Power system frequency characteristic analysis method based on extended frequency response model

Abstract

The invention relates to a power system frequency characteristic analysis method based on an extended frequency response model. The method comprises the following steps: inputting a power change value of a power system into a generator rotor motion model in an extended frequency response model to obtain a frequency change value of the power system; the generator rotor motion model is used for determining a frequency change value according to the electrical angular displacement, the electrical angular speed and the power change value of a rotor of a generator in the power system; the extended frequency response model further comprises a thermal power generating unit frequency response model, a hydroelectric generating unit frequency response model and a wind turbine generator frequency response model; the thermal power generating unit frequency response model, the hydroelectric generating unit frequency response model and the wind power generating unit frequency response model respectively process the frequency change values to obtain corresponding frequency response processing results; the frequency response processing result is used for adjusting a power change value of a power system to be input to the generator rotor motion model. By adopting the method, the accuracy of frequency characteristic analysis can be improved.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a method, device, computer equipment, computer-readable storage medium and computer program product for analyzing frequency characteristics of an electric power system based on an extended frequency response model. Background Art

[0002] In recent years, with the development of new power systems, traditional thermal power units have been gradually replaced by a variety of new energy sources such as wind power and photovoltaics, resulting in a decrease in the system's inertia and frequency regulation capabilities. At the same time, the fluctuations in power supply and demand are becoming increasingly large, and frequency safety issues have become more prominent. Accidents caused by frequency fluctuations have brought great challenges to the safe and stable operation of the power system. Therefore, it is necessary to conduct in-depth analysis and evaluation of the frequency characteristics of traditional thermal power units and wind power units. In traditional technologies, the frequency response model only focuses on the frequency response characteristics of a single energy generator, such as only focusing on the frequency response characteristics of a thermal power unit, resulting in a low accuracy rate in the frequency characteristic analysis when the power system includes generators that combine multiple energy sources. Summary of the invention

[0003] Based on this, it is necessary to provide a method, device, computer equipment, computer-readable storage medium and computer program product for analyzing frequency characteristics of a power system based on an extended frequency response model, which can improve the accuracy of frequency characteristics analysis in order to address the above technical problems.

[0004] In a first aspect, the present application provides a method for analyzing frequency characteristics of a power system based on an extended frequency response model, comprising:

[0005] Inputting the power change value of the power system into the generator rotor motion model in the extended frequency response model to obtain the frequency change value of the power system; the generator rotor motion model is used to determine the frequency change value according to the electrical angular displacement of the rotor of the generator in the power system, the electrical angular velocity of the rotor and the power change value; the frequency change value is used to perform frequency characteristic analysis on the power system;

[0006] Wherein, the extended frequency response model also includes a thermal power unit frequency response model, a hydropower unit frequency response model and a wind power unit frequency response model; the thermal power unit frequency response model, the hydropower unit frequency response model and the wind power unit frequency response model respectively process the frequency change value to obtain a corresponding frequency response processing result; the frequency response processing result is used to adjust the power change value of the power system to be input into the generator rotor motion model. In one embodiment,

[0007] In one embodiment, the generator rotor motion model is represented by a generator rotor motion frequency domain model obtained by Laplace transforming the generator rotor motion time domain model; the generator rotor motion time domain model is represented by:

[0008] ;

[0009] Among them, the is the electrical angular displacement of the rotor of the generator in the power system; is the electrical angular velocity of the rotor; is the frequency change value of the power system; is the rated angular velocity of the rotor; is the inertia time constant of the generator; is the power change value of the power system, Determined according to the change value of the electromagnetic power of the generator; D is the equivalent damping coefficient of the generator.

[0010] In one of the embodiments, the thermal power unit frequency response model includes a thermal power governor model and a thermal power prime mover model;

[0011] The thermal power governor model is expressed as:

[0012] ;

[0013] Among them, the is the inverse of the regulation coefficient of the thermal power unit in the power system; is the equivalent time constant of the speed governor of the thermal power unit; s is a variable in the frequency domain; the thermal power speed governor model is used to output a thermal power speed governor response result according to the input power change value, and input the thermal power speed governor response result into the thermal power prime mover model;

[0014] The thermal power prime mover model is expressed as:

[0015] ;

[0016] Among them, the is the power ratio of the high-pressure cylinder of the prime mover in the thermal power unit; is the reheat time constant of the prime mover; the thermal power prime mover model is used to output the frequency response processing result corresponding to the thermal power unit frequency response model according to the input thermal power governor response result.

[0017] In one of the embodiments, the hydroelectric generator unit frequency response model includes a hydroelectric speed governor model and a hydroelectric prime mover model;

[0018] The hydropower governor model is expressed as:

[0019] ;

[0020] Among them, the is the primary frequency regulation coefficient of the hydropower unit in the power system; is the soft feedback time constant of the hydropower unit; s is a variable in the frequency domain; is the soft feedback coefficient of the hydropower unit; is the regulation coefficient of the hydroelectric generator set; the hydroelectric speed governor model is used to output a hydroelectric speed governor response result according to the input power change value, and input the hydroelectric speed governor response result into the hydroelectric prime mover model;

[0021] The hydropower prime mover model is expressed as:

[0022] ;

[0023] Among them, the is the water hammer effect coefficient; the hydroelectric prime mover model is used to output the frequency response processing result corresponding to the hydroelectric generator set frequency response model according to the input hydroelectric speed governor response result.

[0024] In one embodiment, the wind turbine frequency response model includes a wind turbine model, a rotor mechanical model and a maximum power point tracking control model; wherein the wind turbine model is used to output a mechanical energy value according to an input wind speed, and input the mechanical energy value into the rotor mechanical model; the rotor mechanical model is used to output a per-unit value of a speed change of a wind turbine of a wind turbine of the power system according to the input mechanical energy value, and input the per-unit value of the speed change into the maximum power point tracking control model; the maximum power point tracking control model is used to output a change in the maximum output power under maximum power point tracking control according to the input per-unit value of the speed change; the wind turbine frequency response model is used to output a frequency response processing result corresponding to the wind turbine frequency response model according to the change in the maximum output power and the frequency change value.

[0025] In one embodiment, the wind turbine model is represented as:

[0026] ;

[0027] Among them, the is the air density; R is the blade radius of the wind turbine; is the wind energy utilization coefficient; v is the wind speed;

[0028] The rotor mechanical model is expressed as:

[0029] ;

[0030] Among them, the is the rotor inertia time constant of the wind turbine; s is a variable in the frequency domain;

[0031] The maximum power point tracking control model is expressed as:

[0032] ;

[0033] Among them, the is the optimal control coefficient of the wind turbine; is the per-unit value of the speed change.

[0034] In a second aspect, the present application also provides a device for analyzing frequency characteristics of a power system based on an extended frequency response model, comprising:

[0035] a processing module, configured to input the power change value of the power system into the generator rotor motion model in the extended frequency response model to obtain the frequency change value of the power system; the generator rotor motion model is configured to determine the frequency change value according to the electrical angular displacement of the rotor of the generator in the power system, the electrical angular velocity of the rotor and the power change value; the frequency change value is configured to perform frequency characteristic analysis on the power system;

[0036] Among them, the extended frequency response model also includes a frequency response model of a thermal power unit, a frequency response model of a hydropower unit and a frequency response model of a wind power unit; the frequency response model of the thermal power unit, the frequency response model of the hydropower unit and the frequency response model of the wind power unit respectively process the frequency change value to obtain corresponding frequency response processing results; the frequency response processing results are used to adjust the power change value of the power system to be input into the generator rotor motion model.

[0037] In a third aspect, the present application further provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0038] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.

[0039] In a fifth aspect, the present application also provides a computer program product, including a computer program, which implements the steps of the above method when executed by a processor.

[0040] The above-mentioned method, device, computer equipment, computer-readable storage medium and computer program product for analyzing the frequency characteristics of the power system based on the extended frequency response model input the power change value of the power system into the generator rotor motion model in the extended frequency response model to obtain the frequency change value of the power system; the generator rotor motion model is used to determine the frequency change value according to the electrical angular displacement of the rotor of the generator in the power system, the electrical angular velocity of the rotor and the power change value; the frequency change value is used to perform frequency characteristic analysis on the power system; wherein, the extended frequency response model also includes a thermal power unit frequency response model, a hydropower unit frequency response model and a wind power unit frequency response model; the thermal power unit frequency response model, the hydropower unit frequency response model and the wind power unit frequency response model respectively process the frequency change value to obtain the corresponding frequency response processing results; the frequency response processing results are used to adjust the power change value of the power system to be input into the generator rotor motion model. By integrating the frequency response models of generator sets of multiple energy sources such as thermal power, hydropower and wind power, a complete extended frequency response model is obtained, so that the frequency characteristic analysis results of the power system can accurately reflect the dynamic response of generator sets of different energy types when the frequency fluctuates, which improves the comprehensiveness and accuracy of the frequency characteristic analysis results and overcomes the limitation that the traditional frequency response model is only applicable to the analysis of a single energy unit; the frequency change value is processed by the frequency response model of the generator sets of multiple energy sources to obtain the power change value after dynamic adjustment based on the frequency response characteristics of the generator sets of different energy types, and the adjusted power change value, the electrical angular displacement of the generator rotor, and the electrical angular velocity are used to determine the frequency change value for frequency characteristic analysis, which can more accurately evaluate the frequency characteristics of the power system, improve the frequency stability of the power system under complex working conditions such as new energy access and load fluctuations, avoid the safety problems of the power system caused by frequency fluctuations, improve the safety of the power system, and improve the accuracy of frequency characteristic analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0042] FIG1 is an application environment diagram of a method for analyzing frequency characteristics of a power system based on an extended frequency response model in one embodiment;

[0043] FIG2 is a schematic flow chart of a method for analyzing frequency characteristics of a power system based on an extended frequency response model in one embodiment;

[0044] FIG3 is a schematic diagram of a speed governor model of a thermal power unit and a prime mover model of the thermal power unit in one embodiment;

[0045] FIG4 is a schematic diagram of a frequency response model of a thermal power unit in one embodiment;

[0046] FIG5 is a schematic diagram of a speed governor model of a hydroelectric generator set and a prime mover model of the hydroelectric generator set in one embodiment;

[0047] FIG6 is a schematic diagram of a frequency response model of a hydropower unit in one embodiment;

[0048] FIG7 is a schematic diagram of a frequency response model of a wind turbine generator system in one embodiment;

[0049] FIG8 is a logic diagram of a method for analyzing frequency characteristics of a power system based on an extended frequency response model in one embodiment;

[0050] FIG9 is a structural block diagram of a device for analyzing frequency characteristics of a power system based on an extended frequency response model in one embodiment;

[0051] FIG. 10 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0053] The method for analyzing the frequency characteristics of a power system based on an extended frequency response model provided in an embodiment of the present application can be applied in an application environment as shown in FIG1. ​​Among them, the terminal 102 communicates with the server 104 through a network. The data storage system can store data that the server 104 needs to process. The data storage system can be integrated on the server 104, or it can be placed on a cloud or other network server. The terminal 102 inputs the power change value of the power system into the generator rotor motion model in the extended frequency response model to obtain the frequency change value of the power system; the generator rotor motion model is used to determine the frequency change value according to the electrical angular displacement of the rotor of the generator in the power system, the electrical angular velocity of the rotor and the power change value; the frequency change value is used to analyze the frequency characteristics of the power system; wherein the extended frequency response model also includes a thermal power unit frequency response model, a hydropower unit frequency response model and a wind turbine unit frequency response model; the thermal power unit frequency response model, the hydropower unit frequency response model and the wind turbine unit frequency response model respectively process the frequency change value to obtain the corresponding frequency response processing result; the frequency response processing result is used to adjust the power change value of the power system to be input into the generator rotor motion model. The terminal 102 may be, but is not limited to, various personal computers, laptops, smart phones, tablet computers, IoT devices, and portable wearable devices. The IoT devices may be smart speakers, smart TVs, smart air conditioners, smart car devices, projection devices, etc. Portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc. Head-mounted devices may be virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, etc. The server 104 may be an independent physical server, a server cluster or distributed system consisting of multiple physical servers, or a cloud server that provides cloud computing services.

[0054] In an exemplary embodiment, as shown in FIG2 , a method for analyzing frequency characteristics of a power system based on an extended frequency response model is provided, and the method is described by taking the application of the method to the terminal in FIG1 as an example, including:

[0055] Step S202: inputting the power change value of the power system into the generator rotor motion model in the extended frequency response model to obtain the frequency change value of the power system.

[0056] The generator rotor motion model is used to determine the frequency change value according to the electrical angular displacement of the rotor of the generator in the power system, the electrical angular velocity of the rotor and the power change value.

[0057] Among them, the power change value may refer to the quantitative result of the power imbalance of the power grid caused by the change of load or power generation in the power system. Since the power generation and load demand in the power system fluctuate from time to time, resulting in the deviation of the frequency of the power grid, it is necessary to respond to this imbalance. In a specific implementation, when the mechanical power and electromagnetic power of the generator set in the power system are unbalanced, the power change value will affect the acceleration or deceleration of the generator rotor, thereby causing a change in frequency. Among them, the generator sets in the power system may include thermal power sets, wind power sets, and hydropower sets.

[0058] The generator rotor motion model is used to derive the frequency fluctuation of the power system based on the influence of the power disturbance on the rotor motion of the generator in the power system.

[0059] The electrical angular displacement can be the relative electrical angle between the generator rotor and the synchronous grid, reflecting the change in the generator rotor position. When frequency deviation occurs, the angular displacement of the rotor will change, affecting the power output of the system.

[0060] The electrical angular velocity can be the rotation speed of the generator rotor, which is usually proportional to the frequency of the power grid. When the power grid frequency changes, the angular velocity of the rotor will also change. The relationship between the change in rotor angular velocity and the change in frequency can be derived through the rotor motion model.

[0061] Optionally, the generator rotor motion model can derive a frequency change value of the power system by solving the change value of the rotor's electrical angular displacement, the rated angular velocity of the electrical angular velocity relative to the rated frequency, and the input power change value. The frequency change value can be used to indicate the deviation of the grid frequency from the standard frequency.

[0062] Among them, the extended frequency response model also includes a thermal power unit frequency response model, a hydropower unit frequency response model and a wind power unit frequency response model; the thermal power unit frequency response model, the hydropower unit frequency response model and the wind power unit frequency response model respectively process the frequency change value to obtain the corresponding frequency response processing result; the frequency response processing result is used to adjust the power change value of the power system to be input into the generator rotor motion model.

[0063] The extended frequency response model includes frequency response models of different types of generator sets, such as thermal power, hydropower, and wind power. Each type of generator set will handle frequency change values ​​separately according to its unique dynamic response characteristics.

[0064] Among them, the frequency response model of the thermal power unit can take into account the dynamic response of the speed governor and the steam turbine, especially the power adjustment process of the reheat steam turbine. When facing frequency changes, the thermal power unit relies on the speed governor to gradually adjust the power output and restore the system frequency.

[0065] Among them, the frequency response model of the hydropower unit can be a model that considers the dynamic characteristics of the turbine, including transient phenomena such as the water hammer effect. In the response model of the hydropower unit, the frequency deviation will affect the water intake of the turbine, thereby adjusting the output power and responding to frequency fluctuations.

[0066] The frequency response model of a wind turbine can simulate the inertial response of a traditional generator by using technologies such as virtual inertia and maximum power point tracking control. The frequency response model of a wind turbine helps maintain the frequency stability of the system by adjusting the speed and output power of the wind turbine.

[0067] Each generator set processes the frequency change value through its corresponding frequency response model to obtain the corresponding frequency response processing result. This frequency response processing result is used to adjust the power change value to be input into the generator rotor motion model in the next step, thereby forming a closed-loop control process; based on the frequency response model of each generator set, an extended frequency response model of the power system considering water-fire-wind power is constructed, so that the frequency characteristic analysis results of the power system can accurately reflect the dynamic response of generator sets of different energy types when the frequency fluctuates, improving the comprehensiveness and accuracy of the frequency characteristic analysis results.

[0068] The frequency change value is used to analyze the frequency characteristics of the power system. In a specific implementation, a frequency curve can be drawn according to the frequency change value to perform frequency characteristic analysis, such as analyzing the frequency regulation capability of the power system.

[0069] The above-mentioned method, device, computer equipment, computer-readable storage medium and computer program product for analyzing the frequency characteristics of the power system based on the extended frequency response model input the power change value of the power system into the generator rotor motion model in the extended frequency response model to obtain the frequency change value of the power system; the generator rotor motion model is used to determine the frequency change value according to the electrical angular displacement of the rotor of the generator in the power system, the electrical angular velocity of the rotor and the power change value; the frequency change value is used to perform frequency characteristic analysis on the power system; wherein, the extended frequency response model also includes a thermal power unit frequency response model, a hydropower unit frequency response model and a wind power unit frequency response model; the thermal power unit frequency response model, the hydropower unit frequency response model and the wind power unit frequency response model respectively process the frequency change value to obtain the corresponding frequency response processing results; the frequency response processing results are used to adjust the power change value of the power system to be input into the generator rotor motion model. By integrating the frequency response models of generator sets of multiple energy sources such as thermal power, hydropower and wind power, a complete extended frequency response model is obtained, so that the frequency characteristic analysis results of the power system can accurately reflect the dynamic response of generator sets of different energy types when the frequency fluctuates, which improves the comprehensiveness and accuracy of the frequency characteristic analysis results and overcomes the limitation that the traditional frequency response model is only applicable to the analysis of a single energy unit; the frequency change value is processed by the frequency response model of the generator sets of multiple energy sources to obtain the power change value after dynamic adjustment based on the frequency response characteristics of the generator sets of different energy types, and the adjusted power change value, the electrical angular displacement of the generator rotor, and the electrical angular velocity are used to determine the frequency change value for frequency characteristic analysis, which can more accurately evaluate the frequency characteristics of the power system, improve the frequency stability of the power system under complex working conditions such as new energy access and load fluctuations, avoid the safety problems of the power system caused by frequency fluctuations, improve the safety of the power system, and improve the accuracy of frequency characteristic analysis.

[0070] In another embodiment, the generator rotor motion model is represented by a generator rotor motion frequency domain model obtained by Laplace transforming the generator rotor motion time domain model; the generator rotor motion time domain model is represented by:

[0071] ;

[0072] in, is the electrical angular displacement of the rotor of the generator in the power system; is the electrical angular velocity of the rotor; is the frequency change value of the power system; is the rated angular velocity of the rotor; is the inertia time constant of the generator; is the power change value of the power system, Determined according to the change value of the electromagnetic power of the generator; D is the equivalent damping coefficient of the generator.

[0073] The rated angular velocity of the rotor may be related to the standard frequency of the power system, may be used as a reference value for frequency response analysis, and may refer to the standard angular velocity of the generator rotor rotating under normal operating conditions of the power system.

[0074] Among them, the inertia time constant of the generator describes the inertia of the generator system. The generator rotor has a certain mechanical inertia. When the power changes, the speed of the rotor will not change immediately. The inertia time constant determines the speed of this change.

[0075] The equivalent damping coefficient represents the damping effect in the system. The damping coefficient affects the decay rate of the system frequency deviation. When the system deviates from the synchronous state, the damping effect will help slow down the frequency deviation.

[0076] The power change value can be determined according to the change value of the electromagnetic power of the generator. In a specific implementation, the power change value can be determined according to the difference between the electromagnetic power of the generator in the generator set and the mechanical power of the prime mover in the generator set, and the power change value can be equal to the change amount of the difference. The prime mover refers to a power device that can provide mechanical energy to the generator. For example, the prime mover in a thermal power unit can be a steam turbine, and the prime mover in a hydropower unit can be a water turbine.

[0077] In the time domain model of generator rotor motion, It can represent the change of the electrical angular displacement of the generator rotor over time, which is related to the angular velocity and rated angular velocity of the rotor. When the angular velocity of the rotor deviates, the electrical angular displacement will change over time. This is a direct reflection of the movement of the generator rotor under the influence of frequency deviation. The time variation of the generator rotor's angular velocity is described, which is related to the power variation value, the inertia time constant and the equivalent damping coefficient.

[0078] because , f is the frequency, is the angular velocity, so the frequency change value of the power system can be obtained by the change of the angular velocity of the generator rotor over time.

[0079] In a specific implementation, a Laplace transform is performed on the generator rotor motion time domain model to obtain a generator rotor motion frequency domain model as the generator rotor motion model.

[0080] The frequency domain model of the generator rotor motion can be expressed as:

[0081] ;

[0082] Where H is equal to , D is the equivalent damping coefficient of the generator, s is the variable in the frequency domain, It is the efficiency coefficient of the generator, which reflects the operating efficiency of the generator rotor under the current load.

[0083] The generator rotor motion model describes the motion state of the rotor (angular velocity and angular displacement) and the relationship between it and the power change value, and the frequency change can be reflected by the power change.

[0084] The technical solution of this embodiment significantly improves the accuracy of the frequency characteristic analysis of the power system by performing frequency domain analysis on the generator rotor motion. By converting the time domain equation to the frequency domain equation, the complex differential equation is simplified to ensure that the analysis process is more intuitive and accurate; combined with the electrical angular displacement, angular velocity and power change value, it can more comprehensively reflect the response characteristics of the generator to the frequency deviation; in addition, the inertia and damping effects are taken into account, which is crucial for accurately predicting the frequency dynamic behavior and system recovery capabilities. In general, it effectively improves the accuracy of the frequency response characteristic analysis of multiple types of generator sets and enhances the accuracy of the frequency safety assessment of the power system.

[0085] In another embodiment, the frequency response model of the thermal power unit includes a thermal power governor model and a thermal power prime mover model; the thermal power governor model is expressed as:

[0086] ;

[0087] in, It is the inverse of the regulation coefficient of the thermal power units in the power system; is the equivalent time constant of the speed governor of the thermal power unit; s is a variable in the frequency domain; the thermal power speed governor model is used to output the thermal power speed governor response result according to the input power change value, and input the thermal power speed governor response result into the thermal power prime mover model;

[0088] The thermal power prime mover model is expressed as:

[0089] ;

[0090] in, is the proportion of high-pressure cylinder power of the prime mover in the thermal power unit; is the reheating time constant of the prime mover; the thermal power prime mover model is used to output the frequency response processing result corresponding to the thermal power unit frequency response model according to the input thermal power governor response result.

[0091] In the specific implementation, the frequency response model of the thermal power unit includes a thermal power governor model and a thermal power prime mover model, which respectively explain the response process of the governor in the thermal power unit to the frequency deviation and the dynamic response characteristics of the prime mover in the thermal power unit.

[0092] A thermal power unit can be a system that generates electricity by burning fuel to generate steam to drive a generator. A thermal power unit can include a speed governor, a prime mover, and a generator. Optionally, the prime mover of the thermal power unit can be a steam turbine, and the speed governor controls the steam input of the steam turbine to adjust the power output of the generator; the steam energy generated by the combustion of fuel is converted into mechanical energy to drive the generator to rotate. Optionally, the prime mover can be a reheat steam turbine.

[0093] For the thermal power governor model, the inverse of the regulation coefficient of the thermal power unit in the power system is , which is the primary frequency regulation coefficient of the thermal power unit. The differential regulation coefficient refers to the ability of the thermal power unit to adjust the output power through the speed governor when facing frequency deviation. The smaller the differential regulation coefficient, the faster the generator unit responds to frequency changes and the higher the sensitivity of frequency regulation. is the inverse of the adjustment coefficient, then The larger the frequency is, the more sensitive the thermal power unit is to frequency deviation and the faster it can adjust power output.

[0094] Equivalent time constant of speed governor of thermal power unit Reflects the speed of the speed regulator's response to power changes. The larger the time constant, the slower the speed regulator's response, and the slower the system frequency response speed.

[0095] The thermal power speed governor model outputs the frequency deviation (i.e., frequency change value) as the thermal power speed governor response result, which is used to be transmitted to the thermal power prime mover model to adjust the power change value.

[0096] For the thermal power prime mover model, the power proportion of the high-pressure cylinder of the prime mover in the thermal power unit It reflects the power output ratio of the high-pressure cylinder in the prime mover. The function of the high-pressure cylinder is to first absorb the steam energy and convert it into mechanical power, so it occupies the main part of the total power.

[0097] Reheat time constant of prime mover The delay effect of the steam reheating process in the steam turbine on the power response is described. The larger the reheating time constant, the more significant the delay effect in the power regulation process.

[0098] The technical solution of this embodiment can more accurately determine the response of the thermal power unit to the frequency change of the power system through the thermal power speed regulator model and the thermal power prime mover model. Through the transfer function of the speed regulator and the prime mover, it can accurately describe the dynamic response process of the thermal power unit when the frequency fluctuates, thereby improving the accuracy of the frequency characteristic analysis results.

[0099] In order to facilitate the understanding of those skilled in the art, FIG3 exemplarily provides a schematic diagram of a speed regulator model of a thermal power unit and a prime mover model of a thermal power unit. The speed regulator model and prime mover model of the thermal power unit in FIG3 can be simplified and multi-machine aggregated, and only the key parameters that have a greater impact on the primary frequency regulation are retained to obtain the frequency response model of the thermal power unit of the present application. In a specific implementation, the thermal power speed regulator model in the frequency response model of the thermal power unit of the present application adds a first-order inertia link on the basis of the traditional differential coefficient to simulate the dynamic characteristics of the speed regulator; the thermal power prime mover model in the frequency response model of the thermal power unit of the present application can adopt the reheat steam turbine of the traditional frequency response model. The equivalent model obtained after the above processing is the frequency response model of the thermal power unit. The schematic diagram of the frequency response model of the thermal power unit of the present application can be shown in FIG4. Among them, FIG4 is the response result of the thermal power governor, It is the frequency response processing result corresponding to the frequency response model of thermal power unit.

[0100] In another embodiment, the hydroelectric generator unit frequency response model includes a hydroelectric speed governor model and a hydroelectric prime mover model;

[0101] The hydropower governor model is expressed as:

[0102] ;

[0103] in, is the primary frequency regulation coefficient of the hydropower unit in the power system; is the soft feedback time constant of the hydropower unit; s is the variable in the frequency domain; is the soft feedback coefficient of the hydropower unit; is the regulation coefficient of the hydropower unit; the hydropower speed governor model is used to output the hydropower speed governor response result according to the input power change value, and input the hydropower speed governor response result into the hydropower prime mover model;

[0104] The hydropower prime mover model is expressed as:

[0105] ;

[0106] in, is the water hammer effect coefficient; the hydroelectric prime mover model is used to output the frequency response processing result corresponding to the hydroelectric unit frequency response model according to the input hydroelectric speed governor response result.

[0107] In the specific implementation, the frequency response model of the hydropower unit includes a hydropower speed governor model and a hydropower prime mover model, which respectively explain the response process of the speed governor in the hydropower unit to the frequency deviation and the dynamic response characteristics of the prime mover in the hydropower unit.

[0108] A hydroelectric unit can be a system that uses the potential energy or kinetic energy of water to generate electricity. A hydroelectric unit can include a speed governor, a prime mover, and a generator. Optionally, the prime mover of the hydroelectric unit can be a turbine, and water flows through the turbine to drive its blades to rotate, converting water energy into mechanical energy, and then the generator converts the mechanical energy into electrical energy.

[0109] For the hydropower governor model, the primary frequency regulation coefficient of the hydropower unit in the power system Related to the system's response sensitivity to frequency deviation, The larger the value, the stronger the frequency modulation capability.

[0110] Soft feedback time constant of hydropower unit It reflects the reaction speed of the speed regulator and controls how the speed regulator handles power change signals.

[0111] The hydropower speed governor model outputs the frequency deviation (i.e., the frequency change value) as a hydropower speed governor response result, which is used to be transmitted to the hydropower prime mover model to adjust the power change value.

[0112] For the hydroelectric prime mover model, the water hammer effect coefficient It is used to indicate the delay time of water hammer effect and reflect the influence of water hammer effect on frequency response. Water hammer effect is a common dynamic phenomenon in hydropower units. When the flow rate of the turbine changes rapidly, the inertia of the water flow in the pipe causes pressure fluctuations, which will affect the power output of the turbine.

[0113] The technical solution of this embodiment can more accurately determine the response of the hydropower unit to the frequency change of the power system through the hydropower speed regulator model and the hydropower prime mover model. Through the transfer function of the speed regulator and the prime mover, it can accurately describe the dynamic response process of the hydropower unit when the frequency fluctuates, thereby improving the accuracy of the frequency characteristic analysis results.

[0114] In order to facilitate the understanding of those skilled in the art, FIG5 exemplarily provides a speed governor model of a hydroelectric unit and a prime mover model of a hydroelectric unit. The speed governor model and prime mover model of the hydroelectric unit of FIG5 can be simplified and aggregated to obtain the frequency response model of the hydroelectric unit of the present application. Since there is an obvious water hammer effect phenomenon in the frequency regulation process of the turbine, a transient compensation link needs to be added to suppress the reverse regulation effect caused by the water hammer in the turbine pipeline. The equivalent model obtained after the above processing is the frequency response model of the hydroelectric unit. The schematic diagram of the frequency response model of the hydroelectric unit of the present application can be shown in FIG6. Among them, FIG6 is the response result of the hydropower speed governor, This is the frequency response processing result corresponding to the frequency response model of the hydropower unit.

[0115] In another embodiment, the wind turbine frequency response model includes a wind turbine model, a rotor mechanical model and a maximum power point tracking control model; wherein the wind turbine model is used to output a mechanical energy value according to an input wind speed, and input the mechanical energy value into the rotor mechanical model; the rotor mechanical model is used to output a per-unit value of a speed change of a wind turbine of a wind turbine of a power system according to the input mechanical energy value, and input the per-unit value of the speed change into the maximum power point tracking control model; the maximum power point tracking control model is used to output a change in the maximum output power under maximum power point tracking control according to the input per-unit value of the speed change; the wind turbine frequency response model is used to output a frequency response processing result corresponding to the wind turbine frequency response model according to the change in the maximum output power and the frequency change value.

[0116] A wind turbine generator system can be a system that generates electricity by capturing wind energy. A wind turbine generator system can include a speed regulator, a prime mover, and a generator. Optionally, the prime mover of the wind turbine generator system can be a wind turbine that captures the kinetic energy of the wind, converts it into mechanical energy, and then drives the generator to generate electricity.

[0117] In a specific implementation, the wind turbine frequency response model can be obtained by combining the wind turbine model, maximum power point tracking control and rotor mechanical characteristics of the wind turbine on the basis of the wind turbine inertia control model. The wind turbine inertia control model can be a model including droop control and virtual inertia control. The droop control makes the wind power frequency modulation power respond to the system frequency change. The virtual inertia control makes the wind power frequency modulation power respond to the system frequency change rate change. The wind turbine inertia control model synchronizes the inertia link and the primary frequency modulation process of the unit. The key parameters in the wind turbine inertia control model may include the droop control coefficient, the virtual inertia and the damping coefficient.

[0118] Among them, the wind turbine model can be used to calculate and output the mechanical energy generated by the wind turbine according to the input wind speed.

[0119] Among them, the rotor mechanical model can be used to calculate the speed change of the wind turbine according to the input mechanical energy, and express it as a per-unit value. The speed change per-unit value can represent the change of the current speed relative to the rated speed.

[0120] Among them, the maximum power point tracking (MPPT) control model can adjust the operating state of the wind turbine according to the per-unit value of the speed change, so that it always remains at the maximum power point at the current wind speed, thereby outputting the change in maximum mechanical power. The change in maximum mechanical power output by the maximum power point tracking control model can be used to combine the frequency change value to obtain the frequency response processing result.

[0121] The technical solution of this embodiment can convert mechanical energy into a per-unit value of speed change through a rotor mechanical model, which can more accurately reflect the dynamic response of the wind turbine when the frequency fluctuates, thereby improving the accuracy of the frequency characteristic analysis; the maximum power point tracking control model can accurately adjust the output power of the wind turbine according to the speed change, ensuring that the power adjustment is more accurate during frequency deviation, further improving the accuracy of the frequency characteristic analysis; the wind turbine frequency response model comprehensively analyzes the impact of power grid frequency fluctuations by simultaneously considering the power change and frequency deviation value, making the frequency response process more accurate and real-time, and improving the accuracy of the overall frequency characteristic analysis.

[0122] In another embodiment, the wind turbine model is represented as:

[0123] ;

[0124] in, is the air density; R is the blade radius of the wind turbine; is the wind energy utilization coefficient; v is the wind speed;

[0125] The rotor mechanical model is expressed as:

[0126] ;

[0127] in, is the rotor inertia time constant of the wind turbine; s is the variable in the frequency domain;

[0128] The maximum power point tracking control model is expressed as:

[0129] ;

[0130] in, is the optimal control coefficient of the wind turbine; is the per unit value of speed change.

[0131] In specific implementation, wind turbines are important devices for energy conversion. The mechanical energy generated by wind turbines is With wind speed v, air density , wind turbine blade radius R, wind energy utilization coefficient , pitch angle , Tip Speed ​​Ratio Satisfies the equation: .

[0132] In order to improve the wind energy utilization efficiency of wind turbines, wind turbines can be operated in the maximum power tracking state in most cases. The maximum output power of the wind turbine under the maximum power point tracking control This can be shown as follows:

[0133] ;

[0134] in, is the optimal tip speed ratio, is the maximum wind energy utilization coefficient, is the speed of the wind turbine.

[0135] Therefore, the small signal model of wind turbine output power under maximum power point tracking control is: ;

[0136] in, is the change in maximum output power, is the optimal control coefficient of the wind turbine, is the per unit value of the wind turbine speed change.

[0137] The mechanical structure of the rotor is an important structure that converts the mechanical power captured by the wind turbine into electromagnetic power. If the rotor shaft system of the wind turbine is a rigid structure, that is, the transient characteristics of the shaft system are ignored, the rotor structure of the wind turbine can be equivalently replaced by a single mass block model. Its mathematical model is as follows:

[0138] ;

[0139] in, is the wind turbine rotor inertia time constant, , are the mechanical torque and electromagnetic torque of the wind turbine respectively, , are the mechanical power and electromagnetic power of the wind turbine respectively.

[0140] Rewrite the mathematical model of the above formula into a small signal model in the frequency domain and simplify it to get the expression of the speed:

[0141] ;

[0142] In summary, the frequency response model of the wind turbine can be shown in Figure 7. Specifically, the frequency change value Feedback is sent to the wind turbine frequency response model, which can be adjusted according to the grid frequency deviation (i.e. frequency change value) through the additional frequency control model. ) to adjust the power output of the wind turbine, The wind turbine generator system changes according to the frequency The power adjustment amount performed. Among them, the additional frequency control model can be expressed as , is the differential coefficient in the additional frequency control, is the proportional coefficient in the additional frequency control. It can be seen that after being processed by the wind turbine model, rotor mechanical model and maximum power point tracking control model, the change in maximum output power can be obtained. , and then according to the change of maximum output power Power adjustment The result obtained by subtraction is the frequency response processing result corresponding to the frequency response model of the wind turbine. .

[0143] In another embodiment, as shown in FIG8 , a logic diagram of a method for analyzing the frequency characteristics of a power system based on an extended frequency response model is provided, wherein the extended frequency response model includes a generator rotor motion model, a thermal power unit frequency response model, a hydropower unit frequency response model, and a wind power unit frequency response model. Input to the frequency domain model of the generator rotor motion The description of this model can refer to the above embodiment. Output frequency change value through generator rotor motion frequency domain model . Change the frequency value The feedback is respectively given to the frequency response model of wind turbine, the frequency response model of thermal power unit and the frequency response model of hydropower unit. , and They are the frequency response processing results corresponding to the wind turbine frequency response model, thermal power unit frequency response model and hydropower unit frequency response model. It can be seen that the power change value to be input can be added , and minus , get the adjusted power change value, input the adjusted power change value into the generator rotor motion model, and get the output frequency change value It should be noted that the frequency response model of thermal power units It can be the reheat ratio of the thermal power unit, that is, the power distribution between the high-pressure cylinder and the reheat section, which can describe the power proportion of the reheat system in the thermal power unit; It can be the adjustment coefficient of thermal power units; It can be the weight coefficient of the frequency regulation process of the hydropower unit.

[0144] It can be seen that compared with the traditional frequency response model, the extended frequency response model of the present application combines the speed regulator model and prime mover model of thermal power units and hydropower units; and takes into account the influence of wind speed changes, the mechanical characteristics of wind turbines, and the maximum power point tracking control on the frequency regulation capability of wind turbines, and can reflect the characteristics of power drop after the release of rotor kinetic energy and the wind turbine speed recovery process; taking into account the capacity proportion of various types of power sources in the power system and the frequency regulation reserve capacity and climbing power limit of synchronous units, the primary frequency regulation capability of the power system can be analyzed more accurately. Therefore, the extended frequency response model of the present application that combines hydropower, wind power, and thermal power units can analyze the frequency regulation mechanism of various types of units. Based on the extended frequency response model, the key factors of the frequency characteristics of the power system can be studied, and the primary frequency regulation characteristics of the power system can be analyzed.

[0145] It should be noted that the specific limitations of the above steps can refer to the specific limitations of a method for analyzing frequency characteristics of a power system based on an extended frequency response model.

[0146] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0147] Based on the same inventive concept, the embodiment of the present application also provides a device for analyzing the frequency characteristics of a power system based on an extended frequency response model for implementing the method for analyzing the frequency characteristics of a power system based on an extended frequency response model. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of one or more devices for analyzing the frequency characteristics of a power system based on an extended frequency response model provided below can refer to the limitations of the method for analyzing the frequency characteristics of a power system based on an extended frequency response model above, and will not be repeated here.

[0148] In an exemplary embodiment, as shown in FIG9 , a device for analyzing frequency characteristics of a power system based on an extended frequency response model is provided, comprising:

[0149] The processing module 910 is used to input the power change value of the power system into the generator rotor motion model in the extended frequency response model to obtain the frequency change value of the power system; the generator rotor motion model is used to determine the frequency change value according to the electrical angular displacement of the rotor of the generator in the power system, the electrical angular velocity of the rotor and the power change value; the frequency change value is used to perform frequency characteristic analysis on the power system;

[0150] Among them, the extended frequency response model also includes the frequency response model of the thermal power unit, the frequency response model of the hydropower unit and the frequency response model of the wind turbine unit; the frequency response model of the thermal power unit, the frequency response model of the hydropower unit and the frequency response model of the wind turbine unit respectively process the frequency change value to obtain corresponding frequency response processing results; the frequency response processing results are used to adjust the power change value of the power system to be input into the generator rotor motion model.

[0151] In one embodiment, the generator rotor motion model is represented by a generator rotor motion frequency domain model obtained by Laplace transforming the generator rotor motion time domain model; the generator rotor motion time domain model is represented by:

[0152] ;

[0153] Among them, the is the electrical angular displacement of the rotor of the generator in the power system; is the electrical angular velocity of the rotor; is the frequency change value of the power system; is the rated angular velocity of the rotor; is the inertia time constant of the generator; is the power change value of the power system, Determined according to the change value of the electromagnetic power of the generator; D is the equivalent damping coefficient of the generator.

[0154] In one of the embodiments, the thermal power unit frequency response model includes a thermal power governor model and a thermal power prime mover model;

[0155] The thermal power governor model is expressed as:

[0156] ;

[0157] Among them, the is the inverse of the regulation coefficient of the thermal power unit in the power system; is the equivalent time constant of the speed governor of the thermal power unit; s is a variable in the frequency domain; the thermal power speed governor model is used to output a thermal power speed governor response result according to the input power change value, and input the thermal power speed governor response result into the thermal power prime mover model;

[0158] The thermal power prime mover model is expressed as:

[0159] ;

[0160] Among them, the is the power ratio of the high-pressure cylinder of the prime mover in the thermal power unit; is the reheat time constant of the prime mover; the thermal power prime mover model is used to output the frequency response processing result corresponding to the thermal power unit frequency response model according to the input thermal power governor response result.

[0161] In one of the embodiments, the hydroelectric generator unit frequency response model includes a hydroelectric speed governor model and a hydroelectric prime mover model;

[0162] The hydropower governor model is expressed as:

[0163] ;

[0164] Among them, the is the primary frequency regulation coefficient of the hydropower unit in the power system; is the soft feedback time constant of the hydropower unit; s is a variable in the frequency domain; is the soft feedback coefficient of the hydropower unit; is the regulation coefficient of the hydroelectric generator set; the hydroelectric speed governor model is used to output a hydroelectric speed governor response result according to the input power change value, and input the hydroelectric speed governor response result into the hydroelectric prime mover model;

[0165] The hydropower prime mover model is expressed as:

[0166] ;

[0167] Among them, the is the water hammer effect coefficient; the hydroelectric prime mover model is used to output the frequency response processing result corresponding to the hydroelectric generator set frequency response model according to the input hydroelectric speed governor response result.

[0168] In one embodiment, the wind turbine frequency response model includes a wind turbine model, a rotor mechanical model and a maximum power point tracking control model; wherein the wind turbine model is used to output a mechanical energy value according to an input wind speed, and input the mechanical energy value into the rotor mechanical model; the rotor mechanical model is used to output a per-unit value of a speed change of a wind turbine of a wind turbine of the power system according to the input mechanical energy value, and input the per-unit value of the speed change into the maximum power point tracking control model; the maximum power point tracking control model is used to output a change in the maximum output power under maximum power point tracking control according to the input per-unit value of the speed change; the wind turbine frequency response model is used to output a frequency response processing result corresponding to the wind turbine frequency response model according to the change in the maximum output power and the frequency change value.

[0169] In one embodiment, the wind turbine model is represented as:

[0170] ;

[0171] Among them, the is the air density; R is the blade radius of the wind turbine; is the wind energy utilization coefficient; v is the wind speed;

[0172] The rotor mechanical model is expressed as:

[0173] ;

[0174] Among them, the is the rotor inertia time constant of the wind turbine; s is a variable in the frequency domain;

[0175] The maximum power point tracking control model is expressed as:

[0176] ;

[0177] Among them, the is the optimal control coefficient of the wind turbine; is the per-unit value of the speed change.

[0178] Each module in the above-mentioned power system frequency characteristic analysis device based on the extended frequency response model can be implemented in whole or in part by software, hardware and a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0179] In an exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be shown in FIG10. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, the memory, and the input / output interface are connected via a system bus, and the communication interface, the display unit, and the input device are connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner may be implemented through WIFI, a mobile cellular network, near field communication (NFC) or other technologies. When the computer program is executed by the processor, a method for analyzing the frequency characteristics of a power system based on an extended frequency response model is implemented. The display unit of the computer device is used to form a visually visible picture, which may be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0180] Those skilled in the art will understand that the structure shown in FIG. 10 is merely a block diagram of a partial structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0181] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0182] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0183] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0184] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0185] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0186] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0187] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for analyzing frequency characteristics of a power system based on an extended frequency response model, characterized in that: The method comprises: Inputting the power change value of the power system into the generator rotor motion model in the extended frequency response model to obtain the frequency change value of the power system; the generator rotor motion model is used to determine the frequency change value according to the electrical angular displacement of the rotor of the generator in the power system, the electrical angular velocity of the rotor and the power change value; the frequency change value is used to perform frequency characteristic analysis on the power system; Among them, the extended frequency response model also includes a frequency response model of a thermal power unit, a frequency response model of a hydropower unit and a frequency response model of a wind power unit; the frequency response model of the thermal power unit, the frequency response model of the hydropower unit and the frequency response model of the wind power unit respectively process the frequency change value to obtain corresponding frequency response processing results; the frequency response processing results are used to adjust the power change value of the power system to be input into the generator rotor motion model.

2. The method according to claim 1, characterized in that The generator rotor motion model is represented by a generator rotor motion frequency domain model obtained by Laplace transforming the generator rotor motion time domain model; the generator rotor motion time domain model is represented by: ； Among them, the is the electrical angular displacement of the rotor of the generator in the power system; is the electrical angular velocity of the rotor; is the frequency change value of the power system; is the rated angular velocity of the rotor; is the inertia time constant of the generator; is the power change value of the power system, Determined according to the change value of the electromagnetic power of the generator; D is the equivalent damping coefficient of the generator.

3. The method according to claim 1, characterized in that The thermal power unit frequency response model includes a thermal power governor model and a thermal power prime mover model; The thermal power governor model is expressed as: ； Among them, the is the inverse of the regulation coefficient of the thermal power unit in the power system; is the equivalent time constant of the speed governor of the thermal power unit; s is a variable in the frequency domain; the thermal power speed governor model is used to output a thermal power speed governor response result according to the input power change value, and input the thermal power speed governor response result into the thermal power prime mover model; The thermal power prime mover model is expressed as: ； Among them, the is the power ratio of the high-pressure cylinder of the prime mover in the thermal power unit; is the reheat time constant of the prime mover; the thermal power prime mover model is used to output the frequency response processing result corresponding to the thermal power unit frequency response model according to the input thermal power governor response result.

4. The method according to claim 1, characterized in that: The frequency response model of the hydroelectric generator set includes a hydroelectric speed governor model and a hydroelectric prime mover model; The hydropower governor model is expressed as: ； Among them, the is the primary frequency regulation coefficient of the hydropower unit in the power system; is the soft feedback time constant of the hydropower unit; s is a variable in the frequency domain; is the soft feedback coefficient of the hydropower unit; is the regulation coefficient of the hydroelectric generator set; the hydroelectric speed governor model is used to output a hydroelectric speed governor response result according to the input power change value, and input the hydroelectric speed governor response result into the hydroelectric prime mover model; The hydropower prime mover model is expressed as: ； Among them, the is the water hammer effect coefficient; the hydroelectric prime mover model is used to output the frequency response processing result corresponding to the hydroelectric generator unit frequency response model according to the input hydroelectric speed governor response result.

5. The method according to claim 1, characterized in that The wind turbine frequency response model includes a wind turbine model, a rotor mechanical model and a maximum power point tracking control model; wherein the wind turbine model is used to output a mechanical energy value according to an input wind speed, and input the mechanical energy value into the rotor mechanical model; the rotor mechanical model is used to output a per-unit value of a speed change of a wind turbine of a wind turbine of the power system according to an input mechanical energy value, and input the per-unit value of the speed change into the maximum power point tracking control model; the maximum power point tracking control model is used to output a change in the maximum output power under maximum power point tracking control according to the input per-unit value of the speed change; the wind turbine frequency response model is used to output a frequency response processing result corresponding to the wind turbine frequency response model according to the change in the maximum output power and the frequency change value.

6. The method according to claim 5, characterized in that The wind turbine model is expressed as: ； Among them, the is the air density; R is the blade radius of the wind turbine; is the wind energy utilization coefficient; v is the wind speed; The rotor mechanical model is expressed as: ； Among them, the is the rotor inertia time constant of the wind turbine; s is a variable in the frequency domain; The maximum power point tracking control model is expressed as: ； Among them, the is the optimal control coefficient of the wind turbine; is the per-unit value of the speed change.

7. A device for analyzing frequency characteristics of a power system based on an extended frequency response model, characterized in that: The device comprises: a processing module, configured to input the power change value of the power system into the generator rotor motion model in the extended frequency response model to obtain the frequency change value of the power system; the generator rotor motion model is configured to determine the frequency change value according to the electrical angular displacement of the rotor of the generator in the power system, the electrical angular velocity of the rotor and the power change value; the frequency change value is configured to perform frequency characteristic analysis on the power system; Among them, the extended frequency response model also includes a frequency response model of a thermal power unit, a frequency response model of a hydropower unit and a frequency response model of a wind power unit; the frequency response model of the thermal power unit, the frequency response model of the hydropower unit and the frequency response model of the wind power unit respectively process the frequency change value to obtain corresponding frequency response processing results; the frequency response processing results are used to adjust the power change value of the power system to be input into the generator rotor motion model.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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