Disturbance level determination method and device of power distribution system and electronic equipment

Abstract

The invention discloses a disturbance level determination method and device of a power distribution system and electronic equipment. The method comprises the steps that fan rotor change information of a power distribution system is acquired, the power distribution system is a wind power distribution system, and the fan rotor change information is used for representing change information of fan rotor rotating speeds of the power distribution system under different disturbances; a rotating speed disturbance analysis relation of the power distribution system is constructed based on the fan rotor change information, and the rotating speed disturbance analysis relation is used for representing an analysis relation related to the fan rotor rotating speed and the active disturbance level; a disturbance level result of the power distribution system is determined based on the rotating speed disturbance analysis relation, and the disturbance level result is used for representing the disturbance level of the power distribution system under the condition that the wind power frequency modulation response is considered. According to the invention, the technical problem of low efficiency of determining the disturbance level of the power distribution system in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of power distribution system disturbance determination, and in particular to a method, device and electronic equipment for determining a disturbance level of a power distribution system. Background Art

[0002] So far, wind power generation has developed rapidly. However, as power electronic interface power supplies represented by wind power replace synchronous units to access the distribution system, the frequency stability of the distribution system has gradually weakened because the mainstream wind turbines in the market basically do not have the ability to support active frequency. In order to effectively solve this problem, it is necessary to transform the control structure of wind turbines so that they have active frequency support capabilities similar to synchronous units. Virtual inertia control is the most classic frequency control method for wind turbines. Its basic principle is to control the output active power of the wind turbine by accelerating or decelerating the rotor of the wind turbine, thereby providing frequency support for the distribution system. This control method has a simple control structure and does not require reserved spare capacity, so it is widely used. Considering that the output power limit of the wind turbine is mainly limited by the converter capacity and the minimum rotor speed, how wind power can reasonably and effectively provide active power to the system to improve the system frequency stability is a key issue in the field of new energy rapid frequency support.

[0003] Most of the existing research on wind power rapid frequency support focuses on the design of control strategies, starting from the core demand of maximizing the improvement of system frequency response characteristics. However, the scope of application of various control strategies is ignored. Specifically, when the wind turbine participates in the primary frequency modulation of the system by reducing the rotor speed, its output active power is mainly limited by the rotor speed. Under a certain control strategy, as the active power shortage disturbance increases, there will be an upper limit value that causes the wind turbine to just trigger the speed protection. In theory, the limit disturbance values ​​under different control strategies are different, that is, at least the above problem exists, resulting in low efficiency in determining the disturbance level of the distribution system in related technologies.

[0004] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0005] The embodiments of the present invention provide a method, a device and an electronic device for determining a disturbance level of a power distribution system, so as to at least solve the technical problem of low efficiency in determining the disturbance level of a power distribution system in the related art.

[0006] According to one aspect of an embodiment of the present invention, there is provided a method for determining a disturbance level of a power distribution system, comprising: obtaining fan rotor change information of the power distribution system, wherein the power distribution system is a wind power distribution system, and the fan rotor change information is used to characterize change information of the fan rotor speed of the power distribution system under different disturbances; constructing a speed disturbance analytical relationship of the power distribution system based on the fan rotor change information, wherein the speed disturbance analytical relationship is used to characterize an analytical relationship between the fan rotor speed and the active power disturbance level; determining a disturbance level result of the power distribution system based on the speed disturbance analytical relationship, wherein the disturbance level result is used to characterize the disturbance level of the power distribution system taking into account the wind power frequency modulation response.

[0007] Optionally, constructing a speed disturbance analytical relationship of a power distribution system based on the fan rotor change information includes: constructing a target transfer function expression of the power distribution system based on the fan rotor change information, wherein the target transfer function expression is used to represent a transfer function expression of the fan rotor speed; determining a target analytical expression of the power distribution system based on the target transfer function expression, wherein the target analytical expression is used to represent an analytical expression of the fan rotor speed; constructing a speed disturbance analytical relationship based on the target transfer function expression and the target analytical expression.

[0008] Optionally, constructing a target transfer function expression of the distribution system based on the fan rotor change information includes: constructing a swing equation expression of the distribution system based on the fan rotor change information, wherein the swing equation expression is used to characterize the dynamic frequency characteristics of the distribution system; and determining the target transfer function expression based on the swing equation expression.

[0009] Optionally, constructing a swing equation expression for a power distribution system based on the fan rotor change information includes: determining a system frequency change and a fan output active power change of the power distribution system based on the fan rotor change information; and determining to construct a swing equation expression based on the system frequency change and the fan output active power change.

[0010] Optionally, the wind turbine output active power change is composed of a target output power change of the distribution system and a primary frequency modulation active output power, wherein the target output power change is used to represent the output power change of the distribution system under a preset power point operation mode.

[0011] Optionally, determining a target analytical expression of the power distribution system based on the target transfer function expression includes: performing fractional expansion on the target transfer function expression to obtain a target analytical expression of the power distribution system.

[0012] According to another aspect of an embodiment of the present invention, there is also provided a disturbance level determination device for a distribution system, comprising: an acquisition module, used to acquire fan rotor change information of the distribution system, wherein the distribution system is a wind power distribution system, and the fan rotor change information is used to characterize the change information of the fan rotor speed of the distribution system under different disturbances; a construction module, used to construct a speed disturbance analytical relationship of the distribution system based on the fan rotor change information, wherein the speed disturbance analytical relationship is used to characterize the analytical relationship between the fan rotor speed and the active disturbance level; a determination module, used to determine the disturbance level result of the distribution system based on the speed disturbance analytical relationship, wherein the disturbance level result is used to characterize the disturbance level of the distribution system considering the wind power frequency modulation response.

[0013] According to another aspect of an embodiment of the present invention, there is further provided an electronic device, comprising: a memory storing an executable program; and a processor for running the program, wherein the method in each embodiment of the present invention is executed when the program is running.

[0014] According to another aspect of an embodiment of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium includes a stored executable program, wherein when the executable program is running, the device where the computer-readable storage medium is located is controlled to execute the methods in various embodiments of the present invention.

[0015] According to another aspect of an embodiment of the present invention, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the method in each embodiment of the present invention is implemented.

[0016] According to another aspect of an embodiment of the present invention, a computer program product is provided, including a non-volatile computer-readable storage medium, wherein the non-volatile computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method in each embodiment of the present invention is implemented.

[0017] According to another aspect of the embodiments of the present invention, a computer program is further provided. When the computer program is executed by a processor, the methods in the embodiments of the present invention are implemented.

[0018] In an embodiment of the present invention, a method for determining the disturbance level of a power distribution system is provided, comprising: obtaining fan rotor change information of the power distribution system, wherein the power distribution system is a wind power distribution system, and the fan rotor change information is used to characterize the change information of the fan rotor speed of the power distribution system under different disturbances; constructing a speed disturbance analytical relationship of the power distribution system based on the fan rotor change information, wherein the speed disturbance analytical relationship is used to characterize the analytical relationship between the fan rotor speed and the active power disturbance level; determining the disturbance level result of the power distribution system based on the speed disturbance analytical relationship, wherein the disturbance level result is used to characterize the disturbance level of the power distribution system considering the wind power frequency modulation response. It is easy to notice that, by obtaining the fan rotor change information, the present application can better understand the response of the power distribution system under different disturbances, thereby determining the disturbance level of the system, considering that the speed change of the fan rotor is related to the active power disturbance level of the system, constructing the speed disturbance analytical relationship of the power distribution system based on the fan rotor change information, can more accurately understand the relationship between the fan rotor speed and the active power disturbance, and provide more targeted suggestions and measures for system operation and optimization. By analyzing the relationship between fan speed disturbance and active power disturbance, the disturbance level of the distribution system under different working conditions can be evaluated. This can better understand the operating status of the distribution system, promptly identify problems and take measures to make adjustments. By considering the relationship between fan speed and active power disturbance, the disturbance level of the distribution system under different working conditions can be more accurately evaluated, helping operation and maintenance personnel to promptly identify problems and make adjustments. The disturbance level of the distribution system can be understood in a timely manner, which can better prevent system failures and improve the stability and reliability of the system. This solves the technical problem of low efficiency in determining the disturbance level of the distribution system in related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 is a flow chart of a method for determining a disturbance level of a power distribution system according to an embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of a disturbance level determination device for a power distribution system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] It can be explained that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] According to an embodiment of the present invention, an embodiment of a method for determining a disturbance level of a power distribution system is provided. It can be explained that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and, although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0025] Figure 1 is a flow chart of a method for determining a disturbance level of a power distribution system according to an embodiment of the present invention. Figure 1 As shown, the method comprises the following steps:

[0026] Step S102, obtaining fan rotor change information of the power distribution system.

[0027] The power distribution system is a wind power distribution system, and the wind turbine rotor change information is used to characterize the change information of the wind turbine rotor speed of the power distribution system under different disturbances.

[0028] The above-mentioned wind turbine rotor change information may refer to the change in the speed of the wind turbine rotor under different disturbance levels. The disturbance level may be factors such as system load changes, grid voltage fluctuations, and wind speed changes. The speed of the wind turbine rotor may affect the power generation performance of the wind turbine. The wind turbine rotor change information may include, but is not limited to, real-time data of the wind turbine rotor speed under different disturbance levels; the stability and response speed of the wind turbine rotor under different disturbances; the relationship between the wind turbine rotor speed and the power generation power; the degree of influence of different disturbances on the wind turbine rotor speed; the dynamic characteristics and control strategies of the wind turbine rotor. By analyzing the wind turbine rotor change information, it can help optimize the operation of the wind power generation system, improve power generation efficiency, reduce failure rate, and provide data reference for system maintenance and management.

[0029] In an optional embodiment, the wind power distribution system can be a distribution system with wind power generation as the main energy source, in which the speed of the fan rotor has a great influence on the stability and performance of the system. By obtaining the change information of the fan rotor, the response of the distribution system under different disturbances can be better understood, thereby determining the disturbance level of the system. Specifically, first, a sensor or monitoring device can be installed on the fan rotor to collect the speed data of the fan rotor in real time, which can be transmitted to the data acquisition system by wireless transmission or wired transmission. The collected fan rotor speed data can be processed, which can include operations such as data cleaning, filtering and correction to ensure the accuracy and reliability of the data. Feature information can also be extracted from the processed data, such as average speed, maximum speed, speed change frequency, etc. These features can be used to characterize the changes of the fan rotor under different disturbances. By obtaining the change information of the fan rotor of the distribution system, the disturbance level of the system can be better determined, and the reliability and performance of the system can be improved. Combined with data analysis and prediction technology, intelligent monitoring and optimized operation of the system can be realized, providing important support for the stable operation of the distribution system.

[0030] Step S104: constructing a speed disturbance analytical relationship of the power distribution system based on the wind turbine rotor change information.

[0031] Among them, the speed disturbance analytical relationship is used to characterize the analytical relationship between the wind turbine rotor speed and the active disturbance level.

[0032] In an optional embodiment, in the power distribution system, considering that the speed change of the fan rotor is related to the active disturbance level of the system, the speed disturbance analysis relationship of the power distribution system can be constructed based on the fan rotor change information. Specifically, the speed data of the fan rotor can be collected first, and compared and analyzed with the real-time operation data of the power distribution system. Through comparative analysis, the relationship between the change of the fan rotor speed and the active disturbance level of the power distribution system can be determined. Data mining and machine learning methods can be used to process and analyze a large amount of data to find out the trend. A mathematical model or algorithm can be established to describe the relationship between the fan rotor speed and the active disturbance. Time domain analysis, frequency domain analysis or wavelet analysis methods can be used to process and analyze the data to find out the correlation between the two. It is also possible to combine system identification and model prediction technologies to model and predict the relationship between speed disturbance and active disturbance. Finally, the accuracy and effectiveness of the established speed disturbance analysis relationship can be verified through actual operation verification and testing. Through actual testing, it can be verified whether this relationship can accurately reflect the impact of wind turbine rotor speed changes on the active disturbance level of the power distribution system, thereby providing a reference for system operation and optimization. This application constructs a speed disturbance analysis relationship of the power distribution system based on wind turbine rotor change information, which can more accurately understand the relationship between wind turbine rotor speed and active disturbance, and provide more targeted suggestions and measures for system operation and optimization.

[0033] Step S106, determining the disturbance level result of the power distribution system based on the rotational speed disturbance analytical relationship.

[0034] Among them, the disturbance level results are used to characterize the disturbance level of the distribution system considering the wind power frequency regulation response.

[0035] In an optional embodiment, by considering the relationship between the wind turbine rotor speed and the active power disturbance level, the speed disturbance analytical relationship can help more accurately evaluate the disturbance level of the distribution system, especially when considering the wind power frequency modulation response. A mathematical model between the speed disturbance and the active power disturbance can be established. There is a correlation between the speed of the wind turbine and the active power output, and this relationship can be characterized by measured data or a mathematical model. By analyzing the characteristic curve of the wind turbine and the dynamic response characteristics of the system, a mathematical model of the speed disturbance analytical relationship can be established. This mathematical model can be used to determine the disturbance level of the distribution system. By analyzing the relationship between the wind turbine speed disturbance and the active power disturbance, the disturbance level of the distribution system under different working conditions can be evaluated. In this way, the operating status of the distribution system can be better understood, problems can be found in time, and measures can be taken to adjust them. By considering the relationship between the wind turbine speed and the active power disturbance, the disturbance level of the distribution system under different working conditions can be more accurately evaluated, helping operation and maintenance personnel to find problems in time and make adjustments. And the disturbance level of the distribution system can be understood in time, which can better prevent system failures and improve the stability and reliability of the system. It can also help to better understand the system's operating status, improve the system's stability and reliability, and optimize the system's operating strategy.

[0036] In an embodiment of the present invention, a method for determining the disturbance level of a power distribution system is provided, comprising: obtaining fan rotor change information of the power distribution system, wherein the power distribution system is a wind power distribution system, and the fan rotor change information is used to characterize the change information of the fan rotor speed of the power distribution system under different disturbances; constructing a speed disturbance analytical relationship of the power distribution system based on the fan rotor change information, wherein the speed disturbance analytical relationship is used to characterize the analytical relationship between the fan rotor speed and the active power disturbance level; determining the disturbance level result of the power distribution system based on the speed disturbance analytical relationship, wherein the disturbance level result is used to characterize the disturbance level of the power distribution system considering the wind power frequency modulation response. It is easy to notice that, by obtaining the fan rotor change information, the present application can better understand the response of the power distribution system under different disturbances, thereby determining the disturbance level of the system, considering that the speed change of the fan rotor is related to the active power disturbance level of the system, constructing the speed disturbance analytical relationship of the power distribution system based on the fan rotor change information, can more accurately understand the relationship between the fan rotor speed and the active power disturbance, and provide more targeted suggestions and measures for system operation and optimization. By analyzing the relationship between fan speed disturbance and active power disturbance, the disturbance level of the distribution system under different working conditions can be evaluated. This can better understand the operating status of the distribution system, promptly identify problems and take measures to make adjustments. By considering the relationship between fan speed and active power disturbance, the disturbance level of the distribution system under different working conditions can be more accurately evaluated, helping operation and maintenance personnel to promptly identify problems and make adjustments. The disturbance level of the distribution system can be understood in a timely manner, which can better prevent system failures and improve the stability and reliability of the system. This solves the technical problem of low efficiency in determining the disturbance level of the distribution system in related technologies.

[0037] Optionally, constructing a speed disturbance analytical relationship of a power distribution system based on the fan rotor change information includes: constructing a target transfer function expression of the power distribution system based on the fan rotor change information, wherein the target transfer function expression is used to represent a transfer function expression of the fan rotor speed; determining a target analytical expression of the power distribution system based on the target transfer function expression, wherein the target analytical expression is used to represent an analytical expression of the fan rotor speed; constructing a speed disturbance analytical relationship based on the target transfer function expression and the target analytical expression.

[0038] In an optional embodiment, the speed disturbance analytical relationship of the power distribution system can be constructed based on the change information of the fan rotor. Specifically, first, a transfer function expression of the fan rotor speed can be established. The transfer function can describe the mathematical model of the relationship between the system input and output. In the fan system, the speed of the rotor can be affected by factors such as wind speed. By analyzing the dynamic characteristics of the fan rotor, a transfer function expression of the fan rotor speed can be established to express the law of change of the speed over time. Secondly, the target analytical expression of the power distribution system can be determined based on the target transfer function expression. In the power distribution system, the speed disturbance of the fan rotor may affect the stability and operation effect of the system. By analyzing the relationship between the fan rotor speed and the power distribution system, an analytical expression of the fan rotor speed can be established to express the influence of the speed disturbance on the power distribution system. Finally, the speed disturbance analytical relationship can be constructed according to the target transfer function expression and the target analytical expression. By integrating and analyzing the speed transfer function of the fan rotor with the analytical expression of the power distribution system, a relationship model between the speed disturbance and the power distribution system can be obtained. It can help to better understand the influence mechanism of the fan rotor speed disturbance in the power distribution system and provide guidance and basis for system operation and maintenance. By constructing a speed disturbance analytical relationship, this application can provide a more accurate analysis method for fault diagnosis and prediction of the power distribution system, which helps to detect problems in a timely manner and take effective measures to solve them, thereby improving the operating efficiency and safety of the system.

[0039] Optionally, constructing a target transfer function expression of the distribution system based on the fan rotor change information includes: constructing a swing equation expression of the distribution system based on the fan rotor change information, wherein the swing equation expression is used to characterize the dynamic frequency characteristics of the distribution system; and determining the target transfer function expression based on the swing equation expression.

[0040] In an optional embodiment, by analyzing the change information of the fan rotor, the target transfer function expression of the distribution system can be constructed, so as to better understand the dynamic characteristics and frequency response of the system. Specifically, first, the swing equation expression of the distribution system can be constructed based on the change information of the fan rotor. The swing equation can describe the motion equation of the system under the action of disturbance, and can be expressed in the form of a differential equation. By modeling the motion characteristics of the fan rotor, the swing equation expression can be obtained, which includes parameters such as inertia, damping and elasticity of the fan rotor. Then, the swing equation expression can be used to determine the target transfer function expression of the distribution system. The target transfer function is a mathematical model that describes the input-output relationship of the system, which can be used to analyze the frequency response and stability of the system. By performing frequency domain analysis on the swing equation, the transfer function expression of the system can be obtained, thereby determining the frequency characteristics of the system. The target transfer function expression constructed by the present application based on the change information of the fan rotor can provide a data reference basis for the control and optimization of the system. By analyzing the transfer function, the response of the system at different frequencies can be predicted, and then the corresponding control strategy can be designed to improve the stability and performance of the system. This can effectively help analyze and optimize the dynamic characteristics of the system, improve the reliability and stability of the system, and better meet the requirements of the distribution system for the disturbance level.

[0041] Optionally, constructing a swing equation expression for a power distribution system based on the fan rotor change information includes: determining a system frequency change and a fan output active power change of the power distribution system based on the fan rotor change information; and determining to construct a swing equation expression based on the system frequency change and the fan output active power change.

[0042] In an optional embodiment, by constructing a swing equation expression of a power distribution system based on the change information of the fan rotor, the dynamic response of the system can be predicted more accurately, thereby improving the stability and reliability of the system. Specifically, first, according to the change information of the fan rotor, the system frequency change of the power distribution system and the change of the fan output active power can be determined. The system frequency can reflect the stability of the system operation. The change in the output power of the fan will cause the fluctuation of the system frequency, thereby affecting the operation of the system. By monitoring the change information of the fan rotor, the change of the system frequency and the fan output power can be obtained in time. Secondly, based on the change of the system frequency and the change of the fan output active power, it can be determined to construct a swing equation expression. The swing equation can describe the mathematical model of the dynamic response of the system, which can help analyze the response of the system when it is disturbed. By establishing a swing equation expression, the oscillation of the system can be predicted, so as to formulate a corresponding control strategy to ensure the stability of the system. In the actual implementation process, the change information of the fan rotor can be collected first, including parameters such as speed and power output. Then, the system frequency change and the fan output active power change are calculated using this information. Finally, the swing equation expression is constructed according to these changes to analyze the dynamic response of the system and provide stronger support for the safe operation of the distribution system.

[0043] Optionally, the wind turbine output active power change is composed of a target output power change of the distribution system and a primary frequency modulation active output power, wherein the target output power change is used to represent the output power change of the distribution system under a preset power point operation mode.

[0044] In an optional embodiment, the change in the active power output of the fan can affect the stability and performance of the system. The present application considers two factors: the target output power change of the power distribution system and the primary frequency modulation active output power. The target output power change may refer to the output power change of the power distribution system under the preset power point operation mode, which can be achieved through the system's control strategy and regulator. According to the operating state of the system and the influence of the external environment, the system can dynamically adjust the target output power to maintain the stability and performance of the system. The primary frequency modulation active output power may refer to the active power actually output by the fan during operation. This parameter is affected by factors such as the speed, load condition, and wind speed of the fan. By monitoring the operating state and output power of the fan, the change in the active power output of the fan can be obtained in real time. By comprehensively considering the two factors of the target output power change and the primary frequency modulation active output power, the change in the active power output of the fan can be accurately determined. By dynamically adjusting the target output power and monitoring the actual output power of the fan, the present application can promptly discover the unstable factors of the system and take corresponding measures to maintain the stability of the system. By combining the target output power change and the primary frequency modulation active output power, the intelligent control of the system can be realized, and the system's adaptability and response speed can be improved.

[0045] Optionally, determining a target analytical expression of the power distribution system based on the target transfer function expression includes: performing fractional expansion on the target transfer function expression to obtain a target analytical expression of the power distribution system.

[0046] In an optional embodiment, the target analytical expression of the system can be determined by the target transfer function expression. Specifically, the target transfer function expression can be expanded into a fraction, so that the transfer function can be expressed in a more concise and easy-to-analyze form. Through fraction expansion, the target analytical expression of the distribution system can be obtained, that is, a mathematical expression representing the target performance of the system. When implementing this step, a suitable fraction expansion method can be selected, such as using Taylor series expansion or Laplace transform technology. Through fraction expansion, the frequency domain characteristics of the system can be obtained, and then the frequency response, stability and other indicators of the system can be analyzed. By expanding the transfer function expression into a fraction, a more concise and easy-to-understand system expression can be obtained, which is helpful for analyzing system performance. Fraction expansion can convert complex transfer function expressions into simple forms, improve calculation efficiency, and speed up the analysis of system performance.

[0047] The technical solution proposed in this application is described below in combination with an optional embodiment. This application aims to provide a method for evaluating the extreme disturbance level of a distribution system taking into account the optimal frequency regulation response of wind power, which can accurately estimate the extreme disturbance level of the system in advance and provide a clear frequency regulation capacity boundary for scheduling. At the same time, for extreme scenarios outside the extreme disturbance level, it provides a basis and guidance for the necessity of scheduling other emergency frequency control resources.

[0048] Definition: The indicator of the limit disturbance level represents the limit disturbance value. Its physical meaning is that for the shortage disturbance within the limit disturbance level, the wind turbine is not affected by the speed protection and can adjust the output signal according to the specified control strategy; for the shortage disturbance exceeding the limit disturbance level, the wind turbine frequency regulation capability is insufficient to meet the frequency regulation requirements of the existing scenario, which will trigger the speed protection and cause the system to have a secondary frequency drop. By evaluating the limit disturbance level under the specified fast frequency control strategy, it provides a basis and guidance for whether other emergency frequency control resources need to be dispatched in time in extreme scenarios.

[0049] In order to achieve the above-mentioned objectives, the present application adopts the following technical solutions: based on the general morphological characteristics of the optimal system frequency and optimal trajectory, the transfer function expression of the next frequency modulation coefficient of the wind turbine optimal frequency modulation response is determined; based on the partial fraction method, the analytical expression related to the wind turbine rotor speed and the system disturbance level considering the optimal frequency modulation response of wind power is determined; according to the specific wind speed scenario, an estimation-correction method based on the dichotomy method is proposed to obtain the ultimate disturbance level value of the distribution system considering the optimal frequency modulation response of wind power.

[0050] This application aims to quantitatively evaluate the wind power fast frequency support capability based on the full utilization of wind power frequency regulation potential. In order to accurately estimate the extreme disturbance level, the wind turbine rotor speed transfer function expression and analytical expression can be first determined to describe the rotor speed change trajectory under different disturbances, that is, to determine the target transfer function expression and target analytical expression.

[0051] The specific determination steps are as follows: The swing equation expression describing the dynamic frequency characteristics of the distribution system is:

[0052] ;

[0053] In the formula, is the system frequency change; is the inertia time constant of the power distribution system; is the wind power penetration rate based on the total system capacity; The change in active power output of the fan; is the output active power change of the gas unit; is the active disturbance level; is the Laplace operator. Output power change under maximum power point operation mode and primary frequency modulation active output power The wind turbine output active power variation is composed of two parts, that is, the target output power variation of the power distribution system and the primary frequency modulation active output power, namely:

[0054] ;

[0055] Based on small signal analysis, The specific expression is:

[0056] ;

[0057] In the formula, is the air density; is the radius of the wind wheel; is the maximum wind energy utilization coefficient; is the optimal tip speed ratio; The rotor speed of the fan at the steady-state operation point before the disturbance; is the change in fan rotor speed.

[0058] Mechanical power variation captured by wind turbines The expression is approximately expressed as:

[0059] ;

[0060] In the formula, and are the coefficients of the fitted curve describing the trajectory of the mechanical power captured by the wind turbine.

[0061] At this point, the fan rotor motion equation can be obtained as:

[0062] ;

[0063] In the formula, is the fan inertia time constant; is the speed change of the fan at the steady-state operating point before the disturbance; and B is and Linearized constant coefficient expression.

[0064] The variable on the right side of the equal sign in the above formula This brings inconvenience to the determination of the analytical expression of the fan rotor speed later. For the convenience of determination, it is approximated as On this basis, the expression for the change in the fan rotor speed can be determined:

[0065] ;

[0066] In the above formula, since the fan is in the maximum power point operation mode before the disturbance, is 0.

[0067] Considering the primary frequency regulation characteristics of the fan The expression is:

[0068] ;

[0069] in, is the primary frequency modulation coefficient of the fan.

[0070] At this point, the fan rotor speed change transfer function is:

[0071] ;

[0072] It can be seen from the above formula that the rotor speed change trajectory of the fan is related to the fan primary frequency modulation coefficient and the system frequency change, and the system frequency change is directly related to the disturbance level. Therefore, the rotor speed change trajectory of the fan is closely related to the system disturbance level.

[0073] The general morphological characteristics of the optimal trajectory of system frequency considering wind power frequency regulation are that the frequency drops to the lowest point at the initial frequency change rate, and then remains unchanged until the wind turbine exits frequency regulation, and the system frequency transitions from the lowest point to the steady-state value.

[0074] Based on the general morphological characteristics of the optimal trajectory of the optimal system frequency, it can be determined that the system frequency of the fan in the frequency modulation stage is a fixed value, which is recorded as When the gas turbine assembly frequency response model adopts the single-machine equivalent reheat model, the transfer function expression of the next frequency regulation coefficient of the fan optimal frequency regulation response is:

[0075] ;

[0076] ;

[0077] In the above formula, is the boiler time constant; is the work ratio of the boiler high pressure cylinder; is the adjustment coefficient.

[0078] In the optimal system frequency trajectory, the active disturbance level is proportional to the lowest point under the corresponding optimal frequency trajectory, and the ratio is recorded as Then, the wind turbine rotor speed change transfer function expression considering the optimal frequency modulation response of wind power can be obtained, that is, the target transfer function expression, which can be expressed as:

[0079] ;

[0080] In the formula, ; is the boiler time constant; is the work ratio of the high-pressure cylinder of the boiler; is the adjustment coefficient; It is the proportional coefficient between the active disturbance level and the lowest point under its corresponding optimal frequency trajectory.

[0081] The above formula can be expanded into partial fractions to solve its analytical expression , which is the target parsing expression:

[0082] ;

[0083] In the formula, , , , and The expression is as follows:

[0084] ;

[0085] At this point, the fan rotor speed expression is:

[0086] ;

[0087] To estimate the limit disturbance level, the above formula can be converted into an expression related to active disturbance by using Equivalent replacement You can get it.

[0088] The analytical expression related to the fan rotor speed and the active disturbance level, that is, the speed disturbance analytical relationship is:

[0089] ;

[0090] It can be seen from the above formula that the above formula describes the change in velocity within a certain period of time after the disturbance.

[0091] It should be noted that the rotor speed analytical expression determined in this application can only describe the speed change within a certain period of time after the disturbance. , the limit disturbance level value cannot be directly obtained through the above formula This application uses a dichotomy-based estimation-correction method to find , the specific steps are as follows.

[0092] In a certain low wind speed scenario, the estimated limit disturbance level range is 0~0.2pu. Based on the dichotomy method, let n=0 and set ; Get the parameters related to the above formula to determine , , , , , and Specific value, let for (generally Take 0.70pu), select the rotor speed trajectory estimation time as 30s, and calculate the nth rotor speed trajectory according to the above formula: .

[0093] Then determine whether it satisfies ( is a minimum positive value), if it is satisfied, the estimation process ends, and the limit disturbance level is , otherwise you can Correction. Based on the binary search for the nth According to the above formula, let the n+1th limit disturbance level be , find the rotor speed trajectory corresponding to the limit disturbance level at the n+1th time ; Determine whether , if satisfied, the estimation process ends and the limit disturbance level is Otherwise, let n=n+1 and return to step 1 to perform the n-th .

[0094] Through the above method, after several corrections, the extreme disturbance level value of the distribution system considering the optimal frequency regulation response of wind power in a certain scenario can be quickly determined. The extreme disturbance level considering the optimal frequency regulation response of wind power in a specified scenario can be evaluated in advance more accurately and quickly. This application focuses on the field of quantitative evaluation of wind power rapid frequency support capabilities. By quantifying the indicator of extreme disturbance level, the applicable scope of disturbances of related control strategies based on the optimal frequency regulation response of wind power is given. The method for evaluating the extreme disturbance level of a distribution system considering the optimal frequency regulation response of wind power provided in this application can quickly and accurately estimate the smaller disturbance level in a certain scenario under the premise that wind power fully utilizes its frequency regulation capability, and provide a certain basis and guidance for the applicable scope of the control strategy and whether other emergency resources can be called in extreme scenarios.

[0095] According to another aspect of an embodiment of the present application, a device for determining a disturbance level of a power distribution system is also provided. The device can execute the method for determining a disturbance level of a power distribution system of the above embodiment. The specific implementation method and preferred application scenario are the same as those of the above embodiment and will not be repeated here.

[0096] Figure 2 is a schematic diagram of a disturbance level determination device for a power distribution system according to an embodiment of the present application, such as Figure 2 As shown, the device includes the following: an acquisition module 202 , a monitoring module 204 and a determination module 206 .

[0097] Among them, the acquisition module is used to obtain the fan rotor change information of the distribution system, wherein the distribution system is a wind power distribution system, and the fan rotor change information is used to characterize the change information of the fan rotor speed of the distribution system under different disturbances; the construction module is used to construct the speed disturbance analytical relationship of the distribution system based on the fan rotor change information, wherein the speed disturbance analytical relationship is used to characterize the analytical relationship between the fan rotor speed and the active disturbance level; the determination module is used to determine the disturbance level result of the distribution system based on the speed disturbance analytical relationship, wherein the disturbance level result is used to characterize the disturbance level of the distribution system considering the wind power frequency modulation response.

[0098] Among them, the construction module is also used to construct a target transfer function expression of the distribution system based on the fan rotor change information, wherein the target transfer function expression is used to represent the transfer function expression of the fan rotor speed; determine the target analytical expression of the distribution system based on the target transfer function expression, wherein the target analytical expression is used to represent the analytical expression of the fan rotor speed; based on the target transfer function expression and the target analytical expression, construct a speed disturbance analytical relationship.

[0099] Among them, the construction module is also used to construct a swing equation expression of the distribution system based on the fan rotor change information, wherein the swing equation expression is used to characterize the dynamic frequency characteristics of the distribution system; and determine the target transfer function expression based on the swing equation expression.

[0100] Among them, the construction module is also used to determine the system frequency change of the distribution system and the change of the fan output active power based on the fan rotor change information; based on the system frequency change and the fan output active power change, determine the construction swing equation expression.

[0101] Among them, the wind turbine output active power change is composed of the target output power change of the distribution system and the primary frequency modulation active output power, among which the target output power change is used to represent the output power change of the distribution system under the preset power point operation mode.

[0102] Among them, the construction module is also used to perform fractional expansion on the target transfer function expression to obtain the target analytical expression of the distribution system.

[0103] An embodiment of the present application further provides an electronic device, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of the present invention when running.

[0104] The above-mentioned memory may refer to a device inside a computer for storing data and programs, and may include memory, hard disk, etc., wherein the memory may be used to temporarily store running programs and data, the hard disk may be used to store programs and data for a long time, and the memory may be used to enable the computer to read and write data, and execute programs; the above-mentioned processor may be responsible for executing instructions in computer programs and performing data processing, and may be responsible for controlling and executing various operations, including arithmetic operations, logical operations, data transmission, etc.

[0105] An embodiment of the present application further provides a computer-readable storage medium, which includes a stored executable program, wherein when the executable program is running, the device where the computer-readable storage medium is located is controlled to execute the methods in various embodiments of the present invention.

[0106] The above-mentioned computer storage medium may refer to a medium in a computer memory used to store certain discontinuous physical quantities. Computer storage media mainly include semiconductors, magnetic cores, magnetic drums, magnetic tapes, laser disks, etc.; the stored program included in the computer-readable storage medium may be a set of instructions that can be recognized and executed by a computer, running on an electronic computer, and is an information tool that meets certain needs of people.

[0107] An embodiment of the present application further provides a computer program product, including a computer program, which implements the methods in various embodiments of the present invention when executed by a processor.

[0108] The above-mentioned computer program product may refer to a software program that has been written, tested and released and can be run on a computer or other device. The computer program product may include an application, an operating system, tool software, etc., which is used to implement specific functions or solve specific problems.

[0109] An embodiment of the present application further provides a computer program product, including a non-volatile computer-readable storage medium, wherein the non-volatile computer-readable storage medium is used to store a computer program, and when the computer program is executed by a processor, the method in each embodiment of the present invention is implemented.

[0110] The above-mentioned non-volatile computer-readable storage medium may refer to a medium for storing data. The non-volatile computer-readable storage medium can keep the data from being lost when the power is off, and can be used to store long-term data, such as operating systems, applications, and user files. The non-volatile storage medium may include hard disk drives, solid-state drives, optical disks, and flash memory storage devices, etc.

[0111] The embodiments of the present application further provide a computer program, which implements the methods in the above-mentioned embodiments of the present invention when executed by a processor.

[0112] The above-mentioned computer program may refer to a collection of instructions used to tell a computer to perform a specific task or operation. A computer program may be written by a programmer using a specific programming language and may include algorithms, data structures, logic, and control flows. A computer program may be used for a variety of purposes, including application software, operating systems, and the like.

[0113] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0114] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0115] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0116] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0117] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk, etc. Various media that can store program codes.

[0118] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for determining a disturbance level of a power distribution system, characterized in that: include: Obtaining fan rotor change information of a power distribution system, wherein the power distribution system is a wind power distribution system, and the fan rotor change information is used to characterize change information of the fan rotor speed of the power distribution system under different disturbances; Constructing a speed disturbance analytical relationship of the power distribution system based on the wind turbine rotor change information, wherein the speed disturbance analytical relationship is used to characterize an analytical relationship between the speed of the wind turbine rotor and the active disturbance level; A disturbance level result of the power distribution system is determined based on the rotational speed disturbance analytical relationship, wherein the disturbance level result is used to characterize the disturbance level of the power distribution system in consideration of wind power frequency regulation response.

2. The method for determining the disturbance level of a power distribution system according to claim 1, characterized in that: Constructing a speed disturbance analysis relationship of the power distribution system based on the fan rotor change information includes: Constructing a target transfer function expression of the power distribution system based on the fan rotor change information, wherein the target transfer function expression is used to represent a transfer function expression of the fan rotor speed; Determining a target analytical expression of the power distribution system based on a target transfer function expression, wherein the target analytical expression is used to represent an analytical expression of the wind turbine rotor speed; The rotation speed disturbance analytical relationship is constructed based on the target transfer function expression and the target analytical expression.

3. The method for determining the disturbance level of a power distribution system according to claim 2, characterized in that: The target transfer function expression of the power distribution system is constructed based on the wind turbine rotor change information, including: Constructing a swing equation expression of the power distribution system based on the wind turbine rotor change information, wherein the swing equation expression is used to characterize the dynamic frequency characteristics of the power distribution system; The target transfer function expression is determined based on the swing equation expression.

4. The method for determining the disturbance level of a power distribution system according to claim 3, characterized in that: The swing equation expression of the power distribution system is constructed based on the wind turbine rotor change information, including: Determining a system frequency change of the power distribution system and a fan output active power change based on the fan rotor change information; Based on the system frequency change and the wind turbine output active power change, the swing equation expression is determined and constructed.

5. The method for determining the disturbance level of a power distribution system according to claim 4, characterized in that: The wind turbine output active power change is composed of the target output power change of the power distribution system and the primary frequency modulation active output power, wherein the target output power change is used to represent the output power change of the power distribution system under the preset power point operation mode.

6. The method for determining the disturbance level of a power distribution system according to claim 2, characterized in that: Determining a target analytical expression of the power distribution system based on a target transfer function expression includes: The target transfer function expression is fractionally expanded to obtain the target analytical expression of the power distribution system.

7. A disturbance level determination device for a power distribution system, characterized in that: include: An acquisition module, used for acquiring fan rotor change information of a power distribution system, wherein the power distribution system is a wind power distribution system, and the fan rotor change information is used for characterizing the change information of the fan rotor speed of the power distribution system under different disturbances; A construction module, used to construct a speed disturbance analytical relationship of the power distribution system based on the wind turbine rotor change information, wherein the speed disturbance analytical relationship is used to characterize the analytical relationship between the wind turbine rotor speed and the active disturbance level; A determination module is used to determine a disturbance level result of the power distribution system based on the rotational speed disturbance analytical relationship, wherein the disturbance level result is used to characterize the disturbance level of the power distribution system under the condition of considering the wind power frequency regulation response.

8. An electronic device, characterized in that: include: A memory storing an executable program; A processor is used to run the program, wherein the program, when running, executes the method for determining the disturbance level of the power distribution system as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored executable program, wherein when the executable program is executed, the device where the storage medium is located is controlled to execute the method for determining the disturbance level of a power distribution system according to any one of claims 1 to 6.

10. A computer program product, characterized in that The invention comprises a computer program, which, when executed by a processor, implements the method for determining the disturbance level of a power distribution system according to any one of claims 1 to 6.

Images