Generator fixed value setting method with unmatched working condition point and fixed value point and related product

Abstract

The invention discloses a generator constant value setting method with unmatched working condition points and constant value points and a related product, and belongs to the technical field of generator low excitation limit setting. According to the generator fixed value setting method for unmatched working condition points and fixed value points, generator leading phase test data and excitation regulator fixed value points are obtained, a low-excitation limit curve is drawn, the position and leading phase depth relation between the low-excitation limit curve and the to-be-set fixed value points is analyzed, then leading phase values corresponding to the fixed value points are obtained through accurate calculation, and the working condition points and the fixed value points are not matched. The method is not different from people, the efficiency and accuracy of phase-leading fixed value setting are improved, the technical problem that generator phase-leading test data are not matched with the fixed value of the excitation regulator is effectively solved, the efficient, universal and accurate setting process is achieved, and a reliable operation basis is provided for a power plant and a dispatching department.

Description

Technical Field

[0001] The present invention relates to the technical field of low excitation limit setting of generators, and in particular to a method for setting a set value of a generator whose operating point does not match a set value point, and related products. Background Art

[0002] With the increasing demand for reactive power regulation in power systems, the leading phase operation of generators has become a key technical means for grid voltage control. Leading phase operation requires strict compliance with the low excitation limit curve, which specifies the minimum reactive power limit allowed under different active powers and is the core parameter of the excitation regulator protection logic.

[0003] However, the following technical bottlenecks are common in actual projects: The industry standard "DL / T 1523-2023 Guidelines for Phase Advance Test of Synchronous Generators" clearly requires thermal power, hydropower and gas turbine units to carry out phase advance tests at specific operating points (such as thermal power: deep peak regulation, 50%Pn, 75%Pn, 100%Pn; hydropower: 0%Pn, 50%Pn, 75%Pn, 100%Pn). However, there are significant differences in the definitions of set points of the low-excitation limit curve by mainstream excitation regulator manufacturers (such as NARI Electric Control, Guangzhou Qingtian, ABB, Siemens and NARI Relay Protection): some regulators are based on rated active power (Pn) grading (such as 20%Pn, 40%Pn, etc.), while others are based on rated apparent power (Sn) settings (such as 0%Sn, 25%Sn, etc.), resulting in the need for cross-dimensional (Sn and Pn) conversion of test data and the need for complex conversion; at the same time, the guidelines stipulate that the number of test points is limited (3 points for thermal power and 4 points for hydropower), while regulators often require 3 to 5 set points, and it is difficult for test data to directly cover the target set range.

[0004] When the operating point during the phase leading test is not completely consistent with the set point of the excitation regulator, the existing technology relies on manual experience to estimate and give an approximate value. This method has the following problems: there is no regularity, resulting in low estimation efficiency; reliance on personal experience leads to large errors and cannot accurately reflect the actual phase leading ability of the generator, thereby affecting the safe operation of the generator and the power grid.

[0005] Therefore, how to provide an efficient and universal method to solve the problem of mismatch between generator phase leading test data and excitation regulator constants has become a technical problem that technical personnel in this field need to overcome urgently. Summary of the invention

[0006] The purpose of the present invention is to provide a generator constant value adjustment method and related products in which the operating point does not match the set value point, so as to overcome the problem of the mismatch between the generator phase leading test data and the excitation regulator set value in the prior art.

[0007] The present invention solves the above technical problems through the following technical solutions: See Figure 1 , a method for setting generator fixed values when the operating point does not match the fixed value point. When the operating point does not match the fixed value point, the fixed value point is adjusted to obtain the in-phase value, which specifically includes the following steps: Obtain the test data of the generator in-phase test operating point and the fixed value point of the excitation regulator; Draw a low excitation limit curve based on the test data of the generator in-phase test operating point; Analyze the positional relationship and in-phase depth relationship between the fixed value point to be adjusted and the generator in-phase test operating point based on the low excitation limit curve, and determine the type of the fixed value point to be adjusted; According to the type of the fixed value point to be adjusted, combined with the test data of the generator in-phase test operating point, calculate the in-phase value corresponding to the fixed value point; Based on the fixed value point of the excitation regulator and the calculated in-phase value, redraw the low excitation limit curve to reflect the in-phase ability of the generator.

[0008] A further improvement of the present invention is that the number of generator in-phase test operating points is not less than 3.

[0009] A further improvement of the present invention is that the fixed value points of the excitation regulator are 3 to 5.

[0010] A further improvement of the present invention is that let the number of generator in-phase test operating points be N, the operating point G and the operating point H be adjacent operating points in sequence, and the types of the fixed value points to be adjusted specifically include the following four types: Type 1: The fixed value point to be adjusted is between the ordinates of the operating point G and the operating point H, and the abscissas of the operating point G and the operating point H are the same; Type 2: The fixed value point to be adjusted is between the ordinates of the operating point G and the operating point H, the abscissas of the operating point G and the operating point H are different, and the operating point G and the operating point H are the (N - 1)th operating point and the Nth operating point of the generator in-phase test operating points respectively; Type 3: The fixed value point to be adjusted is between the ordinates of the operating point G and the operating point H, the abscissas of the operating point G and the operating point H are different, and the operating point G and the operating point H are not the (N - 1)th operating point and the Nth operating point of the generator in-phase test operating points; Type 4: The fixed value point to be adjusted is outside the ordinates of the operating point G and the operating point H, the abscissas of the operating point G and the operating point H are different, and the operating point G and the operating point H are the (N - 1)th operating point and the Nth operating point of the generator in-phase test operating points respectively.

[0011] A further improvement of the present invention is that when the fixed value point to be adjusted is of Type 1, the in-phase value is equal to the abscissa of the operating point G.

[0012] A further improvement of the present invention lies in that: when the setpoint to be set is of type two or type four, combining the test data of the operating condition points G and H in the generator's leading power factor test, the leading power factor value is calculated by the following method: Based on the horizontal and vertical coordinates of the operating condition points G and H, a linear function is obtained:

[0013] where k is a constant representing the slope; b is a constant representing the vertical axis intercept; Substitute the setpoint to be set into the unknown y in the linear function, and solve for x, which is the leading power factor value.

[0014] A further improvement of the present invention lies in that: when the setpoint to be set is of type three, based on the horizontal and vertical coordinates of the operating condition points G and H, a first linear function is obtained:

[0015] where is a constant representing the first slope; is a constant representing the first vertical axis intercept; The setpoint to be set includes the following three cases: Case 1: Select the setpoint to be set on the left side of the first linear function; Case 2: Select the setpoint to be set on the right side of the first linear function; Case 3: Select the setpoint to be set on the straight line of the first linear function; The leading power factor value is calculated by the following method: Let the previous adjacent operating condition point of the operating condition point G be the operating condition point F, and the next adjacent operating condition point of the operating condition point H be the operating condition point I; Case 1: Based on the horizontal and vertical coordinates of the operating condition points G and F, draw a second linear function, and based on the horizontal and vertical coordinates of the operating condition points I and H, draw a third linear function. The leading power factor value is the abscissa of the intersection point of the second linear function and the third linear function. Along the second linear function and the third linear function, draw the connection line of the operating condition points G and H, and draw a vertical line from the setpoint to be set to the Y-axis of the under-excitation limit curve. The leading power factor value is the abscissa of the intersection point of the connection line and the vertical line; Case 2: Based on the horizontal and vertical coordinates of the operating condition points G and I, draw a fourth linear function:

[0016] where is a constant representing the second slope; is a constant representing the second vertical axis intercept; Substitute the setpoint to be set into the unknown y in the fourth linear function, and solve for x, which is the leading power factor value; Case 3: The leading power factor value is calculated by using the method of Type 2.

[0017] The present invention also provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the generator setting method for the mismatch between the operating point and the set point as described above are implemented.

[0018] The present invention also provides a computer-readable storage medium, on which a computer program is stored. The computer program, when executed by a processor, implements the steps of the generator setting method for the mismatch between the operating point and the set point as described above.

[0019] The present invention also provides a computer program product, including a computer program. The computer program, when executed by a processor, implements the steps of the generator setting method for the mismatch between the operating point and the set point as described above.

[0020] Compared with the prior art, the positive and progressive effects of the present invention are as follows: The generator setting method for the mismatch between the operating point and the set point provided by the present invention obtains the leading power factor test data of the generator and the set points of the excitation regulator, draws the under-excitation limit curve and analyzes the relationship between its position and the leading power factor depth with the set points to be set, and then accurately calculates the leading power factor values corresponding to each set point. This method is not affected by individuals, improves the efficiency and accuracy of the leading power factor setting, effectively solves the technical problem of the mismatch between the leading power factor test data of the generator and the set values of the excitation regulator, realizes an efficient, general and accurate setting process, and provides a reliable operation basis for power plants and dispatching departments.

[0021] Furthermore, by carefully classifying the types of set points to be set and adopting corresponding calculation strategies for different types, the effective solution to the problem of the mismatch between the leading power factor test data of the generator and the set values of the excitation regulator is realized, ensuring the efficiency, accuracy and generality of the setting process, and providing a solid technical support for the safe and stable operation of the generator and the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings in the specification are used to provide a further understanding of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0023] Figure 1 It is a schematic flow chart of a generator setting method for the mismatch between the operating point and the set point according to the present invention; Figure 2 It is a schematic diagram of the case where the set point to be set according to the present invention is of Type 1; Figure 3Schematic diagram of the case where the setting value point to be set in the present invention is of type two; Figure 4 Schematic diagram of the case where the setting value point to be set in the present invention is of type three; Figure 5 Schematic diagram of the case where the setting value point to be set in the present invention is of type four.

[0024] Among them, point A, point B, and point C are the setting value point data to be set, and points 1-5 are the generator leading power factor test data; the vertical axis P and the horizontal axis Q of the generator P-Q curve coordinate axis respectively represent the active power and the reactive power. Detailed implementation manners

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] In the description of the present invention, it should be understood that the terms "include" and "comprise" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0027] Glossary: Leading power factor operation: The operating state where the current phase at the generator terminal leads the voltage at the generator terminal and the generator absorbs reactive power from the system.

[0028] Leading power factor capability: The maximum value of the reactive power absorbed by the generator under different active powers jointly determined by stator end heating, terminal current, terminal voltage, generator power angle, auxiliary power voltage, and step-up substation bus voltage, etc.

[0029] Leading power factor test: The test conducted to determine the leading power factor capability of the generator in the actual power grid; the purpose of conducting the leading power factor test: through the leading power factor test, to determine the under-excitation limit curve for the deep leading power factor operation of the unit, and provide a basis for safe and reliable operation for the power plant and dispatching.

[0030] Under-excitation limit link: An additional unit or function of a voltage regulator used to limit the reactive power of the generator not to be lower than the specified value under different active powers.

[0031] Under-excitation limit curve: The curve of the relationship between the minimum reactive power allowed for the generator and the active power set in the under-excitation limit link.

[0032] Generator leading power factor tests need to be carried out under the following circumstances: 1) When newly built units are put into operation for power generation; 2) When the leading power factor capacity of the generator is affected by generator capacity increase, flexibility transformation, cooling system transformation, etc.; 3) When major changes occur in the generator connection mode to the power grid, the structure of the nearby power grid, etc.; 4) After the excitation system involves upgrades and transformations of the under-excitation limitation function.

[0033] The following further elaborates on the present invention in conjunction with the accompanying drawings and specific embodiments, which is an explanation rather than a limitation of the present invention.

[0034] A method for setting generator fixed values when the operating point does not match the fixed value point. When the operating point does not match the fixed value point, the leading power factor value is obtained by setting the fixed value point, specifically including the following steps: Obtain the test data of the generator leading power factor test operating point and the fixed value point of the excitation regulator; Draw the under-excitation limitation curve based on the test data of the generator leading power factor test operating point; Analyze the positional relationship and leading power factor depth relationship between the fixed value point to be set and the generator leading power factor test operating point based on the under-excitation limitation curve, and determine the type of the fixed value point to be set; According to the type of the fixed value point to be set, combined with the test data of the generator leading power factor test operating point, calculate the leading power factor value corresponding to the fixed value point; Based on the fixed value point of the excitation regulator and the calculated leading power factor value, redraw the under-excitation limitation curve to reflect the leading power factor capacity of the generator.

[0035] The method for setting generator fixed values when the operating point does not match the fixed value point provided by the present invention, by obtaining the generator leading power factor test data and the fixed value point of the excitation regulator, drawing the under-excitation limitation curve and analyzing its positional and leading power factor depth relationships with the fixed value point to be set, and then accurately calculating the leading power factor values corresponding to each fixed value point. This method is not affected by individuals, improves the efficiency and accuracy of leading power factor fixed value setting, effectively solves the technical problem of the mismatch between generator leading power factor test data and the fixed value of the excitation regulator, realizes an efficient, general and accurate setting process, and provides a reliable operation basis for power plants and dispatching departments.

[0036] Specifically, the number of generator leading power factor test operating points is not less than 3; they can be selected according to the "DL / T 1523-2023 Guide for Synchronous Generator Leading Power Factor Tests".

[0037] Specifically, the number of fixed value points of the excitation regulator is 3 to 5.

[0038] The low excitation limit curve is a curve depicted by multiple leading power factor fixed value points. In theory, the more fixed value points there are, the more accurate the curve will be. However, if there are more fixed value points, it will result in more data during the leading power factor test, greater workload, and higher costs. Therefore, the leading power factor guidelines stipulate that for thermal power units, generally 3 operating points are selected for the leading power factor test, and for hydropower units, generally 4 operating points are selected. Currently, for mainstream regulators, there are generally 3 - 5 fixed value points. Since the operating points selected for the test do not have a one-to-one correspondence with the fixed values of the excitation regulator, this means there is a problem of mismatch between the leading power factor test data of the generator and the fixed values of the excitation regulator.

[0039] When a normal generator operates in leading power factor, as the active power increases, the reactive power will gradually decrease. Although in theory, in the minimum excitation current limiter part, it is possible for the leading power factor reactive power to be greater than when the active power is zero, during on-site tests, it is often difficult to achieve such a deep operating condition due to various factors such as the terminal voltage of the machine and the auxiliary power voltage of the plant. Even if it is actually possible to achieve such a depth, due to the excitation regulator also imposing restrictions on the fixed value points, the fixed value with a larger active power can only be less than or equal to the fixed value with a smaller active power. Therefore, the low excitation limit curve can only be a straight line perpendicular to the horizontal axis or an inclined line sloping to the right.

[0040] Therefore, when there is a mismatch between the generator test data and the fixed values of the excitation regulator, there will be four situations, and the unknown fixed value data of the excitation regulator can be deduced and calculated through the obtained test data.

[0041] Specifically, assume that there are N operating points in the generator leading power factor test, and operating points G and H are adjacent operating points in sequence. The specific types of fixed value points to be set include the following four: Type 1: The fixed value point to be set is between the ordinates of operating points G and H, and the abscissas of operating points G and H are the same; the fixed value point to be set is referred to as Figure 2 point A. Point A is between the ordinates of point 2 and point 3, and the abscissas of point 2 and point 3 are the same.

[0042] Type 2: The fixed value point to be set is between the ordinates of operating points G and H, the abscissas of operating points G and H are different, and operating points G and H are the (N - 1)th and Nth operating points of the generator leading power factor test respectively; the fixed value point to be set is referred to as Figure 3 point A. Point A is between the ordinates of point 4 and point 5, and the abscissas of point 4 and point 5 are different. At the same time, point 4 and point 5 are the last two points.

[0043] Type three: The setpoint to be calibrated is between the ordinates of operating points G and H, the abscissas of operating points G and H are different, and operating points G and H are not the (N - 1)th and Nth operating points of the generator's leading power factor test operating points; refer to the setpoint to be calibrated Figure 4 Points A, B, and C in, where point A is between the ordinates of point 3 and point 4, the abscissas of point 3 and point 4 are different, point A is on the straight line connecting point 3 and point 4, and at the same time, point 3 and point 4 are not the last two points of the generator's leading power factor test; point B is between the ordinates of point 3 and point 4, the abscissas of point 3 and point 4 are different, and point B is on the left side of the straight line connecting point 3 and point 4, and at the same time, point 3 and point 4 are not the last two points of the generator's leading power factor test; point C is between the ordinates of point 3 and point 4, the abscissas of point 3 and point 4 are different, and point C is on the right side of the straight line connecting point 3 and point 4, and at the same time, point 3 and point 4 are not the last two points of the generator's leading power factor test.

[0044] Type four: The setpoint to be calibrated is outside the ordinates of operating points G and H, the abscissas of operating points G and H are different, and operating points G and H are respectively the (N - 1)th and Nth operating points of the generator's leading power factor test operating points; refer to the setpoint to be calibrated Figure 5 Point A in, point A is outside the ordinates of point 4 and point 5, the abscissas of point 4 and point 5 are different, and point 4 and point 5 are respectively the last two points of the generator's leading power factor test.

[0045] Specifically, when the setpoint to be calibrated is of type one, the leading power factor value is equal to the abscissa of operating point G; refer to Figure 2 , the leading power factor value of point A is equal to the abscissa of point 2.

[0046] Specifically, when the setpoint to be calibrated is of type two or type four, combining the test data of operating points G and H of the generator's leading power factor test, the leading power factor value is calculated by the following method: Based on the abscissas and ordinates of operating points G and H, a linear function is obtained:

[0047] where k is a constant representing the slope; b is a constant representing the y-intercept; Substitute the setpoint to be calibrated into the unknown y in the linear function, and solve for x, which is the leading power factor value.

[0048] Specifically, when the setpoint to be calibrated is of type three, based on the abscissas and ordinates of operating points G and H, a first linear function is obtained:

[0049] where is a constant representing the first slope; is a constant representing the first vertical axis intercept; The setpoint to be tuned includes the following three cases: Case 1: The setpoint to be tuned is selected on the left side of the first linear function, which is mostly used when considering the in-phase depth on the grid side; Case 2: The setpoint to be tuned is selected on the right side of the first linear function, which is mostly used when considering the safety performance on the power plant side; Case 3: The setpoint to be tuned is selected on the straight line of the first linear function, which is mostly used for the internal description of the low excitation limit curve by the excitation regulator manufacturer.

[0050] The in-phase value is calculated by the following method: Let the previous adjacent operating point of operating point G be operating point F, and the next adjacent operating point of operating point H be operating point I; Case 1: Based on the horizontal and vertical coordinates of operating point G and operating point F, draw the second linear function. Based on the horizontal and vertical coordinates of operating point I and operating point H, draw the third linear function. The in-phase value is the abscissa of the intersection point of the second linear function and the third linear function. Along the second linear function and the third linear function, draw the connection line of operating point G and operating point H. Draw a vertical line from the setpoint to be tuned to the Y-axis of the low excitation limit curve. The in-phase value is the abscissa of the intersection point of the connection line and the vertical line; See Figure 4 For point B, although this setpoint theoretically exists, in reality, on the one hand, the tuning is relatively complex, and on the other hand, this setpoint may be much larger than the test data of point 4, that is, very close to the test data of point 3. Since this setpoint cannot be verified on-site, choosing this setpoint will increase the potential risk. Therefore, this situation can often be ignored.

[0051] Case 2: Based on the horizontal and vertical coordinates of operating point G and operating point I, draw the fourth linear function:

[0052] where is a constant representing the second slope; is a constant representing the second vertical axis intercept; Substitute the setpoint to be tuned into the unknown y in the fourth linear function, and solve for x, which is the in-phase value; See Figure 4 For point C, when the setpoint is on the right side of the straight line formed by point 3 and point 4, it belongs to Case 2. By solving the straight line equation formed by point 3 and point 5, the intersection point of the perpendicular line from point 4 to the X-axis and the straight line of the linear function from point 3 to point 5 is the boundary point. Along the straight line of the linear function from point 3 to point 5, the position of point C may be any point from point 3 to the boundary point. Combining with the setpoint to be tuned, the in-phase value of this setpoint is obtained.

[0053] Case 3: The leading phase value is calculated by using the method of Type 2.

[0054] Specifically, when the setpoint to be determined is of Type 4, based on the horizontal and vertical coordinates of operating point G and operating point H, a fifth linear function is plotted; the extension line of the fifth linear function is made, and the abscissa at the intersection of the extension line and the setpoint to be determined is the leading phase value; see Figure 5 Point A in. Point A is outside the ordinates of Point 4 and Point 5. The abscissas of Point 4 and Point 5 are different, and Point 4 and Point 5 are respectively the last two points of the generator's leading phase test. The straight line of the linear function of Point 4 and Point 5 is plotted, and the extension line is made to intersect with the setpoint to be determined, and the abscissa is the leading phase value.

[0055] The method proposed by the present invention, in order to solve the shortcomings of the current technology, can accurately deduce the leading phase test data that has not been carried out on the generator through the known leading phase test data of the generator, so as to obtain the low excitation limit setting value required by the excitation regulator, plot an accurate low excitation limit curve, and reflect the true leading phase ability of the generator, providing a safe and reliable operation basis for the power plant and the dispatching. By carefully classifying the types of setpoints to be determined and adopting corresponding calculation strategies for different types, the effective solution to the problem of mismatch between the leading phase test data of the generator and the setting value of the excitation regulator is realized, ensuring the efficiency, accuracy and generality of the setting process, and providing a solid technical support for the safe and stable operation of the generator and the power grid.

[0056] Embodiment 1 For a unit in a hydropower plant with a rated apparent power Sn of 76.5 MVA and a rated active power Pn of 65 MW, according to the provisions of the "DL / T 1523-2023 Guide for the Leading Phase Test of Synchronous Generators": The leading phase test conditions of the hydro-generator unit should preferably be 0% (or the lowest stable load), 50%, 75%, and 100% of the rated active power (or the highest stable load recognized by the power plant and the power grid dispatching agency), that is, 4 points (0%Pn, 50%Pn, 75%Pn, and 100%Pn); while the fixed setpoints of the excitation regulator of this generator are (0%Sn, 25%Sn, 50%Sn, 75%Sn, and 100%Sn). It can be seen that there is a problem of mismatch between the leading phase test operating points of this generator and the setpoints of the excitation regulator, and it must be solved through calculation.

[0057] In this embodiment, since the units of the hydropower plant meet certain conditions and can conduct tests at the 25% Sn fixed value point, therefore, under the requirements of the "DL / T 1523-2023 Guide for the Inward Power Factor Test of Synchronous Generators", 5 points were selected for the test, namely 0% Pn, 25% Sn, 50% Pn, 75% Pn, and 100% Pn, reducing the calculation workload for one fixed value point in the later stage. Since 0% Sn and 0% Pn are the same, 0% Sn and 25% Sn are known data and do not require calculation. However, the inward power factor values corresponding to the 50% Sn, 75% Sn, and 100% Sn fixed value points need to be calculated through the test data of 50% Pn, 75% Pn, and 100% Pn on site.

[0058] The (Q, P) test data for the 5 points (0% Pn, 25% Sn, 50% Pn, 75% Pn, and 100% Pn) of the on-site test are obtained as follows: (-40.996 MVar, 0 MW), (-36.648 MVar, 19.125 MW), (-36.648 MVar, 32.5 MW), (-36.648 MVar, 48.75 MW), and (-28.261 MVar, 65 MW). The under-excitation limit curve is plotted based on the test data.

[0059] Based on the under-excitation limit curve, analyze the positional relationship and the relationship of the inward power factor depth between the fixed value points to be set and the operating points of the generator's inward power factor test, and determine the types of the fixed value points to be set (50% Sn, 75% Sn, and 100% Sn): The fixed value point to be set, 50% Sn (38.25 MW), is just between 50% Pn (32.5 MW) and 75% Pn (48.75 MW). Combining with the under-excitation limit curve and according to the classification of the types of the fixed value points to be set in this application, it is determined that this fixed value point to be set conforms to Type I. Thus, the inward power factor value of 50% Sn is directly obtained as the abscissa of the test data of 50% Pn: -36.648 MVar. Then, the fixed value data of 50% Sn is (-36.648 MVar, 38.25 MW).

[0060] The fixed value point to be set, 75% Sn (57.375 MW), is just between 75% Pn (48.75 MW) and 100% Pn (65 MW). Combining with the under-excitation limit curve and according to the classification of the types of the fixed value points to be set in this application, it is determined that this fixed value point to be set conforms to Type II. According to the method of this patent, it can be solved through the linear equation formed by the two points of 75% Pn (-36.648 MVar, 48.75 MW) and 100% Pn (-28.261 MVar, 65 MW).

[0061] Based on (-36.648 MVar, 48.75 MW) and (-28.261 MVar, 65 MW), we can obtain

[0062] Substitute (-36.648, 48.75) into the point - slope formula:

[0063] We can get

[0064] After arrangement, the specific expression of the linear function is obtained:

[0065] Substitute the set - point value of 75%Sn to be determined, that is, y = 57.375MW, into the specific expression of the linear function, we can get

[0066] We obtain x = - 32.193. Therefore, the leading - phase value of the 75%Sn set - point is - 32.193, and the set - point data of 75%Sn is (-32.193 MVar, 57.375MW).

[0067] The set - point value of 100%Sn (76.5MW) to be determined is outside 75%Pn (-36.648MVar, 48.75MW) and 100%Pn (65MW). Combining with the under - excitation limit curve, according to the classification of the set - point types to be determined in this application, it is determined that the set - point to be determined conforms to type four, and the straight - line equation formed by two points can

[0068] be used for solution: Thus, the leading - phase value x of the 100%Sn set - point is directly obtained as - 22.32, and the set - point data of 100%Sn is (-22.32MVar, 76.5MW).

[0069] Through the above calculations, the data of 5 set - point values (0%Sn, 25%Sn, 50%Sn, 75%Sn, and 100%Sn) of the excitation regulator are (-40.996MVar, 0MW), (-36.648MVar, 19.125MW), (-36.648MVar, 38.25MW), (-32.193MVar, 57.375MW), and (-22.32MVar, 76.5MW). Based on the fixed set - point values of the excitation regulator and the calculated leading - phase values, the under - excitation limit curve is redrawn to reflect the leading - phase capacity of the generator.

[0070] The fixed value points calculated by this method may not necessarily be the actual leading power factor values of the generator under this operating condition, and there may also be certain deviations. The actual leading power factor values can only be known through on-site tests. However, when this condition is not available on-site, through this method, under the conditions specified in the guidelines and the regulator, it is the most accurate fixed value point that can be calculated. Through the verification of a large number of on-site test data, this is a fixed value setting method that can quickly solve the mismatch between the leading power factor test data of the generator and the fixed values of the excitation regulator.

[0071] Embodiment 2 For a unit in a hydropower plant with a rated apparent power Sn of 22.2 MVA and a rated active power Pn of 20 MW, according to the provisions of the "DL / T 1523-2023 Guidelines for the Leading Power Factor Test of Synchronous Generators": The leading power factor test operating conditions of hydro-generator units should preferably be 0% (or the lowest stable load), 50%, 75%, and 100% of the rated active power (or the highest stable load recognized by the power plant and the power grid dispatching agency), that is, 4 points (0%Pn, 50%Pn, 75%Pn, and 100%Pn); while the fixed value points of the excitation regulator of this generator are (0%Sn, 25%Sn, 50%Sn, 75%Sn, and 100%Sn). It can be seen that there is a mismatch problem between the leading power factor test operating condition points of this generator and the fixed value points of the excitation regulator, which must be solved through calculation.

[0072] Four points (0%Pn, 50%Pn, 75%Pn, and 100%Pn) were selected for this test. Since 0%Sn and 0%Pn are the same, 0%Sn was directly measured through the test. However, the fixed value data of 25%Sn, 50%Sn, 75%Sn, and 100%Sn need to be calculated based on the test data of 50%Pn, 75%Pn, and 100%Pn on-site.

[0073] The (Q, P) test data of the four points (0%Pn, 50%Pn, 75%Pn, and 100%Pn) of the on-site test were obtained as (-18.891 MVar, 0 MW), (-16.449 MVar, 10 MW), (-11.892 MVar, 15 MW), and (-7.732 MVar, 20 MW) respectively, and the under-excitation limit curve was plotted based on the test data.

[0074] Based on the under-excitation limit curve, analyze the positional relationship and leading power factor depth relationship between the fixed value points to be set and the leading power factor test operating condition points of the generator, and determine the types of the fixed value points to be set (25%Sn, 50%Sn, 75%Sn, and 100%Sn): When calculating the fixed value point of 50%Sn (11.1MW), considering that the unit is in the vibration area in the range of 50%Pn (10MW) and 75%Pn (15MW), especially with relatively large vibrations near 75%Pn (15MW), and the temperature of the stator core and stator coils of the unit is relatively high during the test. To ensure the operation of the unit is safer, according to the method of this application, the leading phase value of the fixed value point is selected in the right - hand area of the straight line of the linear function formed by the two test data of 50%Pn (10MW) and 75%Pn (15MW) (such as Figure 4 the point C), this fixed value point belongs to case two of type three, and the straight - line equation formed by the two points of 50%Pn (10MW) and 100%Pn (20MW) is selected for solution.

[0075] It can be obtained that:

[0076] Substitute (-16.449, 10) into the point - slope formula:

[0077] It can be obtained

[0078] After arrangement, the specific expression of the linear function is obtained:

[0079] Substitute the fixed value point of 50%Sn (11.1MW) to be set into the above formula, and it can be obtained

[0080] Solve for x = - 15.49. Therefore, the leading phase value of the 50%Sn fixed value point is - 15.49, and the data of the 50%Sn fixed value point is (-15.49MVar, 11.1MW); 25%Sn (5.55MW) is between (-18.891MVar, 0MW) and (-16.449MVar, 10MW). After judgment, it belongs to type three. Considering safety, it belongs to case two of type three. After calculation, the data of the 25%Sn fixed value point is (-17.53MVar, 5.55MW); 75%Sn (16.65MW) is between (-11.892MVar, 15MW) and (-7.732MVar, 20MW). After judgment, it belongs to type two. After calculation, the data of the 75%Sn fixed value point is (-10.55MVar, 16.65MW); 100% Sn (22.2 MW) is outside (-11.892 MVar, 15 MW) and (-7.732 MVar, 20 MW). After judgment, it belongs to Type IV. The setpoint data of 100% Sn is calculated to be (-5.94 Mvar, 22.2 MW).

[0081] Based on the same inventive concept, an embodiment of the present application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the generator setting method for the mismatch between the operating point and the setpoint. Among them, the memory may include internal memory, such as high-speed random access memory, and may also include non-volatile memory, such as at least one disk memory, etc.; the processor, network interface, and memory are interconnected through an internal bus, and this internal bus can be an Industry Standard Architecture bus, a Peripheral Component Interconnect Standard bus, an Extended Industry Standard Architecture bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. The memory is used to store programs. Specifically, the program may include program code, and the program code includes computer operation instructions. The memory may include internal memory and non-volatile memory, and provides instructions and data to the processor.

[0082] Based on the same inventive concept, an embodiment of the present application provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the steps of the generator setting method for the mismatch between the operating point and the setpoint. Specifically, the computer-readable storage medium includes, but is not limited to, for example, volatile memory and / or non-volatile memory. The volatile memory may include RAM (Random Access Memory) and / or cache, etc. The non-volatile memory may include ROM (Read-Only Memory), hard disk, flash memory, optical disc, magnetic disk, etc.

[0083] Based on the same inventive concept, an embodiment of the present application provides a computer program product. The computer program product includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer device, the computer device is caused to execute the steps of the above-mentioned generator setting method for the mismatch between the operating point and the setpoint.

[0084] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM (Compact Disc Read-Only Memory), optical memory, etc.) containing computer-usable program code.

[0085] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer device or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0086] These computer program instructions can also be stored in a computer-readable memory that can direct a computer device or other programmable data processing devices to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0087] These computer program instructions can also be loaded onto a computer device or other programmable data processing devices, such that a series of operation steps are executed on the computer device or other programmable devices to generate a process implemented by the computer device. Thus, the instructions executed on the computer device or other programmable devices provide steps for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0088] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they know the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0089] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method for setting a generator constant value when the operating point does not match the set value point, characterized in that: When the operating point does not match the set point, the phase leading value is obtained by adjusting the set point, which specifically includes the following steps: Obtain the test data of the generator phase leading test operating point and the fixed set point of the excitation regulator; Draw the low excitation limit curve based on the test data of the generator phase leading test operating point; Based on the low excitation limit curve, the position relationship and leading depth relationship between the set point to be adjusted and the generator leading phase test operating point are analyzed to determine the type of the set point to be adjusted; According to the type of the set point to be adjusted, combined with the test data of the generator phase leading test condition point, the phase leading value corresponding to the set point is calculated; Based on the fixed set point of the excitation regulator and the calculated phase leading value, the low excitation limit curve is redrawn to reflect the phase leading capability of the generator.

2. A method for setting a generator constant value when the operating point does not match the set value point according to claim 1, characterized in that: The generator phase-advancing test operating points shall be no less than 3.

3. A method for setting a generator constant value when the operating point does not match the set value point according to claim 1, characterized in that: The excitation regulator has 3 to 5 fixed setting points.

4. A method for setting a generator constant value when the operating point does not match the set value point according to claim 1, characterized in that: Assume that there are N operating points for the generator phase leading test, operating point G and operating point H are adjacent operating points in sequence, and the types of set value points to be adjusted specifically include the following four types: Type 1: The set value point to be set is between the ordinates of operating point G and operating point H, and the abscissas of operating point G and operating point H are the same; Type 2: The set value point to be set is between the ordinates of operating point G and operating point H, the abscissas of operating point G and operating point H are different, and operating point G and operating point H are the N-1th operating point and the Nth operating point of the generator leading phase test operating point respectively; Type 3: The set value point to be set is between the ordinates of operating point G and operating point H, the abscissas of operating point G and operating point H are different, and operating point G and operating point H are not the N-1th operating point and the Nth operating point of the generator leading phase test operating point; Type 4: The set point to be adjusted is outside the ordinates of operating point G and operating point H, the abscissas of operating point G and operating point H are different, and operating point G and operating point H are the N-1th operating point and the Nth operating point of the generator leading phase test operating point respectively.

5. A method for setting a generator constant value when the operating point does not match the set value point according to claim 4, characterized in that: When the set point to be adjusted is type 1, the leading phase value is equal to the horizontal coordinate of the operating point G.

6. A method for setting a generator constant value when the operating point does not match the set value point according to claim 4, characterized in that: When the set point to be adjusted is type 2 or type 4, the phase leading value is calculated by the following method in combination with the test data of the generator phase leading test operating point G and operating point H: Based on the horizontal and vertical coordinates of the operating points G and H, the linear function is obtained: Among them, k is a constant, representing the slope; b is a constant, representing the vertical intercept; Substitute the set point to be adjusted into the unknown variable y in the linear function, and solve for x to get the leading value.

7. A method for setting a generator constant value when the operating point does not match the set value point according to claim 6, characterized in that: When the set point to be adjusted is type three, based on the horizontal and vertical coordinates of the operating points G and H, the first linear function is obtained: in, is a constant, indicating the first slope; is a constant, indicating the first vertical intercept; The set value points to be adjusted include the following three situations: Case 1: The set point to be adjusted is selected on the left side of the first linear function; Case 2: The set point to be adjusted is selected on the right side of the first linear function; Case 3: The set point to be adjusted is selected on the straight line of the first linear function; The phase advance value is calculated using the following method: Assume that the previous adjacent operating point of operating point G is operating point F, and the next adjacent operating point of operating point H is operating point I; Case 1: Based on the horizontal and vertical coordinates of the working point G and the working point F, draw the second linear function, based on the horizontal and vertical coordinates of the working point I and the working point H, draw the third linear function, along the second linear function and the third linear function, draw the connecting line between the working point G and the working point H, draw the vertical line between the set value point to be set and the Y axis of the low excitation limit curve, and the leading phase value is the horizontal coordinate of the intersection of the connecting line and the vertical line; Case 2: Based on the horizontal and vertical coordinates of the operating points G and I, draw the fourth linear function: in, is a constant, indicating the second slope; is a constant, indicating the second vertical intercept; Substitute the set value point to be adjusted into the unknown variable y in the fourth linear function, and solve for x to get the phase advance value; Case 3: The phase advance value is calculated using the Type 2 method.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for setting the constant value of a generator when the operating point does not match the set point as described in any one of claims 1 to 7 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, the steps of the method for setting the constant value of a generator when the operating point does not match the set point as described in any one of claims 1 to 7 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by the processor, the steps of the method for setting the constant value of a generator when the operating point does not match the set point as described in any one of claims 1 to 7 are implemented.

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