Effectiveness evaluation method and device for parallel resonance suppression scheme of power system

Abstract

The invention relates to the technical field of resonance analysis, in particular to an effectiveness evaluation method and device for a parallel resonance suppression scheme of a power system. According to the method, the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index are constructed, and the corresponding feasible region is constructed, so that the parallel resonance suppression effect of the access node of the resonance suppression method and the parallel resonance action effect of other surrounding nodes are evaluated. The problems that an application scene of an existing resonance suppression method is limited, and a parallel resonance scene is not matched with the resonance suppression method are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of resonance analysis, and in particular to a method and a device for evaluating the effectiveness of a parallel resonance suppression scheme of a power system. Background Art

[0002] The main principle of parallel resonance suppression is to directly or indirectly enhance the system stability margin and improve the stability of the power system by reducing the resonant impedance and enhancing the system damping. There are various existing parallel resonance suppression methods, which can be classified into several ideas: changing system parameters, installing resonance suppression equipment, and adding active damping control. The research on parallel resonance suppression methods is usually carried out for specific scenarios, and there is less attention paid to its applicability in different scenarios. There is also a lack of corresponding effectiveness analysis methods for parallel resonance suppression methods, which limits the wide application, improvement and expansion of existing methods. Summary of the invention

[0003] In view of this, the present invention provides a method and device for evaluating the effectiveness of a parallel resonance suppression scheme of a power system, so as to solve the problem that there is a lack of effectiveness analysis method of the parallel resonance suppression method in the prior art.

[0004] In a first aspect, the present invention provides a method for evaluating the effectiveness of a parallel resonance suppression scheme for a power system, the method comprising: analyzing the amplitude-frequency distribution of impedance at power system nodes to determine the resonance-required nodes and the resonance suppression scheme action nodes, the impedance amplitude-frequency distribution at power system nodes being determined by inverting the frequency-domain node admittance matrix of the power system; determining a parallel resonance local suppression evaluation index and a parallel resonance remote suppression evaluation index based on whether the resonance-required nodes and the resonance suppression scheme action nodes are the same and the node impedance change; determining a parallel resonance local suppression feasible domain and a parallel resonance abnormal suppression feasible domain 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. The feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance are determined based on the concerned frequency band 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 ideal feasible domain of parallel resonance suppression is determined based on the intersection of the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance; based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible domain, the effectiveness of the resonance suppression scheme is evaluated. The feasible domain includes the feasible domain of local suppression of parallel resonance, the feasible domain of remote suppression of parallel resonance, the relative feasible domain of local suppression of parallel resonance, the relative feasible domain of remote suppression of parallel resonance and the ideal feasible domain of parallel resonance suppression.

[0005] In the present invention, by constructing a parallel resonance local suppression evaluation index and a parallel resonance remote suppression evaluation index, and constructing a corresponding feasible domain, the parallel resonance suppression effect of the access node of the resonance suppression method and the effect of the parallel resonance of other surrounding nodes are evaluated. This solves the problem that the current resonance suppression method has limited application scenarios and the parallel resonance scenario is not compatible with the resonance suppression method.

[0006] In the present invention, the ideal feasible domain of parallel resonance suppression is further determined by the intersection of the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance. The ideal feasible domain is a fully closed range and can be flexibly calculated and selected according to the threshold value, which is more conducive to guiding the design of the resonance suppression method. At the same time, it can guide the design of a resonance suppression method that can suppress multi-node parallel resonances.

[0007] In an optional implementation, the method further includes: determining a plurality of resonance suppression scheme selections and parameter optimization suggestions based on effectiveness evaluation results of the resonance suppression schemes.

[0008] In an optional implementation manner, the parallel resonance local suppression evaluation index is expressed by the following formula:

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

[0010] In the formula, τ represents the threshold of node impedance change, i represents the node when the resonance-required control node and the resonance suppression scheme action node are the same, and 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;

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

[0012] |Z0(j,j)| 2 -|Z(j,j)| 2 >τ

[0013] Where i represents the node where the resonance suppression scheme works, j represents the node that needs to be controlled, 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 invention, the above formula is used to characterize the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index, thereby more accurately realizing the evaluation of resonance suppression.

[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 the equivalent impedance, thereby obtaining the feasible domain of local suppression of parallel resonance and the feasible domain 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, is a circle with a radius of , and the inner area of ​​the circle 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, and the feasible region of parallel resonance local suppression is on the side where the origin is located, where Z 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 off-site suppression domain is a As the center of the circle, is a circle with a radius of , and 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 node j self-impedance Z jj The conjugate of r , B i represent the real and imaginary parts of B respectively.

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

[0020] In an optional embodiment, determining the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance 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 includes: based on the frequency band range and frequency interval of the frequency band of interest of the resonance suppression scheme, combining the feasible domain of local suppression of parallel resonance and the feasible domain of remote suppression of parallel resonance at a single frequency, determining 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, and obtaining the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance.

[0021] In an optional embodiment, the effectiveness of the resonance suppression scheme is evaluated 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.

[0022] In a second aspect, the present invention provides an effectiveness evaluation device for a parallel resonance suppression scheme of a power system, the device comprising: a node determination module, for analyzing the amplitude-frequency distribution of impedance of power system nodes, determining the resonance-required nodes and the action nodes of the resonance suppression scheme, the amplitude-frequency distribution of impedance of power system nodes being determined by inverting the frequency-domain node admittance matrix of the power system; an evaluation index determination module, for determining a parallel resonance local suppression evaluation index and a parallel resonance remote suppression evaluation index based on whether the resonance-required nodes and the action nodes of the resonance suppression scheme are the same and the change of node impedance; a feasible domain determination module, for determining a feasible domain of parallel resonance local suppression and a parallel resonance remote suppression 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 module for determining a feasible domain for parallel resonance suppression; a module for determining a relative feasible domain for local suppression of parallel resonance and a relative feasible domain for remote suppression of parallel resonance based on the concerned frequency band of the resonance suppression scheme and the feasible domain for local suppression of parallel resonance and the feasible domain for remote suppression of parallel resonance at a single frequency; a module for determining an ideal feasible domain for parallel resonance suppression based on the intersection of the relative feasible domain for local suppression of parallel resonance and the relative feasible domain for remote suppression of parallel resonance; 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. The feasible domain includes the feasible domain for local suppression of parallel resonance, the feasible domain for remote suppression of parallel resonance, the relative feasible domain for local suppression of parallel resonance, the relative feasible domain for remote suppression of parallel resonance and the ideal feasible domain for parallel resonance suppression.

[0023] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, 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 of the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[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 for a parallel resonance suppression scheme of a power system according to the 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 of 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 implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying 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 another method for evaluating the effectiveness of a parallel resonance suppression scheme for a power system according to an embodiment of the present invention;

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

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

[0031] Figure 5 is a 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] Figure 7(a) to Figure 7(f)is a schematic diagram of a node impedance amplitude / phase-frequency curve according to an embodiment of the present invention;

[0034] Figure 8(a) to Figure 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] Figure 9(a) to Figure 9(c) is a Bode diagram of node impedance before and after the resonance suppression scheme according to an embodiment of the present invention is connected;

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

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

[0038] Fig.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] Fig.13 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the 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 creative work are within the scope of protection of the present invention.

[0041] In the related technologies, the various types of equipment, complex topological structures and interactions in the power system have led to the diversification of the causes and characteristics of its resonance. The same parallel resonance suppression method may have different effects when applied to different scenarios. Improper strategies may lead to: 1) the resonance amplification frequency is transferred, 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 model 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 the existing parallel resonance suppression method, and the research on the parallel resonance suppression method is of far-reaching significance.

[0042] According to an embodiment of the present invention, an embodiment of a method for evaluating the effectiveness of a parallel resonance suppression scheme for a power system is provided. It should be noted that the steps shown in the flowchart of the accompanying 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 that shown here.

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

[0044] Step S101, analyzing the amplitude-frequency distribution of power system node impedance to determine nodes that require resonance control and nodes where resonance suppression schemes are applied. The amplitude-frequency distribution of power system node impedance is determined by inverting the power system frequency domain node admittance matrix.

[0045] Specifically, based on the frequency domain impedance model of each device in the power system under small disturbances, the system node admittance matrix is ​​established, and the system node impedance matrix is ​​obtained by inverting the node admittance matrix. The system node impedance matrix describes the impedance relationship between each node in the power system. By performing a frequency scan on the impedance between each node in the system node impedance matrix, that is, recalculating the system node impedance matrix at different frequencies, extracting the amplitude part of the impedance between each node, and then obtaining the node impedance amplitude-frequency distribution curve 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 in the system are analyzed to determine the information such as the nodes that need to be governed and the nodes where the resonance suppression scheme works.

[0046] The resonance control node indicates the node where resonance occurs, which is determined by the parallel resonance frequency and amplitude severity of each node, and the resonance suppression scheme action node indicates the node where the resonance suppression scheme is introduced into the resonance control node.

[0047] Step S102, based on whether the resonance-to-be-managed node and the resonance suppression scheme action node are the same and the node impedance change, determine the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index. Specifically, when evaluating the effectiveness of the resonance suppression scheme, it is necessary to evaluate the suppression effectiveness of each node, so the corresponding evaluation index is determined for each node. Among them, when the resonance suppression scheme action node (or the device acting on the node in parallel) and the resonance-to-be-managed node are both i, the resonance suppression of the node is called local suppression, and the parallel resonance local suppression evaluation index for the node can be determined specifically based on the impedance change before and after the resonance suppression of the node. When the resonance suppression scheme action node is i and the resonance-to-be-managed node is j, the resonance suppression of the node is called remote suppression, and the parallel resonance remote suppression evaluation index for the node can be determined specifically based on 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 remote suppression evaluation index are necessary and sufficient conditions for achieving resonance suppression. That is, if the resonance suppression scheme adopted can achieve resonance suppression, it 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 remote suppression evaluation index and the equivalent impedance of the resonance suppression scheme, determine the feasible domain of parallel resonance local suppression and the feasible domain of parallel resonance remote suppression at a single frequency. Specifically, when the resonance suppression scheme is implemented at a node in the power system, its equivalent impedance will change, and after different resonance suppression schemes are implemented, the changes in equivalent impedance are not the same. Therefore, different resonance suppression schemes can be represented by equivalent impedance in the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index. Then, the corresponding feasible domain is obtained in combination with the node impedance changes in the evaluation index. The feasible domain can be understood as the area that characterizes the effect of the resonance suppression scheme.

[0050] Step S104, based on the concerned frequency band 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, determine the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance; specifically, since the resonance suppression scheme may cause the resonance frequency transfer 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 not only at the resonance frequency, but also at the resonance frequency range, and this 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 domain is further adjusted in combination with the concerned frequency band to obtain the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance. The frequency range within the concerned frequency band is [f r-Δf,f r +Δf], where f r is the resonance peak frequency, and the bandwidth Δf can be flexibly designed according to application requirements.

[0051] Step S105, determining the ideal feasible domain of parallel resonance suppression based on the intersection of the relative feasible domain of local parallel resonance suppression and the relative feasible domain of remote parallel resonance suppression. The ideal feasible domain of parallel resonance suppression is determined by the intersection of the relative feasible domain of local parallel resonance suppression and the relative feasible domain of remote parallel resonance suppression. The ideal feasible domain is a fully closed range and can be flexibly calculated and selected according to the threshold value, which is more conducive to guiding the design of the resonance suppression method, and can also guide the design of a resonance suppression method that can suppress multi-node parallel resonances.

[0052] Step S105, based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible domain, the effectiveness of the resonance suppression scheme is evaluated, and 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. 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 domain.

[0053] The effectiveness evaluation method of the parallel resonance suppression scheme of the power system provided by the embodiment of the present invention constructs a local parallel resonance suppression evaluation index and a remote parallel resonance suppression evaluation index, and constructs a corresponding feasible domain, thereby evaluating the parallel resonance suppression effect of the access node of the resonance suppression method and the effect of parallel resonance of other surrounding nodes. The method solves the problem that the current resonance suppression method has limited application scenarios and the parallel resonance scenario is not compatible with the resonance suppression method.

[0054] In this embodiment, a method for evaluating the effectiveness of a parallel resonance suppression scheme for a power system is provided. Figure 2 As shown, the method comprises the following steps:

[0055] Step S201: 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 works. The impedance amplitude-frequency distribution of power system nodes is determined by inverting the power system frequency domain node admittance matrix. Figure 1 Step S101 of the illustrated embodiment will not be described in detail here.

[0056] Step S202: determining 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.

[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] In the formula, τ represents the threshold of node impedance change, i represents the node when the resonance-required control node and the resonance suppression scheme action node are the same, and 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 remote suppression evaluation index is expressed by the following formula:

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

[0062] Where i represents the node where the resonance suppression scheme works, j represents the node that needs to be controlled, 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] Among them, τ ≥ 0. The value of τ can be flexibly selected according to the needs of the actual project.

[0064] Step S203, determining a parallel resonance local suppression feasible region and a parallel resonance remote suppression feasible region 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;

[0065] Specifically, the above step S203 includes:

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

[0067] Step S2032: Substitute 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 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 relationship between the equivalent impedance and the impedance after resonance suppression.

[0069] Among them, the branch addition method is a method of gradually building a circuit model and solving the node impedance matrix. In circuit analysis, you may start with a simple basic circuit, and then gradually add branches (such as branches composed of resistors, inductors, capacitors and other components) to build a complete circuit model. Each additional branch will have a corresponding impact on the node impedance matrix, and the node impedance matrix is ​​updated through a series of matrix operations. Therefore, the parallel resonance suppression implemented in the power system is equivalent to adding a ground-connected branch with an impedance of δ to the system (that is, a branch with one end connected to the system node and the other end grounded).

[0070] Therefore, for local suppression, the self-impedance Z after resonance suppression in equation (1) is f (i,i) 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 in the following text.

[0073] Substituting formula (3) into formula (1) and further rearranging it, we can obtain:

[0074]

[0075] In the formula, δ r ,δ i denote the real and imaginary parts of δ, respectively, Z ii,r , Z ii,i They represent the node i self-impedance Z ii The real and imaginary parts of . Whether the threshold in formula (3) is 0 will affect the final form of the criterion. Further deduction shows that the feasible domain of local suppression of parallel resonance is:

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

[0077]

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

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

[0080]

[0081] Substituting formula (7) into formula (2) and further rearranging it, we can obtain:

[0082]

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

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

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

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

[0087]

[0088] From equations (9)-(10), it can be seen 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, is a circle with a radius of , and the inner area of ​​the circle is the feasible domain of parallel resonance off-site suppression; when τ = 0, the boundary of parallel resonance off-site suppression / amplification is a straight line, and the feasible domain of parallel resonance off-site suppression is on the side of the increasing direction of the real axis.

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

[0090] Step S204, determining a relative feasible region for local suppression of parallel resonance and a relative feasible region for remote suppression of parallel resonance based on the concerned frequency band of the resonance suppression scheme and a feasible region for local suppression of parallel resonance and a feasible region for remote suppression of parallel resonance at a single frequency.

[0091] Specifically, the above step S204 includes:

[0092] Step S2041, 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, determine 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, and obtain the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance.

[0093] Specifically, the frequency domain impedance of resonance is usually presented in the form of a resonance peak, and the frequency band around the resonance frequency will also have a large impedance distribution, that is, resonance suppression should pay attention to the frequency band around the resonance frequency in addition to paying attention to the safe domain distribution under the resonance frequency. Therefore, the resonance frequency band range and frequency interval within the concerned frequency band should be given, and the feasible domain of local suppression of parallel resonance and the feasible domain of remote suppression of parallel resonance within 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 scenarios and resonance characteristics.

[0094] Figure 3 and Figure 4 The figure is a schematic diagram of the distribution of the feasible domains of local suppression and remote suppression of parallel resonance in the resonant frequency band when τ is not 0. According to the deduction in the previous article, the area outside the circle of any circular boundary in the figure is the resonant suppression area of ​​its equivalent impedance, where the dotted line corresponds to the feasible domain boundary of parallel resonance suppression at the resonant peak frequency, and the solid line corresponds to the feasible domain boundary of parallel resonance suppression at other frequencies in the frequency band of interest. In order to ensure that the resonance suppression effect is played in a certain parallel resonance frequency band of interest, the equivalent impedance must be located in the feasible domain of local suppression of parallel resonance or the feasible domain of remote suppression at the same time, that is, the intersection of the feasible domains in the frequency band, which is defined as the relative feasible domain in this article. The relative feasible domains of local / remote suppression of parallel resonance correspond to Figure 3 The gray area and Figure 4The diamond shaded area in the figure. The resonance suppression scheme's equivalent impedance is always in the relatively feasible region within the frequency band, which is a sufficient condition for the resonance to be suppressed.

[0095] Step S205: determining 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.

[0096] Specifically, Figure 3 and Figure 4 The feasible domain range of local suppression of parallel resonance is larger than the feasible domain of remote suppression of parallel resonance. The boundaries of local / remote suppression of parallel resonance are different at the same frequency. When the resonance suppression scheme is not designed reasonably, the parallel resonance of this node will be suppressed while the parallel resonance of other nodes will not be effectively suppressed or even the resonance will be further amplified. In order to ensure the resonance suppression effect on multiple nodes within a certain resonance frequency band, the equivalent impedance of the resonance suppression strategy needs to be simultaneously located in the feasible domain of local / remote suppression of parallel resonance, that is, the intersection of the relative feasible domains of local / remote suppression of resonance, which is defined as the ideal feasible domain of parallel resonance suppression in this paper. Figure 3 and Figure 4 The local enlarged view of Figure 5 The ideal suppression domain shown can provide guidance for the design of resonance suppression strategies.

[0097] Step S206, based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible domain, the effectiveness of the resonance suppression scheme is evaluated, and 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.

[0098] Specifically, the above step S206 includes:

[0099] Step S2061, compare the overlap between the equivalent impedances and feasible domains of multiple resonance suppression schemes, and evaluate the effectiveness of the resonance suppression schemes. Among them, the existing resonance suppression schemes mainly include active damping control, installation of resonance suppression equipment, change of system parameters, etc. The impact of the access of the resonance suppression scheme on the system operation state can be reflected by its equivalent impedance. By comparing the overlap between the distribution of equivalent impedances under different resonance suppression schemes and parameters and the feasible domain of local / remote suppression of parallel resonance in the frequency band, the effectiveness of the resonance suppression strategy can be judged.

[0100] Step S207, based on the effectiveness evaluation results of the resonance suppression scheme, multiple resonance suppression scheme selections and parameter optimization suggestions are determined. Specifically, resonance suppression strategy selections and parameter optimization suggestions can be given by comprehensively considering the resonance suppression strategy effectiveness analysis conclusions in step S206 and combining the degree of overlap between the resonance suppression strategy and the ideal feasible domain.

[0101] As a specific application example 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. In the model, there are 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. 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. The self-impedance amplitude and phase-frequency curve 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). The self-impedance amplitude and phase-frequency curve 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 effectiveness of the parallel resonance suppression scheme can be evaluated by using the feasible domain of local / remote suppression of parallel resonance when τ is 0 proposed in this embodiment. Taking the two resonance suppression schemes of virtual impedance and passive damping of resistor and capacitor in series and resistor and inductor in series as examples, for the resonance frequency of 617Hz, the corresponding frequency band of interest is 597Hz-637Hz. Figures 8(a), 8(b) and 8(c) respectively show the impedance changes of 1Ω-5Ω virtual impedance, passive damping of resistor 0.01Ω-0.05Ω and capacitor 10μF-50μF in series, and passive damping of resistor 0.01Ω-0.05Ω and inductor 1mH-5mH in series, and compare the impedance distribution in the three cases with the feasible domain of local suppression of parallel resonance of node 4 with a threshold τ of 0 in the frequency range and the boundary of the feasible domain of remote suppression of parallel resonance of nodes 1, 2, and 3.

[0107] As can be seen from Figure 8(a), the virtual impedance and the equivalent impedance of the resistor and inductor series passive damping are always located in the relatively feasible domain of local suppression, which can play a local suppression role on node 4. When the capacitance of the resistor and capacitor series passive damping is large (that is, when the corresponding access impedance is small), it is located in the relatively feasible domain of local suppression; but as the capacitance decreases, the impedance gradually enters the resonance amplification region of certain frequency bands and even enters the resonance peak amplification region, that is, the access of passive damping will cause resonance amplification of some frequencies in the frequency band, and when the parameters are small, it may even cause resonance peak amplification. As can be seen from Figures 8(b) and 8(c), the virtual impedance and the resistor and inductor series passive damping are not located in the relatively feasible domain of remote suppression, that is, they are located in the resonance amplification region of certain frequencies, resulting in impedance amplification of some frequency bands of other nodes except the local suppression node 2. In particular, when the passive damping inductance value is large (that is, when the corresponding access impedance is large), it will enter the resonance peak amplification region, causing the resonance to further deteriorate.

[0108] Comparing Figure 8(a) with Figure 8(b) and Figure 8(c), it can also be seen that there is a significant difference between the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression. The virtual impedance is located in the relative feasible domain of local suppression but not in the relative feasible domain of remote suppression, which means that within the frequency band of interest, the access of virtual impedance will lead to impedance amplification of some frequency bands of nodes 1, 2, and 3, but not for node 4. The same passive damping is located in the local resonance amplification area and the remote resonance amplification area at different frequencies, that is, the access of passive damping leads to differences in the frequency bands of impedance amplification of node 4 and nodes 1, 2, and 3. In particular, the range of values ​​of the resistor and inductor series passive damping that can achieve resonance local suppression in Figure 8(a) is larger than the range of values ​​that can achieve resonance remote suppression in Figure 8(b) and Figure 8(c), and the range of values ​​in Figure 8(c) is the smallest, that is, when the inductance value is not appropriate, the resonance of node 4 will be suppressed while the resonance amplification phenomenon of node 1 and nodes 2 and 3 will occur.

[0109] Taking the passive damping scheme 1 with 4Ω virtual impedance, 0.03Ω resistor and 3mH inductor in series and the passive damping scheme 2 with 0.05Ω resistor and 5mH inductor in series as examples, the node self-impedance sweep analysis is 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 Figure 9(a), Figure 9(b) and Figure 9(c). As can be seen from Figure 9(a), the access of passive damping and virtual impedance reduces most of the impedance within the frequency range of node 4, which effectively suppresses the resonance. As can be seen from Figures 9(b) and 9(c), the access of passive damping and virtual impedance leads to the resonant frequency shift and impedance amplification in the frequency band of interest at nodes 1, 2, and 3. At the same time, when the passive damping scheme 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 the passive damping scheme 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 Figure 8(a), Figure 8(b), and Figure 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 found 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 of the resonance suppression strategy. At this time, the ideal feasible domain distribution characteristics of parallel resonance suppression are as follows: Fig.10 Based on Fig.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. Fig.10 It can be seen that it is located in 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 the connection, and the dotted line represents after the connection), where 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 access of 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), Fig.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 requires a large amount of calculation, while Figures 8(a), 8(b), 8(c) and Fig.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] Through the above description, the basic functions of the effectiveness evaluation method of the parallel resonance suppression scheme of the power system have been explained. This method can efficiently evaluate the local suppression effect and the remote suppression effect of the resonance suppression scheme, avoiding the matrix inversion operation, and has good applicability to different types of resonance suppression schemes. It is of great significance to solve the problem that the current resonance suppression method is limited in application scenarios and the parallel resonance scenario is not compatible with the method.

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

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

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

[0117] An evaluation index determination module 122 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;

[0118] A feasible domain determination module 123 is used to determine a feasible domain of parallel resonance local suppression and a feasible domain of parallel resonance remote suppression 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] A relative feasible domain determination module 124 is used to determine a relative feasible domain of local suppression of parallel resonance and a relative feasible domain of remote suppression of parallel resonance based on a concerned frequency band of the resonance suppression scheme and a feasible domain of local suppression of parallel resonance and a feasible domain of remote suppression of parallel resonance at a single frequency;

[0120] An ideal feasible region determination module 125, configured to determine an ideal feasible region for parallel resonance suppression based on an intersection of a relative feasible region for local parallel resonance suppression and a relative feasible region for remote parallel resonance suppression;

[0121] The effectiveness evaluation module 126 is 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. 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.

[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 effectiveness evaluation results of the resonance suppression schemes.

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

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

[0125] In the formula, τ represents the threshold of node impedance change, i represents the node when the resonance-required control node and the resonance suppression scheme action node are the same, and 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;

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

[0127] |Z0(j,j)| 2 -||Z(j,j)| 2 >τ

[0128] Where i represents the node where the resonance suppression scheme works, j represents the node that needs to be controlled, 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 optional embodiment, the feasible domain determination module is specifically used to: determine 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; substitute 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; determine 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.

[0130] 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, is a circle with a radius of , and the inner area of ​​the circle 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, and the feasible region of parallel resonance local suppression is on the side where the origin is located, where Z ii,r , Z ii,i They represent the self-impedance Z of node i after resonance suppression. ii The real and imaginary parts of

[0131] When τ≠0, the boundary of the parallel resonance off-site suppression domain is a As the center of the circle, is a circle with a radius of , and 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 node j self-impedance Z jj The conjugate of r , B i represent the real and imaginary parts of B respectively.

[0132] In an optional embodiment, the relative feasible domain determination module is specifically used to: 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, determine 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, and obtain the relative feasible domain of local suppression of parallel resonance and the relative feasible domain of remote suppression of parallel resonance.

[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 Fig.12 The effectiveness evaluation device of the parallel resonance suppression scheme of the power system is shown.

[0136] See also Fig.13 , Fig.13 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Fig.13 As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, 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 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. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.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 a dedicated 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 executable by at least one processor 10, so that at least one processor 10 executes 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 by the use of a computer device based on the presentation of 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 arranged 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 combinations 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 comprises 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 method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, 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 hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. 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] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0144] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all 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 works, wherein 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 resonance control node and the resonance suppression scheme action node are the same and the node impedance change, the parallel resonance local suppression evaluation index and the parallel resonance remote suppression evaluation index are determined; 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 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 concerned frequency band 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, the relative feasible domain of parallel resonance local suppression and the relative feasible domain of parallel resonance remote suppression 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. Based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible domain, the effectiveness of the resonance suppression scheme is evaluated. The feasible domain includes the feasible domain of local suppression of parallel resonance, the feasible domain of remote suppression of parallel resonance, the relative feasible domain of local suppression of parallel resonance, the relative feasible domain of remote suppression of parallel resonance and the ideal feasible domain of parallel 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 The parallel resonance local suppression evaluation index is expressed by the following formula: |From 0,f (and,and)| 2 -|From f (and,and)| 2 >τ In the formula, τ represents the threshold of node impedance change, i represents the node when the resonance-required control node and the resonance suppression scheme action node are the same, and 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; The parallel resonance remote suppression evaluation index is expressed by the following formula: | Z0(j,j) 2 -|Z(j,j) 2 >τ Where i represents the node where the resonance suppression scheme works, j represents the node that needs to be controlled, 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.

4. The method according to claim 3, characterized in that 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, the feasible domain of parallel resonance local suppression and the feasible domain of parallel resonance remote suppression at a single frequency are determined, including: 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 domain for local suppression of parallel resonance and a feasible domain for remote suppression of parallel resonance at a single frequency are determined.

5. The method according to claim 3, characterized in that: 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, is a circle with a radius of , and the inner area of ​​the circle 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, and the feasible region of parallel resonance local suppression is on the side where the origin is located, where Z ii,r , Z ii,i They represent the self-impedance Z of node i after resonance suppression. ii The real and imaginary parts of When τ≠0, the boundary of the parallel resonance off-site suppression domain is a As the center of the circle, is a circle with a radius of , and 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 , B=AZ * jj , Z ij is the mutual impedance between node i and node j, Z * jj is the node j self-impedance Z jj The conjugate of r , B i represent the real and imaginary parts of B respectively.

6. The method according to claim 1, characterized in that Based on the concerned frequency band 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, 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.

7. The method according to claim 1, characterized in that Based on the relationship between the equivalent impedance of the resonance suppression scheme and the feasible domain, the effectiveness of the resonance suppression scheme is evaluated, 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.

8. 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, determine the nodes that need to be controlled and the nodes where the resonance suppression scheme works, and the amplitude-frequency distribution of the impedance of the power system nodes is determined by inverting the admittance matrix of the power system frequency domain nodes; 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 domain determination module, used to determine the parallel resonance local suppression feasible domain and the parallel resonance remote suppression feasible domain 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 concerned frequency band 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 domain determination module is used to determine an ideal feasible domain for parallel resonance suppression based on the intersection of a relative feasible domain for local parallel resonance suppression and a relative feasible domain for remote parallel resonance suppression; The effectiveness evaluation module is 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, 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.

9. 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 parallel resonance suppression scheme of the power system according to any one of claims 1 to 7 by executing the computer instructions.

10. 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 parallel resonance suppression scheme for a power system according to any one of claims 1 to 7.

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