Method for adjusting position of guide vane of water-turbine generator set

Abstract

The invention relates to the technical field of water and electricity, and discloses a water-turbine generator set guide vane position adjusting method which comprises the steps that in a speed regulator power mode, a speed regulator receives a power constant value and collects the current unit volute pressure, the current guide vane position is calculated according to the water turbine operation characteristic, and then coarse adjustment is conducted according to an opening degree mode; and when the given power and the power feedback reach target values of a set percentage, starting power PI adjustment, and performing fine adjustment according to a power mode. The problems of slow adjustment response, low adjustment precision and the like in the prior art are solved.

Description

Technical Field

[0001] The invention relates to the technical field of hydropower, and in particular to a method for adjusting the position of a guide vane of a hydro-turbine generator set. Background Art

[0002] As my country's power technology develops towards intelligence and informatization, smart substations have become a common configuration for power grid construction. To adapt to the development of smart hydropower plants, turbine speed governors need to meet the requirements of intelligent development in terms of regulation and control.

[0003] At present, the research on intelligent technology in the hydropower industry mainly focuses on the overall architecture, communication interface, hardware configuration, and software function development of turbine speed governors, and has not involved the regulation and control of intelligent turbine speed governors. However, there are common problems in the regulation of hydropower plant turbines, such as the primary frequency regulation integral power assessment not meeting the standards, the conflict between the primary frequency regulation of the speed governor and the automatic generation control system (AGC) of the power plant, the difficulty in adapting the regulation parameters after the volute pressure changes in the speed governor power mode, and the power regulation fluctuations. It is urgently needed that the regulation and control strategies of the intelligent hydropower plant speed regulation system hardware and communication network be upgraded, so that it can have stronger intelligent regulation control and source-network coordination capabilities to meet the increasingly stringent frequency and power control requirements of the power grid.

[0004] 1. Calculation model of guide vane position under normal power generation conditions

[0005] As for the power regulation of the unit, there are generally two ways of regulating the power of the speed governor at present: one is the opening mode, and the other is the power mode. The regulation principles are as follows: Figure 1 , Figure 2 shown.

[0006] 1.1 Monitoring system power closed-loop control

[0007] The closed-loop power regulation of the monitoring system is the active power regulation method adopted by most hydropower plants. Its regulation mode is the monitoring power closed-loop + governor opening closed-loop. The outermost active power closed-loop is on the monitoring system side. The active power regulation module of the monitoring system is output to the next-level governor system. The speed regulation system is responsible for adjusting the position of the active guide vanes to achieve the response of the upper power regulation. After the active PID of the monitoring system is calculated, the active power increase and decrease pulse signals are output to the governor system in a hard-wired manner. Under the grid-connected condition of the unit, the speed regulation system uses the increase and decrease pulse signals of the host computer as the comprehensive load given Pgv, which directly acts on the opening given link. After the closed-loop calculation of the opening, the control signal is output to the hydraulic actuator, thereby realizing the opening and closing of the active guide vanes, and finally completing the adjustment of the active power of the unit together with the monitoring system.

[0008] In practical applications, the closed-loop power monitoring (speed regulation mode) regulation model has certain deficiencies: (1) Regulation continuity problem. The monitoring system executes the AGC new value instruction and calculates and outputs the increase and decrease signals of different pulse widths to the speed regulator opening setting according to the actual power regulation deviation. The interval between adjacent pulse signals is generally close to the difference of the program scanning cycle; at the same time, the speed regulation system adopts the opening setting step limit (opening% / second) for the pulse quantity sent by the monitoring system. This determines that the closed-loop regulation of active power monitoring is not a continuous process. The adjustment of the opening and the power response are a process of step approximation from large to small. (2) The active power regulation dead zone is too large and the regulation accuracy is biased. The dead zone is involved in the calculation throughout the process. The initial purpose of this is to prevent frequent adjustments. However, after the regulation is stable, the power adjustment can only be stabilized at the edge of the dead zone, and the target power cannot be adjusted within the dead zone. The final result is that the power cannot be accurately regulated. It may also be frequently adjusted "close" to the edge of the dead zone under the influence of hydraulic factors. (3) The regulation response is too slow (delay lag) problem. Since two control systems are involved, considering the program cycle scanning period of each controller, from the output of the active calculation module of the monitoring system to the speed control reception processing and then output to the hydraulic execution system, there will inevitably be a time difference in the program scanning calculation, which is easy to cause over-adjustment and frequent adjustment. (4) The relationship between frequency regulation and power regulation. After the frequency regulation function is put into use, the speed regulation system will spontaneously adjust the frequency according to the frequency difference and output it to the opening setting; in addition, the monitoring system executes the new AGC instruction and calculates the output series of long and short pulse width signals to output to the speed regulator opening setting. The superposition result of the two requires the monitoring system to coordinate the relationship between the two, the main and auxiliary, and the locking strategy. Improper handling of the relationship between frequency regulation and power regulation can easily cause mutual interference. This is also the problem of unqualified frequency regulation and AGC assessment that many power plants often face since they participate in the auxiliary frequency regulation market.

[0009] 1.2 Speed ​​​​regulator power closed-loop regulation

[0010] The closed-loop regulation of the speed regulator power is a closed-loop regulation of the speed regulation system based on the power given value issued by the monitoring system and the power feedback collected by its own transmitter. In the power mode, the guide vane moves continuously, the regulation rate is fast, and the accuracy is high. The speed regulator itself can coordinate the relationship between the primary frequency regulation and the AGC regulation command, and the frequency difference is converted into power. The active power change is not affected by the change in the volute pressure. However, in this power mode, the main problem is that it is difficult to select the adjustment parameters: due to the large nonlinearity between the guide vane position and power, the power change caused by the same opening change at different load points of the unit is very different; secondly, it is greatly affected by the volute pressure. When the volute pressure changes, it will also cause a large difference between the opening and the power. Therefore, the power regulation parameters need to adapt to the regulation of different volute pressures and different load points. The parameters should not be too large, but to meet the requirements of the primary frequency regulation assessment, larger parameters are required, and it is difficult to adapt to various situations. Some power stations use multiple sets of parameters to adapt to power regulation under different volute pressures, but because the volute pressure of the power station cannot be changed at will, the adjustment parameters are difficult to obtain through real machine tests and can only be set through experience, and the actual application effect is not ideal.

[0011] A similar method is to use the two-dimensional linear interpolation method to interpolate and calculate the corresponding guide vane position command values ​​under different volute pressures and loads based on the corresponding relationship between volute pressure, load and opening in the turbine operating characteristic curve (see Table 1).

[0012] Table 1 Unit output (MW) at different openings under different volute pressures

[0013]

[0014] Table 1: Unit output (MW) corresponding to each opening under different volute pressures

[0015]

[0016] Table 1: Unit output (MW) corresponding to each opening under different volute pressures

[0017]

[0018] Two-dimensional interpolation calculation is evolved based on one-dimensional interpolation. Figure 3 Demonstrates the principle of two-dimensional linear interpolation, Figure 4 An example of a two-dimensional interpolation method is shown.

[0019] Function values ​​at four interpolation points (four vertices of the rectangle): f(x i ,y j )=f1,,f(x i +1,y j )=f2,f(x i +1,y j+1)=f3,f(x i ,y j +1)=f4.

[0020] For the first slice (lower triangle area)

[0021]

[0022] The interpolation function is:

[0023] f(x,y)=f1+(f2-f1)(x i )+(f3-f2)(yy j )

[0024] For the second slice (upper triangle area)

[0025]

[0026] The interpolation function is:

[0027] f(x,y)=f1+(f4-f1)(yy j )+(f3-f4)(xx i ) gives the two-dimensional interpolation calculation algorithm of the guide vane position as follows:

[0028]

[0029]

[0030]

[0031] Disadvantages of the existing technology: There are problems with the calculation of the conventional closed-loop adjustment opening: a set of PID parameters cannot be applied to the full-volute pressure and full-load working condition adjustment, and due to the lag in the input of the system feedback signal, the adjustment has a certain hysteresis, and the switching of multiple sets of parameters causes the program to be too bloated and the calculation efficiency is reduced. For example, there are certain shortcomings in using a simple linear interpolation to calculate the guide vane position given according to the relationship between volute pressure-power-opening: when the interpolation grid data is relatively sparse, it is easy to produce low calculation accuracy. If the interpolation points are too densely included, the program calculation is too complicated. Summary of the invention

[0032] In order to overcome the deficiencies of the prior art, the present invention provides a method for adjusting the guide vane position of a hydro-turbine generator set, which solves the problems of slow adjustment response and low adjustment accuracy in the prior art.

[0033] The technical solution adopted by the present invention to solve the above problems is:

[0034] A method for adjusting the guide vane position of a hydro-turbine generator set is disclosed. In a governor power mode, the governor receives a power setting and collects the current unit volute pressure, calculates the current guide vane position according to the turbine operation characteristics, and then performs coarse adjustment according to the opening mode; when the power setting and power feedback reach a target value of a set percentage, the power PI adjustment is started and fine adjustment is performed according to the power mode.

[0035] As a preferred technical solution, the current guide vane position is calculated based on the volute pressure / active power / guide vane position relationship curve converted from the turbine operation characteristic curve.

[0036] As a preferred technical solution, the power regulation data include: power setting value PG1, turbine working volute pressure Hy, turbine guide vane position Gv1.

[0037] As a preferred technical solution, the power regulation data includes: a power adjustment amount △P1 generated by a frequency modulation action.

[0038] As a preferred technical solution, the power regulation data includes: a power deviation generated by comparing the power set value PG1 with the power feedback Pf.

[0039] As a preferred technical solution, the guide vane position is reconstructed based on polynomial fitting of the least squares method.

[0040] As a preferred technical solution, the steps of reconstructing the guide vane position by polynomial fitting based on the least squares method include:

[0041] S1, obtaining and importing the real machine and real network operation characteristic data of the unit; wherein the operation characteristic data is expressed in the form of volute pressure, active power, and guide vane position array;

[0042] S2, extract the first column of data from the volute pressure, active power, and guide vane position array and assign it to the matrix X, extract the second column of data from the volute pressure, active power, and guide vane position array and assign it to the matrix Y, extract the third column of data from the volute pressure, active power, and guide vane position array and assign it to the matrix Z; wherein X represents the volute pressure matrix, Y represents the active power matrix, and Z represents the guide vane position matrix;

[0043] S3, generating three-dimensional data scatter points of volute pressure, active power, and guide vane position;

[0044] S4, solving the object Z = f(X, Y), using polynomial fitting to select the order of X and Y; wherein f(X, Y) represents a three-dimensional mapping function;

[0045] S5, setting the fitting result range of the polynomial coefficients;

[0046] S6, based on the least squares method with the goal of minimizing the fitting standard deviation, cyclically iterate the orders of X and Y, optimize the variable-order polynomial fitting formula, and obtain the final optimization formula;

[0047] S7, implanting the final optimization formula obtained in step S6 into the speed governor controller opening given calculation module;

[0048] S8, using a variable order polynomial fitting formula to calculate in real time the opening instruction under the real-time volute pressure and real-time load;

[0049] S9, when the actual opening reaches the target value of the set percentage, if there is a deviation between the target value and the actual value, the deviation value is input into the PI controller.

[0050] As a preferred technical solution, in step S4, 2≤order≤6.

[0051] As a preferred technical solution, in step S8, the opening instruction is output in a ramp manner.

[0052] As a preferred technical solution, the target percentage is set to 99.1% to 99.9% of the target opening.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] (1) The source data of the real machine and real network operation characteristics (three-dimensional data of volute pressure-load-opening) of the present invention is authentic and reliable. The optimal fitting formula obtained by processing is implanted into the speed governor controller opening instruction calculation module. The variables involved in the formula are of REAL type, and the overall calculation accuracy is very high. The feedforward output acts on the actuator, so the regulation response is faster, the regulation accuracy is higher, and the regulation stability is better;

[0055] (2) The present invention adopts a ramp output mode for the output of the opening command, which has a certain improvement effect on the load reverse adjustment phenomenon caused by the water hammer characteristics;

[0056] (3) The grid-connected opening adjustment of the present invention is preferably calculated and outputted through a fitting formula. After the adjustment is basically in place (99.5% of the target opening), the additional power closed-loop link can be timely cut in to play the backup compensation output role of the integral compensator. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is the principle block diagram of the unit active power regulation-speed regulation opening mode;

[0058] Figure 2 This is the principle block diagram of the speed regulator power closed-loop model regulation;

[0059] Figure 3 This is the schematic diagram of two-dimensional linear interpolation;

[0060] Figure 4 This is an example diagram of the two-dimensional interpolation method;

[0061] Figure 5 It is a schematic diagram of power regulation optimization in power mode;

[0062] Figure 6 A flow chart of the calculation method for reconstructing the guide vane position by polynomial fitting;

[0063] Figure 7 Generate schematic diagrams for 3D data scatter of volute pressure, active power, and guide vane position (HPY);

[0064] Figure 8 It is the optimal fitting diagram of the guide vane position based on three-dimensional data fitting;

[0065] Fig. 9 This is one of the fitting process diagrams of different orders of guide vane positions based on three-dimensional data fitting;

[0066] Fig.10 This is the second diagram of the fitting process of different orders of guide vane positions based on three-dimensional data fitting. DETAILED DESCRIPTION

[0067] The present invention will be further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0068] The glossary of technical terms related to the present invention is explained as follows:

[0069] Least Squares Method: Least Squares Method (also known as the least square method) is a mathematical optimization technique. It finds the best function matching data by minimizing the sum of squares of errors. The least squares method can be used to easily obtain unknown data and minimize the sum of squares of errors between the obtained data and the actual data. The least squares method can also be used for curve / surface fitting. Some other optimization problems can also be expressed by the least squares method by minimizing energy or maximizing entropy.

[0070] Surface Fitting Tool: It is the surface fitting toolbox that comes with the numerical calculation and analysis software MATLAB, referred to as sftool.

[0071] SSE: represents the sum of squares, the sum of squares of errors, and the sum of squares of errors between the corresponding points of the fitted data and the original data. The closer it is to 0, the better the model selection and fit, and the more successful the data prediction.

[0072] MSE: stands for mean square error, variance, the mean of the sum of squares of the errors between the corresponding points of the predicted data and the original data, that is, SSE / n.

[0073] RMSE: stands for root mean square, standard deviation, also called the fitting standard deviation of the regression system, which is the square root of MSE.

[0074] SSR: represents the sum of squares of the difference between the predicted data and the original data mean.

[0075] SST: represents the sum of squares of the difference between the original data and the mean, SST = SSE + SSR.

[0076] R-square: indicates the coefficient of determination, mainly evaluated by R-square, R-square = 1-SSE / SST, R-square takes the value [0 1]. The closer it is to 1, the better, indicating that the variables in the equation have a stronger ability to explain y, and the model fits the data better.

[0077] Example 1

[0078] like Figures 1 to 10 As shown, the purpose of the present invention is to propose an intelligent calculation method for the guide vane position of a hydro-turbine generator set under grid-connected conditions based on an improved power mode. The method is independent of the influence of closed-loop PID parameters, and the data is derived from the real machine and real grid characteristics of the actual unit. The fitting formula is calculated in one step, and the output is directly fed forward, which has better adaptability, faster regulation response, and higher regulation accuracy.

[0079] The present invention combines the advantages and disadvantages of the two conventional regulation methods and proposes an improved power regulation mode. Similarly, in the speed regulator power mode, the speed regulator receives the power setting value of the monitoring system, collects the current working volute pressure of the unit, and calculates the current guide vane position based on the volute pressure / active power / guide vane position relationship curve converted from the turbine operating characteristic curve. Rough adjustment is performed according to the opening mode. When the power setting and power feedback are close to the target value, the power PI (PI refers to a PI controller composed of a proportional (P) control link and an integral (I) control link) adjustment is started again, and fine-tuning is performed according to the power mode. This method is no longer sensitive to the regulation parameters, which greatly improves the adaptability and regulation accuracy of the power regulation to changes in the volute pressure / active power point, and further improves the performance of the primary frequency regulation. The detailed regulation method is as follows: Figure 5 As shown. Among them, power setting refers to the load setting, which is the target setting value of load / active power automatically assigned to a single unit by the automatic power generation control system of the plant or manually issued to a single unit. Power feedback refers to the actual value of the unit's power output (active power), which is obtained by measuring the stator voltage and stator current of the generator set by a power transmitter or an AC sampling module and calculating and processing. Regarding the relationship curve of volute pressure / active power / guide vane position, volute pressure is the water head, active power is the power, and guide vane position is the guide vane opening.

[0080] from Figure 5It can be seen that the power regulation of the speed governor is mainly divided into three parts. The first part is based on the power setting PG1 calculated by the monitoring system AGC and the turbine working volute pressure Hy. According to the relationship curve of volute pressure / active power / guide vane position, the turbine guide vane position Gv1 is obtained based on the least squares polynomial fitting formula. The second part is the power adjustment amount △P1 generated by a frequency regulation action. This is the power adjustment amount converted according to the adjustment coefficient when the grid frequency exceeds the artificial frequency dead zone. One part is superimposed on the monitoring power setting, and the partial opening change is obtained by looking up the table. The other part acts on the power PI regulation to produce power changes. The third part is the power deviation generated by comparing the monitoring power setting PG1 with the power feedback Pf. After the limit link and the dead zone link, it acts on the guide vane position adjustment generated by the power PI regulation. The PI regulation parameter is generally small (to ensure stability). The guide vane action amount generated by these three parts is superimposed to obtain the guide vane position setting Gv, which acts on the hydraulic actuator to adjust the unit power to the target value.

[0081] It can be seen that when the power adjustment amount is large, the guide vane position Gv1 of the first part plays a major role. Since the formula is solved very quickly, the guide vane target opening can be determined quickly. The subsequent power PI adjustment generally plays a fine-tuning role in the later stage due to the deviation limit and small PI parameters. The second part is mainly caused by the primary frequency modulation action, which is superimposed on the adjustment amount generated by the power closed-loop regulation, and the two do not affect each other. Compared with the traditional power regulation, the new power regulation has the advantages of fast adjustment speed and stable adjustment. The relationship curve of the volute pressure / active power / guide vane position does not need to be very accurate (it mainly plays a coarse adjustment role), is not sensitive to PI adjustment parameters, can automatically adapt to different volute pressures and load point changes, and can automatically coordinate the monitoring system AGC adjustment instructions and the primary frequency modulation action value.

[0082] The calculation steps of the guide vane position reconstruction based on the least squares polynomial fitting are as follows:

[0083] 1. Obtain and import the real machine and real network operating characteristic data of the unit - volute pressure, active power, guide vane position (HPY) data array.

[0084] 2. Extract the first column in the array and assign it to matrix X, that is, X = data(:, 1). Extract the first column in the array and assign it to matrix Y, that is, Y = data(:, 2). Extract the first column in the array and assign it to matrix Z, that is, Z = data(:, 3).

[0085] 3. Generate three-dimensional data scatter points of volute pressure, active power, and guide vane position (HPY).

[0086] 4. Enter the tool interface toolbox of Surface Fitting Tool, solve the object Z=f(X,Y), use polynomial fitting, and select the order of X and Y, up to 5 times.

[0087] 5. Enter Fit Option to set the fitting result range of polynomial coefficients.

[0088] 6. Based on the least squares method, with the goal of minimizing the fitting standard deviation RMSE, the X and Y orders are iterated cyclically to optimize the variable-order polynomial fitting formula.

[0089] 7. The final optimization formula determined in step 6 is implanted into the speed regulator controller opening given calculation module, and all the variables involved are set to REAL type.

[0090] 8. The fitting formula calculates the opening command under the real-time volute pressure and real-time load in real time, and the opening command is output in a ramp.

[0091] 9. After the actual opening is basically adjusted (99.5% of the target opening), if there is a deviation in the additional power loop, the integral compensator is cut in to play a backup compensation role (the deviation between the target value and the actual value is input to the PI controller for fine-tuning, and the final control is accurate to the target value.). The target guide vane position ranges from the guide vane position at zero power of the unit (such as 15%) to the guide vane position at rated power of the unit (such as 95%). Table 2 The operating characteristics of the unit in real machine and real network - volute pressure, active power, guide vane position (HPY) data array form

[0092]

[0093] The present invention innovatively utilizes the source data of the operating characteristics of the real machine and the real network (three-dimensional data of volute pressure-load-opening) for the first time, applies the binary polynomial surface fitting technology, constructs the Z=f(X,Y) function, and based on the least squares approximation, selects the X and Y orders through cyclic iteration, finally determines the optimal polynomial coefficients and obtains the optimal fitting formula, and implants the formula into the speed regulator controller opening instruction calculation module, and the variables involved in the formula are of REAL type.

[0094] The present invention adopts a ramp output mode for outputting the opening degree instruction.

[0095] The grid-connected opening adjustment of the present invention is preferably outputted by calculating the fitting formula. After the adjustment is basically in place (99.5% of the target opening), the additional power closed-loop link can be timely cut in to exert the backup compensation output of the integral compensator.

[0096] Aiming at the increasingly prominent problem of unqualified power regulation and primary frequency regulation of hydro-turbine generator sets in China, the present invention proposes a novel method for calculating the opening adjustment of a turbine governor. The method is based on the source data of the operating characteristics of the real machine and the real network (volute pressure-load-opening data), processes the optimal fitting formula and implants it into the governor controller opening instruction calculation module. The variables involved in the formula adopt the REAL type, and the formula calculation accuracy is high. The target opening is instantly locked according to the real-time volute pressure and real-time load conditions. The feedforward output form is adopted, and it directly acts on the actuator without relying on PID parameters. The adjustment response is faster, the adjustment accuracy is higher, and the adjustment stability is better.

[0097] The present invention solves a series of problems such as difficulty in selecting PID adjustment parameters of hydro-turbine generator sets, poor parameter adaptability, delayed response of load and frequency adjustment, poor adjustment stability, insufficient precision of integrated electric quantity, etc. The technology contained in the present invention has been tested through actual application, and the test results meet the requirements of the power grid for power regulation and primary frequency regulation assessment, thus truly realizing intelligent regulation of hydro-turbine generator sets under grid-connected working conditions.

[0098] As described above, the present invention can be preferably implemented.

[0099] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0100] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. According to the technical essence of the present invention, within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement made to the above embodiment still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for adjusting the position of guide vanes of a hydro-turbine generator set, characterized in that: In the governor power mode, the governor receives the power setting and collects the current unit volute pressure, calculates the current guide vane position based on the turbine operating characteristics, and then makes coarse adjustments according to the opening mode; when the power setting and power feedback reach the target value of the set percentage, the power PI adjustment is started and fine-tuned according to the power mode.

2. A method for adjusting the position of guide vanes of a hydro-turbine generator set according to claim 1, characterized in that: The current guide vane position is calculated based on the volute pressure / active power / guide vane position relationship curve converted from the turbine operating characteristic curve.

3. A method for adjusting the position of guide vanes of a hydro-generator set according to claim 2, characterized in that: The power regulation data include: power setting PG1, turbine working volute pressure Hy, and turbine guide vane position Gv1.

4. A method for adjusting the position of guide vanes of a hydro-generator set according to claim 3, characterized in that: The power regulation data includes: the power adjustment amount generated by a frequency modulation action △ P1.

5. A method for adjusting the position of guide vanes of a hydro-generator set according to claim 4, characterized in that: The power regulation data includes: the power deviation generated by comparing the power set value PG1 with the power feedback Pf.

6. A method for adjusting the position of guide vanes of a hydro-generator set according to claim 2, characterized in that: The guide vane position is reconstructed by polynomial fitting based on the least squares method.

7. A method for adjusting the position of guide vanes of a hydro-turbine generator set according to claim 6, characterized in that: The steps of reconstructing the guide vane position based on the least squares polynomial fitting include: S1, obtaining and importing the real machine and real network operation characteristic data of the unit; wherein the operation characteristic data is expressed in the form of volute pressure, active power, and guide vane position array; S2, extract the first column of data from the volute pressure, active power, and guide vane position array and assign it to the matrix X, extract the second column of data from the volute pressure, active power, and guide vane position array and assign it to the matrix Y, extract the third column of data from the volute pressure, active power, and guide vane position array and assign it to the matrix Z; wherein X represents the volute pressure matrix, Y represents the active power matrix, and Z represents the guide vane position matrix; S3, generating three-dimensional data scatter points of volute pressure, active power, and guide vane position; S4, solving the object Z = f(X, Y), using polynomial fitting to select the order of X and Y; wherein f(X, Y) represents a three-dimensional mapping function; S5, setting the fitting result range of the polynomial coefficients; S6, based on the least squares method with the goal of minimizing the fitting standard deviation, cyclically iterate the orders of X and Y, optimize the variable-order polynomial fitting formula, and obtain the final optimization formula; S7, implanting the final optimization formula obtained in step S6 into the speed governor controller opening given calculation module; S8, using a variable order polynomial fitting formula to calculate in real time the opening instruction under the real-time volute pressure and real-time load; S9, when the actual opening reaches the target value of the set percentage, if there is a deviation between the target value and the actual value, the deviation value is input into the PI controller.

8. A method for adjusting the position of guide vanes of a hydro-generator set according to claim 7, characterized in that: In step S4, 2≤order≤6.

9. A method for adjusting the position of guide vanes of a hydro-generator set according to claim 7, characterized in that: In step S8, the opening instruction is output in a ramp manner.

10. A method for adjusting the position of guide vanes of a hydro-generator set according to any one of claims 1 to 9, characterized in that: The target value of the set percentage is 99.1% to 99.9% of the target opening.

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