Broadband oscillation identification method and device, computer equipment, readable storage medium and program product

Abstract

The invention relates to a broadband oscillation identification method and device, computer equipment, a computer readable storage medium and a computer program product. Comprising the steps of determining a potential oscillation type of a target power system based on access equipment in the target power system; searching an oscillation stability screening index corresponding to the potential oscillation type; constructing an operation condition space of the target power system, and layering the operation condition space into operation condition subspaces according to the operation condition state; screening out a target typical working condition in each operation working condition subspace according to an oscillation stability screening index; and carrying out oscillation stability analysis processing on the target typical working condition to obtain a broadband oscillation identification result of the target power system. According to the method, the target typical working conditions are screened out and subjected to oscillation stability analysis processing, so that the problem of combined explosion of the operation working conditions is solved, the number of the analyzed operation working conditions is remarkably reduced, and the calculation efficiency of the broadband oscillation evaluation and recognition process can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of power system stability analysis, and particularly to a wide - frequency oscillation identification method, device, computer device, computer - readable storage medium, and computer program product. Background Art

[0002] To achieve the carbon neutrality goal, the access proportion of renewable energy in the power system is increasing rapidly, which has led to significant changes in the dynamic characteristics of the power system. These changes have brought new stability challenges, such as wide - frequency oscillations, which pose a threat to the safe and reliable operation of the power system. Therefore, it is crucial to evaluate the oscillation risk of the system during the planning stage of renewable energy access to the system.

[0003] The main methods for stability analysis of wide - frequency oscillations are model - based methods, including eigenvalue analysis, impedance method, and electromagnetic simulation, etc. However, these methods face the problem of combinatorial explosion of operating conditions in the evaluation and identification of oscillation risks. Existing methods usually adopt a centralized approach, that is, modeling and analyzing the entire system as a unified whole. For example, eigenvalue analysis requires modeling the dynamic equations of all devices in the power system under specific operating conditions. This centralized approach has encountered significant challenges in the face of the combinatorial explosion problem. Due to the sharp increase in the number of combinations of operating conditions of different electrical devices, it has become extremely difficult to evaluate the oscillation risks of the power system under all possible scenarios, resulting in low efficiency in the evaluation and identification of wide - frequency oscillation risks. Summary of the Invention

[0004] Based on this, in view of the above - mentioned technical problems, it is necessary to provide a wide - frequency oscillation identification method, device, computer device, computer - readable storage medium, and computer program product that can improve the efficiency of wide - frequency oscillation identification.

[0005] In a first aspect, the present application provides a wide - frequency oscillation identification method, including:

[0006] Determine the potential oscillation types of the target power system based on the access devices in the target power system;

[0007] Search for oscillation stability screening indicators corresponding to the potential oscillation types;

[0008] Construct the operating condition space of the target power system, and layer the operating condition space into each operating condition subspace according to the operating condition state;

[0009] According to the oscillation stability screening indicators, screen out the target typical operating conditions in each operating condition subspace;

[0010] Perform oscillation stability analysis processing on the target typical operating conditions to obtain the wide - frequency oscillation identification result of the target power system.

[0011] In one embodiment, determining the potential oscillation types of the target power system based on the access devices in the target power system includes:

[0012] When the access devices in the target power system include rotating machines, determining the potential oscillation types of the target power system includes shaft torsional oscillation;

[0013] When the access devices in the target power system include LC oscillation circuit elements, determining the potential oscillation types of the target power system includes LC electromagnetic oscillation;

[0014] When the access devices in the target power system include generator sets and the target power system includes a weak power grid, determining the potential oscillation types of the target power system includes machine-grid coupling oscillation;

[0015] When the access devices in the target power system include flexible HVDC transmission equipment and the target power system includes a weak power grid, determining the potential oscillation types of the target power system includes VSC-HVDC - grid coupling oscillation.

[0016] In one embodiment, finding the oscillation stability screening indexes corresponding to the potential oscillation types includes:

[0017] When the potential oscillation type includes shaft torsional oscillation, finding the shaft mechanical frequency in the target power system and the electrical resonance frequency of the equivalent L-C circuit of the target power system, determining the complementary frequency difference between the shaft mechanical frequency and the electrical resonance frequency, and finding the unit interaction coefficient of the target power system, and using the complementary frequency difference and the unit interaction coefficient as the oscillation stability screening indexes for shaft torsional oscillation;

[0018] When the potential oscillation type includes LC electromagnetic oscillation, finding the line reactance before series compensation of the doubly-fed wind turbine and the series capacitor and the equivalent capacitive reactance of series compensation in the target power system, determining the series compensation degree based on the ratio of the equivalent capacitive reactance to the line reactance, and using the series compensation degree as the oscillation stability screening index for LC electromagnetic oscillation;

[0019] When the potential oscillation type includes machine-grid coupling oscillation, finding the multi-station equivalent short-circuit ratio of the target power system, and using the multi-station equivalent short-circuit ratio as the oscillation stability screening index for machine-grid coupling oscillation;

[0020] In the case where the potential oscillation type includes the flexible DC-grid coupling oscillation, find the short-circuit ratio and the control link delay of the target power system, and use the short-circuit ratio and the control link delay as the oscillation stability screening indexes for the flexible DC-grid coupling oscillation.

[0021] In one embodiment, constructing the operating condition space of the target power system and stratifying the operating condition space into respective operating condition sub-spaces according to the operating condition states includes:

[0022] Determine the feasible operating conditions of the target power system based on the system information of the target power system;

[0023] Construct the operating condition space corresponding to the feasible operating conditions;

[0024] Stratify the operating condition space into respective operating condition sub-spaces according to the different operating condition states of the equipment put into operation in the target power system.

[0025] In one embodiment, screening out the target typical operating conditions in each operating condition sub-space according to the oscillation stability screening indexes includes:

[0026] Construct the nodal admittance matrix of the target power system at power frequency;

[0027] Based on the nodal admittance matrix, calculate the oscillation stability screening indexes of each operating condition in each operating condition sub-space to obtain an index calculation result;

[0028] Based on the index calculation result, perform index sorting processing on the operating conditions of each operating condition sub-space to obtain an index sorting result;

[0029] Based on the index sorting result, screen out the target typical operating conditions in each operating condition sub-space.

[0030] In one embodiment, performing oscillation stability analysis processing on the target typical operating conditions to obtain the broadband oscillation identification result of the target power system includes:

[0031] Determine the output conditions and fault conditions corresponding to the target typical operating conditions;

[0032] Based on the output conditions and the fault conditions, perform oscillation stability analysis processing on the target typical operating conditions to obtain the oscillation indexes and oscillation stability analysis results of the target typical operating conditions;

[0033] Summarize the oscillation indexes and oscillation stability analysis results of different target typical operating conditions to obtain the broadband oscillation identification result of the target power system.

[0034] Second aspect, the present application also provides a wide - frequency oscillation identification device, including:

[0035] An oscillation type identification module, configured to determine potential oscillation types of the target power system based on access devices in the target power system;

[0036] A stability index screening module, configured to find oscillation stability screening indexes corresponding to the potential oscillation types;

[0037] An operating condition space construction module, configured to construct an operating condition space of the target power system and layer the operating condition space into respective operating condition sub - spaces according to operating condition states;

[0038] A typical operating condition screening module, configured to screen out target typical operating conditions in each operating condition sub - space according to the oscillation stability screening indexes;

[0039] A stability analysis module, configured to perform oscillation stability analysis processing on the target typical operating conditions to obtain a wide - frequency oscillation identification result of the target power system.

[0040] Third aspect, the present application also provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0041] Determine potential oscillation types of the target power system based on access devices in the target power system;

[0042] Find oscillation stability screening indexes corresponding to the potential oscillation types;

[0043] Construct an operating condition space of the target power system and layer the operating condition space into respective operating condition sub - spaces according to operating condition states;

[0044] Screen out target typical operating conditions in each operating condition sub - space according to the oscillation stability screening indexes;

[0045] Perform oscillation stability analysis processing on the target typical operating conditions to obtain a wide - frequency oscillation identification result of the target power system.

[0046] Fourth aspect, the present application also provides a computer - readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0047] Determine potential oscillation types of the target power system based on access devices in the target power system;

[0048] Find oscillation stability screening indexes corresponding to the potential oscillation types;

[0049] Construct the operating condition space of the target power system, and layer the operating condition space into respective operating condition sub-spaces according to the operating condition status;

[0050] According to the oscillation stability screening index, screen out the target typical operating conditions in each operating condition sub-space;

[0051] Perform oscillation stability analysis and processing on the target typical operating conditions to obtain the wide-frequency oscillation identification result of the target power system.

[0052] In a fifth aspect, the present application also provides a computer program product, including a computer program, which when executed by a processor implements the following steps:

[0053] Based on the access devices in the target power system, determine the potential oscillation types of the target power system;

[0054] Search for the oscillation stability screening indexes corresponding to the potential oscillation types;

[0055] Construct the operating condition space of the target power system, and layer the operating condition space into respective operating condition sub-spaces according to the operating condition status;

[0056] According to the oscillation stability screening index, screen out the target typical operating conditions in each operating condition sub-space;

[0057] Perform oscillation stability analysis and processing on the target typical operating conditions to obtain the wide-frequency oscillation identification result of the target power system.

[0058] For the above wide-frequency oscillation identification method, device, computer device, computer-readable storage medium and computer program product, first determine the potential oscillation types of the target power system based on the access devices in the target power system; then search for the oscillation stability screening indexes corresponding to the potential oscillation types; construct the operating condition space of the target power system, and layer the operating condition space into respective operating condition sub-spaces according to the operating condition status; according to the oscillation stability screening index, screen out the target typical operating conditions in each operating condition sub-space; perform oscillation stability analysis and processing on the target typical operating conditions to obtain the wide-frequency oscillation identification result of the target power system. By mapping the vector composed of high-dimensional operating condition variables to a set of one-dimensional oscillation stability screening indexes, the present application screens out the target typical operating conditions in each operating condition sub-space according to the oscillation stability screening indexes; and performs oscillation stability analysis and processing on the target typical operating conditions, thus solving the problem of explosion of operating condition combinations, significantly reducing the number of operating conditions that need to be analyzed in detail, and effectively improving the calculation efficiency of the wide-frequency oscillation evaluation and identification process of the power system. Description of the Drawings

[0059] To more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0060] Figure 1 It is an application environment diagram of the broadband oscillation recognition method in an embodiment;

[0061] Figure 2 It is a schematic flowchart of the broadband oscillation recognition method in an embodiment;

[0062] Figure 3 It is a schematic flowchart of the broadband oscillation recognition method in another embodiment;

[0063] Figure 4 It is a structural block diagram of the broadband oscillation recognition device in an embodiment;

[0064] Figure 5 It is an internal structure diagram of a computer device in an embodiment. Detailed implementation manners

[0065] In order to make the objectives, technical solutions and advantages of the present application clearer, the following further details the present application in conjunction with the 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.

[0066] The broadband oscillation recognition method provided by the embodiments of the present application can be applied to, for example Figure 1In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or can be placed on the cloud or other network servers. When the user on the terminal 102 side hopes to evaluate the stability of the target power system and determine the broadband oscillation risk related to the power system, the broadband oscillation risk of the system can be identified and evaluated through the broadband oscillation identification method of the present application. It can initiate a request for broadband oscillation identification to the server 104 through the terminal 102 and provide the relevant data of the target power system. The server 104 then determines the potential oscillation types of the target power system based on the access devices in the target power system; searches for the oscillation stability screening indicators corresponding to the potential oscillation types; constructs the operating condition space of the target power system, and stratifies the operating condition space into each operating condition subspace according to the operating condition status; according to the oscillation stability screening indicators, screens out the target typical operating conditions in each operating condition subspace; performs oscillation stability analysis and processing on the target typical operating conditions to obtain the broadband oscillation identification result of the target power system. Among them, the terminal 102 can be but is not limited to various personal computers, laptop computers, smart phones, tablet computers, Internet of Things devices and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart in-vehicle devices, projection devices, etc. The portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The head-mounted devices can be virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, etc. The server 104 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services.

[0067] In an exemplary embodiment, as Figure 2 shown, a broadband oscillation identification method is provided. Taking the method applied to Figure 1 the server 104 in

[0068] Step 201, based on the access devices in the target power system, determine the potential oscillation types of the target power system.

[0069] Among them, the target power system, which is the object of wide-band oscillation identification in this application, can evaluate the wide-band oscillation risk of the target power system through the wide-band oscillation identification method of this application. The wide-band oscillations (WBOs) of the power grid system refer to the oscillation phenomena that occur in a relatively wide frequency range in the power system, and its frequency range is usually between 0.1 Hz and 2000 Hz. This type of oscillation can span distances of hundreds or even thousands of kilometers and may involve the interaction between multiple power plants, transmission lines, and load centers. The wide-band oscillations are mainly caused by factors such as the large-scale access of new energy, the increase in the complexity of the power network structure, and the growth of the demand for long-distance and large-capacity power transmission. For the access equipment in the target power system, it specifically includes power generation-side equipment, transmission-side equipment, distribution-side equipment, and user-side equipment, etc. Among them, the power generation-side equipment includes generator sets, transformers, etc. The transmission-side equipment includes high-voltage transmission lines and substation equipment, etc. The distribution-side equipment includes medium- and low-voltage distribution lines and load switches, etc. And the common types of wide-band oscillations can be roughly divided into four categories according to the interaction relationship. The first type of oscillation originates from the shaft torsional vibration of the rotating machine. The second type of oscillation originates from the electrical oscillation formed by the inductance (L) - capacitance (C) in the power grid. The third type of oscillation originates from the machine-network coupling oscillation generated by the interaction between generator sets with voltage source converters (VSCs) as interfaces or between them and the AC power grid. The fourth type of oscillation is caused by the interaction between the voltage source converter-based high voltage direct current (VSC-HVDC) transmission system and the power grid.

[0070] Exemplarily, the wide-band oscillations of the power system will bring problems such as decreased stability, equipment damage, increased economic costs, and decreased service quality. Therefore, it is necessary to identify and evaluate the wide-band oscillations of the power system to ensure the service quality of the power system. When the user on the terminal 102 side hopes to perform the evaluation and identification process of wide-band oscillations on a specified power system, a request can be submitted to the server 104 through the terminal 102, and the relevant information of the target power system is provided. After receiving the request from the terminal 102, the server 104 will start the wide-band oscillation identification process of the power system. And the wide-band oscillations are mainly affected by the interaction of different access equipment in the power system, and different access equipment will bring different oscillation risks to the power system. In order to perform efficient wide-band oscillation identification, the potential oscillation types of the target power system can be determined based on the access equipment in the target power system, and it can be determined which one or several of the shaft torsional vibration, electrical oscillation, machine-network coupling oscillation, and DC-grid coupling oscillation the current target power system may include.

[0071] Step 203: Search for oscillation stability screening indicators corresponding to potential oscillation types.

[0072] Exemplarily, the oscillation stability screening indicator refers to the index data used to determine whether there is a broadband oscillation of the corresponding type in the system. Different potential oscillation types correspond to different oscillation stability screening indicators. For example, for shaft torsional oscillation, the complementary frequency difference between the shaft mechanical frequency and the electrical resonance frequency of the system, as well as the unit interaction coefficient, can be used as the oscillation stability screening indicator. For LC electromagnetic oscillation, the series compensation degree of the system can be used as the oscillation stability screening indicator. For machine-network coupling oscillation, the multi-station equivalent short-circuit ratio of the system can be used as the oscillation stability screening indicator. For VSC-HVDC-grid coupling oscillation, the short-circuit ratio and the control link delay of the system can be used as the oscillation stability screening indicator. Therefore, after determining the potential oscillation type of the target power system, the corresponding oscillation stability screening indicator can be searched for the determined potential oscillation type.

[0073] Step 205: Construct the operating condition space of the target power system and layer the operating condition space into each operating condition subspace according to the operating condition state.

[0074] Step 207: Screen out the target typical operating conditions in each operating condition subspace according to the oscillation stability screening indicators.

[0075] Among them, the operating condition of the power grid refers to the operating state and conditions of the power system at a specific time, which reflects the real-time performance, load conditions, equipment status of the power system, as well as the effects of various operations and control measures. The operating condition is an important basis for power system dispatching and operation personnel to make decisions and manage. The operating condition space refers to the space composed of all feasible operating conditions of the target power system, which is related to the electrical equipment put into operation under various conditions in the system. Assume there are i generators and m - i other electrical equipment in the system. The definition of the operating condition space V of this system is as follows:

[0076]

[0077] Among them, are the active power and reactive power output by the generator, is the number of power equipment put into operation, is an integer, and its upper and lower limits are respectively:

[0078]

[0079] Among them, is the maximum number of the i-th equipment.

[0080] And since the stability index is related to Irrelevant, so the relevant power variables can be ignored when calculating the metrics. Without operating condition space is as follows.

[0081]

[0082] Among them, S is the set of combinations of the number of power equipment put into operation in the feasible operating conditions.

[0083] Exemplarily, broadband oscillations generally occur only under specific operating conditions. Therefore, it is necessary to analyze the operating conditions of the target power system. However, the current analysis methods for operating conditions have the problem of combinatorial explosion. Facing this problem, this application combines oscillation stability screening metrics to screen typical conditions. Therefore, before identification and analysis, for the target power system, an operating condition space is constructed. And for the convenience of subsequent analysis, the complete operating condition space is first stratified into individual operating condition sub-spaces according to the operating condition status, and then identification and analysis are performed in each operating condition sub-space. And the target typical condition is the representative condition with broadband oscillations in different operating condition sub-spaces. After stratifying the operating condition sub-spaces, for each operating condition sub-space, the oscillation stability screening metrics can be used to screen and determine the target typical conditions.

[0084] Step 209, perform oscillation stability analysis processing on the target typical conditions to obtain the broadband oscillation identification result of the target power system.

[0085] Exemplarily, after obtaining the target typical conditions, the target typical conditions can be analyzed. For example, existing methods such as impedance method, eigenvalue analysis, electromagnetic transient simulation, etc. can be used to perform oscillation stability analysis on the selected conditions, and finally output the conditions, metrics with high oscillation risk, and the analysis result of oscillation stability as the final broadband oscillation identification result.

[0086] The above broadband oscillation identification method first determines the potential oscillation types of the target power system based on the access devices in the target power system; then searches for the oscillation stability screening indexes corresponding to the potential oscillation types; constructs the operating condition space of the target power system, and stratifies the operating condition space into each operating condition subspace according to the operating condition state; according to the oscillation stability screening indexes, screens out the target typical operating conditions in each operating condition subspace; performs oscillation stability analysis and processing on the target typical operating conditions to obtain the broadband oscillation identification result of the target power system. In this application, by mapping the vector composed of high-dimensional operating condition variables to a group of one-dimensional oscillation stability screening indexes, the target typical operating conditions are screened out in each operating condition subspace according to the oscillation stability screening indexes; and oscillation stability analysis and processing are performed on the target typical operating conditions, thereby solving the problem of operating condition combination explosion, significantly reducing the number of operating conditions that need to be analyzed in detail, and effectively improving the calculation efficiency of the broadband oscillation evaluation and identification process of the power system.

[0087] In an exemplary embodiment, step 201 includes:

[0088] When the access devices in the target power system include rotating machines, determining that the potential oscillation types of the target power system include shaft torsional oscillations.

[0089] When the access devices in the target power system include LC oscillation circuit elements, determining that the potential oscillation types of the target power system include LC electromagnetic oscillations.

[0090] When the access devices in the target power system include generating sets and the target power system includes a weak power grid, determining that the potential oscillation types of the target power system include machine-grid coupling oscillations.

[0091] When the access devices in the target power system include flexible HVDC transmission equipment and the target power system includes a weak power grid, determining that the potential oscillation types of the target power system include VSC-HVDC-grid coupling oscillations.

[0092] Exemplarily, the common broadband oscillation types of the system can be roughly divided into four categories according to the interaction relationship. Therefore, the potential oscillation types corresponding to the target power system can be determined based on the access devices in the target power system.

[0093] The first type of oscillation originates from the torsional oscillation of the shafting of rotating electrical machines, where the rotating electrical machines include large steam turbine units, hydro turbine units, wind turbine units, and large electric motors; series compensation capacitors, converters, etc. in the system respond to mechanical torsional oscillations, which may cause the damping torque of the unit in the corresponding torsional oscillation mode to weaken or even become negative, resulting in the continuation and even amplification of the oscillation. Common first-type oscillations in the power grid include the oscillations generated by the interaction between thermal power units and series compensation capacitors or high-voltage direct current (HVDC) systems in the sub-supersynchronous frequency band (below 100 Hz). Therefore, when the access equipment of the target power system includes rotating electrical machines, it can be determined that the potential oscillation types of the target power system include shafting torsional oscillation

[0094] The second type of oscillation originates from the electrical oscillation formed by inductance (L) - capacitance (C) in the power grid. Series compensation capacitors, various filter circuits, and shunt compensation all have circuit elements that can form L-C oscillations. Rotating electrical machines or power electronic converters may exhibit an "induction generator / negative resistance" effect on this oscillation mode under specific operating conditions. When the negative resistance exceeds the total positive resistance of the power grid, it may cause the L-C oscillation to diverge. Common second-type oscillations in the power grid include the oscillations generated by the interaction between doubly fed induction generator (DFIG) wind turbine units and series compensation capacitors in the sub-supersynchronous frequency band. Therefore, when the access equipment of the target power system includes LC oscillation circuit elements, it can be determined that the potential oscillation types of the target power system include LC electromagnetic oscillation.

[0095] The third type of oscillation originates from the machine-network coupling oscillation generated by the interaction between generator sets with voltage source converter (VSC) as the interface or between them and the AC power grid. This form is often difficult to find the initial inherent oscillation mode from the generator set or grid side. It can be regarded as the phenomenon that the "virtual impedance" formed by multiple converters and the power grid exhibits series-type (the imaginary part of the impedance is zero) or parallel-type (the imaginary part of the admittance is zero) resonance at a specific frequency. Common third-type oscillations in the power grid include the oscillations generated by the interaction between permanent magnet synchronous generator (PMSG) direct-drive wind turbine units and weak power grids in the sub-supersynchronous frequency band and the medium-high frequency band. Therefore, when the access equipment of the target power system includes generator sets and the target power system includes a weak power grid, it can be determined that the potential oscillation types of the target power system include machine-network coupling oscillation.

[0096] The fourth type of oscillation is caused by the interaction between the voltage source converter based high voltage direct current (VSC-HVDC) and the power grid. This type of oscillation usually occurs in the medium and high frequency ranges. Due to the control link delay of the VSC, the real part of the VSC impedance periodically exhibits negative resistance characteristics at high frequencies, while the imaginary part of the impedance swings between inductive and capacitive characteristics. On the other hand, due to the distributed parameter characteristics of the AC transmission line, the imaginary part of the AC grid impedance also fluctuates between inductive and capacitive characteristics at high frequencies. If the converter exhibits negative resistance at the oscillation frequency and the connected AC grid is weak, resulting in a negative equivalent resistance of the system, oscillations will be triggered. Therefore, when the access devices of the target power system include VSC-HVDC devices and the target power system includes a weak grid, it can be determined that the potential oscillation type of the target power system includes the VSC-grid coupling oscillation.

[0097] Combined with the generation causes of the above wide-frequency oscillations, the potential oscillation types in the target power system are obtained according to the device types. For example, when there are a large number of thermal power units connected to the system and there are series compensation capacitors and DC transmission systems, it is necessary to evaluate the oscillation risk of the first type of shaft torsional oscillation. Therefore, in this application, by using the access devices in the target power system to determine the potential oscillation types, the accuracy and efficiency of the analysis of potential oscillation types can be effectively guaranteed.

[0098] In an exemplary embodiment, step 203 includes:

[0099] When the potential oscillation type includes shaft torsional oscillation, find the shaft mechanical frequency in the target power system and the electrical resonance frequency of the equivalent L-C circuit of the target power system, determine the complementary frequency difference between the shaft mechanical frequency and the electrical resonance frequency, and find the unit interaction coefficient of the target power system, and use the complementary frequency difference and the unit interaction coefficient as the oscillation stability screening indexes for shaft torsional oscillation.

[0100] When the potential oscillation type includes LC electromagnetic oscillation, find the line reactance before series compensation of the doubly-fed wind turbine and the series capacitor and the equivalent capacitive reactance of the series compensation in the target power system, determine the series compensation degree based on the ratio of the equivalent capacitive reactance to the line reactance, and use the series compensation degree as the oscillation stability screening index for LC electromagnetic oscillation.

[0101] When the potential oscillation type includes machine-grid coupling oscillation, find the multi-station equivalent short-circuit ratio of the target power system, and use the multi-station equivalent short-circuit ratio as the oscillation stability screening index for machine-grid coupling oscillation.

[0102] When the potential oscillation type includes VSC-grid coupling oscillation, find the short-circuit ratio and the control link delay of the target power system, and use the short-circuit ratio and the control link delay as the oscillation stability screening indexes for VSC-grid coupling oscillation.

[0103] Exemplarily, for the determined different potential oscillation types, corresponding oscillation stability screening indicators can be selected for each oscillation type as the final screening criteria.

[0104] For the first type of oscillation caused by the interaction between a thermal power unit and a series capacitor, the influencing factors are the mechanical frequency of the shafting and the electrical resonance frequency (ERF) of the system equivalent L-C circuit. The closer the two frequencies are, the higher the oscillation risk. Therefore, it is necessary to calculate the frequency difference (FD) , to reflect the risk of this type of oscillation. Its expression is as follows:

[0105]

[0106] where is the electrical resonance frequency, is the mechanical frequency of the shafting, is the fundamental frequency.

[0107] For the first type of oscillation caused by the interaction between a thermal power unit and an HVDC, a unit interaction factor (UIF) can also be used to identify the vulnerable thermal power units. If the UIF is greater than 0.1, there is a risk of oscillation and further detailed modeling research is required. Its corresponding expression can be as follows:

[0108]

[0109] where is the UIF of the i-th generating unit, is the rated power of the HVDC, is the short-circuit capacity of the HVDC AC side busbar excluding the i-th unit, is the short-circuit capacity of the HVDC AC side busbar including the i-th unit.

[0110] For the second type of oscillation, a typical case is the interaction between a DFIG and a series capacitor. The series compensation degree (SCD) is the key influencing factor for oscillation. Generally, a high SCD will reduce the damping and cause oscillation. The series compensation degree can be referred to the following formula:

[0111]

[0112] where is the line reactance before series compensation, is the equivalent capacitive reactance of series compensation.

[0113] For the machine-grid coupled oscillation, the weak grid is the key factor leading to the third type of oscillation. The short circuit ratio (SCR) is the key index to quantify the degree of the weak grid. The common definition of SCR is as follows:

[0114]

[0115] where, is the short circuit capacity of the grid connection point, is the rated capacity of the equipment, is the per-unit value of the grid-side impedance at the grid connection point.

[0116] However, the above definition is usually for a single new energy power station, ignoring the interaction effects between multiple power stations. Therefore, it is necessary to expand the short circuit ratio. The expanded short circuit ratio is defined as the multi-station equivalent short circuit ratio (MESCR):

[0117]

[0118] where i and j are the grid connection node numbers of new energy power stations; is the multi-station equivalent short circuit ratio of the power station with grid connection node i; is the rated capacity of new energy power station j; is the short circuit capacity of node i; is the mutual impedance between nodes i and j, that is, the element in the i-th row and j-th column of matrix Z. Z is the inverse matrix of the nodal admittance matrix at power frequency; ki is the consistency coefficient of new energy power stations, indicating the similarity degree between the units of each new energy power station. The value ranges from 0 to 1. The specific selection method is usually approximate. The oscillation-dominant unit is selected as 1, and other direct-drive wind turbines / photovoltaic units are approximately selected as 0.8, and the doubly-fed wind turbines are approximately selected as 0.2.

[0119] Finally, the key factors for the fourth type of oscillation, the VSC-HVDC-grid coupled oscillation, are the control link delay and the weak grid. Therefore, SCR and the control link delay (CLD) are used as stability indicators. As the control link delay increases, the frequency band where the impedance exhibits negative resistance characteristics will shift to the left, which may lead to oscillation. For the above four types of oscillation and indicators, the summary list can be referred to Table 1 below:

[0120]

[0121] In this embodiment, each potential oscillation type is analyzed separately to determine the oscillation stability screening index for each potential oscillation type, thereby effectively ensuring the accuracy and efficiency of subsequent oscillation risk assessment based on the oscillation stability screening index.

[0122] In an exemplary embodiment, step 205 includes: determining the feasible operating conditions of the target power system based on the system information of the target power system; constructing an operating condition space corresponding to the feasible operating conditions; and stratifying the operating condition space into respective operating condition sub-spaces according to the different operating condition states of the equipment put into operation in the target power system.

[0123] Exemplarily, for the process of constructing and stratifying the operating condition space, specifically, the feasible operating conditions of the target power system can be first determined based on the system information of the target power system, and the feasible operating conditions can be determined by the connectivity of the system, the feasibility of the power flow, and the number of out-of-service equipment. Then, for these feasible operating conditions, the operating condition space is constructed; and then, according to the different operating condition states of the equipment put into operation in the target power system, the operating condition space is stratified into respective operating condition sub-spaces. Specifically, the operating conditions can be stratified according to the severity corresponding to different conditions, such as the number k of equipment such as disconnected lines, transformers, or thermal power units in the system. After stratification, each operating condition space is defined as follows.

[0124]

[0125]

[0126] Common situations during the operation of the power system are normal equipment input, N-1, N-2, and N-3. Therefore, the operating conditions usually belong to (k = 0, 1, 2, 3), and it is necessary to extract risk conditions from these condition spaces.

[0127] In this embodiment, based on the system information of the target power system, the operating condition space can be accurately constructed, and then each operating condition sub-space can be stratified based on the operating condition space, which can effectively ensure the accuracy of subsequent typical condition screening based on the operating condition sub-spaces.

[0128] In an exemplary embodiment, step 207 includes: constructing the nodal admittance matrix of the target power system at power frequency; calculating the oscillation stability screening index for each operating condition in each operating condition sub-space based on the nodal admittance matrix to obtain the index calculation result; performing index sorting processing on the operating conditions of each operating condition sub-space based on the index calculation result to obtain the index sorting result; and screening out the target typical conditions in each operating condition sub-space based on the index sorting result.

[0129] Among them, the Nodal Admittance Matrix (NAM) is an important tool in power system analysis, which is used to describe the electrical connection relationships between nodes in the power network. It has extensive applications in fields such as power system steady-state analysis, power flow calculation, and short-circuit calculation. The nodal admittance matrix Y is an n*n complex matrix, where n is the number of nodes in the power system. Each element Yij in the matrix represents the admittance (i.e., the complex representation of conductance and susceptance) between node i and node j. Specifically: the diagonal element Yii represents the self-admittance of node i, that is, the total admittance between node i and the ground. The off-diagonal element Yij represents the mutual admittance between node i and node j, that is, the connection admittance between node i and node j.

[0130] Exemplarily, to calculate the corresponding indicators for each working condition. First, establish the nodal admittance matrix of the power system under power frequency. The nodal admittance matrix Y when all devices in the system are in operation is as follows:

[0131]

[0132] Among them, A is the node-branch incidence matrix determined by the system topology structure, is the diagonal matrix of the per-unit value of the power-frequency admittance. Introduce the diagonal matrix K to represent the change of the working condition. The admittance network model Y under different working conditions is determined by the following formula:

[0133]

[0134]

[0135] When Ni is 0, a very large value will be used to replace it in the calculation. Then, according to the nodal admittance matrix Y, the oscillation stability screening index of each operating condition in each operating condition subspace can be calculated to obtain the index calculation results, specifically including:

[0136] The per-unit value of the impedance Zi of node i can be expressed as:

[0137]

[0138] The calculation formula for the short-circuit ratio SCR at the connection point i of the generator or converter is:

[0139]

[0140] Among them, is the base capacity of the target power system, is the total rated capacity of the generator or converter.

[0141] The unit interaction factor UIF can be calculated by the short-circuit capacity of the HVDC AC side busbar with / without the i-th thermal power unit included. The short-circuit capacity can be obtained through the impedance Zi.

[0142] The series compensation degree SCD and the frequency difference FD are calculated according to the equivalent L-C circuit. When the series capacitor is out of service and in operation, the reactance on the grid-connected busbar of the thermal power unit and are calculated from Zi. The reactance of the equivalent capacitor is - . Then SCD can be calculated through and . The ERF of the equivalent L-C circuit is as shown in the following formula.

[0143]

[0144] The shafting of a thermal power unit usually has multiple mechanical frequencies. FD is calculated from and the fm closest to the complement. is the power frequency.

[0145] After the index calculation is completed, the indices can be sorted from high to low in each operating condition subspace, and the target typical operating conditions with high oscillation risks can be screened out through the indices.

[0146] In addition, in a specific embodiment, in order to calculate the screening indices under each operating condition, all possible operating conditions need to be traversed in the program. For this purpose, a unique numerical identifier needs to be assigned to each operating condition so that the system can efficiently identify and process different condition conditions. The coding method of

[0147]

[0148]

[0149] is as follows:

[0150]

[0151]

[0152] where i = 1, 2,..., m, and the initial value of the iteration is h, and the function floor(x) finds the largest integer less than or equal to x.

[0153] In this embodiment, the oscillation stability screening index for each operating condition is calculated based on the nodal admittance matrix, and then the target typical operating conditions are screened in each operating condition subspace according to the oscillation stability screening index, which can effectively ensure the efficiency and accuracy of screening the target typical operating conditions.

[0154] In an exemplary embodiment, step 209 includes: determining the output conditions and fault conditions corresponding to the target typical operating conditions; performing oscillation stability analysis processing on the target typical operating conditions based on the output conditions and fault conditions to obtain the oscillation index and oscillation stability analysis results of the target typical operating conditions; summarizing the oscillation indexes and oscillation stability analysis results of different target typical operating conditions to obtain the broadband oscillation identification result of the target power system.

[0155] Exemplarily, for the screened target typical operating conditions, the generator output power situation and the types of faults adopted need to be considered. Usually, light load (P = 0.3 p.u.) and full load (P = 1 p.u.) of the generator or converter are considered. In addition, common fault types include single-phase transient faults and three-phase permanent faults to cover the severity of different faults. Therefore, for each operating condition in the operating condition subspace screening, some typical output conditions and fault conditions need to be selected for analysis. For each group of screened operating conditions, the selected output power conditions and fault types are traversed, and methods (such as impedance method, eigenvalue analysis, electromagnetic transient simulation, etc.) are used to perform oscillation stability analysis. Finally, the operating conditions with high oscillation risk, stability screening indexes, and analysis results of oscillation stability are output. Finally, by summarizing the oscillation indexes and oscillation stability analysis results of different target typical operating conditions, the broadband oscillation identification result of the target power system is obtained. In this embodiment, through the output conditions and fault conditions corresponding to the target typical operating conditions, the oscillation stability analysis processing of the target typical operating conditions can be carried out in a specific operating condition scenario, which can effectively improve the accuracy of the analysis of the oscillation index and oscillation stability analysis results, and thus ensure the analysis and identification effect.

[0156] In a specific embodiment, the flowchart of the broadband oscillation identification of the present application can be referred to Figure 3 as shown, including:

[0157] Step 301, input various information of the target power system, including system parameters, including the impedance of each branch of the system at power frequency, branch connection relationship, system equipment type, number of units, rated capacity, etc.

[0158] Step 302: Determine the potential oscillation types according to the types and parameters of the access devices in the system. When the access devices in the target power system include rotating machines, the potential oscillation types of the target power system include shaft torsional oscillations; when the access devices in the target power system include LC oscillation circuit elements, the potential oscillation types of the target power system include LC electromagnetic oscillations; when the access devices in the target power system include generator sets and the target power system includes a weak power grid, the potential oscillation types of the target power system include machine-grid coupling oscillations; when the access devices in the target power system include flexible HVDC transmission equipment and the target power system includes a weak power grid, the potential oscillation types of the target power system include VSC-HVDC-grid coupling oscillations.

[0159] Step 303: Select the corresponding stability indicators according to the oscillation types. When the potential oscillation types include shaft torsional oscillations, find the shaft mechanical frequency in the target power system and the electrical resonance frequency of the equivalent L-C circuit of the target power system, determine the complementary frequency difference between the shaft mechanical frequency and the electrical resonance frequency, and find the interaction coefficient between the units of the target power system, and use the complementary frequency difference and the interaction coefficient between the units as the oscillation stability screening indicators for shaft torsional oscillations; when the potential oscillation types include LC electromagnetic oscillations, find the line reactance before series compensation of the doubly-fed wind turbine and the series capacitor in the target power system and the equivalent capacitive reactance of the series compensation, determine the series compensation degree based on the ratio of the equivalent capacitive reactance to the line reactance, and use the series compensation degree as the oscillation stability screening indicator for LC electromagnetic oscillations; when the potential oscillation types include machine-grid coupling oscillations, find the multi-station equivalent short-circuit ratio of the target power system, and use the multi-station equivalent short-circuit ratio as the oscillation stability screening indicator for machine-grid coupling oscillations; when the potential oscillation types include VSC-HVDC-grid coupling oscillations, find the short-circuit ratio and the control link delay of the target power system, and use the short-circuit ratio and the control link delay as the oscillation stability screening indicators for VSC-HVDC-grid coupling oscillations.

[0160] Step 304: Select the operating condition variables and construct the operating condition space. That is, based on the system information of the target power system, determine the feasible operating conditions of the target power system; construct the operating condition space corresponding to the feasible operating conditions.

[0161] Step 305: Stratify the operating condition space into individual sub-spaces according to the severity of the operating conditions. Stratify the operating condition space into individual operating condition sub-spaces according to the different operating condition states of the equipment put into operation in the target power system.

[0162] Step 306: Calculate and rank the stability indices for the operating conditions of each subspace, and screen out representative operating conditions. Construct the nodal admittance matrix of the target power system at power frequency; based on the nodal admittance matrix, calculate the oscillation stability screening index for each operating condition in each subspace of operating conditions to obtain the index calculation result; based on the index calculation result, perform index ranking processing on the operating conditions of each subspace of operating conditions to obtain the index ranking result; based on the index ranking result, screen out the target typical operating conditions in each subspace of operating conditions.

[0163] Step 307: Conduct oscillation analysis on the screened operating conditions. First, determine the output conditions and fault conditions corresponding to the target typical operating conditions; based on the output conditions and fault conditions, perform oscillation stability analysis processing on the target typical operating conditions to obtain the oscillation index and oscillation stability analysis result of the target typical operating conditions.

[0164] Step 308: Output the operating conditions, indices, and analysis results of oscillation stability with high oscillation risk. By summarizing the oscillation indices and oscillation stability analysis results of different target typical operating conditions, obtain the wide-frequency oscillation identification result of the target power system.

[0165] This application proposes a stability screening index for oscillation risk assessment according to the classification of system wide-frequency oscillations, which can quickly assess the system wide-frequency oscillation risk; at the same time, according to the index, the operating conditions are screened, greatly reducing the computational workload of multi-operating condition analysis; in addition, the method of this application only depends on the power frequency impedance parameters on the grid side and the rated capacity of new energy power stations, does not depend on detailed models, is simple in calculation, and has strong practicability.

[0166] It should be understood that although the steps in the flowcharts involved in the above embodiments are shown in sequence according to the arrows, these steps do not necessarily need to be executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages. These steps or stages do not necessarily need to be executed at the same moment, but can be executed at different moments. The execution order of these steps or stages does not necessarily need to be sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0167] Based on the same inventive concept, an embodiment of this application also provides a broadband oscillation identification device for implementing the broadband oscillation identification method involved above. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the broadband oscillation identification device provided below can refer to the limitations on the broadband oscillation identification method in the above text, and will not be elaborated here.

[0168] In an exemplary embodiment, as Figure 4 shown, a broadband oscillation identification device is provided, including:

[0169] An oscillation type identification module 401, configured to determine the potential oscillation types of the target power system based on the access devices in the target power system.

[0170] A stability index screening module 403, configured to find the oscillation stability screening indexes corresponding to the potential oscillation types.

[0171] An operating condition space construction module 405, configured to construct the operating condition space of the target power system, and layer the operating condition space into respective operating condition sub-spaces according to the operating condition states.

[0172] A typical operating condition screening module 407, configured to screen out the target typical operating conditions in each operating condition sub-space according to the oscillation stability screening indexes.

[0173] A stability analysis module 409, configured to perform oscillation stability analysis processing on the target typical operating conditions to obtain the broadband oscillation identification result of the target power system.

[0174] In an embodiment, the oscillation type identification module 401 is specifically configured to: when the access devices in the target power system include rotating machines, determine that the potential oscillation types of the target power system include shaft torsional oscillations; when the access devices in the target power system include LC oscillation circuit elements, determine that the potential oscillation types of the target power system include LC electromagnetic oscillations; when the access devices in the target power system include generator sets and the target power system includes a weak power grid, determine that the potential oscillation types of the target power system include machine-grid coupling oscillations; when the access devices in the target power system include flexible HVDC transmission devices and the target power system includes a weak power grid, determine that the potential oscillation types of the target power system include VSC-HVDC-grid coupling oscillations.

[0175] In one embodiment, the stability index screening module 401 is specifically configured to: when the potential oscillation type includes shaft torsional oscillation, find the shaft mechanical frequency in the target power system and the electrical resonance frequency of the equivalent L-C circuit of the target power system, determine the complementary frequency difference between the shaft mechanical frequency and the electrical resonance frequency, and find the unit interaction coefficient of the target power system, and use the complementary frequency difference and the unit interaction coefficient as the oscillation stability screening indexes for shaft torsional oscillation; when the potential oscillation type includes LC electromagnetic oscillation, find the line reactance before series compensation of the doubly-fed wind turbine and the series capacitor in the target power system and the equivalent capacitive reactance of series compensation, determine the series compensation degree based on the ratio of the equivalent capacitive reactance to the line reactance, and use the series compensation degree as the oscillation stability screening index for LC electromagnetic oscillation; when the potential oscillation type includes machine-network coupling oscillation, find the multi-station equivalent short-circuit ratio of the target power system, and use the multi-station equivalent short-circuit ratio as the oscillation stability screening index for machine-network coupling oscillation; when the potential oscillation type includes VSC-HVDC-grid coupling oscillation, find the short-circuit ratio and the control link delay of the target power system, and use the short-circuit ratio and the control link delay as the oscillation stability screening indexes for VSC-HVDC-grid coupling oscillation.

[0176] In one embodiment, the operating condition space construction module 405 is specifically configured to: based on the system information of the target power system, determine the feasible operating conditions of the target power system; construct the operating condition space corresponding to the feasible operating conditions; and divide the operating condition space into respective operating condition sub-spaces according to different operating condition states of the equipment put into operation in the target power system.

[0177] In one embodiment, the typical operating condition screening module 407 is specifically configured to: construct the nodal admittance matrix of the target power system at power frequency; based on the nodal admittance matrix, calculate the oscillation stability screening indexes of each operating condition in each operating condition sub-space to obtain the index calculation result; based on the index calculation result, perform index sorting processing on the operating conditions of each operating condition sub-space to obtain the index sorting result; and based on the index sorting result, screen out the target typical operating conditions in each operating condition sub-space.

[0178] In one embodiment, the stability analysis module 409 is specifically configured to: determine the output conditions and fault conditions corresponding to the target typical operating conditions; perform oscillation stability analysis processing on the target typical operating conditions based on the output conditions and the fault conditions to obtain the oscillation indexes and the oscillation stability analysis results of the target typical operating conditions; and summarize the oscillation indexes and the oscillation stability analysis results of different target typical operating conditions to obtain the wide-frequency oscillation identification result of the target power system.

[0179] Each module in the above broadband oscillation identification device can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above modules can be embedded in the processor of a computer device in hardware form or be independent of it, or can be stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to each of the above modules.

[0180] In an exemplary embodiment, a computer device is provided. The computer device can be a server, and its internal structure diagram can be as Figure 5 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, 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, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data related to broadband oscillation identification and analysis. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, it implements a broadband oscillation identification method.

[0181] Those skilled in the art can understand that Figure 5 the structure shown in

[0182] is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have a different component layout.

[0183] In an embodiment, a computer device is further provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, it implements the steps in each of the above method embodiments.

[0184] In one embodiment, a computer program product or a computer program is provided. The computer program product or the computer program includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, causing the computer device to perform the steps in the foregoing method embodiments.

[0185] 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 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 need to comply with relevant regulations.

[0186] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. 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 methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this 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), magnetoresistive 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. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0187] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered to be within the scope recorded in this application.

[0188] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A broadband oscillation recognition method, characterized in that, The method includes: Based on the access devices in the target power system, determining the potential oscillation types of the target power system; Searching for oscillation stability screening indicators corresponding to the potential oscillation types; Constructing the operating condition space of the target power system and stratifying the operating condition space into respective operating condition sub-spaces according to the operating condition states; According to the oscillation stability screening indicators, screening out target typical operating conditions in each operating condition sub-space; Performing oscillation stability analysis processing on the target typical operating conditions to obtain the wide-frequency oscillation identification result of the target power system.

2. The method according to claim 1, characterized in that The determining the potential oscillation types of the target power system based on the access devices in the target power system includes: When the access devices in the target power system include rotating machines, determining that the potential oscillation types of the target power system include shaft torsional oscillations; When the access devices in the target power system include LC oscillation circuit elements, determining that the potential oscillation types of the target power system include LC electromagnetic oscillations; When the access devices in the target power system include generator sets and the target power system includes a weak power grid, determining that the potential oscillation types of the target power system include machine-grid coupling oscillations; When the access devices in the target power system include flexible HVDC transmission devices and the target power system includes a weak power grid, determining that the potential oscillation types of the target power system include VSC-HVDC-grid coupling oscillations.

3. The method according to claim 2, wherein The searching for oscillation stability screening indicators corresponding to the potential oscillation types includes: When the potential oscillation types include shaft torsional oscillations, searching for the shaft mechanical frequency in the target power system and the electrical resonance frequency of the equivalent L-C circuit of the target power system, determining the complementary frequency difference between the shaft mechanical frequency and the electrical resonance frequency, and searching for the interaction coefficient between the units of the target power system, and taking the complementary frequency difference and the interaction coefficient between the units as the oscillation stability screening indicators for shaft torsional oscillations; When the potential oscillation types include LC electromagnetic oscillations, searching for the line reactance before series compensation of the doubly-fed wind turbine and the series capacitor and the equivalent capacitive reactance of the series compensation in the target power system, determining the series compensation degree based on the ratio of the equivalent capacitive reactance to the line reactance, and taking the series compensation degree as the oscillation stability screening indicator for LC electromagnetic oscillations; When the potential oscillation types include machine-grid coupling oscillations, searching for the multi-station equivalent short-circuit ratio of the target power system, and taking the multi-station equivalent short-circuit ratio as the oscillation stability screening indicator for machine-grid coupling oscillations; When the potential oscillation types include VSC-HVDC-grid coupling oscillations, searching for the short-circuit ratio and the control link delay of the target power system, and taking the short-circuit ratio and the control link delay as the oscillation stability screening indicators for VSC-HVDC-grid coupling oscillations.

4. The method according to claim 1, wherein The constructing the operating condition space of the target power system and stratifying the operating condition space into respective operating condition sub-spaces according to the operating condition states includes: Determine the feasible operating conditions of the target power system based on the system information of the target power system; Construct the operating condition space corresponding to the feasible operating conditions; According to the different operating condition states of the equipment put into operation in the target power system, layer the operating condition space into each operating condition subspace.

5. The method according to any one of claims 1 to 4, characterized in that, The screening of the target typical conditions in each operating condition subspace according to the oscillation stability screening index includes: Construct the nodal admittance matrix of the target power system at power frequency; Based on the nodal admittance matrix, calculate the oscillation stability screening index of each operating condition in each operating condition subspace to obtain the index calculation result; Based on the index calculation result, perform index sorting processing on the operating conditions in each operating condition subspace to obtain the index sorting result; Based on the index sorting result, screen out the target typical conditions in each operating condition subspace.

6. The method according to any one of claims 1 to 4, characterized in that The oscillation stability analysis processing of the target typical conditions to obtain the broadband oscillation identification result of the target power system includes: Determine the output conditions and fault conditions corresponding to the target typical conditions; Based on the output conditions and the fault conditions, perform oscillation stability analysis processing on the target typical conditions to obtain the oscillation index and oscillation stability analysis result of the target typical conditions; Summarize the oscillation indexes and oscillation stability analysis results of different target typical conditions to obtain the broadband oscillation identification result of the target power system.

7. A wideband oscillation recognition device, characterized in that, The device includes: An oscillation type identification module, configured to determine the potential oscillation type of the target power system based on the access devices in the target power system; A stability index screening module, configured to find the oscillation stability screening index corresponding to the potential oscillation type; An operating condition space construction module, configured to construct the operating condition space of the target power system, and layer the operating condition space into each operating condition subspace according to the operating condition state; A typical condition screening module, configured to screen out the target typical conditions in each operating condition subspace according to the oscillation stability screening index; A stability analysis module, configured to perform oscillation stability analysis processing on the target typical conditions to obtain the broadband oscillation identification result of the target power system.

8. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, 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 the 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 the processor, the steps of the method according to any one of claims 1 to 6 are implemented.

Images