A method and system for primary frequency regulation control of hydraulic turbines based on adaptive control characteristics

Abstract

This invention discloses a method and system for primary frequency regulation control of a hydroelectric turbine based on adaptive control characteristics. The method includes: determining a first flow regulation equation for the hydroelectric turbine based on its hydraulic power per unit time; transforming the flow regulation equation to obtain a second flow regulation equation when the turbine's flow rate is determined to be only related to the head, guide vane opening, and blade opening; determining an array corresponding to the hydraulic power per unit time based on the second flow regulation equation; and during the primary frequency regulation response of the hydroelectric turbine, if the ratio of the current change in guide vane opening to the actual total change in the primary frequency regulation guide vane opening is less than or equal to a preset threshold, replacing the array corresponding to the power after the primary frequency regulation action stabilizes at the current moment with the array corresponding to the hydraulic power per unit time, thus completing the primary frequency regulation of the hydroelectric turbine. This solves the problem that the primary frequency regulation capability of hydroelectric power is currently inaccurate with changes in head.

Description

Technical Field

[0001] This application relates to the field of power systems, specifically to a method and system for primary frequency regulation control of a hydro turbine based on adaptive control characteristics. Background Technology

[0002] In new power systems dominated by new energy sources, conventional power sources will gradually evolve from being the main source of electricity to an important component, and ultimately transform into system regulating power sources, ensuring the safety, controllability, flexibility, and efficiency of the new power system. The primary frequency regulation capability of conventional power sources has a crucial impact on the system's frequency stability. Large-scale hydropower units in China are mostly mixed-flow type, and their primary frequency regulation control characteristics are closely related to the water head. Currently, most turbine control systems are PID control, which results in the unit's primary frequency regulation performance meeting standards at high water heads, but failing to meet standards at low water heads. If variable parameter operation is adopted, a significant amount of work is added to the grid stability calculations. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a primary frequency control method for a hydro turbine based on adaptive control characteristics, comprising:

[0004] The first flow regulation equation of the turbine is determined based on the hydraulic power of the turbine per unit time.

[0005] When it is determined that the flow rate of the water turbine is only related to the head, guide vane opening, and blade opening, the flow rate regulation equation is transformed to obtain the second flow rate regulation equation of the water turbine.

[0006] Based on the second flow regulation equation, determine the array corresponding to the hydraulic power of the turbine per unit time;

[0007] During the primary frequency regulation response of the turbine, if the ratio of the change in the current guide vane opening to the actual total change in the primary frequency regulation guide vane opening of the turbine is less than or equal to a preset threshold, then the array corresponding to the power after the primary frequency regulation action of the turbine stabilizes at the current moment will replace the array corresponding to the hydraulic power of the turbine per unit time, thus completing the primary frequency regulation of the turbine.

[0008] Furthermore, based on the hydraulic power of the turbine per unit time, the first flow regulation equation of the turbine is determined, including:

[0009] The formula for calculating the hydraulic power N of a water turbine per unit time is as follows:

[0010] N=γQH

[0011] In the formula, N is the hydraulic power of the turbine, γ is the specific weight of water, and Q is the flow rate;

[0012] Based on the hydraulic power of the turbine per unit time, the first flow regulation equation of the turbine is determined as follows:

[0013]

[0014] In the formula, Q is the flow rate of the turbine per unit time, α0 is the outflow angle at the guide vane outlet, β2 is the runner blade outlet angle, b0 is the guide vane height, and η is the flow rate of the turbine per unit time. r For the blade efficiency, η g Where A is the hydraulic efficiency, A2 is the flow area at the outlet edge of the runner blade, g is the acceleration due to gravity, H is the working head of the turbine, ω is the angular velocity at the outlet of the guide vane, and r is the radius at the outlet of the guide vane.

[0015] Furthermore, when it is determined that the turbine's flow rate is only related to the head, guide vane opening, and blade opening, the flow rate regulation equation is transformed to obtain a second flow rate regulation equation for the turbine, including:

[0016] The first flow regulation equation of the water turbine can be expressed as a function.

[0017] Q=f(Hηα0β2)

[0018] In the formula, η is the overall efficiency of the water turbine;

[0019] Ignoring the overall efficiency of the turbine, and determining that the turbine's flow rate is only related to the head, guide vane opening, and blade opening, the first flow rate regulation equation, expressed as a function, is transformed to obtain the second flow rate regulation equation, also expressed as a function.

[0020] N = f(Hα0β2).

[0021] Furthermore, based on the second flow regulation equation, the array corresponding to the hydraulic power of the turbine per unit time is determined, including:

[0022] According to the second flow regulation equation, when the turbine is without head and at different guide vane openings, the array corresponding to N=f(Hα0β2) is N1=f(H1α 01 β 21 ),

[0023] Where N1 is the power of the turbine at a certain moment, α 01 β is the outflow angle at the guide vane outlet of the turbine at a certain moment. 21 H1 is the runner blade outlet angle of the turbine at a certain moment, and H1 is the operating head of the turbine at a certain moment.

[0024] Furthermore, during the primary frequency regulation response of the turbine, if the ratio of the change in the current guide vane opening to the actual total change in the primary frequency regulation guide vane opening is less than or equal to a preset threshold, then the array corresponding to the power after the turbine's primary frequency regulation action stabilizes at the current moment will replace the array corresponding to the turbine's hydraulic power per unit time, including:

[0025] During the primary frequency regulation response of the water turbine, if ΔGV1 / ΔGV≤85%, then N2=f(H2α) 02 β 22 ) replace N1=f(H1α) 01 β 21 ), where ΔGV1 is the current change in guide vane opening, ΔGV is the actual total change in the primary frequency regulation guide vane opening of the turbine, N2 is the power output of the turbine after the primary frequency regulation operation stabilizes at the current moment, and α 02 β is the outlet angle at the guide vane after the turbine's frequency regulation operation stabilizes at the current moment. 22 H1 represents the turbine runner blade outlet angle after the first frequency regulation operation of the turbine stabilizes at the current moment, and H2 represents the turbine's operating head at the current moment.

[0026] This application also provides a primary frequency regulation control system for a hydro turbine based on adaptive control characteristics, including:

[0027] The first flow regulation equation determination module is used to determine the first flow regulation equation of the turbine based on the hydraulic power of the turbine per unit time.

[0028] The second flow regulation equation determination module is used to transform the flow regulation equation to obtain the second flow regulation equation of the turbine when it is determined that the flow rate of the turbine is only related to the head, guide vane opening and blade opening.

[0029] The array determination module is used to determine the array corresponding to the hydraulic power of the turbine per unit time according to the second flow regulation equation;

[0030] The primary frequency regulation module is used to replace the array corresponding to the hydraulic power of the turbine per unit time with the array corresponding to the power after the primary frequency regulation action of the turbine stabilizes at the current moment during the primary frequency regulation response process. This completes the primary frequency regulation of the turbine.

[0031] This application provides a method and system for primary frequency regulation control of a water turbine based on adaptive control characteristics. It introduces a feedforward function based on adaptive control characteristics into the logic of primary frequency regulation of the water turbine. Its adaptive control characteristics are calculated by directly superimposing the three-dimensional curves of head, opening degree and power onto the actuator, which not only adapts to the influence of water turbine head on primary frequency regulation, but also increases stability. Attached Figure Description

[0032] Figure 1 This is a flowchart illustrating a primary frequency control method for a water turbine based on adaptive control characteristics, provided in an embodiment of this application.

[0033] Figure 2 This is a transfer function diagram of the primary frequency regulation control method for a water turbine involved in the embodiments of this application;

[0034] Figure 3 This is a schematic diagram of the structure of a primary frequency regulation control system for a water turbine based on adaptive control characteristics, provided in an embodiment of this application. Detailed Implementation

[0035] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0036] To address the problem of inaccurate primary frequency regulation capability of hydropower plants due to variations in water head, this application provides a primary frequency regulation control method for turbines based on adaptive control characteristics, the process of which is as follows: Figure 1 As shown, a feedforward function based on adaptive control characteristics is introduced into the logic of primary frequency regulation of a hydro turbine. Its adaptive control characteristic involves calculating the three-dimensional curves of head, turbine opening, and power and directly superimposing them onto the actuator. This adapts to the influence of the turbine head on primary frequency regulation and increases stability. The method includes the following steps:

[0037] Step S101: Determine the first flow regulation equation of the turbine based on the hydraulic power of the turbine per unit time.

[0038] The formula for calculating the hydraulic power N of a water turbine per unit time is as follows:

[0039] N=γQH

[0040] In the formula, N is the hydraulic power of the turbine, γ is the specific weight of water, and Q is the flow rate;

[0041] Based on the hydraulic power of the turbine per unit time, the first flow regulation equation of the turbine is determined as follows:

[0042]

[0043] In the formula, Q is the flow rate of the turbine per unit time, α0 is the outflow angle at the guide vane outlet, β2 is the runner blade outlet angle, b0 is the guide vane height, and η is the flow rate of the turbine per unit time. r For the blade efficiency, η g Where A is the hydraulic efficiency, A2 is the flow area at the outlet edge of the runner blade, g is the acceleration due to gravity, H is the working head of the turbine, ω is the angular velocity at the outlet of the guide vane, and r is the radius at the outlet of the guide vane.

[0044] Step S102: When it is determined that the flow rate of the turbine is only related to the head, guide vane opening and blade opening, the flow rate regulation equation is transformed to obtain the second flow rate regulation equation of the turbine.

[0045] The first flow regulation equation of the water turbine can be expressed as a function.

[0046] Q=f(Hηα0β2)

[0047] In the formula, η is the overall efficiency of the water turbine;

[0048] Ignoring the overall efficiency of the turbine, and determining that the turbine's flow rate is only related to the head, guide vane opening, and blade opening, the first flow rate regulation equation, expressed as a function, is transformed to obtain the second flow rate regulation equation, also expressed as a function.

[0049] Q=f(Hα0β2)

[0050] That is, N = f(Hα0β2).

[0051] Step S103: Determine the array corresponding to the hydraulic power of the turbine per unit time according to the second flow regulation equation.

[0052] According to the second flow regulation equation, when the turbine is without head and at different guide vane openings, there is a corresponding array N1 = f(H1α) in N = f(Hα0β2). 01 β 21 ),

[0053] Where N1 is the power of the turbine at a certain moment, α 01 β is the outflow angle at the guide vane outlet of the turbine at a certain moment. 21 H1 is the runner blade outlet angle of the turbine at a certain moment, and H1 is the operating head of the turbine at a certain moment.

[0054] Step S104: During the primary frequency regulation response of the turbine, if the ratio of the change in the current guide vane opening to the actual total change in the primary frequency regulation guide vane opening of the turbine is less than or equal to a preset threshold, then the array corresponding to the power after the primary frequency regulation action of the turbine stabilizes at the current moment replaces the array corresponding to the hydraulic power of the turbine per unit time, thus completing the primary frequency regulation of the turbine.

[0055] During the primary frequency regulation response of the water turbine, if ΔGV1 / ΔGV≤85%, then N2=f(H2α) 02 β 22 ) replace N1=f(H1α) 01 β 21 ), where ΔGV1 is the current change in guide vane opening, ΔGV is the actual total change in the primary frequency regulation guide vane opening of the turbine, N2 is the power output of the turbine after the primary frequency regulation operation stabilizes at the current moment, and α 02 β is the outlet angle at the guide vane after the turbine's frequency regulation operation stabilizes at the current moment. 22 H1 represents the turbine runner blade outlet angle after the first frequency regulation operation of the turbine stabilizes at the current moment, and H2 represents the turbine's operating head at the current moment.

[0056] The primary frequency regulation process of a water turbine is a process of transferring the correlation function, such as... Figure 2 As shown, during the function transfer process, the three-dimensional curves of head, opening degree, and power of the turbine unit are established based on the theoretical three-dimensional curves and combined with the historical database of actual unit operation. The three-dimensional curves of head, opening degree, and power are mutually verified, which can not only greatly improve the accuracy of the adaptive characteristic feedforward, but also increase the stability of unit operation.

[0057] Based on the same inventive concept, this application also provides a primary frequency control system 300 for a water turbine based on adaptive control characteristics, such as... Figure 3 As shown, it includes:

[0058] The first flow regulation equation determination module 310 is used to determine the first flow regulation equation of the turbine based on the hydraulic power of the turbine per unit time.

[0059] The second flow regulation equation determination module 320 is used to transform the flow regulation equation to obtain the second flow regulation equation of the turbine when it is determined that the flow rate of the turbine is only related to the head, guide vane opening and blade opening.

[0060] The array determination module 330 is used to determine the array corresponding to the hydraulic power of the turbine per unit time according to the second flow regulation equation;

[0061] The primary frequency regulation module 340 is used to replace the array corresponding to the hydraulic power of the turbine per unit time with the array corresponding to the power after the primary frequency regulation action of the turbine stabilizes at the current moment during the primary frequency regulation response process of the turbine. This completes the primary frequency regulation of the turbine.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A primary frequency regulation control method for a hydro turbine based on adaptive control characteristics, characterized in that, include: The first flow regulation equation of the turbine is determined based on the hydraulic power of the turbine per unit time. When it is determined that the flow rate of the water turbine is only related to the head, guide vane opening and blade opening, the first flow rate regulation equation is transformed to obtain the second flow rate regulation equation of the water turbine. Based on the second flow regulation equation, determine the array corresponding to the hydraulic power of the turbine per unit time; During the primary frequency regulation response of the turbine, if the ratio of the change in the current guide vane opening to the actual total change in the primary frequency regulation guide vane opening of the turbine is less than or equal to a preset threshold, then the array corresponding to the power after the primary frequency regulation action of the turbine stabilizes at the current moment will replace the array corresponding to the hydraulic power of the turbine per unit time, thus completing the primary frequency regulation of the turbine. Based on the hydraulic power of the turbine per unit time, the first flow regulation equation of the turbine is determined, including: The formula for calculating the hydraulic power N of a water turbine per unit time is as follows: In the formula, N is the hydraulic power of the turbine. The density of water, For traffic; Based on the hydraulic power of the turbine per unit time, the first flow regulation equation of the turbine is determined as follows: In the formula, Q is the flow rate of the water turbine per unit time. The outflow angle at the guide vane outlet. The runner blade exit angle, For guide vane height, For blade efficiency, For hydraulic efficiency, This refers to the flow area at the outlet edge of the impeller blades. It is the acceleration due to gravity. For the working head of the water turbine, The angular velocity at the outlet of the guide vane. The radius at the outlet of the guide vane; When it is determined that the turbine's flow rate is only related to the head, guide vane opening, and blade opening, the first flow rate regulation equation is transformed to obtain the turbine's second flow rate regulation equation, which includes: The first flow regulation equation of the water turbine can be expressed as a function. In the formula, The total efficiency of the water turbine; Ignoring the overall efficiency of the turbine, and determining that the turbine's flow rate is only related to the head, guide vane opening, and blade opening, the first flow rate regulation equation, expressed as a function, is transformed to obtain the second flow rate regulation equation, also expressed as a function. 。 2. The method according to claim 1, characterized in that, Based on the second flow regulation equation, the array corresponding to the hydraulic power of the turbine per unit time is determined, including: According to the second flow regulation equation, the turbine operates under no-head conditions and different guide vane openings. The corresponding array is , in, The power output of the turbine at a certain moment. The outflow angle at the guide vane outlet of the turbine at a certain moment. The turbine runner blade exit angle at a certain moment. The operating head of the water turbine at a certain moment.

3. The method according to claim 2, characterized in that, During the primary frequency regulation response of the turbine, if the ratio of the change in the current guide vane opening to the actual total change in the primary frequency regulation guide vane opening is less than or equal to a preset threshold, then the array corresponding to the power after the turbine's primary frequency regulation action stabilizes at the current moment will replace the array corresponding to the turbine's hydraulic power per unit time, including: During the primary frequency regulation response of the water turbine, if At that time, then replace Where ΔGV1 is the current change in guide vane opening, and ΔGV is the actual total change in the primary frequency-regulating guide vane opening of the turbine. The power output of the turbine after a single frequency regulation operation stabilizes at the current moment. The outflow angle at the guide vane outlet after the frequency regulation operation of the turbine stabilizes at the current moment. The turbine runner blade exit angle after the frequency regulation operation stabilizes at the current moment. This represents the current operating head of the water turbine.

4. A primary frequency control system for a hydro turbine based on adaptive control characteristics, characterized in that, include: The first flow regulation equation determination module is used to determine the first flow regulation equation of the turbine based on the hydraulic power of the turbine per unit time. The second flow regulation equation determination module is used to transform the first flow regulation equation to obtain the second flow regulation equation of the turbine when it is determined that the flow rate of the turbine is only related to the head, guide vane opening and blade opening. The array determination module is used to determine the array corresponding to the hydraulic power of the turbine per unit time according to the second flow regulation equation; The primary frequency regulation module is used to replace the array of hydraulic power per unit time of the turbine with the array of power corresponding to the power after the primary frequency regulation action of the turbine stabilizes at the current moment during the primary frequency regulation response process of the turbine. This completes the primary frequency regulation of the turbine. Based on the hydraulic power of the turbine per unit time, the first flow regulation equation of the turbine is determined, including: The formula for calculating the hydraulic power N of a water turbine per unit time is as follows: In the formula, N is the hydraulic power of the turbine. The density of water, For traffic; Based on the hydraulic power of the turbine per unit time, the first flow regulation equation of the turbine is determined as follows: In the formula, Q is the flow rate of the water turbine per unit time. The outflow angle at the guide vane outlet. The runner blade exit angle, For guide vane height, For blade efficiency, For hydraulic efficiency, This refers to the flow area at the outlet edge of the impeller blades. It is the acceleration due to gravity. For the working head of the water turbine, The angular velocity at the outlet of the guide vane. The radius at the outlet of the guide vane; When it is determined that the turbine's flow rate is only related to the head, guide vane opening, and blade opening, the first flow rate regulation equation is transformed to obtain the turbine's second flow rate regulation equation, which includes: The first flow regulation equation of the water turbine can be expressed as a function. In the formula, The total efficiency of the water turbine; Ignoring the overall efficiency of the turbine, and determining that the turbine's flow rate is only related to the head, guide vane opening, and blade opening, the first flow rate regulation equation, expressed as a function, is transformed to obtain the second flow rate regulation equation, also expressed as a function. 。

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