of pressure

0 (IPN), 8 - power change mechanism (MIM), 9 - computing device (VU), P - electric active power of the generator, RP - set power, N - pressure, F - signal proportional to opening

5 (position of the servomotor).

In this example, the computing device 9, which stores information about the function F (H.P) of this unit, is located directly in the controller 4

0 turbine. When a new RP reference is received at the input of computing device 9, it determines the actual position of the servo motor (signal F from the output of converter 6), and for the combination of RE and H it calculates the required new position of the servo motor. The difference between the required and actual positions of the servomotor 5 is the value of the interval and the sign of the impact on the MIM 8. The implementation of this

0 control action will provide a given power from the generator 1. Another example of the implementation of the method is shown in Fig.Z. Here 10 is indicated - a group control system for active

5 power (GRAM), 11 - measuring power converter (IPM).

In this example, computing device 9 is located within the GRAM system 10, upon receipt of a new RP task. computing device 9 first by

signals H and P determine the actual position of the servomotor, and then, using a combination of H, Pz determines the required new position of the servomotor. After that, the parameters of the control action on the MIM are found 8. The processing by the aggregate controller 4 of this action displays the generator 1 at a given power.

Since the computing device 9 is in the GRAM system 10, and the measuring transducer 6 is in the aggregate controller 4, it is more convenient to indirectly determine the actual position of the servomotor 5 rather than directly from the signal of the converter 6.

The proposed control method was tested in a computational experiment using a detailed digital model of a hydraulic unit and an electrohydraulic controller.

The results of two experiments are shown in the combined graph of figure 4. Curve 1 corresponds to the conventional method for controlling the development of a load task with the correction of opening the turbine according to the actual generator power. Curve 2 illustrates the claimed control method with predicting the new position of the servo motor. In the latter case, the process ends much earlier, which confirms the effectiveness of the method.

The computing device required to implement the claimed method,

soo can be found both in the digital station group control system (GRAM) and in the digital electro-hydraulic controller of the frequency and power of the unit.

Claims (2)

1. A method of controlling a hydraulic unit having a guiding apparatus with a servomotor and a measuring transducer, including generating and supplying a control signal to a mechanism for changing the power of the regulator, characterized in that the dependence of the position of the servomotor (F) on the effective pressure (H ) and the electric power of the unit (P), and the formation of the control signal is carried out by measuring the effective pressure using a measuring transducer, determining the actual position of the servo motor, and the dependence F (H, P) - the required, corresponding to the given generator power, comparing the latter and determining the duration and sign of the specified signal. 2. The method according to claim 1, with the fact that the actual position of the servomotor is determined by measuring the effective pressure and electric power of the generator and then finding the position of the servomotor according to the dependence F (H.P).  f $ 4 $ - $ Di ° 11 W- I