A method and device for evaluating effectiveness of a parallel resonance suppression scheme of a power system

Abstract

The present application relates to the technical field of resonance analysis, and in particular to a method and device for evaluating effectiveness of a parallel resonance suppression scheme in a power system. In the present application, a local parallel resonance suppression evaluation index and a non-local parallel resonance suppression evaluation index are constructed, and corresponding feasible regions are constructed, so as to evaluate the parallel resonance suppression effect of a resonance suppression method access node and the effect of parallel resonance of surrounding other nodes. The present application solves the problem that the application scene of a resonance suppression method is limited and the parallel resonance scene is not compatible with the resonance suppression method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of resonance analysis, and particularly relates to a method and device for evaluating effectiveness of a parallel resonance suppression scheme of a power system. BACKGROUND

[0002] The main principle of parallel resonance suppression is to directly or indirectly enhance system stability margin and improve power system stability by reducing resonance impedance and enhancing system damping. Existing parallel resonance suppression methods are diverse and can be classified into three categories: changing system parameters, installing resonance suppression devices, and adding active damping control. The research on parallel resonance suppression methods is usually carried out for specific scenarios, and less attention is paid to their applicability in different scenarios. Moreover, there is a lack of corresponding effectiveness analysis methods for parallel resonance suppression methods, which limits the wide application, improvement and expansion of existing methods. SUMMARY

[0003] Therefore, the present application provides a method and device for evaluating effectiveness of a parallel resonance suppression scheme of a power system to solve the problem of lacking effectiveness analysis methods for parallel resonance suppression methods in the prior art.

[0004] In a first aspect, the present application provides a method for evaluating effectiveness of a parallel resonance suppression scheme of a power system, which comprises: analyzing the amplitude-frequency distribution of node impedance of the power system to determine a resonance node to be governed and an action node of the resonance suppression scheme, wherein the amplitude-frequency distribution of node impedance of the power system is determined by inverting the frequency-domain node admittance matrix of the power system; determining a local parallel resonance suppression evaluation index and a remote parallel resonance suppression evaluation index based on whether the resonance node to be governed and the action node of the resonance suppression scheme are the same and the change in node impedance; determining a local parallel resonance suppression feasible region and a remote parallel resonance suppression feasible region at a single frequency based on the local parallel resonance suppression evaluation index, the remote parallel resonance suppression evaluation index, and the equivalent impedance of the resonance suppression scheme; determining a relative local parallel resonance suppression feasible region and a relative remote parallel resonance suppression feasible region based on the concerned frequency band of the resonance suppression scheme and the local parallel resonance suppression feasible region and the remote parallel resonance suppression feasible region at the single frequency; determining an ideal parallel resonance suppression feasible region based on the intersection of the relative local parallel resonance suppression feasible region and the relative remote parallel resonance suppression feasible region; and evaluating the effectiveness of the resonance suppression scheme based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible region, wherein the feasible region includes the local parallel resonance suppression feasible region, the remote parallel resonance suppression feasible region, the relative local parallel resonance suppression feasible region, the relative remote parallel resonance suppression feasible region, and the ideal parallel resonance suppression feasible region.

[0005] In the present application, by constructing the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index, and constructing the corresponding feasible region, the effect of the resonance suppression method access node parallel resonance suppression and the surrounding other nodes parallel resonance is evaluated. The problem of limited application scene of the resonance suppression method, and the inadaptation of the parallel resonance scene and the resonance suppression method is solved.

[0006] In the present application, the intersection of the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region is further determined to determine the parallel resonance suppression ideal feasible region, the ideal feasible region is a fully enclosed range, and the threshold value can be flexibly calculated and selected, which is more conducive to guiding the resonance suppression method design, and can guide the design of the resonance suppression method capable of realizing the suppression of multiple nodes parallel resonance.

[0007] In an optional embodiment, the method further comprises: determining a plurality of resonance suppression scheme selection and parameter optimization suggestions based on the effectiveness evaluation result of the resonance suppression scheme.

[0008] In an optional embodiment, the parallel resonance local suppression evaluation index is represented by the following formula:

[0009] |Z 0,f (i,i)| 2 -|Z f (i,i)| 2 >τ

[0010] In the formula, τ represents a node impedance change threshold, i represents a node when the resonance to be governed node and the resonance suppression scheme action node are the same, Z 0f (i,i) represents the self-impedance of node i before resonance suppression at frequency f, and Z f (i,i) represents the self-impedance after resonance suppression.

[0011] The parallel resonance remote suppression evaluation index is represented by the following formula:

[0012] |Z0(j,j)| 2 -|Z(j,j)| 2 >τ

[0013] In the formula, i represents the resonance suppression scheme action node, j represents the resonance to be governed node, Z0(j,j) represents the impedance of node j before resonance suppression, and Z(j,j) represents the impedance of node j after resonance suppression.

[0014] In the present application, by using the above formula to represent the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index, the evaluation of the resonance suppression can be more accurately realized.

[0015] In an optional embodiment, the feasible domain of parallel resonance local suppression and the feasible domain of parallel resonance remote suppression at a single frequency are determined based on the parallel resonance local suppression evaluation index, the parallel resonance remote suppression evaluation index and the equivalent impedance of the resonance suppression scheme, including: determining the relationship between the impedance after resonance suppression and the impedance after resonance suppression according to the branch addition method and the equivalent impedance of the resonance suppression scheme; substituting the relationship into the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index to obtain the relationship between the equivalent impedance and the impedance after resonance suppression; determining the feasible domain of parallel resonance local suppression and the feasible domain of parallel resonance remote suppression at a single frequency based on the relationship between the equivalent impedance and the impedance after resonance suppression.

[0016] In the present invention, the resonance suppression is characterized in the evaluation index by adopting the branch addition method and equivalent impedance, thereby obtaining the feasible region of local suppression of parallel resonance and the feasible region of remote suppression of parallel resonance, which provides a data basis for the analysis of resonance suppression.

[0017] In an optional embodiment, when τ≠0, the boundary of the feasible region of parallel resonance local suppression is a region with ((|Z ii | 2 -τ)Z ii,r / τ,(|Z ii | 2 -τ)Z ii,i / τ) is the center of the circle, The circle with radius Z is the feasible region of parallel resonance local suppression. When τ = 0, the boundary of the feasible region of parallel resonance local suppression is a straight line. The feasible region of parallel resonance local suppression is on the side of the origin. ii,r , Z ii,i They represent the self-impedance Z of node i after resonance suppression. ii The real and imaginary parts of

[0018] When τ≠0, the boundary of the parallel resonance suppression region is a As the center of the circle, The inner area of ​​the circle is the feasible region of parallel resonance remote suppression; when τ = 0, the boundary of the feasible region of parallel resonance remote suppression is a straight line, and the feasible region of parallel resonance remote suppression is on the side of the increasing direction of the real axis, where A = Z jj Z ii -Z 2 ij , Z ij is the mutual impedance between node i and node j, is the self-impedance Z of node j jj The conjugate, B r 、B i represent the real and imaginary parts of B respectively.

[0019] In the present application, the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region are represented by circles and straight lines, etc., so that the representation of the feasible region is more intuitive.

[0020] In an alternative embodiment, the determination of the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region based on the concerned frequency band of the resonance suppression scheme and the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region at a single frequency comprises: determining the intersection of the parallel resonance local suppression feasible region or the parallel resonance remote suppression feasible region at each frequency of the concerned frequency band of the resonance suppression scheme, in combination with the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region at a single frequency, based on the frequency band range and the frequency interval of the concerned frequency band of the resonance suppression scheme, to obtain the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region.

[0021] In an alternative embodiment, the evaluation of the effectiveness of the resonance suppression scheme based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible region comprises: comparing the overlapping conditions of the equivalent impedance and the feasible region of a plurality of resonance suppression schemes to evaluate the effectiveness of the resonance suppression scheme.

[0022] In a second aspect, the present application provides an effectiveness evaluation device for a parallel resonance suppression scheme of a power system. The device comprises: a node determination module for analyzing the impedance amplitude-frequency distribution of the nodes of the power system to determine the resonance nodes to be governed and the nodes to be acted on by the resonance suppression scheme, the impedance amplitude-frequency distribution of the nodes of the power system being determined by inverting the frequency-domain node admittance matrix of the power system; an evaluation index determination module for determining the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index based on whether the resonance nodes to be governed and the nodes to be acted on by the resonance suppression scheme are the same and the impedance variation of the nodes; a feasible region determination module for determining the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region at a single frequency based on the parallel resonance local suppression evaluation index, the parallel resonance remote suppression evaluation index, and the equivalent impedance of the resonance suppression scheme; a relative feasible region determination module for determining the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region based on the concerned frequency band of the resonance suppression scheme and the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region at a single frequency; an ideal feasible region determination module for determining the ideal parallel resonance suppression feasible region based on the intersection of the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region; and an effectiveness evaluation module for evaluating the effectiveness of the resonance suppression scheme based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible region, the feasible region comprising the parallel resonance local suppression feasible region, the parallel resonance remote suppression feasible region, the parallel resonance local suppression relative feasible region, the parallel resonance remote suppression relative feasible region, and the ideal parallel resonance suppression feasible region.

[0023] In a third aspect, the present invention provides a computer device comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to execute the effectiveness evaluation method of the power system parallel resonance suppression scheme of the above-mentioned first aspect or any corresponding embodiment thereof.

[0024] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the effectiveness evaluation method of the power system parallel resonance suppression scheme of the above-mentioned first aspect or any corresponding embodiment thereof.

[0025] In a fifth aspect, the present invention provides a computer program product comprising computer instructions for causing a computer to execute the effectiveness evaluation method for a parallel resonance suppression scheme for a power system according to the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 is a flow chart of a method for evaluating the effectiveness of a parallel resonance suppression scheme for a power system according to an embodiment of the present invention;

[0028] Figure 2 is a flow chart of a method for evaluating the effectiveness of another power system parallel resonance suppression scheme according to an embodiment of the present invention;

[0029] Figure 3 2. It is a schematic diagram of the boundary distribution of the feasible region of local suppression of parallel resonance according to an embodiment of the present invention;

[0030] Figure 4 2. It is a schematic diagram of the boundary distribution of the feasible region for remote suppression of parallel resonance according to an embodiment of the present invention;

[0031] Figure 5 2. Schematic diagram of an ideal feasible region for parallel resonance suppression according to an embodiment of the present invention;

[0032] Figure 6 is a schematic diagram of a simplified power system network structure according to an embodiment of the present invention;

[0033] Figures 7(a) to 7(f)is a schematic diagram of a node impedance amplitude / phase-frequency curve according to an embodiment of the present invention;

[0034] Figures 8(a) to 8(c) is a schematic diagram of the distribution of a resonance suppression solution in a feasible domain according to an embodiment of the present invention;

[0035] Figures 9(a) to 9(c) 1. This is a Bode diagram of the node impedance before and after the resonance suppression solution according to an embodiment of the present invention is connected;

[0036] Figure 10 2. It is a schematic diagram of an optimized resonance suppression scheme and a distribution of a resonance suppression feasible region according to an embodiment of the present invention;

[0037] Figures 11(a) to 11(f) is a schematic diagram of a node impedance amplitude / phase-frequency curve according to an embodiment of the present invention;

[0038] Figure 12 is a structural block diagram of a device for evaluating the effectiveness of a parallel resonance suppression scheme for a power system according to an embodiment of the present invention;

[0039] Figure 13 Schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0041] In related technologies, the diverse types of equipment, complex topologies, and interactions in power systems lead to diverse causes and characteristics of resonance. The same parallel resonance suppression method may have very different effects when applied to different scenarios. Improper strategies may lead to: 1) the resonance amplification frequency shift, that is, the resonance peak is amplified at the new resonance frequency; 2) the resonance of the node where the resonance suppression strategy is applied is suppressed, while other nodes experience resonance amplification. At the same time, the coupling between the resonance suppression link and the mathematical models of other parts of the system makes it more difficult to adjust and optimize it in a targeted manner. Therefore, it is necessary to analyze the effectiveness of the parallel resonance suppression method in different scenarios, which will help promote the application and optimization of existing parallel resonance suppression methods and have far-reaching significance for the research on parallel resonance suppression methods.

[0042] According to the embodiment of the present application, a method for evaluating effectiveness of a parallel resonance suppression scheme of a power system is provided. It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from here.

[0043] In the embodiment, a method for evaluating effectiveness of a parallel resonance suppression scheme of a power system is provided, which can be used in electronic devices such as computers, mobile phones, tablet computers, etc. Figure 1 The flowchart of the method for evaluating effectiveness of a parallel resonance suppression scheme of a power system according to the embodiment of the present application is shown in FIG. 1, which includes the following steps: Figure 1

[0044] In step S101, the amplitude-frequency distribution of the node impedance of the power system is analyzed to determine the resonance management node and the node for the resonance suppression scheme. The amplitude-frequency distribution of the node impedance of the power system is determined by inverting the node admittance matrix of the power system in the frequency domain.

[0045] Specifically, based on the frequency domain impedance model of each device in the power system under small disturbance, the node admittance matrix of the system is established, and the node impedance matrix of the system is obtained by inverting the node admittance matrix, which describes the impedance relationship between each node in the power system. By frequency scanning the impedance between each node in the node impedance matrix of the system, i.e. recalculating the node impedance matrix at different frequencies, the amplitude part of the impedance between each node is extracted, and then the node impedance amplitude-frequency distribution curve is obtained with frequency as the horizontal axis and node impedance value as the vertical axis. Then, based on the node impedance amplitude-frequency distribution curve, the parallel resonance frequency and amplitude severity of each node of the system are analyzed to determine the resonance management node and the node for the resonance suppression scheme, etc.

[0046] Among them, the resonance management node represents the node that appears resonance determined by the parallel resonance frequency and amplitude severity of each node, and the node for the resonance suppression scheme represents the node that introduces the resonance suppression scheme in the resonance management node.

[0047] ​Step S102, based on whether the resonance node to be governed and the resonance suppression scheme acting node are the same and the node impedance change, determine the parallel resonance local suppression evaluation index and the parallel resonance non-local suppression evaluation index. Specifically, when evaluating the effectiveness of the resonance suppression scheme, the effectiveness of the suppression of each node needs to be evaluated, so the corresponding evaluation index is determined for each node. Among them, when the resonance suppression scheme acting node (or acting on the device connected in parallel to the node) and the resonance node to be governed are both i, then the resonance suppression of the node is called local suppression, and the parallel resonance local suppression evaluation index for the node can be determined according to the impedance change before and after the resonance suppression of the node. When the resonance suppression scheme acting node is i and the resonance node to be governed is j, then the resonance suppression of the node is called non-local suppression, and the parallel resonance non-local suppression evaluation index for the node can be determined according to the impedance change before and after the resonance suppression of the node.

[0048] It can be understood that the parallel resonance local suppression evaluation index and the parallel resonance non-local suppression evaluation index are necessary and sufficient conditions for realizing resonance suppression. That is, the resonance suppression scheme adopted can realize resonance suppression, which needs to meet the conditions in the evaluation index, or the impedance change of the node needs to meet the requirements in the evaluation index.

[0049] Step S103, based on the parallel resonance local suppression evaluation index, the parallel resonance non-local suppression evaluation index, and the equivalent impedance of the resonance suppression scheme, determine the parallel resonance local suppression feasible region and the parallel resonance non-local suppression feasible region at a single frequency. Specifically, when the node in the power system implements the resonance suppression scheme, its equivalent impedance will change, and the change of the equivalent impedance after the implementation of different resonance suppression schemes is not the same, so the different resonance suppression schemes can be represented by the equivalent impedance in the parallel resonance local suppression evaluation index and the parallel resonance non-local suppression evaluation index. Then, the corresponding feasible region is obtained by combining the node impedance change in the evaluation index. The feasible region can be understood as a region representing the effect of the resonance suppression scheme.

[0050] Step S104, based on the concerned frequency band of the resonance suppression scheme and the parallel resonance local suppression feasible region and the parallel resonance non-local suppression feasible region at a single frequency, determine the parallel resonance local suppression relative feasible region and the parallel resonance non-local suppression relative feasible region; Specifically, since the resonance suppression scheme may cause resonance frequency shift phenomenon (i.e. the impedance at the resonance frequency decreases and the impedance at the surrounding frequency increases), the resonance suppression domain near the resonance frequency range should be analyzed, and the range should be combined with the resonance suppression requirements. Thus, the corresponding concerned frequency band is determined for each resonance suppression scheme, and the feasible region is further adjusted to obtain the parallel resonance local suppression relative feasible region and the parallel resonance non-local suppression relative feasible region. The frequency range in the concerned frequency band is [f r-Δf, f r +Δf], wherein f r is the resonance peak frequency, and the frequency band width Δf can be flexibly designed according to application requirements.

[0051] Step S105, determining a parallel resonance suppression ideal feasible region based on an intersection of the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region. The ideal feasible region is a full closed range by determining the parallel resonance suppression ideal feasible region based on the intersection of the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region, and can be flexibly calculated and selected according to a threshold value, which is more conducive to guiding the design of the resonance suppression method, and can guide the design of the resonance suppression method capable of achieving suppression of parallel resonance of multiple nodes.

[0052] Step S105, evaluating the effectiveness of the resonance suppression scheme based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible region, and the feasible region includes the parallel resonance local suppression feasible region, the parallel resonance remote suppression feasible region, the parallel resonance local suppression relative feasible region, the parallel resonance remote suppression relative feasible region and the parallel resonance suppression ideal feasible region. Specifically, the effectiveness of the corresponding resonance suppression scheme can be evaluated by the distribution of the equivalent impedance of the resonance suppression scheme in the feasible region.

[0053] The effectiveness evaluation method of the parallel resonance suppression scheme of the power system provided by the embodiment of the present application realizes the evaluation of the parallel resonance suppression effect of the resonance suppression method access node and the effect of the parallel resonance of the surrounding other nodes by constructing the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index, and constructing the corresponding feasible region. The problems that the application scene of the resonance suppression method is limited and the parallel resonance scene is not suitable for the resonance suppression method are solved.

[0054] In the embodiment, an effectiveness evaluation method of a parallel resonance suppression scheme of a power system is provided, as shown in Figure 2 The method comprises the following steps:

[0055] Step S201, analyzing the amplitude-frequency distribution of the power system node impedance to determine the resonance node to be governed and the action node of the resonance suppression scheme, and the amplitude-frequency distribution of the power system node impedance is determined by inverting the frequency domain node admittance matrix of the power system. For details, please refer to step S101 of the embodiment shown in Figure 1 The details are not described here.

[0056] Step S202, determining the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index based on whether the resonance node to be governed and the action node of the resonance suppression scheme are the same and the node impedance change.

[0057] The parallel resonance local suppression evaluation index is expressed by the following formula:

[0058] |Z 0,f (i,i)| 2 -|Z f (i,i)| 2 >τ (1)

[0059] wherein τ represents a node impedance change threshold, i represents a node when the resonance management node and the resonance suppression scheme action node are the same, Z 0f (i,i) represents the self-impedance of node i before resonance suppression at frequency f, Z f (i,i) represents the self-impedance after resonance suppression;

[0060] The parallel resonance local suppression evaluation index is expressed by the following formula:

[0061] |Z0(j,j)| 2 -||Z(j,j)| 2 >τ (2)

[0062] wherein i represents the resonance suppression scheme action node, j represents the resonance management node, Z0(j,j) represents the impedance of node j before resonance suppression, and Z(j,j) represents the impedance of node j after resonance suppression.

[0063] Wherein τ≥0. The value of τ can be flexibly selected according to the actual engineering needs.

[0064] Step S203, determining the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region at a single frequency based on the parallel resonance local suppression evaluation index, the parallel resonance remote suppression evaluation index, and the equivalent impedance of the resonance suppression scheme;

[0065] Specifically, the above step S203 includes:

[0066] Step S2031, determining the impedance after resonance suppression and the relationship between the impedance after resonance suppression according to the branch addition method and the equivalent impedance of the resonance suppression scheme.

[0067] Step S2032, substituting the relationship into the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index to obtain the relationship between the equivalent impedance and the impedance after resonance suppression.

[0068] Step S2033, determining the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region at a single frequency based on the relationship between the equivalent impedance and the impedance after resonance suppression.

[0069] Among them, the branch addition method is a method of gradually constructing a circuit model and solving the node impedance matrix. In circuit analysis, it may start from a simple basic circuit at first, and then gradually add branches (such as branches composed of resistors, inductors, capacitors, etc.) to build a complete circuit model. Each branch added will have a corresponding impact on the node impedance matrix, and the node impedance matrix will be updated through a series of matrix operations. Thus, the parallel resonance suppression implemented in the power system is equivalent to adding a branch with impedance δ to the ground (i.e. a branch with one end connected to the system node and the other end grounded) in the system.

[0070] Thus, for local suppression, the self-impedance Z f (i,i) in formula (1) after resonance suppression can be transformed into:

[0071]

[0072] In the formula, δ represents the equivalent impedance corresponding to the resonance suppression strategy. To simplify the symbols, the subscript f will be omitted hereinafter.

[0073] Substituting formula (3) into formula (1) and further organizing can obtain:

[0074]

[0075] In the formula, δ r , δ i respectively represent the real part and the imaginary part of δ, Z ii,r , Z ii,i respectively represent the real part and the imaginary part of the self-impedance Z ii of the node i. Whether the threshold value in formula (3) is 0 will affect the final form of the criterion. Further derivation can obtain that the feasible region of parallel resonance local suppression is:

[0076] Ω LRF = {(δ r , δ i ) | ε1(δ r , δ i ) < 0} (5)

[0077]

[0078] From formula (5), (6), it can be seen that when τ≠0, the boundary of parallel resonance local suppression is a circle with ( (Z ii | 2 -τ)Z ii,r / τ, (Z ii | 2 -τ)Z ii,i / τ) as the center, The inner area of ​​the circle is the feasible region of parallel resonance local suppression; when τ = 0, the boundary of parallel resonance local suppression / amplification is a straight line, and the feasible region of parallel resonance local suppression is on the side where the origin is located.

[0079] For allostatic suppression, Z(j,j) in formula (2) can be transformed into:

[0080]

[0081] Substituting formula (7) into formula (2) and further sorting it out, we can get:

[0082]

[0083] Where A = Z jj Z ii -Z 2 ij , Z ij is the mutual impedance between node i and node j, is the self-impedance Z of node j jj The conjugate, B r 、B i represent the real and imaginary parts of B respectively.

[0084] Further deduction shows that the feasible region of parallel resonance remote suppression is:

[0085] Ω RRF ={(δ r ,δ i )|ε2(δ r ,δ i )<0} (9)

[0086] Where ε2(δ r ,δ i ) The specific expression is shown in formula (10):

[0087]

[0088] From equations (9) and (10), we can see that, similar to the feasible region of local suppression of parallel resonance, when τ≠0, the boundary of remote suppression of parallel resonance is a region with As the center of the circle, The inner area of ​​the circle is the feasible region of parallel resonance remote suppression; when τ = 0, the boundary of parallel resonance remote suppression / amplification is a straight line, and the feasible region of parallel resonance remote suppression is on the side of the increasing direction of the real axis.

[0089] As can be seen from formula (5) and formula (10), the parallel resonance suppression feasible region decouples the equivalent impedance of the resonance suppression link and the system impedance, and the distribution position of the equivalent impedance of the resonance suppression link in the feasible region can be used to judge the rationality of the resonance suppression strategy and to optimize it. The distribution of the parallel resonance local / remote suppression feasible region when τ is 0 can be used to judge the effect of the suppression strategy on the resonance (i.e. whether the resonance impedance is reduced or amplified); the parallel resonance local / remote suppression feasible region when τ is not 0 can be used to judge the suppression effect of the suppression strategy on the resonance (i.e. whether the resonance impedance is reduced) and to guide the design of the resonance suppression strategy.

[0090] In step S204, the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region are determined based on the concerned frequency band of the resonance suppression scheme and the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region at a single frequency.

[0091] Specifically, the above step S204 includes:

[0092] In step S2041, the intersection of the parallel resonance local suppression feasible region or the parallel resonance remote suppression feasible region at each frequency of the concerned frequency band is determined based on the frequency band range and the frequency interval of the concerned frequency band of the resonance suppression scheme, in combination with the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region at a single frequency, to obtain the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region.

[0093] Specifically, the frequency domain impedance of the resonance usually presents in the form of a resonance peak, and the frequency band around the resonance frequency also has a large impedance distribution, that is, the resonance suppression should be concerned about the frequency band around the resonance frequency in addition to the safety domain distribution at the resonance frequency. Therefore, the resonance frequency band range and the frequency interval in the concerned frequency band should be given, and the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region in the frequency band should be drawn one by one. The concerned frequency band should be designed according to the analysis and suppression requirements under different scenes and resonance characteristics.

[0094] Figure 3 and Figure 4 For the distribution diagram of the parallel resonance local suppression feasible region and the remote suppression feasible region of the resonance frequency band when τ is not 0, according to the foregoing derivation, the outer region of any circular boundary in the figure is the resonance suppression region of the equivalent impedance thereof, wherein the dashed line corresponds to the parallel resonance suppression feasible region boundary at the resonance peak frequency, and the solid line corresponds to the parallel resonance suppression feasible region boundary at other frequencies in the concerned frequency band. In order to ensure that the resonance suppression is performed on the concerned frequency band of the parallel resonance, the equivalent impedance needs to be located in the parallel resonance local suppression feasible region or the remote suppression feasible region at the same time, that is, the intersection of the feasible regions in the frequency band, which is defined as the relative feasible region in this paper. The parallel resonance local / remote suppression relative feasible region corresponds to the gray region in Figure 3 and Figure 4The paralleling resonance local suppression feasible region and the paralleling resonance remote suppression feasible region are shown in the paralleling resonance local suppression feasible region and the paralleling resonance remote suppression feasible region in FIG. 6. The resonant suppression scheme equivalent impedance is always located in the relative feasible region in the frequency band, which is a sufficient condition for the resonance to be suppressed.

[0095] In step S205, the ideal feasible region of the paralleling resonance suppression is determined based on the intersection of the relative feasible region of the local suppression of the paralleling resonance and the relative feasible region of the remote suppression of the paralleling resonance.

[0096] Specifically, Figure 3 With Figure 4 The paralleling resonance local suppression feasible region is greater than the paralleling resonance remote suppression feasible region in FIG. 6. The boundaries of the paralleling resonance local / remote suppression feasible region at the same frequency have differences. When the resonant suppression scheme design is unreasonable, the local paralleling resonance of the node is suppressed, but the paralleling resonance of other nodes is not effectively suppressed, and even the resonance is further amplified. To ensure that the multiple nodes in a certain resonant frequency band are suppressed, the resonant suppression strategy equivalent impedance needs to be located in the paralleling resonance local / remote suppression feasible region, that is, the intersection of the relative feasible region of the local / remote suppression of the paralleling resonance. This is defined as the ideal feasible region of the paralleling resonance suppression. In combination with Figure 3 and Figure 4 The local amplification diagram of FIG. 6 can obtain the ideal suppression region shown in FIG. 7, which can guide the design of the resonant suppression strategy. Figure 5

[0097] In step S206, the effectiveness of the resonant suppression scheme is evaluated based on the relationship between the equivalent impedance of the resonant suppression scheme and the feasible region. The feasible region includes the paralleling resonance local suppression feasible region, the paralleling resonance remote suppression feasible region, the relative feasible region of the local suppression of the paralleling resonance, the relative feasible region of the remote suppression of the paralleling resonance, and the ideal feasible region of the paralleling resonance suppression.

[0098] Specifically, the above step S206 includes:

[0099] In step S2061, the effectiveness of the resonant suppression scheme is evaluated by comparing the overlapping of the equivalent impedance of multiple resonant suppression schemes and the feasible region. The existing resonant suppression schemes mainly include active damping control, installation of resonant suppression equipment, and change of system parameters. The influence of the resonant suppression scheme on the system operation state can be reflected by the equivalent impedance. By comparing the overlapping of the equivalent impedance distribution under different resonant suppression schemes and parameters and the paralleling resonance local / remote suppression feasible region in the frequency band, the effectiveness of the resonant suppression strategy can be determined.

[0100] In step S207, the resonant suppression scheme selection and parameter optimization suggestions are determined based on the effectiveness evaluation results of the resonant suppression scheme. Specifically, the resonant suppression strategy selection and parameter optimization suggestions can be given by comprehensively considering the resonant suppression strategy effectiveness analysis conclusion in step S206 and the overlapping degree of the resonant suppression strategy and the ideal feasible region.​

[0101] As a specific application example of the embodiment of the present invention, in order to verify the effectiveness evaluation method of the proposed power system parallel resonance suppression scheme, Figure 6 The model is the analysis object. It includes three lines connected to the point of common coupling (PCC, also known as the grid connection point). Each line includes a voltage source converter (VSC) composed of an LCL filter (including two inductors and one capacitor) and a switching element. The impedance between the VSC and the grid connection point is represented by Z l Indicates that the grid connection point to the grid u g The impedance between Z g , nodes 2, 3, and 4 represent the output terminals of the VSC, and node 1 represents the connection location between the intermediate line and the grid connection point. The model parameter settings are shown in Table 1 below. Figure 6 The node admittance matrix of the mathematical model is Y, and the node impedance matrix is ​​Z. The modeling process is omitted here. By analyzing the node impedances one by one, it is found that Figure 6 The model has two resonant frequencies of 617 Hz and 742 Hz. The parallel resonance distribution of each node is shown in Table 2 below. The self-impedance amplitude and phase-frequency curves of node 1 are shown in Figures 7(a) and 7(b), the self-impedance amplitude and phase-frequency curves of nodes 2 and 3 are shown in Figures 7(c) and 7(d), and the self-impedance amplitude and phase-frequency curves of node 4 are shown in Figures 7(e) and 7(f).

[0102] Table 1 Figure 4 Parameter settings

[0103]

[0104] Table 2 Node impedance matrix traditional resonance distribution

[0105]

[0106] The parallel resonance local / remote suppression feasible region of τ=0 proposed in the embodiment can be used to evaluate the effectiveness of the parallel resonance suppression scheme. Taking the two resonance suppression schemes of virtual impedance and passive damping with series connection of resistance and capacitance, and series connection of resistance and inductance as examples, for a resonance frequency of 617 Hz, the frequency band of interest is 597 Hz-637 Hz, FIG. 8(a), FIG. 8(b) and FIG. 8(c) respectively show the impedance variation of passive damping with series connection of 1 Ω-5 Ω virtual impedance, resistance 0.01 Ω-0.05 Ω and capacitance 10 μF-50 μF, and passive damping with series connection of resistance 0.01 Ω-0.05 Ω and inductance 1 mH-5 mH, and the impedance distribution in the three cases is compared with the node 4 parallel resonance local suppression feasible region with threshold τ=0 and the node 1, 2, 3 parallel resonance remote suppression feasible region boundary in the frequency range.

[0107] As can be seen from FIG. 8(a), the equivalent impedance of the virtual impedance and the passive damping with series connection of resistance and inductance is always located in the local suppression relative feasible region, i.e. it can play a local suppression role on node 4. The capacitance of the passive damping with series connection of resistance and capacitance is relatively large (i.e. the corresponding access impedance is relatively small) and is located in the local suppression relative feasible region; but as the capacitance decreases, the impedance gradually enters the resonance amplification region in some frequency bands or even enters the resonance peak amplification region, i.e. the access of the passive damping will cause resonance amplification in some frequencies in the frequency band, and when the parameters are small, it may even cause resonance peak amplification. As can be seen from FIG. 8(b) and FIG. 8(c), the virtual impedance and the passive damping with series connection of resistance and inductance are not located in the remote suppression relative feasible region, i.e. they are located in the resonance amplification region at some frequencies, resulting in impedance amplification in some frequency bands of other nodes except the local suppression node 2. In particular, when the inductance value of the passive damping is large (i.e. the corresponding access impedance is large), it will enter the resonance peak amplification region, causing further resonance deterioration.

[0108] As can also be seen from the comparison of FIG. 8(a) and FIG. 8(b), FIG. 8(c), the parallel resonance local suppression relative feasible region and the remote suppression relative feasible region have obvious differences. The virtual impedance is located in the local suppression relative feasible region but not in the remote suppression relative feasible region, i.e. the access of the virtual impedance will cause impedance amplification in some frequency bands of nodes 1, 2, 3 but not in node 4 in the frequency band of interest. The same passive damping is located in the local resonance amplification region and the remote resonance amplification region at different frequencies, i.e. the access of the passive damping causes differences in the frequency bands of impedance amplification of node 4 and nodes 1, 2, 3. In particular, the resistance and inductance series passive damping that can achieve resonance local suppression in FIG. 8(a) has a larger value range than the resistance and inductance series passive damping that can achieve resonance remote suppression in FIG. 8(b) and FIG. 8(c), and the value range in FIG. 8(c) is the smallest, i.e. when the inductance value is not appropriate, resonance suppression of node 4 will occur while resonance amplification of nodes 1 and nodes 2, 3 will occur.

[0109] Taking the passive damping scheme 1 (4Ω virtual impedance, 0.03Ω resistor, and 3mH inductor in series) and the passive damping scheme 2 (0.05Ω resistor and 5mH inductor in series) connected to node 4 as examples, a frequency sweep analysis of the node self-impedance was performed to verify the accuracy of the resonance suppression scheme effectiveness evaluation method based on the resonance suppression feasible domain. The node impedance before and after resonance suppression is shown in Figures 9(a), 9(b), and 9(c). As can be seen from Figure 9(a), the connection of passive damping and virtual impedance reduces most of the impedance within the frequency range of node 4, effectively suppressing resonance. As can be seen from Figures 9(b) and 9(c), the connection of passive damping and virtual impedance causes the resonant frequency to shift and the impedance to be amplified within the frequency band of interest at nodes 1, 2, and 3. At the same time, when passive damping scheme 1 is used, the original resonance points of nodes 1 and 4 are suppressed, while the impedance of the original resonance points of nodes 2 and 3 is amplified. When passive damping scheme 2 is used, the original resonance point of node 4 is suppressed, while the impedance of the original resonance points of nodes 1, 2, and 3 is amplified. The above conclusions are consistent with the analysis results of Figures 8(a), 8(b), and 8(c).

[0110] It can be seen that both passive damping and virtual impedance resonance suppression methods are not suitable for 617 Hz resonance, and a more suitable resonance suppression scheme should be further explored through the distribution of the resonance suppression feasible domain.

[0111] Therefore, for the 617Hz resonance point, the node impedance change threshold τ is selected as 20, the bandwidth Δf is selected as 20Hz, the corresponding frequency band of interest is 597Hz-637Hz, and node 4 is selected as the node for the resonance suppression strategy. At this time, the ideal feasible domain distribution characteristics of parallel resonance suppression are as follows: Figure 10 Based on Figure 10 The ideal feasible domain distribution characteristics in the virtual impedance control strategy showing resistance and capacitance characteristics have better consistency with the ideal feasible domain distribution. Figure 10 It can be seen that it is within the ideal feasible domain within the frequency band, which is called the optimized resonance suppression strategy. Figures 11(a) to 11(f) show the node impedance Bode diagrams before and after the optimized resonance suppression strategy is connected (the solid line represents before access, and the dotted line represents after access). Among them, Figures 11(a) and 11(b) are the self-impedance amplitude and phase-frequency curves of node 4 before and after the optimized resonance suppression strategy is connected, Figures 11(c) and 11(d) are the self-impedance amplitude and phase-frequency curves of node 1 before and after the optimized resonance suppression strategy is connected, and Figures 11(e) and 11(f) are the self-impedance amplitude and phase-frequency curves of node 2 and node 3 before and after the optimized resonance suppression strategy is connected. It can be seen that the optimized resonance suppression strategy has a good resonance suppression effect on the impedance within the frequency band.

[0112] The effectiveness of the above resonance suppression scheme is evaluated in Figure 8(a), Figure 8(b), Figure 8(c), Figure 9(a), Figure 9(b), Figure 9(c), Figure 10 , but the node impedance Bode diagrams shown in Figures 9(a), 9(b), 9(c), and 11(a) to 11(f) require the mathematical model of the resonance suppression scheme to be substituted into the admittance matrix one by one and inverted, which is computationally intensive. Figure 10 The feasible domain analysis only starts from the perspective of the equivalent impedance of the resonance suppression scheme. By analyzing its distribution in the feasible domain, the rationality of the resonance suppression scheme can be directly judged and parameter setting suggestions can be given. The analysis results are more efficient and direct.

[0113] The above description illustrates the basic functionality of this method for evaluating the effectiveness of parallel resonance suppression schemes in power systems. This method efficiently evaluates both the local and remote suppression effects of resonance suppression schemes, avoiding matrix inversion operations. It is well-suited for different types of resonance suppression schemes and is crucial for addressing the current limitations of resonance suppression methods in their application scenarios and the incompatibility of these methods with parallel resonance scenarios.

[0114] This embodiment also provides a device for evaluating the effectiveness of a parallel resonance suppression scheme for a power system. The device is used to implement the above-mentioned embodiments and preferred embodiments, and the details that have been described will not be repeated. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0115] This embodiment provides a device for evaluating the effectiveness of a parallel resonance suppression scheme for a power system. Figure 12 Shown, including:

[0116] The node determination module 121 is used to analyze the impedance amplitude-frequency distribution of the power system nodes to determine the nodes that need to be controlled and the nodes where the resonance suppression scheme is effective. The impedance amplitude-frequency distribution of the power system nodes is determined by inverting the power system frequency domain node admittance matrix;

[0117] An evaluation index determination module 122 is configured to determine a parallel resonance local suppression evaluation index and a parallel resonance remote suppression evaluation index based on whether the resonance control node and the resonance suppression scheme action node are the same and the node impedance change;

[0118] A feasible region determination module 123 is configured to determine a feasible region for local suppression of parallel resonance and a feasible region for remote suppression of parallel resonance at a single frequency based on a parallel resonance local suppression evaluation index, a parallel resonance remote suppression evaluation index, and an equivalent impedance of a resonance suppression scheme;

[0119] The relative feasible region determination module 124 is configured to determine the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region based on the concerned frequency band of the resonance suppression scheme and the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region at a single frequency.

[0120] The ideal feasible region determination module 125 is configured to determine the parallel resonance suppression ideal feasible region based on the intersection of the parallel resonance local suppression relative feasible region and the parallel resonance remote suppression relative feasible region.

[0121] The effectiveness evaluation module 126 is configured to evaluate the effectiveness of the resonance suppression scheme based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible region, and the feasible region includes the parallel resonance local suppression feasible region, the parallel resonance remote suppression feasible region, the parallel resonance local suppression relative feasible region, the parallel resonance remote suppression relative feasible region, and the parallel resonance suppression ideal feasible region.

[0122] In an optional implementation, the device further includes an optimization module configured to determine a plurality of resonance suppression scheme selections and parameter optimization suggestions based on the evaluation result of the effectiveness of the resonance suppression scheme.

[0123] In an optional implementation, the parallel resonance local suppression evaluation index is represented by the following formula:

[0124] |Z 0,f (i,i)| 2 -|Z f (i,i)| 2 >τ

[0125] In the formula, τ represents a node impedance change threshold, i represents a node in which the resonance management node and the resonance suppression scheme action node are the same, Z 0f (i,i) represents the self-impedance of node i before resonance suppression at frequency f, and Z f (i,i) represents the self-impedance after resonance suppression.

[0126] The parallel resonance remote suppression evaluation index is represented by the following formula:

[0127] |Z0(j,j)| 2 -||Z(j,j)| 2 >τ

[0128] In the formula, i represents the resonance suppression scheme action node, j represents the resonance management node, Z0(j,j) represents the impedance of node j before resonance suppression, and Z(j,j) represents the impedance of node j after resonance suppression.

[0129] In an alternative embodiment, the feasible region determining module is specifically configured to: determine the relationship between the impedance after resonance suppression and the equivalent impedance according to the branch appending method and the equivalent impedance of the resonance suppression scheme; substitute the relationship into the local parallel resonance suppression evaluation index and the remote parallel resonance suppression evaluation index to obtain the relationship between the equivalent impedance and the impedance after resonance suppression; and determine the local parallel resonance suppression feasible region and the remote parallel resonance suppression feasible region at a single frequency based on the relationship between the equivalent impedance and the impedance after resonance suppression.

[0130] In an alternative embodiment, when τ≠0, the boundary of the local parallel resonance suppression feasible region is a circle with (|Z ii |-τ)Z 2 / τ as the center and |Z ii,r / τ| as the radius, and the internal region of the circle is the local parallel resonance suppression feasible region; when τ=0, the boundary of the local parallel resonance suppression feasible region is a straight line, and the local parallel resonance suppression feasible region is on the side of the origin, where Z ii |-τ)Z 2 / τ, Z ii,i / τ respectively represent the real part and the imaginary part of the self-impedance Z ii,r of the node i after resonance suppression. When τ≠0, the boundary of the remote parallel resonance suppression feasible region is a circle with

[0131] as the center and as the radius, and the internal region of the circle is the remote parallel resonance suppression feasible region; when τ=0, the boundary of the remote parallel resonance suppression feasible region is a straight line, and the remote parallel resonance suppression feasible region is on the side of the real axis in the increasing direction, where A=Z ii,i Z ii -Z jj ii , 2 ij , Z ij is the mutual impedance between the node i and the node j, and jj is the conjugate of the self-impedance Z r of the node j, B i , B respectively represent the real part and the imaginary part of B.

[0132] In an alternative embodiment, the relative feasible region determining module is specifically configured to: determine the intersection of the local parallel resonance suppression feasible region or the remote parallel resonance suppression feasible region at each frequency of the frequency band of interest based on the frequency band range and the frequency interval of the frequency band of interest of the resonance suppression scheme and in combination with the local parallel resonance suppression feasible region and the remote parallel resonance suppression feasible region at a single frequency, to obtain the local parallel resonance suppression relative feasible region and the remote parallel resonance suppression relative feasible region.

[0133] In an optional embodiment, the effectiveness evaluation module is specifically used to evaluate the effectiveness of the resonance suppression scheme based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible domain, including: comparing the overlap between the equivalent impedance of multiple resonance suppression schemes and the feasible domain, and evaluating the effectiveness of the resonance suppression scheme.

[0134] The further functional description of each of the above modules is the same as that of the above corresponding embodiments and will not be repeated here.

[0135] The embodiment of the present invention also provides a computer device having the above Figure 12 The effectiveness evaluation device of the power system parallel resonance suppression scheme is shown.

[0136] See also Figure 13 , Figure 13 is a structural diagram of a computer device provided by an optional embodiment of the present invention, such as Figure 13 As shown, the computer device includes: one or more processors 10, memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in the memory or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Equally, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 13 A processor 10 is taken as an example.

[0137] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0138] The memory 20 stores instructions that can be executed by at least one processor 10, so as to enable at least one processor 10 to execute the method shown in the above embodiment.

[0139] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created based on the use of a computer device for displaying a small program landing page, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0140] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0141] The computer device further includes a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0142] The embodiment of the present invention also provides a computer-readable storage medium. The above-mentioned method according to the embodiment of the present invention can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.

[0143] Part of the present application can be applied as a computer program product, for example, computer program instructions, when executed by a computer, through the operation of the computer, can invoke or provide the method and / or technical solutions according to the present application. Those skilled in the art should understand that the form of computer program instructions in computer readable medium includes but is not limited to source file, executable file, installation package file and the like, and accordingly, the way of computer program instructions executed by computer includes but is not limited to: the computer directly executes the instructions, or the computer compiles the instructions and then executes the corresponding compiled program, or the computer reads and executes the instructions, or the computer reads and installs the instructions and then executes the corresponding installed program. Here, the computer readable medium can be any available computer readable storage medium or communication medium accessible to the computer.

[0144] Although the embodiments of the present application are described in conjunction with the drawings, various modifications and changes can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes fall within the scope defined by the appended claims.

Claims

1. A method for evaluating the effectiveness of a parallel resonance suppression scheme for a power system, characterized in that: The method comprises: Analyze the impedance amplitude-frequency distribution of power system nodes to determine the nodes that need to be controlled and the nodes where the resonance suppression scheme is effective. The impedance amplitude-frequency distribution of power system nodes is determined by inverting the power system frequency domain node admittance matrix; Based on whether the nodes to be managed and the nodes affected by the resonance suppression scheme are the same and the changes in node impedance, the local and remote parallel resonance suppression evaluation indices are determined. Determining a feasible region for local suppression of parallel resonance and a feasible region for remote suppression of parallel resonance at a single frequency based on the parallel resonance local suppression evaluation index, the parallel resonance remote suppression evaluation index, and the equivalent impedance of the resonance suppression scheme; Based on the frequency band of interest of the resonance suppression scheme and the feasible domain of local suppression of parallel resonance and the feasible domain of remote suppression of parallel resonance at a single frequency, the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance are determined; The ideal feasible region of parallel resonance suppression is determined based on the intersection of the relative feasible region of local parallel resonance suppression and the relative feasible region of remote parallel resonance suppression. The effectiveness of the resonance suppression scheme is evaluated based on the relationship between the equivalent impedance and the feasible domain of the resonance suppression scheme, which includes the feasible domain of parallel resonance local suppression, the feasible domain of parallel resonance remote suppression, the relatively feasible domain of parallel resonance local suppression, the relatively feasible domain of parallel resonance remote suppression, and the ideal feasible domain of parallel resonance suppression; The evaluation index of parallel resonance local suppression is expressed by the following formula: Where, represents the node impedance change threshold, Indicates the node where the resonance needs to be controlled and the node where the resonance suppression scheme works are the same. Z 0f ( i , i ) indicates frequency f Next node i The self-impedance before resonance suppression, Z f ( i , i ) represents the self-impedance after resonance suppression; The parallel resonance remote suppression evaluation index is expressed by the following formula: Where, Indicates the node where the resonance suppression scheme works. Indicates that the resonance requires governance nodes, Z 0 ( j , j ) represents a node j The impedance before resonance suppression, Z ( j , j ) represents a node j Impedance after resonance suppression.

2. The method according to claim 1, characterized in that The method further comprises: Based on the effectiveness evaluation results of the resonance suppression scheme, multiple resonance suppression scheme selections and parameter optimization suggestions are determined.

3. The method according to claim 1, characterized in that Determining a feasible region for local suppression of parallel resonance and a feasible region for remote suppression of parallel resonance at a single frequency based on the parallel resonance local suppression evaluation index, the parallel resonance remote suppression evaluation index, and the equivalent impedance of the resonance suppression scheme includes: Determine the relationship between the impedance after resonance suppression and the impedance after resonance suppression based on the branch addition method and the equivalent impedance of the resonance suppression scheme; Substituting the relationship into the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index to obtain the relationship between the equivalent impedance and the impedance after resonance suppression; Based on the relationship between the equivalent impedance and the impedance after resonance suppression, a feasible region for local suppression of parallel resonance and a feasible region for remote suppression of parallel resonance at a single frequency are determined.

4. The method according to claim 1, wherein: when ≠0, the boundary of the feasible region of parallel resonance local suppression is a is the center of the circle, The inner area of ​​the circle is the feasible region for local suppression of parallel resonance. = 0, the boundary of the parallel resonance local suppression feasible region is a straight line, and the parallel resonance local suppression feasible region is on the side where the origin is located, where Z ii,r 、 Z ii,i Represents nodes respectively i Self-impedance after resonance suppression Z ii The real and imaginary parts of when ≠0, the boundary of the parallel resonance suppression domain is a As the center of the circle, The inner area of ​​the circle is the feasible area for parallel resonance suppression. = 0, the boundary of the feasible region of parallel resonance suppression is a straight line, and the feasible region of parallel resonance suppression is on the side of the increasing direction of the real axis, where A = Z jj Z ii - Z 2 ij , B = AZ * jj , Z ij For nodes i With node j The mutual impedance between Z * jj For nodes j Self-impedance Z jj The conjugate of B r 、 B i Respectively B The real and imaginary parts of .

5. The method according to claim 1, wherein Based on the frequency band of interest of the resonance suppression scheme and the feasible domain of local parallel resonance suppression and the feasible domain of remote parallel resonance suppression at a single frequency, the relative feasible domain of local parallel resonance suppression and the relative feasible domain of remote parallel resonance suppression are determined, including: Based on the frequency band range and frequency interval of the frequency band of interest of the resonance suppression scheme, combined with the feasible domain of local suppression of parallel resonance and the feasible domain of remote suppression of parallel resonance at a single frequency, the intersection of the feasible domain of local suppression of parallel resonance or the feasible domain of remote suppression of parallel resonance at each frequency in the frequency band of interest is determined, and the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance are obtained.

6. The method according to claim 1, characterized in that The effectiveness of the resonance suppression scheme is evaluated based on the relationship between the equivalent impedance and the feasible region, including: The overlap between the equivalent impedance and feasible domain of multiple resonance suppression schemes is compared to evaluate the effectiveness of the resonance suppression schemes.

7. A device for evaluating the effectiveness of a parallel resonance suppression scheme for a power system, characterized in that: The device comprises: A node determination module is used to analyze the amplitude-frequency distribution of the impedance of the power system nodes and determine the nodes that need to be controlled and the nodes where the resonance suppression scheme is effective. The amplitude-frequency distribution of the impedance of the power system nodes is determined by inverting the frequency-domain node admittance matrix of the power system; An evaluation index determination module is used to determine a parallel resonance local suppression evaluation index and a parallel resonance remote suppression evaluation index based on whether the resonance control node and the resonance suppression scheme action node are the same and the node impedance change; A feasible region determination module is used to determine the parallel resonance local suppression feasible region and the parallel resonance remote suppression feasible region at a single frequency based on the parallel resonance local suppression evaluation index, the parallel resonance remote suppression evaluation index and the equivalent impedance of the resonance suppression scheme; A relative feasible domain determination module is used to determine the relative feasible domain of parallel resonance local suppression and the relative feasible domain of parallel resonance remote suppression based on the frequency band of interest of the resonance suppression scheme and the feasible domain of parallel resonance local suppression and the feasible domain of parallel resonance remote suppression at a single frequency; An ideal feasible region determination module is used to determine an ideal feasible region for parallel resonance suppression based on the intersection of a relative feasible region for local parallel resonance suppression and a relative feasible region for remote parallel resonance suppression; an effectiveness evaluation module for evaluating the effectiveness of the resonance suppression scheme based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible domain, wherein the feasible domain includes the parallel resonance local suppression feasible domain, the parallel resonance remote suppression feasible domain, the parallel resonance local suppression relative feasible domain, the parallel resonance remote suppression relative feasible domain, and the parallel resonance suppression ideal feasible domain; The evaluation index of parallel resonance local suppression is expressed by the following formula: Where, represents the node impedance change threshold, Indicates the node where the resonance needs to be controlled and the node where the resonance suppression scheme works are the same. Z 0f ( i , i ) indicates frequency f Next node i The self-impedance before resonance suppression, Z f ( i , i ) represents the self-impedance after resonance suppression; The parallel resonance remote suppression evaluation index is expressed by the following formula: Where, Indicates the node where the resonance suppression scheme works. Indicates that the resonance requires governance nodes, Z 0 ( j , j ) represents a node j The impedance before resonance suppression, Z ( j , j ) represents a node j Impedance after resonance suppression.

8. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the effectiveness evaluation method of the power system parallel resonance suppression scheme according to any one of claims 1 to 6 by executing the computer instructions.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the effectiveness evaluation method for a power system parallel resonance suppression scheme according to any one of claims 1 to 6.

Images