Novel power system static synchronous stability security domain fast solving method and system

Abstract

The application belongs to the field of power system synchronous stability evaluation calculation, and particularly relates to a novel power system static synchronous stability security domain fast solving method and system, and aims to solve the problems of difficult determination of static synchronous stability criterion and construction of static synchronous security domain. The application comprises obtaining steady-state operation data of a power system as input data; based on the input data, equivalent impedance of the power grid is calculated, and then the decay coefficient of the state of the power system is obtained; in combination with the decay coefficient, a prediction correction method is used to calculate the static synchronous stability security domain of the power system. The application can accurately quantify the static synchronous stability margin of the system; the prediction correction method solves the security domain, effectively eliminates the influence of solving accuracy caused by concave planes, can significantly improve the solving speed, reduce the calculation time, and solve a more accurate security domain.

Description

Technical Field

[0001] This invention belongs to the field of power system synchronization stability assessment and calculation, and specifically involves a novel method and system for rapidly solving the static synchronization stability security domain of a power system. Background Technology

[0002] In recent years, with the development of photovoltaic new energy power generation technology, the proportion of distributed photovoltaic in the distribution network has increased rapidly, and the dynamic behavior has become more complex, increasing the risk of static synchronization instability of the system and affecting the utilization rate of new energy.

[0003] Impedance analysis can effectively evaluate the static synchronous stability characteristics of new energy power generation systems. However, there are two difficulties in analyzing system stability using impedance analysis: first, determining the reference frame for a system with multiple grid-connected converters in parallel; and second, selecting stability criteria, which requires further expansion of impedance analysis stability criteria.

[0004] Existing research has conducted detailed analyses of the factors affecting static synchronization stability, which can be summarized into three main points:

[0005] (1) The static synchronization stability of the system is affected by voltage. When voltage drops, the output power of the grid-connected converter drops sharply, and the system is prone to synchronization instability. (2) The static synchronization stability of the system is affected by grid impedance. After the grid-connected converter is connected to the system, a higher grid impedance value will result in a smaller overall equivalent damping of the system, or even negative damping, which will cause low-frequency oscillation. (3) The static synchronization stability of the system is affected by the control mode and parameters of the grid-connected converter.

[0006] In power distribution networks, the impedance distribution, grid-connected converter control methods, and parameters are fixed in engineering applications. Therefore, the static synchronization stability of the system is mainly affected by voltage factors. Considering that the power flow distribution in the system will affect the voltage at the grid connection point of the grid-connected converter, and thus affect the static synchronization stability of the system, it is necessary to construct a photovoltaic power distribution network security domain that satisfies the static synchronization stability constraints and can be solved quickly and reliably, so as to provide important guidance for the power distribution and safe and stable operation of the power distribution network. Summary of the Invention

[0007] To address the aforementioned problems in the prior art, namely the difficulty in determining the static synchronization stability criterion and the need to construct a static synchronization safety domain, the first aspect of this invention proposes a novel method for rapidly solving the static synchronization stability safety domain of a power system. This method includes the following steps:

[0008] Step S1: Obtain steady-state operating data of the power system as input data; based on the input data, calculate the equivalent impedance of the power grid, and then obtain the attenuation coefficient of the power system state; the steady-state operating data includes the voltage, current, and power of each node;

[0009] The attenuation coefficient is calculated as follows:

[0010] Step S11: Based on the node type of the power system and the input data, construct the node voltage equation; the node type includes generator nodes, tie nodes, and load nodes.

[0011] Step S12, construct the node power equations;

[0012] Step S13: Combine the node voltage equation and the node power equation to obtain the relationship between generator node voltage and current;

[0013] Step S14: Select the slack node as the equivalent infinite grid unit, and calculate the equivalent impedance based on the voltage and current relationship of the generator node;

[0014] Step S15: Calculate the attenuation coefficient based on the equivalent impedance;

[0015] Step S2: Based on the attenuation coefficient, calculate the static synchronization stability security domain of the power system using a predictive correction method.

[0016] In some preferred embodiments, the equivalent impedance is:

[0017] ;

[0018] In the formula, To balance the voltage of the node units, U G,i For generator nodes i The voltage phasor, b ik For the first element in matrix B i Line number k Column elements, U G,k For generator nodes k The voltage phasor.

[0019] In some preferred embodiments, the equivalent transfer function is calculated based on the equivalent impedance, and the equivalent transfer function is:

[0020] ;

[0021] In the formula, K (s) is the equivalent transit function. E Y is the identity matrix. inv For the converter output impedance matrix, Z g,i This is the equivalent impedance.

[0022] In some preferred embodiments, the attenuation coefficient is:

[0023] ;

[0024] ;

[0025] In the formula: p ki Let Res[K(s) be the modulus of the residue. p i For in p i The number of places to leave.

[0026] In some preferred embodiments, the method for calculating the static synchronization stability security region of the power system using a predictive correction method is as follows:

[0027] S31, Obtain the nodes in the power system a The boundary points of the power transformation direction in a single direction are calculated to obtain the set of boundary points of the power transformation direction in a single direction. N s， As the first set;

[0028] S32, let k=1, d=1, take the running solution of any single-direction power conversion direction boundary point in the first set as the search starting point, and take the other boundary points of the first set except the search starting point as the search ending point in turn; the subscript of the search ending point is greater than the subscript of the search starting point; k is the number of iterations calculated;

[0029] S33, Based on the value of the search starting point and the value of the search ending point, calculate the predicted solution according to the predicted solution solution method;

[0030] S34, Calculate the correction direction based on the predicted solution;

[0031] S35, Combining the predicted solution and the correction direction, a critical point search model is constructed and solved to obtain the corrected solution;

[0032] S36, determine whether there are any elements in the corrected solution that are less than 0. If so, complete the search for the safety domain boundary between the search start point and the search end point, and set d = d + 1, then jump to S37. Otherwise, set k = k + 1, then jump to S34. d represents the number of new sets.

[0033] S37, the correction is released into a new set. N s,d In the middle, as the second set, it is determined whether the set of boundary points of the single-direction power conversion direction has been traversed to P. M-1 0 and P M0 Boundary point, M is the number of nodes of the generator set. If it is, jump to S38; otherwise, jump to S34.

[0034] S38, by progressively expanding the second set as the search starting point and search ending point; the second set is a new set into which corrected solutions are added in sequence; the second set is a new set into which corrected solutions are added in sequence;

[0035] S39, based on the newly determined search start point and search end point, execute S33-S35 to obtain the corrected solution, and check whether there are any elements in the corrected solution that are less than 0. If they are, complete the search for the safety domain boundary between the search start point and the search end point, and jump to S40. If they are not, return to step S38.

[0036] S40: Determine whether the last item in the second set has been traversed. If yes, connect all boundary points to form the safety domain boundary. If no, return to step S38 until the last item in the second set has been traversed, and no new set is generated.

[0037] In some preferred embodiments, the predicted solution is calculated as follows:

[0038] ;

[0039] ;

[0040] In the formula: This represents the predicted solution obtained from the k-th iteration calculation between the a-direction and the a+1-direction; k This represents the number of iterations. For the first k Predicted step size; This represents a boundary point where the direction of 'a' changes unidirectionally. This represents a boundary point where the direction of a+1 changes unidirectionally. This represents the predicted solution obtained from the (k-1)th iteration between the a and a+1 directions;

[0041] Define equivalent coefficient Reflecting nodes i and nodes j Changes in active power at nodes q The influence of voltage amplitude, namely:

[0042] ;

[0043] In the formula, i and j It is a numerical variable. right Equivalence coefficients for node analysis i

[0044] for , j for , q is , Represents the change in active power at node i. This represents the change in active power at node j.

[0045] In some preferred embodiments, the correction direction is calculated. The method is as follows:

[0046] ;

[0047] In the formula: For the first k The predicted solution obtained from this calculation. For the first k The modulus of the predicted solution obtained from the calculation.

[0048] In some preferred embodiments, the critical point search model is:

[0049] ;

[0050] In the formula: x represents the node voltage vector of the system; y represents the power vector injected into the system; f(x,y) is the power flow equation of the AC system; and These are the upper and lower limits of the voltage amplitude at node i, respectively; and These are the upper and lower limits of the allowed changeable active power value for node i, respectively; and These are the upper and lower limits of the allowed reactive power value to change at node i, respectively. N a The set of nodes in a photovoltaic system; β a ref To satisfy the maximum allowable attenuation coefficient under stable conditions; sgn() is the sign function.

[0051] In some preferred embodiments, the corrected solution is calculated. The method is as follows:

[0052] ;

[0053] In the formula, Let be the correction step size for the k-th step.

[0054] A second aspect of the present invention provides a novel fast solution system for the static synchronization stability security domain of a power system, comprising: a static synchronization stability margin quantification module and a fast solution module for the static synchronization stability security domain;

[0055] The static synchronization stability margin quantification module is configured to acquire steady-state operating data of the power system as input data; based on the input data, calculate the equivalent impedance of the power grid, and then obtain the attenuation coefficient of the power system state; the steady-state operating data includes the voltage, current, and power of each node;

[0056] The fast solution module for the static synchronization stability security domain is configured to calculate the static synchronization stability security domain of the power system by combining the attenuation coefficient and using a prediction correction method.

[0057] The beneficial effects of this invention are:

[0058] (1) The static synchronous stability margin of the system is quantified by using the attenuation coefficient index. A series of accurate equations and relationships are constructed (such as node voltage equation, node power equation, generator node voltage and current relationship, selecting the balance node as the equivalent infinite grid unit, calculating the equivalent impedance and equivalent transfer function, and finally calculating the attenuation coefficient). Considering the actual operating conditions of the system, the static synchronous stability margin of the system can be accurately quantified.

[0059] (2) The prediction correction method is used to solve the safe region and combined with the superposition law. This method not only considers the power constraint condition, but also the influence of the new current source on the system voltage, the correction amount of the node injection current, and other factors. It also constructs a critical point search model, realizes the fitting of the safe region boundary, reduces the error with the actual boundary, effectively eliminates the concave plane, significantly improves the solution speed, reduces the calculation time, and solves a more accurate safe region. Attached Figure Description

[0060] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0061] Figure 1 This is a schematic diagram of the static security domain solution process of this invention;

[0062] Figure 2 This is a schematic diagram of the boundary point selection method of the present invention;

[0063] Figure 3 This is a schematic diagram of the boundary region calculation logic of the present invention. Detailed Implementation

[0064] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0065] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0066] To more clearly explain the novel fast solution method for the static synchronization stability security domain of power systems, the following section combines... Figures 1 to 3 The steps in the embodiments of the present invention will be described in detail below.

[0067] The novel fast solution method for the static synchronization stability security domain of a power system according to the first embodiment of the present invention includes the following steps:

[0068] Step S1: Obtain steady-state operating data of the power system as input data; based on the input data, calculate the equivalent impedance of the power grid, and then obtain the attenuation coefficient of the power system state; the steady-state operating data includes the voltage, current, and power of each node;

[0069] In this embodiment, the static synchronization stability margin of the system is quantified by the attenuation coefficient index, as follows:

[0070] Step S11: Based on the node types of the power system and the input data, construct the node voltage equations; the node types include generator nodes, tie nodes, and load nodes, and the node voltage equations can be expressed as:

[0071] ;

[0072] In the formula: Y is the system node admittance matrix, I is the node current column vector, U is the node voltage column vector, and L, C and G represent the load node, tie node and generator node, respectively;

[0073] Step S12, construct the node power equations:

[0074] ;

[0075] ;

[0076] ;

[0077] In the formula: S L Here, is the load power matrix, and diag is a diagonal matrix. S L,iFor load nodes i Complex power, U L,i For load nodes i Voltage phasors;

[0078] Step S13: Combine the node voltage equation and the node power equation to obtain the relationship between generator node voltage and current;

[0079] ;

[0080] ;

[0081] We can obtain:

[0082] ;

[0083] In the formula: I G,i For generator nodes i The current phasor, U G,k For generator nodes k The voltage phasor, b ik For the first element in matrix B i Line number k Column elements;

[0084] Step S14: Select the slack node as the equivalent infinite grid unit, and calculate the equivalent impedance based on the voltage and current relationship of the generator node;

[0085] ;

[0086] In the formula: Z g,i , R g,i and L g,i Let i be the generator node and the equivalent grid impedance vector, and let i be the impedance value and inductance value, respectively. U G,k For generator nodes k The voltage phasor, b ik For the first element in matrix B i Line number k Column elements, U G,i For generator nodes i The voltage phasor, To balance the voltage of the node units;

[0087] The equivalent transfer function must be calculated if the system satisfies the static synchronous stability condition. KThe real parts of the eigenvalues ​​of (s) are all negative, and the equivalent transfer function K (s) is:

[0088] ;

[0089] In the formula: E Y is the identity matrix. inv This is the output impedance matrix of the converter;

[0090] Step S15: Calculate the attenuation coefficient based on the equivalent impedance.

[0091] The attenuation coefficient for:

[0092] ;

[0093] ;

[0094] In the formula: Res[K(s), p i For in p i Residue at the location; p ki The magnitude of the residue reflects the degree of influence of the poles on the system oscillation;

[0095] Step S2: Based on the attenuation coefficient, calculate the static synchronization stability security domain of the power system using a predictive correction method;

[0096] In this embodiment, refer to Figure 1 , with nodes a Taking this example, the predictive correction method is used to calculate the static synchronization stability security region of the system. The method is as follows:

[0097] S31, obtain the single-direction power transformation direction boundary points of each node in the power system, and add them to the pre-constructed single-direction power transformation direction boundary point set. a There are two boundary points for the unidirectional power conversion direction:

[0098] ;

[0099] ;

[0100] Unidirectional power refers to the boundary points calculated when only the power of unit a node changes, while the power of other units remains unchanged. The calculated set of boundary points Ns representing the unidirectional power transformation direction is used as the first set, which is a set of feasible solutions that meet the operating conditions. Figure 2 middle , , Each one is a single running solution in that direction, and M is the number of nodes of the generator set;

[0101] S32, let k=1, d=1, take the running solution of any single-direction power conversion direction boundary point in the first set as the search starting point, and take the other boundary points of the first set except the search starting point as the search ending point in turn; the subscript of the search ending point is greater than the subscript of the search starting point; k is the number of iterations calculated, and d represents the number of new sets;

[0102] S33, Based on the value of the search starting point and the value of the search ending point, calculate the predicted solution according to the predicted solution solution method;

[0103] ;

[0104]

[0105] In the formula: This represents the predicted solution obtained from the k-th iteration calculation between the a-direction and the a+1-direction; k This represents the number of iterations. For the first k Predicted step size; This represents a boundary point where the direction of 'a' changes unidirectionally. This represents a boundary point where the direction of a+1 changes unidirectionally. This represents the predicted solution obtained from the (k-1)th iteration between the a and a+1 directions;

[0106] Define equivalent coefficient Reflecting nodes i and nodes j Changes in active power at nodes q The influence of voltage amplitude, namely:

[0107] ;

[0108] In the formula, i and j It is a numerical variable. right Equivalence coefficients for node analysis i

[0109] for , j for , q is , Represents the change in active power at node i. This represents the change in active power at node j;

[0110] S34, Calculate the correction direction based on the predicted solution:

[0111] ;

[0112] In the formula: For the first k The predicted solution obtained from this calculation. For the first k The modulus of the predicted solution obtained from this calculation;

[0113] S35, Combining the predicted solution and the correction direction, a critical point search model is constructed and solved to obtain the corrected solution;

[0114] The critical point search model:

[0115] ;

[0116] In the formula: x represents the node voltage vector of the system; y represents the power vector injected into the system; f(x,y) is the power flow equation of the AC system; and These are the upper and lower limits of the voltage amplitude at node i, respectively; and These are the upper and lower limits of the allowed changeable active power value for node i, respectively; and These are the upper and lower limits of the allowed reactive power value to change at node i, respectively. N a The set of nodes in a photovoltaic system; β a ref To satisfy the maximum allowable attenuation coefficient under stable conditions; sgn() is the sign function;

[0117] The sgn() symbolic function is:

[0118] ;

[0119] The corrected solution was calculated. :

[0120] ;

[0121] In the formula, Let k be the correction step size.

[0122] S36, determine whether any element in the corrected solution is less than 0. If so, complete the search for the safety region boundary between the search start point and the search end point, and set d = d + 1, then jump to S37. Otherwise, set K = K + 1, then jump to S34. Specifically, determine... If an element exists, Δ Pa If the value is less than 0, then the search starting point is complete. Search endpoint Specifically, the search for the safe domain boundary between boundary points... If an element exists, Δ P 1 If the value is less than 0, then the search starting point is complete. and search endpoint Searching for safe domain boundaries between boundary points;

[0123] S37, the corrected power is released into a new set Ns,d. Since d = d + 1, this is used as the second set. It is then determined whether the set of boundary points for the single-direction power transformation direction has been traversed to... and If it is a boundary point, jump to S38; otherwise, jump to S34, and so on, changing the search endpoint in sequence. Add the set of boundary points for the single-direction power conversion direction. The logic for changing boundary points is as follows: Figure 2 As shown, change the search starting point to In order To determine the search endpoint, add the set of boundary points in the single-direction power conversion direction. 、 Change the search starting point to In order To determine the search endpoint, add the set of boundary points along the single-direction power conversion direction. Change the search starting point to by To determine the search endpoint, add the set of boundary points in the single-direction power conversion direction. ;in ;

[0124] S38, the search start point and search end point are determined by progressively expanding the second set; the second set is a new set into which corrected solutions are added in sequence, that is, corrected solutions are added in sequence. When selecting the start point and end point, after completing the traversal of the Ns set, the Ns,d set is used as the selection set for the start point and end point, according to... Figure 3 The search is iterated through the starting and ending points in a specific manner. This represents the corrected solution obtained by searching starting from Ns,(a-1)M+am. The traversal method is as follows: First, perform... and Search between spaces, and conduct further investigations. and Space search;

[0125] S39, based on the newly determined search start point and search end point, execute S33-S35 to obtain the corrected solution, and check whether there are any elements in the corrected solution that are less than 0. If they are, complete the search for the safety domain boundary between the search start point and the search end point, and jump to S40. If they are not, return to step S38.

[0126] S40: Determine whether the last item in the second set has been traversed. If yes, connect all boundary points to form the safety domain boundary. If no, return to step S38 until the last item in the second set has been traversed, and no new set is generated.

[0127] Although the steps in the above embodiments are described in the above order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not need to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple variations are all within the protection scope of this invention.

[0128] The novel fast solution system for the static synchronous stability security domain of a power system according to the second embodiment of the present invention includes: a static synchronous stability margin quantification module and a fast solution module for the static synchronous stability security domain. The static synchronous stability margin quantification module is configured to acquire steady-state operating data of the power system as input data; and calculate the equivalent impedance of the power grid based on the input data, thereby obtaining the attenuation coefficient of the state of the power system.

[0129] Based on the attenuation coefficient, the static synchronization stability security domain of the power system is calculated using a predictive correction method.

[0130] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the system described above can be found in the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0131] It should be noted that the novel fast solution system for the static synchronization stability security domain of power systems provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be further decomposed or combined. For example, the modules in the above embodiments can be merged into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the various modules or steps and are not considered as an improper limitation of the present invention.

[0132] An electronic device according to a third embodiment of the present invention includes: at least one processor; and a memory communicatively connected to at least one of the processors; wherein the memory stores instructions executable by the processor, the instructions being executed by the processor to implement the above-described method for fast solution of static synchronous stable security domain.

[0133] The fourth embodiment of the present invention provides a computer-readable storage medium storing computer instructions, which are executed by the computer to implement the novel method for rapidly solving the static synchronization stability security domain of a power system described above.

[0134] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the electronic device and computer-readable storage medium described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0135] Those skilled in the art will recognize that the modules and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. The programs corresponding to the software modules and method steps can be placed in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. To clearly illustrate the interchangeability of electronic hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the invention.

[0136] The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or indicate a specific order or sequence.

[0137] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0138] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A novel method for rapidly solving the static synchronization stability security domain of a power system, characterized in that, The method includes the following steps: Step S1: Obtain steady-state operating data of the power system as input data; based on the input data, calculate the equivalent impedance of the power grid, and then obtain the attenuation coefficient of the power system state; the steady-state operating data includes the voltage, current, and power of each node; Step S2: Based on the attenuation coefficient, calculate the static synchronization stability security domain of the power system using a predictive correction method; The method for calculating the static synchronization stability security region of the power system using the predictive correction method is as follows: S31, Obtain the nodes in the power system a The boundary points of the power transformation direction in a single direction are calculated to obtain the set of boundary points of the power transformation direction in a single direction. N s， As the first set; S32, let k=1, d=1, take the running solution of any single-direction power conversion direction boundary point in the first set as the search starting point, and take the other boundary points of the first set except the search starting point as the search ending point in turn; the subscript of the search ending point is greater than the subscript of the search starting point; k is the number of iterations calculated; S33, Based on the value of the search starting point and the value of the search ending point, calculate the predicted solution according to the predicted solution solution method; S34, Calculate the correction direction based on the predicted solution; S35, Combining the predicted solution and the correction direction, a critical point search model is constructed and solved to obtain the corrected solution; S36, determine whether there are any elements in the corrected solution that are less than 0. If so, complete the search for the safety domain boundary between the search start point and the search end point, and set d = d + 1, then jump to S37. Otherwise, set k = k + 1, then jump to S34. d represents the number of new sets. S37, add the corrected solution to the new set. N s,d In the middle, as the second set, it is determined whether the first set has been traversed to P. M-1 0 and P M 0 Boundary point, M is the number of generator nodes. If it is, jump to S38; otherwise, jump to S34. S38, by progressively expanding the second set as the search start point and search end point; the second set is a new set into which the corrected solutions are sequentially added; S39, based on the newly determined search start point and search end point, execute S33-S35 to obtain the corrected solution, and check whether there are any elements in the corrected solution that are less than 0. If so, complete the search for the safety domain boundary between the search start point and the search end point, and jump to S40; if not, return to step S38. S40: Determine whether the last item in the second set has been traversed. If yes, connect all boundary points to form the safety domain boundary. If no, return to step S38 until the last item in the second set has been traversed, and no new set is generated.

2. The novel method for fast solution of the static synchronization stability security domain of a power system according to claim 1, characterized in that, The equivalent impedance is: ； In the formula, To balance the voltage of the node units, U G,i For generator nodes i The voltage phasor, b ik For the first element in matrix B i Line number k Column elements, U G,k For generator nodes k The voltage phasor.

3. The novel method for rapidly solving the static synchronization stability security domain of a power system according to claim 2, characterized in that, The equivalent transfer function is calculated based on the equivalent impedance, and the equivalent transfer function is as follows: ； In the formula, K (s) is the equivalent transfer function. E Y is the identity matrix. inv For the converter output impedance matrix, Z g,i This is the equivalent impedance.

4. The novel method for rapidly solving the static synchronization stability security domain of a power system according to claim 1, characterized in that, The attenuation coefficient is calculated as follows: Step S11: Based on the node type of the power system and the input data, construct the node voltage equation; the node type includes generator nodes, tie nodes, and load nodes. Step S12, construct the node power equations; Step S13: Combine the node voltage equation and the node power equation to obtain the relationship between generator node voltage and current; Step S14: Select the slack node as the equivalent infinite grid unit, and calculate the equivalent impedance based on the voltage and current relationship of the generator node; Step S15: Calculate the attenuation coefficient based on the equivalent impedance.

5. The novel method for rapidly solving the static synchronization stability security domain of a power system according to claim 4, characterized in that, The attenuation coefficient is: ； ； In the formula: K (s) is the equivalent transfer function. p ki Let Res[K(s)] be the modulus of the residue. p i For in p i The number of places to leave.

6. The novel method for fast solution of the static synchronization stability security domain of a power system according to claim 1, characterized in that, The method for calculating the predicted solution is as follows: ； ； In the formula: This represents the predicted solution obtained from the k-th iteration calculation between the a-direction and the a+1-direction; k This represents the number of iterations. d k For the first k Predicted step size; This represents a boundary point where the direction of 'a' changes unidirectionally. This represents a boundary point where the direction of a+1 changes unidirectionally. This represents the predicted solution obtained from the (k-1)th iteration between the a and a+1 directions; Define equivalent coefficient h i,j,q Reflecting nodes i and nodes j Changes in active power at nodes q The influence of voltage amplitude, namely: ； In the formula, i and j It is a numerical variable. right Equivalence coefficients for node analysis i for , j for , q is , Represents the change in active power at node i. This represents the change in active power at node j.

7. The novel method for rapidly solving the static synchronization stability security domain of a power system according to claim 1, characterized in that, Calculate the correction direction The method is as follows: ; In the formula: For the first k The predicted solution obtained from this calculation. For the first k The modulus of the predicted solution obtained from the calculation.

8. The novel method for fast solution of the static synchronization stability security domain of a power system according to claim 1, characterized in that, The critical point search model is as follows: ； In the formula: x represents the node voltage vector of the system; y represents the power vector injected into the system; f(x,y) is the power flow equation of the AC system; and These are the upper and lower limits of the voltage amplitude at node i, respectively; and These are the upper and lower limits of the allowed changeable active power value for node i, respectively; and These are the upper and lower limits of the allowed reactive power value for node i, respectively. N a The set of nodes in a photovoltaic system; β a ref To satisfy the maximum allowable attenuation coefficient under stable conditions; sgn() is the sign function.

9. The novel method for fast solution of the static synchronization stability security domain of a power system according to claim 1, characterized in that, Calibrated solution The calculation method is as follows: ； In the formula, Let be the correction step size for the k-th step.

10. A novel fast solution system for the static synchronization stability security domain of a power system, based on the novel fast solution method for the static synchronization stability security domain of a power system as described in any one of claims 1-9, characterized in that, include: Static synchronization stability margin quantification module, static synchronization stability safety domain fast solution module; The static synchronous stability margin quantification module is configured to acquire steady-state operating data of the power system as input data; based on the input data, calculate the equivalent impedance of the power grid, and then obtain the attenuation coefficient of the state of the power system. The steady-state operating data includes the voltage, current, and power of each node; The fast solution module for the static synchronization stability security domain is configured to calculate the static synchronization stability security domain of the power system by combining the attenuation coefficient and using a prediction and correction method. The method for calculating the static synchronization stability security region of the power system using the predictive correction method is as follows: S31, Obtain the nodes in the power system a The boundary points of the power transformation direction in a single direction are calculated to obtain the set of boundary points of the power transformation direction in a single direction. N s， As the first set; S32, let k=1, d=1, take the running solution of any single-direction power conversion direction boundary point in the first set as the search starting point, and take the other boundary points of the first set except the search starting point as the search ending point in turn. The index of the search endpoint is greater than the index of the search starting point; k is the number of iterations for calculation; S33, Based on the value of the search starting point and the value of the search ending point, calculate the predicted solution according to the predicted solution solution method; S34, Calculate the correction direction based on the predicted solution; S35, Combining the predicted solution and the correction direction, a critical point search model is constructed and solved to obtain the corrected solution; S36, determine whether there are any elements in the corrected solution that are less than 0. If so, complete the search for the safety domain boundary between the search start point and the search end point, and set d = d + 1, then jump to S37. Otherwise, set k = k + 1, then jump to S34. d represents the number of new sets. S37, add the corrected solution to the new set. N s,d In the middle, as the second set, it is determined whether the first set has been traversed to P. M-1 0 and P M 0 Boundary point, M is the number of generator nodes. If it is, jump to S38; otherwise, jump to S34. S38, by progressively expanding the second set as the search start point and search end point; the second set is a new set into which the corrected solutions are sequentially added; S39, based on the newly determined search start point and search end point, execute S33-S35 to obtain the corrected solution, and check whether there are any elements in the corrected solution that are less than 0. If so, complete the search for the safety domain boundary between the search start point and the search end point, and jump to S40; if not, return to step S38. S40: Determine whether the last item in the second set has been traversed. If yes, connect all boundary points to form the safety domain boundary. If no, return to step S38 until the last item in the second set has been traversed, and no new set is generated.

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