Primary frequency modulation method and device based on combination strategy

Abstract

The invention provides a primary frequency modulation method and device based on a combinatorial strategy, and relates to the technical field of primary frequency modulation of a wind turbine generator, and the method comprises the steps: optimizing virtual inertia control of a power tracking characteristic through additional inertia control and switching a power tracking curve, so as to obtain an inertia control strategy of the wind turbine generator; the pitch angle is controlled by introducing the frequency variation of the power system, so that a pitch angle frequency modulation control strategy is obtained; according to the inertia control strategy and the pitch angle frequency modulation control strategy, primary frequency modulation is conducted on the wind turbine generator. According to the method, the inertia control strategy and the pitch angle control strategy are combined, the dynamic characteristic of the frequency of the power system is improved through inertia control, the steady-state deviation of the frequency is reduced through the pitch angle control strategy, and therefore the dynamic and static response of the frequency of the power system can be well achieved.

Description

Technical Field

[0001] The present application relates to the technical field of primary frequency regulation of wind turbines, and in particular to a primary frequency regulation method and device based on a combination strategy. Background Art

[0002] Frequency quality is an important indicator to measure the power quality of the power system. The frequency fluctuation of the power system will bring many adverse effects to power plants and power users, so it is necessary to adjust the frequency to maintain the stability of the power grid frequency. Generally speaking, there is a close relationship between the speed of the synchronous generator and the frequency of the power system, so if all parallel generators can be guaranteed to run synchronously, the frequency of the power system is fixed. However, when the load of the power system fluctuates, the output electromagnetic power of the generator will change, causing the speed of the generator to change, resulting in frequency fluctuations in the power system. Therefore, it is difficult to maintain a constant frequency, so the common method is to control the frequency change of the power system within a certain range, and the existing primary frequency regulation strategy cannot solve the dynamic and static responses of the power system at the same time. Summary of the invention

[0003] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, the first purpose of this application is to propose a primary frequency regulation method based on a combined strategy, which solves the technical problem that the existing primary frequency regulation strategy cannot simultaneously solve the dynamic and static responses of the power system. The inertia control strategy and the pitch angle control strategy are combined to improve the dynamic characteristics of the power system frequency through inertia control, and to reduce the steady-state deviation of the frequency through the pitch angle control strategy, thereby being able to solve the dynamic and static responses of the power system frequency well.

[0005] The second objective of the present application is to propose a primary frequency modulation device based on a combination strategy.

[0006] The third objective of the present application is to provide a computer device.

[0007] A fourth object of the present application is to provide a non-transitory computer-readable storage medium.

[0008] To achieve the above-mentioned purpose, the first aspect of the embodiment of the present application proposes a primary frequency regulation method based on a combined strategy, including: optimizing the virtual inertia control of the power tracking characteristics by additional inertia control and switching the power tracking curve to obtain the inertia control strategy of the wind turbine; controlling the pitch angle by introducing the frequency change of the power system to obtain the pitch angle frequency modulation control strategy; and performing primary frequency regulation on the wind turbine according to the inertia control strategy and the pitch angle frequency modulation control strategy.

[0009] Optionally, in one embodiment of the present application, the additional inertial control simulates the inertial response of the wind turbine according to the rate of change of the power system frequency. When the power system frequency changes, the electromagnetic power of the wind turbine is quickly adjusted to compensate for the power shortage of the power system, and then the rotational kinetic energy of the wind turbine is released or absorbed by changing the speed of the wind turbine, so that the wind turbine can inertially support the power system.

[0010] Among them, the active increment of the additional inertia control output is expressed as:

[0011]

[0012] Where K represents the differential control proportional coefficient, which is used to simulate the virtual inertia of the wind turbine, f sys Indicates the power system frequency.

[0013] Optionally, in one embodiment of the present application, the switching power tracking curve is adjusted by adding a frequency deviation signal to the maximum power tracking curve, thereby adjusting the active output of the wind turbine set, sharing the sudden change of the active power of the power grid, and adjusting the change of the frequency by changing its own speed and kinetic energy, so that the wind turbine set has an inertial response capability, wherein the active power of the wind turbine set is adjusted by changing the proportional coefficient of the power tracking curve;

[0014] Among them, the preset curve of wind turbine command power changing with rotor speed, that is, the relationship between active power and speed is expressed as:

[0015]

[0016] Among them, k opt represents the coefficient of the maximum wind power tracking curve, ω0 represents the initial speed of the wind turbine, ω1 represents the rated speed of the wind turbine, ω max Indicates the maximum speed of the wind turbine, P max Indicates the maximum output active power of the wind turbine;

[0017] The proportional coefficient of the power tracking curve under inertial control is expressed as:

[0018]

[0019] Where p0 represents the initial electromagnetic power, ω r0 represents the initial speed, Δf represents the frequency deviation signal, and η represents the speed adjustment coefficient.

[0020] Optionally, in one embodiment of the present application, the pitch angle is controlled by introducing the frequency variation of the power system to obtain a pitch angle frequency modulation control strategy, including:

[0021] The pitch angle is controlled by introducing the frequency change of the power system, and the angle of the blades is adjusted according to the pitch angle so that the wind turbine can capture power. At the same time, the wind turbine is operated outside the point of the maximum power curve, so that the wind turbine has frequency regulation reserve capacity to participate in the primary frequency regulation of the power system.

[0022] Optionally, in one embodiment of the present application, the wind turbine generator set is frequency modulated once according to the inertia control strategy and the pitch angle frequency modulation control strategy, including:

[0023] The inertia control strategy and the pitch angle frequency modulation control strategy are combined to perform a frequency modulation on the wind turbine to improve the dynamic characteristics of the system frequency through inertia control, and to reduce the steady-state deviation of the frequency through the pitch angle control strategy.

[0024] To achieve the above-mentioned purpose, the second aspect of the present application proposes a primary frequency modulation device based on a combination strategy, including:

[0025] An inertia control strategy acquisition module is used to optimize the virtual inertia control of the power tracking characteristic by adding inertia control and switching the power tracking curve to obtain the inertia control strategy of the wind turbine;

[0026] A pitch angle frequency modulation control strategy acquisition module is used to control the pitch angle by introducing the frequency variation of the power system to obtain the pitch angle frequency modulation control strategy;

[0027] The primary frequency modulation module is used to perform primary frequency modulation on the wind turbine according to the inertia control strategy and the pitch angle frequency modulation control strategy.

[0028] To achieve the above-mentioned purpose, the third aspect of the present application proposes 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, the primary frequency modulation method based on the combination strategy described in the above-mentioned embodiment is implemented.

[0029] In order to achieve the above-mentioned objectives, the fourth aspect embodiment of the present application proposes a non-temporary computer-readable storage medium, which, when the instructions in the storage medium are executed by a processor, can execute a primary frequency modulation method based on a combination strategy.

[0030] The primary frequency regulation method, apparatus, computer equipment and non-temporary computer-readable storage medium based on a combined strategy in the embodiments of the present application solve the technical problem that the existing primary frequency regulation strategy cannot effectively solve the dynamic and static responses of the power system at the same time. The inertia control strategy and the pitch angle control strategy are combined to improve the dynamic characteristics of the power system frequency through inertia control and reduce the steady-state deviation of the frequency through the pitch angle control strategy, thereby effectively solving the dynamic and static responses of the power system frequency.

[0031] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0033] Figure 1 A flow chart of a primary frequency modulation method based on a combination strategy provided in the first embodiment of the present application;

[0034] Figure 2 A schematic diagram of a combined control structure of a primary frequency modulation method based on a combined strategy according to an embodiment of the present application;

[0035] Figure 3 This is a structural schematic diagram of a primary frequency modulation device based on a combination strategy provided in Example 2 of the present application. DETAILED DESCRIPTION

[0036] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0037] The following describes a primary frequency modulation method and device based on a combination strategy according to an embodiment of the present application with reference to the accompanying drawings.

[0038] Figure 1 A flowchart of a primary frequency modulation method based on a combination strategy provided in Example 1 of the present application.

[0039] like Figure 1 As shown, the primary frequency modulation method based on the combination strategy includes the following steps:

[0040] Step 101, optimizing virtual inertia control of power tracking characteristics by additional inertia control and switching power tracking curves to obtain an inertia control strategy for a wind turbine generator set;

[0041] Step 102, controlling the pitch angle by introducing the frequency variation of the power system to obtain a pitch angle frequency modulation control strategy;

[0042] Step 103: frequency-modulate the wind turbine generator system according to the inertia control strategy and the pitch angle frequency modulation control strategy.

[0043] The primary frequency modulation method based on the combined strategy of the embodiment of the present application obtains the inertia control strategy of the wind turbine by optimizing the virtual inertia control of the power tracking characteristics by adding inertia control and switching the power tracking curve; controls the pitch angle by introducing the frequency variation of the power system to obtain the pitch angle frequency modulation control strategy; and performs primary frequency modulation on the wind turbine according to the inertia control strategy and the pitch angle frequency modulation control strategy. Thus, the technical problem that the existing primary frequency modulation strategy cannot well solve the dynamic and static responses of the power system at the same time can be solved, the inertia control strategy and the pitch angle control strategy are combined, the dynamic characteristics of the power system frequency are improved by inertia control, and the steady-state deviation of the frequency is reduced by the pitch angle control strategy, so that the dynamic and static responses of the power system frequency can be well solved.

[0044] Furthermore, in the embodiment of the present application, the additional inertial control simulates the inertial response of the wind turbine according to the rate of change of the power system frequency. When the power system frequency changes, the electromagnetic power of the wind turbine is quickly adjusted to compensate for the power shortage of the power system, and then the rotational kinetic energy of the wind turbine is released or absorbed by changing the speed of the wind turbine, so that the wind turbine can inertially support the power system.

[0045] Among them, the active increment of the additional inertia control output is expressed as:

[0046]

[0047] Where K represents the differential control proportional coefficient, which is used to simulate the virtual inertia of the wind turbine, f sys Indicates the power system frequency.

[0048] Further, in the embodiment of the present application, the switching power tracking curve adjusts the active output of the wind turbine by adding a frequency deviation signal to the maximum power tracking curve, shares the sudden change of the active power of the power grid, and adjusts the change of frequency by changing its own speed and kinetic energy, so that the wind turbine has inertial response capability, wherein the active power of the wind turbine is adjusted by changing the proportional coefficient of the power tracking curve;

[0049] Among them, the preset curve of wind turbine command power changing with rotor speed, that is, the relationship between active power and speed is expressed as:

[0050]

[0051] Among them, k opt represents the coefficient of the maximum wind power tracking curve, ω0 represents the initial speed of the wind turbine, ω1 represents the rated speed of the wind turbine, ω max Indicates the maximum speed of the wind turbine, P max Indicates the maximum output active power of the wind turbine;

[0052] The proportional coefficient of the power tracking curve under inertial control is expressed as:

[0053]

[0054] Where p0 represents the initial electromagnetic power, ω r0 represents the initial speed, Δf represents the frequency deviation signal, and η represents the speed adjustment coefficient.

[0055] In the embodiment of the present application, the virtual inertial response control can enable the wind turbine to have inertial response capability. After the variable speed wind turbine is added with the additional inertial control strategy, it is equivalent to increasing the moment of inertia of the power system and reducing the rate of frequency change of the power system, thereby increasing the lowest point of frequency drop. However, the inertial control strategy can only provide dynamic support for the frequency and has no contribution to the steady-state frequency deviation.

[0056] Further, in the embodiment of the present application, the pitch angle is controlled by introducing the frequency variation of the power system to obtain a pitch angle frequency modulation control strategy, including:

[0057] The pitch angle is controlled by introducing the frequency change of the power system, and the angle of the blades is adjusted according to the pitch angle so that the wind turbine can capture power. At the same time, the wind turbine is operated outside the point of the maximum power curve, so that the wind turbine has frequency regulation reserve capacity to participate in the primary frequency regulation of the power system.

[0058] In the embodiment of the present application, in order to enable the wind turbine to have the ability to adjust the steady-state frequency deviation, a pitch angle frequency modulation control strategy is generally introduced to change the power output of the wind turbine by adjusting the pitch angle, thereby having the ability of primary frequency modulation. However, although the pitch angle control strategy reduces the steady-state frequency deviation, it does not contribute to the rotational inertia of the system.

[0059] Further, in the embodiment of the present application, according to the inertia control strategy and the pitch angle frequency modulation control strategy, the wind turbine is frequency modulated once, including:

[0060] The inertia control strategy and the pitch angle frequency modulation control strategy are combined to perform a frequency modulation on the wind turbine to improve the dynamic characteristics of the system frequency through inertia control, and to reduce the steady-state deviation of the frequency through the pitch angle control strategy.

[0061] In the embodiment of the present application, it is considered to combine the inertia control strategy and the pitch angle control strategy, improve the dynamic characteristics of the system frequency through inertia control, and reduce the steady-state deviation of the frequency through the pitch angle control strategy. The combination of the two can well solve the dynamic and static responses of the system frequency.

[0062] Figure 3This is a structural schematic diagram of a primary frequency modulation device based on a combination strategy provided in Example 2 of the present application.

[0063] like Figure 3 As shown, the primary frequency modulation device based on the combination strategy includes:

[0064] An inertia control strategy acquisition module 10 is used to optimize the virtual inertia control of the power tracking characteristic by additional inertia control and switching the power tracking curve to obtain the inertia control strategy of the wind turbine;

[0065] A pitch angle frequency modulation control strategy acquisition module 20 is used to control the pitch angle by introducing the frequency variation of the power system to obtain the pitch angle frequency modulation control strategy;

[0066] The primary frequency modulation module 30 is used to perform primary frequency modulation on the wind turbine generator set according to the inertia control strategy and the pitch angle frequency modulation control strategy.

[0067] The primary frequency regulation device based on the combined strategy of the embodiment of the present application includes an inertia control strategy acquisition module, which is used to optimize the virtual inertia control of the power tracking characteristics by adding inertia control and switching the power tracking curve to obtain the inertia control strategy of the wind turbine; a pitch angle frequency modulation control strategy acquisition module, which is used to control the pitch angle by introducing the frequency change of the power system to obtain the pitch angle frequency modulation control strategy; and a primary frequency modulation module, which is used to perform primary frequency modulation on the wind turbine according to the inertia control strategy and the pitch angle frequency modulation control strategy. Thus, the technical problem that the existing primary frequency modulation strategy cannot well solve the dynamic and static responses of the power system at the same time can be solved, the inertia control strategy and the pitch angle control strategy are combined, the dynamic characteristics of the power system frequency are improved by inertia control, and the steady-state deviation of the frequency is reduced by the pitch angle control strategy, so that the dynamic and static responses of the power system frequency can be well solved.

[0068] In order to implement the above embodiments, the present application also proposes 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, the primary frequency modulation method based on the combination strategy described in the above embodiments is implemented.

[0069] In order to implement the above embodiment, the present application also proposes a non-temporary computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the primary frequency modulation method based on the combination strategy of the above embodiment is implemented.

[0070] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0071] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0072] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0073] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0074] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0075] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0076] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0077] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A primary frequency modulation method based on a combination strategy, characterized in that: The inertia control strategy of the wind turbine is obtained by optimizing the virtual inertia control of the power tracking characteristics by adding inertia control and switching the power tracking curve. The pitch angle is controlled by introducing the frequency variation of the power system to obtain the pitch angle frequency regulation control strategy; According to the inertia control strategy and the pitch angle frequency modulation control strategy, the wind turbine generator set is frequency modulated once.

2. The method according to claim 1, characterized in that The additional inertia control simulates the inertial response of the wind turbine according to the rate of change of the power system frequency. When the power system frequency changes, the electromagnetic power of the wind turbine is quickly adjusted to compensate for the power shortage of the power system. Then, by changing the speed of the wind turbine, the rotational kinetic energy of the wind turbine is released or absorbed, so that the wind turbine can inertially support the power system. The active increment of the additional inertia control output is expressed as: Where K represents the differential control proportional coefficient, which is used to simulate the virtual inertia of the wind turbine. sys Indicates the power system frequency.

3. The method according to claim 1, characterized in that The switching power tracking curve adjusts the active output of the wind turbine set by adding a frequency deviation signal to the maximum power tracking curve, shares the sudden change of the active power of the power grid, and adjusts the change of frequency by changing its own speed and kinetic energy, so that the wind turbine set has inertial response capability, wherein the active power of the wind turbine set is adjusted by changing the proportional coefficient of the power tracking curve; Among them, the preset curve of wind turbine command power changing with rotor speed, that is, the relationship between active power and speed is expressed as: Among them, k opt represents the coefficient of the maximum wind power tracking curve, ω0 represents the initial speed of the wind turbine, ω1 represents the rated speed of the wind turbine, ω max Indicates the maximum speed of the wind turbine, P max Indicates the maximum output active power of the wind turbine; The proportional coefficient of the power tracking curve under inertial control is expressed as: Where p0 represents the initial electromagnetic power, ω r0 represents the initial speed, Δf represents the frequency deviation signal, and η represents the speed adjustment coefficient.

4. The method according to claim 1, characterized in that The method of controlling the pitch angle by introducing the frequency variation of the power system to obtain the pitch angle frequency modulation control strategy includes: The pitch angle is controlled by introducing the frequency variation of the power system, and the angle of the blades is adjusted according to the pitch angle so that the wind turbine can capture power. At the same time, the wind turbine is operated outside the point of the maximum power curve, so that the wind turbine has frequency regulation reserve capacity to participate in the primary frequency regulation of the power system.

5. The method according to claim 1, characterized in that The step of performing a frequency modulation on the wind turbine generator set according to the inertia control strategy and the pitch angle frequency modulation control strategy includes: The inertia control strategy and the pitch angle frequency modulation control strategy are combined to perform a frequency modulation on the wind turbine set to improve the dynamic characteristics of the system frequency through inertia control, and to reduce the steady-state deviation of the frequency through the pitch angle control strategy.

6. A primary frequency modulation device based on a combination strategy, characterized in that: include: An inertia control strategy acquisition module is used to optimize the virtual inertia control of the power tracking characteristic by adding inertia control and switching the power tracking curve to obtain the inertia control strategy of the wind turbine; A pitch angle frequency modulation control strategy acquisition module is used to control the pitch angle by introducing the frequency variation of the power system to obtain the pitch angle frequency modulation control strategy; The primary frequency modulation module is used to perform primary frequency modulation on the wind turbine generator set according to the inertia control strategy and the pitch angle frequency modulation control strategy.

7. A computer device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method according to any one of claims 1 to 5 is implemented.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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