Method and system for verifying GPSS low-frequency oscillation damping control effect

Abstract

The invention discloses a method and system for verifying a GPSS low-frequency oscillation damping control effect, and relates to the technical field of power systems, and the method comprises the steps: selecting a fault-free disconnection test wiring working condition, and constructing a unit test working condition; the method comprises the following steps: testing power plant outgoing line fault-free disconnection, and collecting a unit electromagnetic power fluctuation recording curve; and comparing the low-frequency oscillation damping effects under different GPSS controller settings, evaluating the effects and circulating the test. According to the method for verifying the GPSS low-frequency oscillation damping control effect, the success rate and the safety of the test are improved by optimizing the wiring working condition, the stability and the anti-vibration capability of the system are improved by calculating the total output of each unit, and the stability and the anti-vibration capability of the system are improved by calculating the damping ratio and the frequency offset of the system. The stability of the system under different GPSS controller settings is evaluated in detail, the overall stability and the anti-vibration capability of the system are improved, and better effects are achieved in the aspects of safety, the success rate and the anti-vibration capability.

Description

Technical Field

[0001] The invention relates to the technical field of power systems, and in particular to a method for verifying the low-frequency oscillation damping control effect of a GPSS. Background Art

[0002] With the development of power systems and the increasing requirements for grid stability, the suppression of low-frequency oscillations (LFO) has become one of the important topics in the study of power system stability. Low-frequency oscillations are a periodic electromagnetic oscillation phenomenon caused by internal or external disturbances in the system, which often occurs between 0.1 and 2.0 Hz. The traditional method of suppressing low-frequency oscillations mainly relies on the application of power system stabilizers (PSS, also known as EPSS). PSS can effectively improve the damping characteristics of the system and reduce the oscillation amplitude by introducing additional damping control signals in the generator excitation control system. However, with the complexity of the grid structure and the increase in large-scale new energy grid connection, the vibration suppression effect of relying solely on PSS has gradually shown its limitations. For this reason, researchers began to explore the introduction of additional damping controllers (GPSS) on the generator speed control system side, and demonstrated its feasibility and superiority in multi-machine systems through theoretical research and simulation analysis. However, although GPSS has shown significant advantages in improving the stability of multi-machine systems with small and large disturbances, its practical application is still mainly in the simulation stage, lacking large-scale field tests and application verification.

[0003] Although the existing technology has made certain progress in suppressing low-frequency oscillations, it still has many shortcomings. First, PSS mainly relies on the excitation system of the generator when suppressing low-frequency oscillations. Its effect is more significant in strongly interconnected systems, but it has limited effect in weakly interconnected systems and systems with a high proportion of new energy. It is difficult to deal with oscillation problems in complex power grid environments. Secondly, existing GPSS research is mostly focused on theory and simulation, and lacks systematic field verification methods, making it difficult to evaluate its actual effect and reliability. In addition, existing vibration suppression control strategies often lack comprehensive consideration of the overall performance of the system and fail to fully utilize the coordinated control capabilities between units, resulting in the stability and response speed of the system under complex working conditions. There is still room for improvement. Summary of the invention

[0004] In view of the above-mentioned problems, the present invention is proposed.

[0005] Therefore, the technical problem solved by the present invention is: the existing method for verifying the low-frequency oscillation damping control effect has great limitations, lacks systematic verification, lacks comprehensive consideration of the overall performance of the system, and how to systematically verify the optimization problem of the vibration suppression effect of GPSS.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: a method for verifying the low-frequency oscillation damping control effect of GPSS, comprising selecting a fault-free disconnection test wiring condition and constructing a unit test condition; conducting a test on a fault-free disconnection of a power plant outgoing line and collecting a recording curve of the electromagnetic power fluctuation of the unit; comparing the low-frequency oscillation damping effect under different GPSS controller settings, evaluating the effect and conducting a cyclic test.

[0007] As a preferred solution of the method for verifying the low-frequency oscillation damping control effect of GPSS described in the present invention, wherein: the selection of the fault-free disconnection test wiring condition includes determining the equivalent impedance and analyzing the system stability, calculating the equivalent impedance of multiple lines, comprehensively evaluating the influence of line impedance and reactance on the system, summarizing the resistance and reactance of all lines, combining the apparent power of the lines, and calculating the equivalent impedance by weighted average, introducing fine-tuning parameters, and correcting the sign of the power of each line. The equivalent impedance is expressed as:

[0008]

[0009] Among them, Z eq is the system equivalent impedance, R i is the resistance of the ith circuit, X i is the reactance of the ith line, S i is the apparent power of the ith line, ∈ is the fine-tuning parameter, sign is the sign function, P i is the power of the i-th line, and the system stability is analyzed. The system stability is measured by the real part of the system eigenvalue. The smaller the real part of the eigenvalue, the higher the system stability. By solving the eigenvalue of the system matrix and taking the minimum value of the real part as the system stability index, it is expressed as:

[0010] y sys =min(Re(λi))

[0011] Among them, y sys is the system eigenvalue, λ i is the i-th eigenvalue and Re is the real part.

[0012] As a preferred solution of the method for verifying the GPSS low-frequency oscillation damping control effect of the present invention, the construction of the unit test condition includes configuring the unit output, calculating the total output of all units based on the benchmark output of each unit, and introducing a dynamic adjustment factor to simulate the output fluctuation of the unit in actual operation, which is expressed as:

[0013]

[0014] Among them, P total is the total output of all units, P j,base is the base output of the jth unit, Aj is the output fluctuation amplitude of the jth unit, ω is the angular frequency, φ j is the phase of the jth unit, m is the number of units, and t is the time. Based on the sensitivity of each unit to the control parameters and the influence of the system equivalent impedance on the total output, the control parameter setting is obtained by minimizing the sum of squares of the derivatives of the output of each unit to the control parameters and combining the sum of squares of the derivatives of the equivalent impedance to the total output, which is expressed as:

[0015]

[0016] Among them, K opt is the control parameter.

[0017] As a preferred solution of the method for verifying the low-frequency oscillation damping control effect of GPSS described in the present invention, the test of the fault-free disconnection of the power plant outgoing line includes evaluating the degree of electromagnetic power fluctuation, simulating the power fluctuation under the disconnection condition based on the total output and combining the dynamic adjustment factor. In the simulation of power fluctuation, the amplitude of power fluctuation is dynamically adjusted in combination with the system characteristic value to reflect the response characteristics of the system under the disconnection condition. The degree of fluctuation is quantified by calculating the variance of power fluctuation. The larger the variance, the more severe the power fluctuation and the worse the system stability. The power fluctuation variance in the entire cycle is calculated by integration to evaluate the stability of the system under the disconnection condition, which is expressed as:

[0018]

[0019] Among them, P(t) is the power at time t, k is the attenuation coefficient, α is the exponential attenuation constant, β is the fluctuation frequency, γ is the phase angle, η is the correction coefficient, λ is the nonlinear coefficient, η is the time constant, is the power fluctuation variance, T is the period, is the average power.

[0020] As a preferred solution of the method for verifying the low-frequency oscillation damping control effect of GPSS described in the present invention, the collecting of the electromagnetic power fluctuation recording curve of the unit includes analyzing the system response characteristics, calculating the effective value voltage, obtaining the voltage fluctuation of the system in the whole cycle, combining the sine function and the smoothing parameter to simulate the power fluctuation curve, correcting the power fluctuation variance, reflecting the power fluctuation of the system in the case of disconnection, which is expressed as:

[0021]

[0022] Among them, V rms is the effective value voltage, v(t) is the voltage at time t, δ is the weighting coefficient, ΔP(t) is the power fluctuation at time t, θ is the smoothing parameter, and k is the time constant.

[0023] As a preferred solution of the method for verifying the low-frequency oscillation damping control effect of GPSS described in the present invention, wherein: the comparison of the low-frequency oscillation damping effect under different GPSS controller settings includes calculating the damping ratio, quantifying the damping effect of the system under different control parameters, combining the initial frequency offset, the system natural frequency, the damped oscillation frequency and the correction of the power fluctuation curve, calculating the frequency offset, and reflecting the response characteristics of the system under different control parameters by dynamically adjusting the frequency offset, which is expressed as:

[0024]

[0025] Among them, ζ is the damping ratio, c is the damping coefficient, m1 is the mass, k1 is the stiffness, δ is the integral coefficient, ρ is the time attenuation coefficient, Δf(t) is the frequency offset at time t, Δf0 is the initial frequency offset, ω n is the natural frequency of the system, ω d is the damped oscillation frequency, μ is the time constant, and v is the attenuation factor.

[0026] As a preferred solution of the method for verifying the low-frequency oscillation damping control effect of GPSS described in the present invention, wherein: the evaluation effect and cyclic test include optimizing the control parameters, calculating the damping ratio change by comparing the new damping ratio and the old damping ratio, the new damping ratio is calculated according to the latest test data, and the old damping ratio is the reference value before optimization. The damping ratio change reflects the impact of GPSS on system stability under the current configuration. If the change is positive and greater than the threshold, it means that the damping improvement effect of GPSS is effective and the test ends. If the change is relatively negative or less than the threshold, the lead-lag parameters of the controller are optimized and the test is repeated, which is expressed as:

[0027] Δζ=ζ n -ζ o

[0028]

[0029] Among them, Δζ is the change of damping ratio, ζ n is the new damping ratio, ζ o is the old damping ratio, ζ t is the threshold value of the damping effect, τ' lead-lag is the adjusted lead-lag time constant, τ lead-lag is the original lead-lag time constant, dτ lead-lag is the derivative of the damping ratio with respect to the lead-lag time constant, Δτ lead-lag is the change of the lead-lag time constant.

[0030] Another object of the present invention is to provide a system for verifying the low-frequency oscillation damping control effect of GPSS, which can perform a fault-free disconnection test on the power plant outgoing line through a test collection module, and systematically collect the electromagnetic power fluctuation recording curve of the unit, thereby solving the current problem of difficulty in quantifying the system response.

[0031] As a preferred solution of the system for verifying the low-frequency oscillation damping control effect of GPSS described in the present invention, it includes: a test condition module, a test collection module, and a comparison and evaluation module; the test condition module is used to select a fault-free disconnection test wiring condition and construct a unit test condition; the test collection module is used to test a fault-free disconnection of the power plant outgoing line and collect the electromagnetic power fluctuation recording curve of the unit; the comparison and evaluation module is used to compare the low-frequency oscillation damping effect under different GPSS controller settings, evaluate the effect and conduct a cyclic test.

[0032] A computer device includes a memory and a processor, wherein the memory stores a computer program, and is characterized in that the processor executes the computer program to implement a step of a method for verifying the effect of GPSS low-frequency oscillation damping control.

[0033] A computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps of a method for verifying the effect of GPSS low-frequency oscillation damping control are implemented.

[0034] Beneficial effects of the present invention: The method for verifying the low-frequency oscillation damping control effect of GPSS provided by the present invention reduces possible risks in actual experiments and improves the success rate and safety of the experiments by optimizing the wiring conditions. The representativeness of the experiments is improved by calculating the total output of each unit, and the stability and vibration resistance of the system are improved. The stability of the system under different GPSS controller settings is evaluated in detail by calculating the damping ratio and frequency offset of the system, and the overall stability and vibration resistance of the system are improved. The stability and response speed of the system are improved by optimizing the control parameters and dynamically adjusting the control gain. The present invention achieves better results in terms of safety, success rate and vibration resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0036] Figure 1 An overall flow chart of a method for verifying the low-frequency oscillation damping control effect of GPSS provided in the first embodiment of the present invention.

[0037] Figure 2 A schematic diagram of a wiring condition for a fault-free disconnection test of a method for verifying the effect of GPSS low-frequency oscillation damping control provided by a second embodiment of the present invention.

[0038] Figure 3 A method for verifying the low-frequency oscillation damping control effect of GPSS provided in the second embodiment of the present invention is a simulation curve of electromagnetic power fluctuation of the unbroken line after the power plant outgoing line is disconnected without fault.

[0039] Figure 4 A method for verifying the low-frequency oscillation damping control effect of GPSS provided in the second embodiment of the present invention is a simulation curve of electromagnetic power fluctuation of different units after a power plant outgoing line is disconnected without fault.

[0040] Figure 5 A mathematical model of a speed governor additional damping controller is provided for a method of verifying the GPSS low-frequency oscillation damping control effect provided in the second embodiment of the present invention.

[0041] Figure 6 An overall module diagram of a system for verifying the low-frequency oscillation damping control effect of GPSS provided in the third embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0043] Example 1

[0044] Reference Figure 1 , as an embodiment of the present invention, provides a method for verifying the effect of GPSS low-frequency oscillation damping control, comprising:

[0045] S1: Select the no-fault disconnection test wiring condition and construct the unit test condition.

[0046] Furthermore, the selection of the wiring condition for the fault-free disconnection test includes determining the equivalent impedance and analyzing the system stability.

[0047] It should be noted that by calculating the equivalent impedance of multiple lines, comprehensively evaluating the impact of line impedance and reactance on the system, summarizing the resistance and reactance of all lines, combining the apparent power of the lines, and calculating the equivalent impedance by weighted average, fine-tuning parameters are introduced, and the sign of the power of each line is corrected. The equivalent impedance is expressed as:

[0048]

[0049] Among them, Z eq is the system equivalent impedance, R i is the resistance of the ith circuit, X i is the reactance of the ith line, S i is the apparent power of the ith line, ∈ is the fine-tuning parameter, sign is the sign function, P i is the power of the i-th line, and the system stability is analyzed. The system stability is measured by the real part of the system eigenvalue. The smaller the real part of the eigenvalue, the higher the system stability. By solving the eigenvalue of the system matrix and taking the minimum value of the real part as the system stability index, it is expressed as:

[0050] λ sys =min(Re(θ i ))

[0051] Among them, λ sys is the system eigenvalue, λ i is the i-th eigenvalue and Re is the real part.

[0052] Furthermore, constructing the unit test conditions includes configuring the unit output.

[0053] It should be noted that based on the benchmark output of each unit, the total output of all units is calculated, and a dynamic adjustment factor is introduced to simulate the output fluctuation of the units in actual operation, which is expressed as:

[0054]

[0055] Among them, P total is the total output of all units, P j,base is the base output of the jth unit, A j is the output fluctuation amplitude of the jth unit, ω is the angular frequency, φ j is the phase of the jth unit, m is the number of units, and t is the time. Based on the sensitivity of each unit to the control parameters and the influence of the system equivalent impedance on the total output, the control parameter setting is obtained by minimizing the sum of squares of the derivatives of the output of each unit to the control parameters and combining the sum of squares of the derivatives of the equivalent impedance to the total output, which is expressed as:

[0056]

[0057] Among them, K opt is the control parameter.

[0058] S2: Test the power plant's outgoing line for fault-free disconnection and collect the unit's electromagnetic power fluctuation recording curve.

[0059] Furthermore, the testing of the power plant outgoing line without fault disconnection includes the evaluation of the degree of electromagnetic power fluctuation.

[0060] It should be noted that based on the total output, combined with the dynamic adjustment factor, the power fluctuation under the disconnection condition is simulated. In the simulation of power fluctuation, the amplitude of power fluctuation is dynamically adjusted in combination with the system characteristic value to reflect the response characteristics of the system under the disconnection condition. The degree of fluctuation is quantified by calculating the variance of power fluctuation. The larger the variance, the more severe the power fluctuation and the worse the system stability. The power fluctuation variance in the entire cycle is calculated by integration to evaluate the stability of the system under the disconnection condition, which is expressed as:

[0061]

[0062] Among them, P(t) is the power at time t, k is the attenuation coefficient, α is the exponential attenuation constant, β is the fluctuation frequency, γ is the phase angle, η is the correction coefficient, λ is the nonlinear coefficient, η is the time constant, is the power fluctuation variance, T is the period, is the average power.

[0063] Furthermore, collecting the electromagnetic power fluctuation recording curve of the unit includes analyzing the system response characteristics.

[0064] It should be noted that the effective value voltage is calculated to obtain the voltage fluctuation of the system in the entire cycle. The power fluctuation curve is simulated by combining the sine function and smoothing parameters, and the power fluctuation variance is corrected to reflect the power fluctuation of the system in the case of line disconnection, which is expressed as:

[0065]

[0066] Among them, V rms is the effective value voltage, v(t) is the voltage at time t, σ is the weighting coefficient, ΔP(t) is the power fluctuation at time t, θ is the smoothing parameter, and k is the time constant.

[0067] S3: Compare the low frequency oscillation damping effect of different GPSS controller settings, evaluate the effect and repeat the test.

[0068] Furthermore, the low frequency oscillation damping effects of different GPSS controller settings are compared including the calculation of the damping ratio.

[0069] It should be noted that the damping effect of the quantified system under different control parameters is calculated by combining the initial frequency offset, the system natural frequency, the damped oscillation frequency and the correction of the power fluctuation curve. By dynamically adjusting the frequency offset, the response characteristics of the system under different control parameters are reflected, which is expressed as:

[0070]

[0071] Among them, ζ is the damping ratio, c is the damping coefficient, m1 is the mass, k1 is the stiffness, δ is the integral coefficient, ρ is the time attenuation coefficient, Δf(t) is the frequency offset at time t, Δf0 is the initial frequency offset, ω n is the natural frequency of the system, ω d is the damped oscillation frequency, μ is the time constant, and v is the attenuation factor.

[0072] Furthermore, the effects are evaluated and the experiments are repeated including the optimization of the control parameters.

[0073] It should be noted that by comparing the new damping ratio with the old damping ratio, the damping ratio change is calculated. The new damping ratio is calculated based on the latest test data, and the old damping ratio is the baseline value before optimization. The damping ratio change reflects the impact of GPSS on system stability under the current configuration. If the change is positive and greater than the threshold, it means that the damping improvement effect of GPSS is effective and the test is over. If the change is relatively negative or less than the threshold, the lead-lag parameters of the controller are optimized and the test is repeated, which is expressed as:

[0074] Δζ=ζ n -ζ o

[0075]

[0076] Among them, Δζ is the change of damping ratio, ζ n is the new damping ratio, ζ o is the old damping ratio, ζ t is the threshold value of the damping effect, τ' lead-lag is the adjusted lead-lag time constant, τ lead-lag is the original lead-lag time constant, dτ lead-lag is the derivative of the damping ratio with respect to the lead-lag time constant, Δτ lead-lag is the change of the lead-lag time constant.

[0077] Example 2

[0078] Reference Figure 2-5 , which is an embodiment of the present invention, provides a method for verifying the low-frequency oscillation damping control effect of GPSS. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through simulation experiments.

[0079] The working condition diagram selected in this embodiment is as follows Figure 2As shown, there are 2 outgoing lines between the power plant and the AC system. The power plant starts 3 units to keep the output of the 3 units consistent and between 80% and 90% of the rated power. At the same time, the frequency modulation, single-machine AGC and single-machine AVC functions are deactivated. The GPSS hardware device is installed on the G3 unit and the EPSS function is kept in the activated state. The G1 unit is not equipped with the GPSS hardware device and the EPSS function is in the deactivated state. The G2 unit is not equipped with the GPSS hardware device but the EPSS function is in the activated state. Disconnect one of the outgoing lines of the power plant and observe the electromagnetic power fluctuation of the other line. The electromagnetic power fluctuation simulation curve of the unbroken line is shown as follows Figure 3 As shown in the figure, the electromagnetic power fluctuation curves of different units are collected through PMU or recording device after the power plant outgoing line is disconnected without fault. The electromagnetic power fluctuation simulation curves of the three units are shown in Figure 4 shown.

[0080] from Figure 4 It can be seen that the low-frequency oscillation damping of G2 with EPSS is significantly improved compared with G1 without EPSS, and the low-frequency oscillation damping of G3 is further improved after adding GPSS compared with G2. If the damping improvement effect of GPSS is not obvious, then Figure 5 The lead-lag parameters in are optimized and the test is repeated until the damping improvement requirements are met.

[0081] Example 3

[0082] Reference Figure 6 , as an embodiment of the present invention, provides a system for verifying the low-frequency oscillation damping control effect of GPSS, including: a test condition module, a test collection module, and a comparison and evaluation module.

[0083] The test condition module is used to select the wiring condition for the fault-free line break test and construct the unit test condition. The test collection module is used to test the fault-free line break of the power plant outgoing line and collect the electromagnetic power fluctuation recording curve of the unit. The comparison and evaluation module is used to compare the low-frequency oscillation damping effect under different GPSS controller settings, evaluate the effect and conduct cyclic testing.

[0084] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0085] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0086] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering, or processing in another suitable manner as necessary, and then stored in a computer memory.

[0087] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc. It should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and are not limited. Although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

[0088] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for verifying the effect of GPSS low-frequency oscillation damping control, characterized in that: include: Select the no-fault disconnection test wiring condition and construct the unit test condition; Test the power plant outgoing line without fault disconnection and collect the electromagnetic power fluctuation recording curve of the unit; Compare the low frequency oscillation damping effects of different GPSS controller settings, evaluate the effects and perform loop tests.

2. The method for verifying the GPSS low-frequency oscillation damping control effect as claimed in claim 1, characterized in that: The selection of the wiring condition for the fault-free disconnection test includes determining the equivalent impedance and analyzing the system stability. By calculating the equivalent impedance of multiple lines, the influence of line impedance and reactance on the system is comprehensively evaluated. The resistance and reactance of all lines are summarized. In combination with the apparent power of the lines, the equivalent impedance is calculated by weighted average. Fine-tuning parameters are introduced to correct the sign of the power of each line. The equivalent impedance is expressed as: Among them, Z eq is the system equivalent impedance, R i is the resistance of the ith circuit, X i is the reactance of the ith line, S i is the apparent power of the ith line, ∈ is the fine-tuning parameter, sign is the sign function, P i is the power of the i-th line, and the system stability is analyzed. The system stability is measured by the real part of the system eigenvalue. The smaller the real part of the eigenvalue, the higher the system stability. By solving the eigenvalue of the system matrix and taking the minimum value of the real part as the system stability index, it is expressed as: l sys =min(Re(λ i )) Among them, λ sys is the system eigenvalue, λ i is the i-th eigenvalue and Re is the real part.

3. The method for verifying the GPSS low frequency oscillation damping control effect as claimed in claim 2, characterized in that: The construction of the unit test condition includes configuring the unit output, calculating the total output of all units based on the benchmark output of each unit, and introducing a dynamic adjustment factor to simulate the output fluctuation of the unit in actual operation, which is expressed as: Among them, P total is the total output of all units, P j，base is the base output of the jth unit, A j is the output fluctuation amplitude of the jth unit, ω is the angular frequency, φ j is the phase of the jth unit, m is the number of units, and t is the time. Based on the sensitivity of each unit to the control parameters and the influence of the system equivalent impedance on the total output, the control parameter setting is obtained by minimizing the sum of squares of the derivatives of the output of each unit to the control parameters and combining the sum of squares of the derivatives of the equivalent impedance to the total output, which is expressed as: Among them, K opt is the control parameter.

4. The method for verifying the GPSS low frequency oscillation damping control effect as claimed in claim 3, characterized in that: The test of the power plant outgoing line without fault disconnection includes evaluating the degree of electromagnetic power fluctuation. Based on the total output, combined with the dynamic adjustment factor, the power fluctuation under the disconnection condition is simulated. In the simulation of power fluctuation, the amplitude of power fluctuation is dynamically adjusted in combination with the system characteristic value to reflect the response characteristics of the system under the disconnection condition. The degree of fluctuation is quantified by calculating the variance of power fluctuation. The larger the variance, the more severe the power fluctuation and the worse the system stability. The power fluctuation variance in the entire cycle is calculated by integration to evaluate the stability of the system under the disconnection condition, which is expressed as: Among them, P(t) is the power at time t, k is the attenuation coefficient, α is the exponential attenuation constant, β is the fluctuation frequency, γ is the phase angle, ξ is the correction coefficient, λ is the nonlinear coefficient, and η is the time constant. is the power fluctuation variance, 0 is the period, is the average power.

5. The method for verifying the GPSS low frequency oscillation damping control effect as claimed in claim 4, characterized in that: The collecting unit electromagnetic power fluctuation recording curve includes analyzing the system response characteristics, calculating the effective value voltage, obtaining the voltage fluctuation of the system in the whole cycle, combining the sine function and the smoothing parameter to simulate the power fluctuation curve, correcting the power fluctuation variance, and reflecting the power fluctuation of the system in the case of disconnection, which is expressed as: Among them, V rms is the effective value voltage, v(t) is the voltage at time t, σ is the weighting coefficient, ΔP(t) is the power fluctuation at time t, θ is the smoothing parameter, and K is the time constant.

6. The method for verifying the GPSS low frequency oscillation damping control effect as claimed in claim 5, characterized in that: The comparison of the low-frequency oscillation damping effect under different GPSS controller settings includes calculating the damping ratio, quantifying the damping effect of the system under different control parameters, and calculating the frequency offset in combination with the initial frequency offset, the system natural frequency, the damped oscillation frequency and the correction of the power fluctuation curve. By dynamically adjusting the frequency offset, the response characteristics of the system under different control parameters are reflected, which is expressed as: Among them, ζ is the damping ratio, c is the damping coefficient, m1 is the mass, k1 is the stiffness, δ is the integral coefficient, ρ is the time attenuation coefficient, Δf(t) is the frequency offset at time t, Δf0 is the initial frequency offset, ω n is the natural frequency of the system, ω d is the damped oscillation frequency, μ is the time constant, and v is the attenuation factor.

7. The method for verifying the GPSS low frequency oscillation damping control effect as claimed in claim 6, characterized in that: The evaluation effect and cyclic test include optimizing control parameters, calculating the change of damping ratio by comparing the new damping ratio with the old damping ratio, the new damping ratio is calculated according to the latest test data, and the old damping ratio is the reference value before optimization. The change of damping ratio reflects the influence of GPSS on system stability under the current configuration. If the change is positive and greater than the threshold, it means that the damping improvement effect of GPSS is effective and the test ends. If the change is relatively negative or less than the threshold, the lead-lag parameters of the controller are optimized and the test is repeated, which is expressed as: Δζ=ζ n -g o Among them, Δζ is the change of damping ratio, ζ n is the new damping ratio, ζ o is the old damping ratio, ζ t is the threshold value of the damping effect, τ′ lead-lag is the adjusted lead-lag time constant, τ lead-lag is the original lead-lag time constant, dτ lead-lag is the derivative of the damping ratio with respect to the lead-lag time constant, Δτ lead-lag is the change of the lead-lag time constant.

8. A system using the method for verifying the effect of GPSS low-frequency oscillation damping control as claimed in any one of claims 1 to 7, characterized in that: It includes test condition module, test collection module and comparison and evaluation module; The test condition module is used to select a no-fault disconnection test wiring condition and construct a unit test condition; The test collection module is used to test the power plant outgoing line without fault disconnection and collect the electromagnetic power fluctuation recording curve of the unit; The comparison and evaluation module is used to compare the low-frequency oscillation damping effects under different GPSS controller settings, evaluate the effects and conduct cyclic tests.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for verifying the GPSS low-frequency oscillation damping control effect according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for verifying the effect of GPSS low-frequency oscillation damping control according to any one of claims 1 to 7 are implemented.

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