Method for monitoring and evaluating power system broadband oscillation, control device and power system

Abstract

The application discloses a kind of power system broadband oscillation monitoring evaluation method, control device and power system, it is related to power system technical field.The method of power system broadband oscillation monitoring evaluation method includes: obtaining the fundamental wave phasor parameter and first broadband phasor parameter of target monitoring node on power system, to determine whether power system is in target state;In the case where power system is in target state, target detection node and target detection frequency band are determined, to generate corresponding perturbation probe signal;Superimpose perturbation probe signal on the control instruction of power electronic equipment, and obtain the second broadband phasor data on each monitoring node when not superimposed perturbation probe signal and the third broadband phasor data on each monitoring node when superimposed perturbation probe signal;Based on second broadband phasor data and third broadband phasor data, determine the oscillation risk degree of each monitoring node.The application aims at improving the accuracy of power system broadband oscillation monitoring.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a method, control device, and power system for monitoring and evaluating broadband oscillations in power systems. Background Technology

[0002] With the increasing integration of power electronic devices such as wind power, photovoltaics, energy storage, flexible DC transmission, and SVG into power systems, the dynamic characteristics of power systems have undergone significant changes. Traditional power grids are mainly dominated by synchronous generators, and their dynamic behavior is relatively concentrated in the low-frequency electromechanical oscillation range. However, with the integration of a high proportion of new energy sources and power electronic devices, broadband oscillation problems have emerged in the power system caused by the interaction of converter control, grid impedance, substation-level control, flexible DC control, and reactive power compensation control.

[0003] Wideband oscillations have a broad frequency range, occurring in subsynchronous / supersynchronous bands from several Hz to tens of Hz, or even in hundreds of Hz or higher frequencies. These oscillations typically exhibit the following characteristics: they may cover low-frequency, subsynchronous, mid-frequency, and high-frequency ranges, making comprehensive coverage difficult with single-band monitoring methods; they may be caused by a combination of factors, including renewable energy converter control parameters, grid strength, flexible DC control strategies, SVG control parameters, parallel coupling of multiple power plants, and line impedance characteristics; changes in renewable energy output, flexible DC transmission power, load levels, equipment commissioning / discontinuation status, and grid operation modes can rapidly decrease the system's wideband stability margin; even before significant oscillations appear in the power system, the apparent operating status may be normal, but impedance matching conditions or loop gains in certain frequency bands may already be approaching instability boundaries; wideband oscillations often involve multiple nodes, multiple devices, and multiple frequency bands, making it difficult to determine specific risk frequency bands, risk nodes, and equipment coupling relationships based solely on oscillation amplitude or alarm signals.

[0004] Most existing broadband oscillation monitoring and risk assessment methods employ passive observation, offline simulation, historical operating condition matching, or data-driven prediction. Therefore, these methods cannot accurately and effectively monitor and assess broadband oscillations in power systems. Summary of the Invention

[0005] The main objective of this invention is to provide a method, control device, and power system for monitoring and evaluating broadband oscillations in power systems, aiming to improve the accuracy of broadband oscillation monitoring in power systems.

[0006] To achieve the above objectives, this invention proposes a method for monitoring and evaluating broadband oscillations in power systems. The power system includes multiple power electronic devices and multiple monitoring devices installed at various monitoring nodes. The method for monitoring and evaluating broadband oscillations in power systems includes: The fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system are obtained to determine whether the power system is in the target state. When the power system is in the target state, the target detection node and target detection frequency band are determined in order to generate the corresponding perturbation probe signal; The perturbation probe signal is superimposed on the control command of the power electronic equipment, and the second broadband phasor data of each monitoring node without the perturbation probe signal superimposed and the third broadband phasor data of each monitoring node with the perturbation probe signal superimposed are obtained. Based on the second and third broadband phasor data, the degree of oscillation risk of each monitoring node is determined.

[0007] In one embodiment, the step of obtaining the fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system to determine whether the power system is in the target state specifically includes: The fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system are obtained. When the fundamental phasor parameters and the first broadband phasor parameters are within the preset range of the fundamental phasor parameters and the preset range of the broadband phasor parameters, respectively, the power system is determined to be in the target state. The fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system are obtained. If the fundamental phasor parameters are not within the preset range of the fundamental phasor parameters or the first broadband phasor parameters are not within the preset range of the broadband phasor parameters, it is determined that the power system is not in the target state.

[0008] In one embodiment, the step of determining the target detection node and target detection frequency band to generate the corresponding perturbation probe signal when the power system is in the target state specifically includes: When the power system is in the target state, obtain the operating status parameters of the power electronic equipment on each corresponding monitoring node; The target detection nodes are determined based on the target detection node weighting algorithm and the operating status parameters of the power electronic equipment on each monitoring node; The target detection frequency band is determined based on the target detection frequency band weighting algorithm and the operating status parameters of the power electronic equipment on each monitoring node; Based on the target detection node, the target detection frequency band, and the multiple sinusoidal superposition function, the corresponding perturbation probe signal is generated.

[0009] In one embodiment, the target detection node weighting algorithm is as follows:

[0010] Among them, the Indicates the first The detection applicability of each monitoring node; This indicates the capacity margin of power electronic equipment; the aforementioned This indicates the control response capability of power electronic equipment; the This represents the excitation capability of the j-th monitoring node for the target detection frequency band; the... This represents the observability of the j-th monitoring node relative to the risk area; the This indicates a safety constraint penalty item; the aforementioned to These are the weighting coefficients; The target detection frequency band weighting algorithm is as follows:

[0011] Among them, the Indicates the first The detection priority of each frequency band; Indicates historical risk level; the stated Indicates the uncertainty of risk; the stated Indicates the multi-node coupling strength; the This indicates a decreasing trend in stability margin; the aforementioned Indicates the degree of broadband phasor energy anomaly; the to These are the weighting coefficients; The superposition function of multiple sinuses is:

[0012] Among them, the This represents the perturbation probe signal; the Indicates the number of detection frequency points; the Indicates the first The perturbation amplitude at each detection frequency point; Indicates the first The frequency of each detection point; the Indicates the first The initial phase of each detection frequency point.

[0013] In one embodiment, after the step of generating the corresponding perturbation probe signal based on the target detection node, the target detection frequency band, and the multiple sinusoidal superposition function, the method further includes: The perturbation amplitude of the perturbation probe signal is smaller than the target amplitude; The perturbation amplitude is ; Among them, the This represents the maximum amplitude determined based on the rated capacity of the power electronic equipment; the This represents the maximum amplitude determined based on the target detection node voltage deviation limit; the This represents the maximum amplitude determined based on the current margin of the power electronic equipment; the This represents the maximum amplitude determined based on the reactive power capacity margin; the... This represents the maximum amplitude determined based on broadband energy or power quality constraints; the... This indicates the maximum amplitude determined based on the protection or operational safety boundary.

[0014] In one embodiment, the step of determining the oscillation risk level of each monitoring node based on the second broadband phasor data and the third broadband phasor data specifically includes: Based on the difference between the second and third broadband phasor data of each monitoring node, the voltage phasor response increment and current phasor response increment of each monitoring node are determined. Based on the voltage phasor response increment and current phasor response increment of each monitoring node, the equivalent impedance and equivalent admittance of each monitoring node are determined. Based on the equivalent impedance and equivalent admittance of each monitoring node, the stable distance margin of each monitoring node in the target detection frequency band is determined. Based on the stable distance margin of each monitoring node in the target detection frequency band, the degree of oscillation risk of each monitoring node in the target detection frequency band is determined.

[0015] In one embodiment, the step of determining the voltage phasor response increment and current phasor response increment of each monitoring node based on the difference between the second broadband phasor data and the third broadband phasor data of each monitoring node specifically includes:

[0016]

[0017] Among them, the The first in the second wideband phasor data The monitoring node at the first The voltage broadband phasor at each detection frequency point, the The first in the second wideband phasor data The monitoring node at the first The current broadband phasor at each detection frequency point, the The third wideband phasor data The monitoring node at the first The voltage broadband phasor at each detection frequency point, the The third wideband phasor data The monitoring node at the first The current broadband phasor at each detection frequency point, the Indicates the first The monitoring node at the first The voltage phasor response increment at each detection frequency point, the Indicates the first The monitoring node at the first The increment of the current phasor response at each detection frequency; The steps for determining the equivalent impedance and equivalent admittance of each monitoring node based on the voltage phasor response increment and current phasor response increment of each monitoring node are as follows:

[0018]

[0019] in, This represents the voltage broadband phasor response increment vector for each monitoring node; This represents the current or equivalent current disturbance increment vector for each monitoring node. The equivalent impedance of each monitoring node is given. The equivalent admittance for each monitoring node. For measurement error and modeling error; The specific steps for determining the stable range margin of each monitoring node in the target detection frequency band based on the equivalent impedance and equivalent admittance of each monitoring node are as follows:

[0020] in, The equivalent impedance on the grid side. For the equivalent admittance of power electronic equipment, For the first The loop gain matrix at each detection frequency point; the equivalent impedance and equivalent admittance of each monitoring node include the equivalent impedance on the grid side and the equivalent admittance on the power electronic equipment side.

[0021] In one embodiment, after the step of acquiring the fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system to determine whether the power system is in the target state, the method further includes: When the power system is in the target state, multiple target detection nodes and multiple target detection frequency bands are determined, and multiple corresponding perturbation probe signals are generated in sequence. Multiple corresponding perturbation probe signals are sequentially superimposed on the control commands of the power electronic equipment according to the evaluation cycle, and the second broadband phasor data of each monitoring node when multiple perturbation probe signals are not superimposed and the third broadband phasor data of each monitoring node when multiple perturbation probe signals are superimposed are sequentially acquired according to the evaluation cycle. Based on multiple second-band broadband phasor data and multiple third-band broadband phasor data, the oscillation risk level of each monitoring node in multiple evaluation periods is determined.

[0022] The present invention also proposes a control device, the control device comprising a memory, a processor, and a power system broadband oscillation monitoring and evaluation program stored in the memory and executable on the processor, the power system broadband oscillation monitoring and evaluation program being configured to implement the steps of the power system broadband oscillation monitoring and evaluation method as described in any of the preceding claims.

[0023] The present invention also proposes a power system comprising multiple power electronic devices, multiple monitoring devices installed at various monitoring nodes, and a control device as described above.

[0024] This invention employs a monitoring and evaluation method for broadband oscillations in power systems, which can effectively improve the accuracy of broadband oscillation monitoring in power systems. The method includes: acquiring the fundamental phasor parameters and first broadband phasor parameters of the target monitoring nodes in the power system to determine whether the power system is in a target state; if the power system is in the target state, determining the target detection node and target detection frequency band to generate a corresponding perturbation probe signal; superimposing the perturbation probe signal onto the control commands of the power electronic equipment, and acquiring second broadband phasor data on each monitoring node without the perturbation probe signal superimposed and third broadband phasor data on each monitoring node with the perturbation probe signal superimposed; and determining the oscillation risk level of each monitoring node based on the second and third broadband phasor data. It is understandable that by actively acquiring the fundamental phasor parameters and the first broadband phasor parameters of the power system, and assessing whether the current state of the power system is suitable for injecting a perturbation probe signal, and based on the second broadband phasor data and the third broadband phasor data acquired after the perturbation probe signal injection, the oscillation risk level of each monitoring node is determined, and then corresponding control suggestions are output based on the oscillation risk level of each monitoring node, so as to improve the stability of the power system operation. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0026] Figure 1 This is a flowchart illustrating the monitoring and evaluation method for broadband oscillations in power systems according to the present invention. Figure 2 This is a flowchart illustrating an embodiment of the monitoring and evaluation method for broadband oscillations in power systems according to the present invention. Figure 3This is a flowchart illustrating another embodiment of the monitoring and evaluation method for broadband oscillations in power systems according to the present invention; Figure 4 This is a flowchart illustrating another embodiment of the monitoring and evaluation method for broadband oscillations in power systems according to the present invention; Figure 5 This is a flowchart illustrating another embodiment of the monitoring and evaluation method for broadband oscillations in power systems according to the present invention.

[0027] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0030] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0031] With the increasing integration of power electronic devices such as wind power, photovoltaics, energy storage, flexible DC transmission, and SVG into power systems, the dynamic characteristics of power systems have undergone significant changes. Traditional power grids are mainly dominated by synchronous generators, and their dynamic behavior is relatively concentrated in the low-frequency electromechanical oscillation range. However, with the integration of a high proportion of new energy sources and power electronic devices, broadband oscillation problems have emerged in the power system caused by the interaction of converter control, grid impedance, substation-level control, flexible DC control, and reactive power compensation control.

[0032] Wideband oscillations have a broad frequency range, occurring in subsynchronous / supersynchronous bands from several Hz to tens of Hz, or even in hundreds of Hz or higher frequencies. These oscillations typically exhibit the following characteristics: they may cover low-frequency, subsynchronous, mid-frequency, and high-frequency ranges, making comprehensive coverage difficult with single-band monitoring methods; they may be caused by a combination of factors, including renewable energy converter control parameters, grid strength, flexible DC control strategies, SVG control parameters, parallel coupling of multiple power plants, and line impedance characteristics; changes in renewable energy output, flexible DC transmission power, load levels, equipment commissioning / discontinuation status, and grid operation modes can rapidly decrease the system's wideband stability margin; even before significant oscillations appear in the power system, the apparent operating status may be normal, but impedance matching conditions or loop gains in certain frequency bands may already be approaching instability boundaries; wideband oscillations often involve multiple nodes, multiple devices, and multiple frequency bands, making it difficult to determine specific risk frequency bands, risk nodes, and equipment coupling relationships based solely on oscillation amplitude or alarm signals.

[0033] Most existing broadband oscillation monitoring and risk assessment methods employ passive observation, offline simulation, historical operating condition matching, or data-driven prediction. Therefore, these methods cannot accurately and effectively monitor and assess broadband oscillations in power systems.

[0034] To solve the above problems, refer to Figure 1 This invention proposes a method for monitoring and evaluating broadband oscillations in a power system. The power system includes multiple power electronic devices and multiple monitoring devices installed at various monitoring nodes. The method for monitoring and evaluating broadband oscillations in a power system includes: Step S100: Obtain the fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system to determine whether the power system is in the target state; Step S200: When the power system is in the target state, determine the target detection node and the target detection frequency band to generate the corresponding perturbation probe signal; Step S300: Superimpose the perturbation probe signal onto the control command of the power electronic device, and acquire the second broadband phasor data of each monitoring node without superimposing the perturbation probe signal and the third broadband phasor data of each monitoring node with superimposed the perturbation probe signal; Step S400: Based on the second broadband phasor data and the third broadband phasor data, determine the oscillation risk level of each monitoring node.

[0035] In this embodiment, power electronic equipment includes, but is not limited to, new energy converters, energy storage converters, flexible DC converter stations, and SVG. Monitoring nodes include, but are not limited to, grid connection points of new energy power plants, grid connection points of energy storage converters, AC side buses of flexible DC converter stations, grid connection points of SVG, STATCOM or other reactive power compensation devices, generator terminals of thermal power units, busbars or grid connection points of step-up substations, busbars of new energy collection stations, grid connection points of large-capacity loads, key AC buses of AC / DC hybrid systems, and transmission line ports with broadband oscillation risks. Monitoring equipment can be implemented using broadband measurement devices, with the number of detection devices corresponding one-to-one with the number of monitoring nodes, thereby enabling the detection devices to collect fundamental phasor data and broadband phasor data at each monitoring node.

[0036] In this embodiment, by acquiring real-time measurement data output by a broadband measurement device installed at the monitoring node, it is further determined whether the power system is in the target state. The real-time measurement data includes fundamental phasor parameters and first broadband phasor parameters. The fundamental phasor parameters include fundamental voltage phasor, fundamental current phasor, fundamental frequency, fundamental active power, fundamental reactive power, fundamental voltage phase angle, fundamental current phase angle, and corresponding timestamp. The first broadband phasor parameters include voltage broadband phasor, current broadband phasor, broadband phasor amplitude, broadband phasor phase, broadband phasor frequency, and broadband phasor timestamp within the target frequency point or target frequency band. It can be understood that the fundamental phasor parameters are used to characterize the current operating state of the power system from aspects such as fundamental voltage amplitude, fundamental current amplitude, system frequency, active power, reactive power, voltage phase angle, current phase angle, and their rate of change. The operating status of a power system can include whether voltage exceeds limits, whether frequency deviates from rated values, power flow direction and magnitude, renewable energy output level, energy storage charging and discharging status, reactive power support margin, equipment capacity margin, grid strength, and critical section load factor. The first broadband phasor parameter is used to characterize the broadband dynamic response characteristics of voltage and current response within the target frequency point or target frequency band, including amplitude, phase, frequency, increments before and after injection, amplitude growth rate, phase change rate, response duration, and decay rate. By using the fundamental phasor parameter and the first broadband phasor parameter, it can be determined whether the power system is in the target state.

[0037] By collecting fundamental phasor data and broadband phasor data output from monitoring devices installed at power system nodes, the current operating status is identified based on the fundamental phasor data. Combined with historical risk information, broadband phasor energy, and risk uncertainty, the target frequency band and detection node are determined. A low-amplitude broadband perturbation probe signal is generated and injected into the perturbation signal by new energy converters, energy storage converters, flexible DC converter stations, SVG, or other controllable power electronic devices. Subsequently, based on the broadband phasor data output from the broadband measurement device, the voltage and current broadband phasor response increments before and after the perturbation probe signal injection are extracted. The equivalent impedance, admittance, or loop gain characteristics of the system are identified online. The stability margin, margin change rate, multi-node coupling amplification factor, broadband phasor response energy, and identification uncertainty of each node and frequency band are calculated, forming a broadband oscillation risk index and a node-frequency band risk map. This allows for proactive acquisition of broadband dynamic characteristics under current operating conditions before significant power system oscillations occur, enabling early warning of broadband oscillation risks, risk frequency band location, and risk node location.

[0038] refer to Figure 2 Optionally, the step of obtaining the fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system to determine whether the power system is in the target state specifically includes: Step S110: Obtain the fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system. When the fundamental phasor parameters and the first broadband phasor parameters are respectively within the preset range of the fundamental phasor parameters and the preset range of the broadband phasor parameters, determine that the power system is in the target state. Step S120: Obtain the fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system. If the fundamental phasor parameters are not within the preset range of fundamental phasor parameters or the first broadband phasor parameters are not within the preset range of broadband phasor parameters, determine that the power system is not in the target state.

[0039] In this embodiment, multiple monitoring devices will monitor each monitoring node, thereby outputting the fundamental phasor parameters and the first broadband phasor parameters corresponding to each monitoring node. The control device can determine the operating state of the power electronic equipment through the fundamental phasor parameters and the first broadband phasor parameters of each monitoring node. For example, at the i-th monitoring node, the operating state of the power electronic system can be expressed as follows: .in, Indicates the first The fundamental voltage amplitude of each monitoring node; This represents the fundamental current amplitude of the i-th monitoring node; Indicates the first The fundamental frequency of each monitoring node; Indicates the first The active power of each monitoring node; Indicates the first The reactive power of each monitoring node; Indicates the first Voltage phase angle of each monitoring node; Indicates the first The current phase angle of each monitoring node. Specifically, in a power system with a nominal frequency of 50Hz, the following parameters can be set: 0.95pu≤node fundamental voltage≤1.05pu, |f-50Hz|≤0.05Hz, node fundamental current not exceeding 80% of the equipment's allowable current, active or reactive power capacity margin of power electronic equipment not less than 10%, critical section load rate not exceeding 90%, no protection action or blocking signal within the past 10 seconds, and background broadband phasor energy of the target frequency band lower than the preset warning threshold. When the fundamental phasor parameter and the first broadband phasor parameter are within the preset fundamental phasor parameter range and the preset broadband phasor parameter range, respectively, the current power system operating condition is deemed suitable for low-amplitude active perturbation detection; when the fundamental phasor parameter is not within the preset fundamental phasor parameter range or the first broadband phasor parameter is not within the preset broadband phasor parameter range, detection is suspended. The preset fundamental phasor parameter range or preset wideband phasor parameter range can be the preset parameter range of the fundamental voltage of the node, the preset parameter range of the fundamental current of the node, or the preset parameter range of the active or reactive power capacity margin of the power electronic equipment. For example, at the grid connection point N1 of the 220kV new energy collection station, if the fundamental measurement results are voltage 1.02pu, current 0.63pu, frequency 50.01Hz, active power 180MW, reactive power 15Mvar, and voltage phase angle -3.2°, it can be characterized that the node is in an operating state with qualified voltage, normal frequency, and still has a certain reactive power regulation margin, that is, the power system is in the target state.

[0040] In this embodiment, when the power system is determined to be in the target state, i.e., when the power system is in a state where perturbation probe signals can be injected, the control device will determine the corresponding target detection node and target detection frequency band based on the fundamental phasor parameters, the first broadband phasor parameters, and the preset parameters of each detection node, each detection device, and each power electronic device, in order to generate the corresponding perturbation probe signal. The determination of the target detection node and target detection frequency band can be confirmed based on a corresponding algorithm. It is understood that while multiple power electronic devices are installed on the power system, not all power electronic devices are suitable for injecting perturbation probe signals. The broadband oscillation range of the power system can also be divided into multiple frequency bands, such as the subsynchronous band (5 to 45 Hz), the supersynchronous band (55 Hz to 100 Hz), the mid-frequency band (100 Hz to 500 Hz), and the high-frequency band (500 Hz to 2500 Hz). Once the target detection node and target detection frequency band are determined, perturbation probe signals can be generated using methods such as multi-sine superposition signals, sparse multi-frequency point signals, segmented frequency sweep signals, pseudo-random sequence signals, or orthogonally coded multi-node signals.

[0041] refer to Figure 3 Optionally, the step of determining the target detection node and target detection frequency band to generate the corresponding perturbation probe signal when the power system is in the target state specifically includes: Step S210: When the power system is in the target state, obtain the operating status parameters of the power electronic equipment on each monitoring node; Step S220: Determine the target detection nodes based on the target detection node weighting algorithm and the operating status parameters of the power electronic equipment on each monitoring node; Step S230: Determine the target detection frequency band based on the target detection frequency band weighting algorithm and the operating status parameters of the power electronic equipment on each monitoring node; Step S240: Generate the corresponding perturbation probe signal based on the target detection node, the target detection frequency band, and the multiple sinusoidal superposition function.

[0042] In this embodiment, the target detection node is determined using a target detection node weighting algorithm and the operating status parameters of the power electronic devices on each monitoring node. The target detection frequency band is determined using a target detection frequency band weighting algorithm and the operating status parameters of the power electronic devices on each monitoring node. Specifically, the target detection node weighting algorithm is as follows:

[0043] Among them, the Indicates the first The detection applicability of each monitoring node; This indicates the capacity margin of power electronic equipment; the aforementioned This indicates the control response capability of power electronic equipment; the This represents the excitation capability of the j-th monitoring node for the target detection frequency band; the... This represents the observability of the j-th monitoring node relative to the risk area; the This indicates a safety constraint penalty item; the aforementioned to These are the weighting coefficients; The target detection frequency band weighting algorithm is as follows:

[0044] Among them, the Indicates the first The detection priority of each frequency band; Indicates historical risk level; the stated Indicates the uncertainty of risk; the stated Indicates the multi-node coupling strength; the This indicates a decreasing trend in stability margin; the aforementioned Indicates the degree of broadband phasor energy anomaly; the to For example, the weighting coefficients are as follows. It is important to note that the detection applicability of monitoring nodes, the capacity margin of power electronic equipment, the control response capability of power electronic equipment, the excitation capability of the target detection frequency band, the observability of the risk area, the safety constraint penalty term, the weighting coefficients, the detection priority, the historical risk level, the risk uncertainty, the multi-node coupling strength, the stability margin decline trend, and the degree of broadband phasor energy anomaly can be obtained through monitoring equipment or preset in advance. For example, let the weights be... to The values ​​are 0.25, 0.20, 0.20, 0.20, and 0.15, respectively. For SVG node P2, if the capacity margin... =0.80, control response capability =0.90, Motivational ability =0.85, observability =0.75, safety constraint penalty =0.10, then the detection suitability can be calculated as 0.25×0.80+0.20×0.90+0.20×0.85+0.20×0.75-0.15×0.10=0.685. If the detection suitability of energy storage node P1 and photovoltaic node P3 are 0.620 and 0.540 respectively, then SVG node P2 is preferentially selected as the detection node for this round. Alternatively, P2 and P1 can be selected for multi-node collaborative detection. In addition, when determining the frequency band to be detected, a preset threshold for detection priority can be set, and the judgment can be made in combination with the ranking results. For example, the preset threshold can be set to 0.60. When the detection priority of a candidate frequency band is not lower than 0.60, the frequency band is included in the frequency band to be detected in this round; when the detection priority is not lower than 0.80, the frequency band is marked as a key detection frequency band and the detection frequency is increased; when the detection priority of all candidate frequency bands is lower than 0.40, only low-frequency routine inspection detection is performed. For example, if the detection priorities of the four candidate frequency bands F1 to F4 are 0.32, 0.78, 0.61 and 0.44 respectively, then F2 and F3 both exceed the preset threshold of 0.60, and the system selects F2 and F3 as the frequency bands to be detected in this round; among them, F2 has the highest priority and can be allocated a longer data window or a higher detection frequency density.

[0045] Furthermore, the perturbation probe signal can be generated using a multi-sine superposition function. The multi-sine superposition function is:

[0046] Among them, the This represents the perturbation probe signal; the Indicates the number of detection frequency points; the Indicates the first The perturbation amplitude at each detection frequency point; Indicates the first The frequency of each detection point; the Indicates the first The initial phase of each detection frequency point.

[0047] Understandably, the number of detection frequency points can be set according to the target detection frequency band. For example, if the target detection frequency band is 55Hz to 60Hz, then a detection frequency point can be set every 1Hz, i.e., detection frequency points are 55Hz, 56Hz, 57Hz, 58Hz, 56Hz, 60Hz, etc. In this case, the number of detection frequency points is 6, and the frequencies of the detection frequency points correspond to 55Hz, 56Hz, 57Hz, 58Hz, 56Hz, and 60Hz, respectively. Furthermore, the perturbation amplitude of the perturbation probe signal needs to be determined according to the target detection node to avoid the perturbation amplitude of the perturbation probe signal affecting the normal operation of the power system.

[0048] Optionally, after the step of generating the corresponding perturbation probe signal based on the target detection node, the target detection frequency band, and the multiple sinusoidal superposition function, the method further includes: The perturbation amplitude of the perturbation probe signal is smaller than the target amplitude; The perturbation amplitude is ; Among them, the This represents the maximum amplitude determined based on the rated capacity of the power electronic equipment; the This represents the maximum amplitude determined based on the target detection node voltage deviation limit; the This represents the maximum amplitude determined based on the current margin of the power electronic equipment; the This represents the maximum amplitude determined based on the reactive power capacity margin; the... This represents the maximum amplitude determined based on broadband energy or power quality constraints; the... This indicates the maximum amplitude determined based on the protection or operational safety boundary.

[0049] Understandably, limiting the amplitude of the perturbation probe signal can effectively prevent its input from affecting the stability of the power system. It's important to note that the perturbation probe signal input needs to be superimposed on the control commands of the power electronic equipment. Therefore, monitoring equipment is required to monitor the power electronic equipment to determine the maximum amplitude determined by its rated capacity, the maximum amplitude determined by the target probe node voltage deviation limit, the maximum amplitude determined by the power electronic equipment's current margin, and the maximum amplitude determined by the reactive power capacity margin. The maximum amplitudes determined based on broadband energy or power quality constraints and the maximum amplitudes determined based on protection or operational safety boundaries can be preset in advance. When the perturbation amplitude exceeds any one of the following: the maximum amplitude determined by the rated capacity of the power electronic equipment, the maximum amplitude determined by the voltage deviation limit of the target detection node, the maximum amplitude determined by the current margin of the power electronic equipment, the maximum amplitude determined by the reactive capacity margin, the maximum amplitude determined based on broadband energy or power quality constraints, or the maximum amplitude determined based on protection or operational safety boundaries, it is necessary to reduce the perturbation amplitude of the perturbation probe signal or stop the superposition of perturbation probe signals to avoid the input of the perturbation probe signal affecting the stability of the power system operation.

[0050] In this embodiment, by superimposing the perturbation probe signal onto the control command of the power electronic device, and acquiring the second broadband phasor data of each monitoring node without the perturbation probe signal and the third broadband phasor data of each monitoring node with the perturbation probe signal superimposed, the oscillation risk level of each monitoring node can be determined. The control command of the power electronic device includes, but is not limited to, active power setpoints, reactive power setpoints, d-axis current setpoints, q-axis current setpoints, AC voltage setpoints, DC voltage setpoints, virtual impedance parameters, station-level reactive voltage control commands, flexible DC converter station power control commands, and SVG or STATCOM reactive power regulation commands. The superposition of the perturbation probe signal does not change the original main control objective of the power electronic device; it is only superimposed as a low-amplitude detection component in the control command. For example, for an energy storage converter, the perturbation probe signal can be superimposed on the q-axis current command.

[0051] in: This represents the q-axis current setpoint after superimposing the perturbation probe signal; This represents the original q-axis current setpoint; This indicates a broadband perturbation probe signal.

[0052] For SVG, a perturbation probe signal can be superimposed on the reactive power command:

[0053] in: This represents the reactive power setpoint after superimposing the perturbation probe signal; This represents the original reactive power setpoint.

[0054] In this embodiment, multiple monitoring devices can monitor each monitoring node before and during the superposition of perturbation probes, and output wideband voltage and current phasors. The control device determines the oscillation risk level of each monitoring node by determining the wideband voltage and current phasors.

[0055] By employing a monitoring and evaluation method for broadband oscillations in power systems, the accuracy of broadband oscillation monitoring in power systems can be effectively improved. The method includes: acquiring the fundamental phasor parameters and first broadband phasor parameters of the target monitoring nodes in the power system to determine whether the power system is in a target state; if the power system is in the target state, determining the target detection node and target detection frequency band to generate corresponding perturbation probe signals; superimposing the perturbation probe signals onto the control commands of the power electronic equipment, and acquiring second broadband phasor data at each monitoring node without superimposed perturbation probe signals and third broadband phasor data at each monitoring node with superimposed perturbation probe signals; and determining the oscillation risk level of each monitoring node based on the second and third broadband phasor data. It is understandable that by actively acquiring the fundamental phasor parameters and the first broadband phasor parameters of the power system, and assessing whether the current state of the power system is suitable for injecting a perturbation probe signal, and based on the second broadband phasor data and the third broadband phasor data acquired after the perturbation probe signal injection, the oscillation risk level of each monitoring node is determined, and then corresponding control suggestions are output based on the oscillation risk level of each monitoring node, so as to improve the stability of the power system operation.

[0056] refer to Figure 4 In one embodiment of the present invention, the step of determining the oscillation risk level of each monitoring node based on the second broadband phasor data and the third broadband phasor data specifically includes: Step S410: Based on the difference between the second broadband phasor data and the third broadband phasor data of each monitoring node, determine the voltage phasor response increment and the current phasor response increment of each monitoring node; Step S420: Based on the voltage phasor response increment and current phasor response increment of each monitoring node, determine the equivalent impedance and equivalent admittance of each monitoring node. Step S430: Based on the equivalent impedance and equivalent admittance of each monitoring node, determine the stable distance margin of each monitoring node in the target detection frequency band; Step S440: Based on the stable distance margin of each monitoring node in the target detection frequency band, determine the degree of oscillation risk of each monitoring node in the target detection frequency band.

[0057] In this embodiment, multiple monitoring devices continuously monitor each monitoring node to determine the second and third broadband phasor data of each monitoring node. The control device, through communication connections with these multiple monitoring devices, subtracts the second and third broadband phasor data of each monitoring node to obtain the difference value. Based on this difference value, the voltage phasor response increment and current phasor response increment of each monitoring node are determined. It is understood that the ratio of the voltage phasor response increment to the current phasor response increment is the equivalent impedance of the corresponding monitoring node, and the ratio of the current phasor response increment to the voltage phasor response increment is the equivalent admittance of the corresponding monitoring node. Based on this, the stability distance margin of each monitoring node in the target detection frequency band can be calculated. Then, by determining the magnitude of the stability distance margin of each monitoring node in the target detection frequency band, the oscillation risk level of each monitoring node in the target detection frequency band can be determined. The smaller the stable distance margin in the target detection frequency band, the greater the oscillation risk of the monitoring node in the target detection frequency band.

[0058] Optionally, the step of determining the voltage phasor response increment and current phasor response increment of each monitoring node based on the difference between the second broadband phasor data and the third broadband phasor data of each monitoring node specifically includes:

[0059]

[0060] Among them, the The first in the second wideband phasor data The monitoring node at the first The voltage broadband phasor at each detection frequency point, the The first in the second wideband phasor data The monitoring node at the first The current broadband phasor at each detection frequency point, the The third wideband phasor data The monitoring node at the first The voltage broadband phasor at each detection frequency point, the The third wideband phasor data The monitoring node at the first The current broadband phasor at each detection frequency point, the Indicates the first The monitoring node at the first The voltage phasor response increment at each detection frequency point, the Indicates the first The monitoring node at the first The increment of the current phasor response at each detection frequency; The steps for determining the equivalent impedance and equivalent admittance of each monitoring node based on the voltage phasor response increment and current phasor response increment of each monitoring node are as follows:

[0061]

[0062] in, This represents the voltage broadband phasor response increment vector for each monitoring node; This represents the current or equivalent current disturbance increment vector for each monitoring node. The equivalent impedance of each monitoring node is given. The equivalent admittance for each monitoring node. For measurement error and modeling error; The specific steps for determining the stable range margin of each monitoring node in the target detection frequency band based on the equivalent impedance and equivalent admittance of each monitoring node are as follows:

[0063] in, The equivalent impedance on the grid side. For the equivalent admittance of power electronic equipment, For the first The loop gain matrix at each detection frequency point; the equivalent impedance and equivalent admittance of each monitoring node include the equivalent impedance on the grid side and the equivalent admittance on the power electronic equipment side.

[0064] In this embodiment, the loop gain matrix is ​​obtained by calculating the equivalent impedance and equivalent admittance of each monitoring node. The eigenvalue distance of the loop gain matrix can be calculated as follows:

[0065] Among them, the Indicates the first The stable distance margin at each frequency point, the The first element of the loop gain matrix represents the... Each eigenvalue. When The smaller the value, the closer the system is to the instability boundary at that frequency. For example, at a frequency of 180Hz... =0.72∠-145°, then the gain margin can be calculated as 1 / 0.72, approximately 1.39 times; the phase margin can be calculated as 180°-145°, which is 35°; the distance from the critical point can be calculated as |1+ The calculated value is approximately 0.58, indicating that this frequency point still has a certain stability margin. If it is identified at 210Hz... =0.96∠-176°, then its distance from the critical point is about 0.08, indicating that the system is close to the unstable boundary at this frequency point. This frequency point or the frequency band should be judged as high risk and the priority of subsequent detection should be increased.

[0066] Based on this, the oscillation risk level corresponding to each frequency point in the target detection frequency band at the target detection node can be constructed. For monitoring nodes... and target detection frequency band Alternatively, construct a broadband oscillation risk index for each frequency point k in the target detection frequency band:

[0067] in, Indicates monitoring node In frequency band The risk value of wideband oscillation. Indicates stability margin, Indicates the rate of change of stability margin. Indicates the multi-node coupling amplification factor. Indicates the uncertainty of identification. This represents the broadband phasor response energy. to These are the weighting coefficients.

[0068] The stability margin risk function can be defined as:

[0069] in, To prevent positive numbers with a denominator of zero.

[0070] The margin decline risk function can be defined as: ; The multi-node coupling amplification factor can be defined as: ; The broadband phasor response energy can be defined as: .

[0071] Furthermore, based on the risk indicators of each detection node and each target detection frequency band... This forms a node-frequency band risk map.

[0072] Risk maps can include: node-frequency two-dimensional risk heat map; region-frequency band risk distribution map; risk frequency band ranking table; risk node ranking table; stability margin trend curve; broadband phasor response energy trend curve; multi-node coupling strength relationship diagram; and risk confidence distribution map.

[0073] Risk levels can be classified according to risk indicators as follows:

[0074] in, Indicates monitoring node In frequency band Risk level; to This sets a preset risk threshold. The risk levels can be interpreted as follows: Level 1 corresponds to low risk; Level 2 corresponds to risk of concern; Level 3 corresponds to risk of warning; Level 4 corresponds to high risk; and Level 5 corresponds to emergency risk.

[0075] Furthermore, once the node-frequency band risk map is determined, corresponding control measure recommendations can be generated. These recommendations include, but are not limited to, adjusting the reactive power voltage control parameters of renewable energy power plants, adjusting the virtual impedance parameters of converters, adjusting the phase-locked loop bandwidth, adjusting the current loop control parameters, enabling additional damping control, adjusting the charging and discharging power of energy storage, adjusting the active or reactive power of flexible DC converter stations, adjusting the SVG or STATCOM control mode, adjusting the output of renewable energy power plants, changing the on / off status of reactive power compensation devices, increasing the online detection frequency of high-risk frequency bands, and sending broadband oscillation early warning information to the operation control system.

[0076] refer to Figure 5 In one embodiment of the present invention, after the step of obtaining the fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system to determine whether the power system is in the target state, the method further includes: Step S500: When the power system is in the target state, determine multiple target detection nodes and multiple target detection frequency bands, and generate multiple corresponding perturbation probe signals in sequence; Step S600: Superimpose multiple corresponding perturbation probe signals onto the control command of the power electronic equipment according to the evaluation cycle, and sequentially acquire the second broadband phasor data of each monitoring node when multiple perturbation probe signals are not superimposed and the third broadband phasor data of each monitoring node when multiple perturbation probe signals are superimposed according to the evaluation cycle. Step S700: Based on multiple second-band broadband phasor data and multiple third-band broadband phasor data, determine the oscillation risk level of each monitoring node in multiple evaluation periods.

[0077] Understandably, the number of target detection nodes and target detection frequency bands are often more than one in actual verification. For example, if the power system is in the target state and the number of target detection nodes is determined to be 4 and the number of target detection frequency bands to be 2, then the target detection nodes and target detection frequency bands need to be combined one by one to form 8 assessment cycles. Among these 8 assessment cycles, there are multiple perturbation probe signals, which in turn correspond to the oscillation risk levels of various monitoring nodes.

[0078] This invention proactively acquires the broadband dynamic response of the target frequency band under current operating conditions before significant power system oscillations occur. Without affecting the normal operation of the power system, it generates and injects low-amplitude, controllable, and safety-constrained broadband perturbation probes. Based on real-time operating status, historical risk information, and risk uncertainty, it adaptively selects the frequency band and nodes to be probed. It extracts the voltage and current phasor response increments before and after perturbation injection based on broadband phasor data. It identifies the system's equivalent impedance, admittance, impedance ratio, loop gain, or multi-port coupling matrix online. It constructs a broadband oscillation risk index including stability margin, margin change rate, multi-node coupling amplification factor, response energy, and identification uncertainty. It outputs the risk level, risk frequency band, risk node, risk trend, and control recommendations.

[0079] The present invention also proposes a control device, which includes a memory, a processor, and a power system broadband oscillation monitoring and evaluation program stored in the memory and executable on the processor. The power system broadband oscillation monitoring and evaluation program is configured to implement the steps of the power system broadband oscillation monitoring and evaluation method as described in any of the preceding claims. It is worth noting that since the control device of the present invention is based on the aforementioned power system broadband oscillation monitoring and evaluation method, the embodiments of the control device of the present invention include all the technical solutions of all embodiments of the aforementioned power system broadband oscillation monitoring and evaluation method, and the achieved technical effects are also completely identical, and will not be repeated here.

[0080] The present invention also proposes a power system, characterized in that the power system includes multiple power electronic devices, multiple monitoring devices installed at various monitoring nodes, and a control device as described above. It is worth noting that since the power system of the present invention is based on the aforementioned control device, the embodiments of the power system of the present invention include all the technical solutions of all embodiments of the aforementioned control device, and the achieved technical effects are also completely identical, and will not be repeated here.

[0081] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for monitoring and evaluating broadband oscillations in power systems, characterized in that, The power system includes multiple power electronic devices and multiple monitoring devices installed at various monitoring nodes; The monitoring and evaluation methods for broadband oscillations in power systems include: The fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system are obtained to determine whether the power system is in the target state. When the power system is in the target state, the target detection node and target detection frequency band are determined in order to generate the corresponding perturbation probe signal; The perturbation probe signal is superimposed on the control command of the power electronic equipment, and the second broadband phasor data of each monitoring node without the perturbation probe signal superimposed and the third broadband phasor data of each monitoring node with the perturbation probe signal superimposed are obtained. Based on the second and third broadband phasor data, the degree of oscillation risk of each monitoring node is determined.

2. The monitoring and evaluation method for broadband oscillations in power systems as described in claim 1, characterized in that, The step of obtaining the fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system to determine whether the power system is in the target state specifically includes: The fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system are obtained. When the fundamental phasor parameters and the first broadband phasor parameters are within the preset range of the fundamental phasor parameters and the preset range of the broadband phasor parameters, respectively, the power system is determined to be in the target state. The fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system are obtained. If the fundamental phasor parameters are not within the preset range of the fundamental phasor parameters or the first broadband phasor parameters are not within the preset range of the broadband phasor parameters, it is determined that the power system is not in the target state.

3. The monitoring and evaluation method for broadband oscillations in power systems as described in claim 1, characterized in that, The specific steps for determining the target detection node and target detection frequency band to generate the corresponding perturbation probe signal when the power system is in the target state are as follows: When the power system is in the target state, obtain the operating status parameters of the power electronic equipment on each corresponding monitoring node; The target detection nodes are determined based on the target detection node weighting algorithm and the operating status parameters of the power electronic equipment on each monitoring node; The target detection frequency band is determined based on the target detection frequency band weighting algorithm and the operating status parameters of the power electronic equipment on each monitoring node; Based on the target detection node, the target detection frequency band, and the multiple sinusoidal superposition function, the corresponding perturbation probe signal is generated.

4. The monitoring and evaluation method for broadband oscillations in power systems as described in claim 3, characterized in that, The target detection node weighting algorithm is as follows: Among them, the Indicates the first The detection applicability of each monitoring node; This indicates the capacity margin of power electronic equipment; the aforementioned This indicates the control response capability of power electronic equipment; the This represents the excitation capability of the j-th monitoring node for the target detection frequency band; the... This represents the observability of the j-th monitoring node relative to the risk area; the This indicates a safety constraint penalty item; the aforementioned to These are the weighting coefficients; The target detection frequency band weighting algorithm is as follows: Among them, the Indicates the first The detection priority of each frequency band; Indicates historical risk level; the stated Indicates the uncertainty of risk; the stated Indicates the multi-node coupling strength; the This indicates a decreasing trend in stability margin; the aforementioned Indicates the degree of broadband phasor energy anomaly; the to These are the weighting coefficients; The superposition function of multiple sinuses is: Among them, the This represents the perturbation probe signal; the Indicates the number of detection frequency points; the Indicates the first The perturbation amplitude at each detection frequency point; Indicates the first The frequency of each detection point; the Indicates the first The initial phase of each detection frequency point.

5. The monitoring and evaluation method for broadband oscillations in power systems as described in claim 4, characterized in that, After the step of generating the corresponding perturbation probe signal based on the target detection node, the target detection frequency band, and the multiple sinusoidal superposition function, the method further includes: The perturbation amplitude of the perturbation probe signal is smaller than the target amplitude; The perturbation amplitude is ; Among them, the This represents the maximum amplitude determined based on the rated capacity of the power electronic equipment; the This represents the maximum amplitude determined based on the target detection node voltage deviation limit; the This represents the maximum amplitude determined based on the current margin of the power electronic equipment; the This represents the maximum amplitude determined based on the reactive power capacity margin; the... This represents the maximum amplitude determined based on broadband energy or power quality constraints; the... This indicates the maximum amplitude determined based on the protection or operational safety boundary.

6. The monitoring and evaluation method for broadband oscillations in power systems as described in claim 1, characterized in that, The specific steps for determining the oscillation risk level of each monitoring node based on the second and third broadband phasor data are as follows: Based on the difference between the second and third broadband phasor data of each monitoring node, the voltage phasor response increment and current phasor response increment of each monitoring node are determined. Based on the voltage phasor response increment and current phasor response increment of each monitoring node, the equivalent impedance and equivalent admittance of each monitoring node are determined. Based on the equivalent impedance and equivalent admittance of each monitoring node, the stable distance margin of each monitoring node in the target detection frequency band is determined. Based on the stable distance margin of each monitoring node in the target detection frequency band, the degree of oscillation risk of each monitoring node in the target detection frequency band is determined.

7. The monitoring and evaluation method for broadband oscillations in power systems as described in claim 6, characterized in that, The specific steps for determining the voltage phasor response increment and current phasor response increment of each monitoring node based on the difference between the second and third broadband phasor data of each monitoring node are as follows: Among them, the The first in the second wideband phasor data The monitoring node at the first The voltage broadband phasor at each detection frequency point, the The first in the second wideband phasor data The monitoring node at the first The current broadband phasor at each detection frequency point, the The third wideband phasor data The monitoring node at the first The voltage broadband phasor at each detection frequency point, the The third wideband phasor data The monitoring node at the first The current broadband phasor at each detection frequency point, the Indicates the first The monitoring node at the first The voltage phasor response increment at each detection frequency point, the Indicates the first The monitoring node at the first The increment of the current phasor response at each detection frequency; The steps for determining the equivalent impedance and equivalent admittance of each monitoring node based on the voltage phasor response increment and current phasor response increment of each monitoring node are as follows: in, This represents the voltage broadband phasor response increment vector for each monitoring node; This represents the current or equivalent current disturbance increment vector for each monitoring node. The equivalent impedance of each monitoring node is given. The equivalent admittance for each monitoring node. For measurement error and modeling error; The specific steps for determining the stable range margin of each monitoring node in the target detection frequency band based on the equivalent impedance and equivalent admittance of each monitoring node are as follows: in, The equivalent impedance on the grid side. For the equivalent admittance of power electronic equipment, For the first The loop gain matrix at each detection frequency point; the equivalent impedance and equivalent admittance of each monitoring node include the equivalent impedance on the grid side and the equivalent admittance on the power electronic equipment side.

8. The monitoring and evaluation method for broadband oscillations in power systems as described in any one of claims 1 to 7, characterized in that, After the step of acquiring the fundamental phasor parameters and the first broadband phasor parameters of the target monitoring node on the power system to determine whether the power system is in the target state, the method further includes: When the power system is in the target state, multiple target detection nodes and multiple target detection frequency bands are determined, and multiple corresponding perturbation probe signals are generated in sequence. Multiple corresponding perturbation probe signals are sequentially superimposed on the control commands of the power electronic equipment according to the evaluation cycle, and the second broadband phasor data of each monitoring node when multiple perturbation probe signals are not superimposed and the third broadband phasor data of each monitoring node when multiple perturbation probe signals are superimposed are sequentially acquired according to the evaluation cycle. Based on multiple second-band broadband phasor data and multiple third-band broadband phasor data, the oscillation risk level of each monitoring node in multiple evaluation periods is determined.

9. A control device, characterized in that, The control device includes a memory, a processor, and a power system broadband oscillation monitoring and evaluation program stored in the memory and executable on the processor, the power system broadband oscillation monitoring and evaluation program being configured to implement the steps of the power system broadband oscillation monitoring and evaluation method as described in any one of claims 1 to 8.

10. An electric power system, characterized in that, The power system includes multiple power electronic devices, multiple monitoring devices installed at each monitoring node, and the control device as described in claim 9.

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