Transient stability optimization method and system for ultrahigh-proportion new energy power grid

Abstract

The invention discloses a transient stability optimization method and system for an ultrahigh-proportion new energy power grid. The method comprises the following steps: determining a new energy access point and a new energy installed capacity of a target power grid; establishing multiple groups of operation mode data of a direct current receiving end power grid of the target power grid under different operation conditions; calculating a node shrinkage admittance matrix after any new energy is accessed to the target power grid based on the installed capacity of the new energy; performing power grid simulation based on the operation mode data, and determining a dominant unstable equilibrium point; based on the node contraction admittance matrix and the dominant unstable equilibrium point, calculating a transient stability risk margin under any fault after any new energy is accessed to the target power grid; and performing transient stability optimization of the target power grid based on the transient stability risk margin. According to the method, the transient stability risk of the power system after the new energy is accessed can be effectively avoided, so that the safe and stable operation of the ultrahigh-proportion new energy power grid is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and more specifically, to a transient stability optimization method and system for an ultra-high proportion of new energy power grid. Background Art

[0002] As the proportion of renewable energy continues to increase, local high-proportion renewable energy access to the power grid lacks synchronous support power sources, the short-circuit current level continues to decline, showing the characteristics of a weak AC power grid, and the transient stability margin is reduced. Network construction technology is an important way to improve the short-circuit capacity of weak power grids and optimize the transient stability characteristics of the system. After ultra-large-scale renewable energy access, for a specific power grid, due to the uneven distribution of traditional power grid stability support resources such as synchronous machines and wind and solar power generation resources in the power grid, the system grid structure and transient stability strength are also different in different locations. At present, time domain simulation methods are usually used to determine the transient stability characteristics of the system, but it is difficult to quantitatively determine the system transient stability margin based on time domain simulation.

[0003] Therefore, a transient stability optimization method for ultra-high-proportion renewable energy power grids is needed. Summary of the invention

[0004] The present invention proposes a transient stability optimization method and system for a super-high proportion of renewable energy power grid to solve the problem of how to optimize the temporary stability of the power system after the access of renewable energy and ensure the safe and stable operation of the power system.

[0005] In order to solve the above problems, according to one aspect of the present invention, a transient stability optimization method for a super-high proportion of new energy power grid is provided, the method comprising:

[0006] Determine the new energy access points and new energy installed capacity of the target power grid;

[0007] Establishing multiple groups of operation mode data of the DC receiving-end power grid of the target power grid under different operation conditions;

[0008] Calculate the node contraction admittance matrix after any new energy source is connected to the target power grid based on the installed capacity of the new energy source;

[0009] Performing power grid simulation based on the operation mode data to determine a dominant unstable balance point;

[0010] Based on the node contraction admittance matrix and the dominant unstable equilibrium point, calculating the transient stability risk margin of any new energy source under any fault after being connected to the target power grid;

[0011] The transient stability optimization of the target power grid is performed based on the transient stability risk margin.

[0012] Preferably, the node contraction admittance matrix after any new energy source is connected to the target power grid is calculated based on the new energy installed capacity, including:

[0013]

[0014] Among them, Y s is the node contraction admittance matrix; Y q is the n-th order total admittance matrix of the target power grid; n is the number of nodes of the target power grid; Y m,m is the m-order matrix composed of nodes in the generator, Y w,w is the matrix composed of the nodes other than the nodes in the generator, Y m,w and Y w,m is the mutual admittance matrix; Y q The element in the i-th row and i-th column is Y ii =Y ii.0 +y i , Y ii.0 The matrix Y is when the new energy source i is not connected q The i-th row and i-th column element in y i is the constant admittance; S N.i is the installed capacity of new energy i; U N.i is the rated voltage of the new energy source i; Y w,w The inverse matrix of q Calculate the node contraction admittance matrix.

[0015] Preferably, the performing of power grid simulation to determine the unstable units and the dominant unstable balance point includes:

[0016]

[0017] Among them, θ u is the dominant unstable equilibrium point; θ s is a stable equilibrium point; are the rotor angles of the first, second and mth conventional generator sets under steady-state operation of the power grid; m is the number of conventional generator sets in the power grid; the unstable generator sets are numbered as e and f; and are the rotor angles of the e-th, f-th and k-th conventional units under steady-state operation of the power grid.

[0018] Preferably, based on the node contraction admittance matrix and the dominant unstable equilibrium point, calculating the transient stability risk margin of any new energy source under any fault after connecting to the target power grid includes:

[0019]

[0020] Where ΔV is the transient stability risk margin; m is the number of conventional generators in the power grid; M o and are the moment of inertia and angular velocity of the oth generator respectively; P mo is the mechanical power of the oth generator; and They are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes of the target power grid; C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of the oth generator and the pth generator, respectively, and B op and G op are the real and imaginary parts of the elements in the oth row and pth column of the node contraction matrix Ys, respectively; θ t To carry out fault simulation calculation for the power system after the access of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and They are θ u and θ t The oth element in C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of generators o and p respectively.

[0021] Preferably, performing transient stability optimization of the target power grid based on the transient stability risk margin includes:

[0022] If the transient stability risk margin is greater than or equal to 0, the transient stability of the target power grid is determined; if the transient stability risk margin is less than 0, it is determined that it is necessary to carry out new energy distribution and storage grid-building transformation in any new energy near the fault area; among them, if the transient stability risk margin is less than -1, the rated capacity of the grid-building energy storage inverter is determined to be 5S0; if the transient stability risk margin is greater than or equal to -1 and less than 0, the rated capacity of the grid-building energy storage inverter is determined to be 3S0, and S0 is the original capacity configuration.

[0023] According to another aspect of the present invention, a transient stability optimization system for an ultra-high proportion of new energy power grid is provided, the system comprising:

[0024] A new energy data determination unit, used to determine the new energy access point and new energy installed capacity of the target power grid;

[0025] An operation mode data establishing unit, used to establish multiple groups of operation mode data of the DC receiving-end power grid of the target power grid under different operation conditions;

[0026] A node contraction admittance matrix calculation unit, used for calculating the node contraction admittance matrix after any new energy source is connected to the target power grid based on the installed capacity of the new energy source;

[0027] A dominant unstable balance point determination unit, configured to perform power grid simulation based on the operation mode data to determine a dominant unstable balance point;

[0028] A transient stability risk margin determination unit, configured to calculate the transient stability risk margin of any new energy source under any fault after it is connected to the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point;

[0029] A transient stability optimization unit is used to perform transient stability optimization of the target power grid based on the transient stability risk margin.

[0030] Preferably, the node contraction admittance matrix calculation unit calculates the node contraction admittance matrix after any new energy source is connected to the target power grid based on the new energy installed capacity, including:

[0031]

[0032] Among them, Y s is the node contraction admittance matrix; Y q is the n-th order total admittance matrix of the target power grid; n is the number of nodes of the target power grid; Y m,m is the m-order matrix composed of nodes in the generator, Y w,w is the matrix composed of the nodes other than the nodes in the generator, Y m,w and Y w,m is the mutual admittance matrix; Yq The element in the i-th row and i-th column is Y ii =Y ii.0 +y i , Y ii.0 The matrix Y is when the new energy source i is not connected q The i-th row and i-th column element in y i is the constant admittance; S N.i is the installed capacity of new energy i; U N.i is the rated voltage of the new energy source i; Y w,w The inverse matrix of q Calculate the node contraction admittance matrix.

[0033] Preferably, the dominant unstable balance point determination unit performs power grid simulation to determine the unstable units and the dominant unstable balance point, including:

[0034]

[0035] Among them, θ u is the dominant unstable equilibrium point; θ s is a stable equilibrium point; are the rotor angles of the first, second and mth conventional generator sets under steady-state operation of the power grid; m is the number of conventional generator sets in the power grid; the unstable generator sets are numbered as e and f; and are the rotor angles of the e-th, f-th and k-th conventional units under steady-state operation of the power grid.

[0036] Preferably, the transient stability risk margin determination unit calculates the transient stability risk margin of any new energy source under any fault after it is connected to the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point, including:

[0037]

[0038] Where ΔV is the transient stability risk margin; m is the number of conventional generators in the power grid; M o and are the moment of inertia and angular velocity of the oth generator respectively; P mo is the mechanical power of the oth generator; and They are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes of the target power grid; C op =E oE p B op , D op =E o E p G op , E o and E p are the internal potentials of the oth generator and the pth generator, respectively, and B op and G op are the real and imaginary parts of the elements in the oth row and pth column of the node contraction matrix Ys, respectively; θ t To carry out fault simulation calculation for the power system after the access of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and They are θ u and θ t The oth element in C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of generators o and p respectively.

[0039] Preferably, the transient stability optimization unit performs transient stability optimization of the target power grid based on the transient stability risk margin, including:

[0040] If the transient stability risk margin is greater than or equal to 0, the transient stability of the target power grid is determined; if the transient stability risk margin is less than 0, it is determined that it is necessary to carry out new energy distribution and storage grid-building transformation in any new energy near the fault area; among them, if the transient stability risk margin is less than -1, the rated capacity of the grid-building energy storage inverter is determined to be 5S0; if the transient stability risk margin is greater than or equal to -1 and less than 0, the rated capacity of the grid-building energy storage inverter is determined to be 3S0, and S0 is the original capacity configuration.

[0041] Based on another aspect of the present invention, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any step of a transient stability optimization method for an ultra-high proportion of new energy power grid.

[0042] According to another aspect of the present invention, the present invention provides an electronic device, including:

[0043] The computer-readable storage medium described above; and

[0044] One or more processors are used to execute the program in the computer-readable storage medium.

[0045] The present invention provides a method and system for optimizing transient stability of a super-high-proportion new energy power grid, including: determining the new energy access point and new energy installed capacity of the target power grid; establishing multiple groups of operation mode data of the DC receiving end power grid of the target power grid under different operation conditions; calculating the node contraction admittance matrix after any new energy is connected to the target power grid based on the new energy installed capacity; performing power grid simulation based on the operation mode data to determine the dominant unstable equilibrium point; calculating the transient stability risk margin of any new energy under any fault after the new energy is connected to the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point; optimizing the transient stability of the target power grid based on the transient stability risk margin. The present invention adopts the grid-building transformation technology of electrochemical energy storage power stations to optimize the transient stability of the power grid, which can provide technical support for the safe and stable operation of super-high-proportion new energy power grids, and can effectively avoid the transient stability risk of the power system after the new energy is connected, thereby ensuring the safe and stable operation of super-high-proportion new energy power grids. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0047] Figure 1 It is a flow chart of a transient stability optimization method 100 for a super-high proportion new energy power grid according to an embodiment of the present invention;

[0048] Figure 2 Schematic diagram of the structure of a transient stability optimization system 200 for a super-high-proportion new energy power grid according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] Now, exemplary embodiments of the present invention are described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0050] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0051] Figure 1FIG. 1 is a flow chart of a transient stability optimization method 100 for a super-high-proportion new energy power grid according to an embodiment of the present invention. Figure 1 As shown, the transient stability optimization method for a super-high-proportion new energy power grid provided by the embodiment of the present invention adopts the grid-building transformation technology of the electrochemical energy storage power station to optimize the transient stability of the power grid, which can provide technical support for the safe and stable operation of the super-high-proportion new energy power grid, and can effectively avoid the transient stability risk of the power system after the access of new energy, thereby ensuring the safe and stable operation of the super-high-proportion new energy power grid. The transient stability optimization method 100 for a super-high-proportion new energy power grid provided by the embodiment of the present invention starts from step 101. In step 101, the new energy access point and the new energy installed capacity of the target power grid are determined.

[0052] In step 102, multiple groups of operation mode data of the DC receiving-end power grid of the target power grid under different operation conditions are established.

[0053] In the present invention, it is necessary to obtain the nodes i (i=1, 2, ..., m) and the installed capacity S of new energy sources such as wind power and photovoltaic power in the area through investigation and collection for the grid area to be studied. N.i , and establish multiple sets of operating mode data under different startup combinations, load levels, grid structures and other conditions of the DC receiving end power grid to be studied.

[0054] The execution order of steps 101 and 102 can be swapped.

[0055] In step 103, a node contraction admittance matrix after any new energy source is connected to the target power grid is calculated based on the new energy installed capacity.

[0056] Preferably, the node contraction admittance matrix after any new energy source is connected to the target power grid is calculated based on the new energy installed capacity, including:

[0057]

[0058]

[0059] Among them, Y s is the node contraction admittance matrix; Y q is the n-th order total admittance matrix of the target power grid; n is the number of nodes of the target power grid; Y m,m is the m-order matrix composed of nodes in the generator, Y w,w is the matrix composed of the nodes other than the nodes in the generator, Y m,w and Y w,m is the mutual admittance matrix; Y q The element in the i-th row and i-th column is Y ii =Y ii.0 +yi , Y ii.0 The matrix Y is when the new energy source i is not connected q The i-th row and i-th column element in y i is the constant admittance; S N.i is the installed capacity of new energy i; U N.i is the rated voltage of the new energy source i; Y w,w The inverse matrix of q Calculate the node contraction admittance matrix.

[0060] In the present invention, for any node i (i=1, 2, ..., m) to which a new energy source is connected, the node contraction admittance matrix of the power grid after the new energy source i is connected is calculated.

[0061] Specifically, it includes: according to the access capacity of new energy i, the new energy i is equivalent to the constant admittance y according to formula (1): i .

[0062]

[0063] Among them, U N.i is the rated voltage of the new energy source i.

[0064] Then, the node contraction admittance matrix including all nodes in the conventional generator sets in the power grid and the node access point i of the new energy source is calculated. Assuming that there are m conventional generator sets in the power grid and the number of system nodes is n, the n-order total admittance matrix Y of the system is q Can be divided into

[0065]

[0066] Among them, Y m,m is the m-order matrix composed of nodes in the generator, Y w,w is the matrix composed of the nodes other than the nodes in the generator, Y m,w and Y w,m is the mutual admittance matrix.

[0067] When new energy source i is connected to the grid, it is only necessary to q The element in row i and column i in is modified as follows:

[0068] Y ii =Y ii.0 +y i (3)

[0069] Among them, Y ii.0 When new energy source i is not connected, matrix Y q The element in the i-th row and i-th column.

[0070] Then use formula (3) to calculate Y q After updating, the node contraction admittance matrix Y is calculated by formula (4): s :

[0071]

[0072] in, Y w,w It should be noted that each matrix element in formula (4) is the value updated according to formula (3).

[0073] In step 104, a power grid simulation is performed based on the operation mode data to determine a dominant unstable balance point.

[0074] Preferably, the performing of power grid simulation to determine the unstable units and the dominant unstable balance point includes:

[0075]

[0076] Among them, θ u is the dominant unstable equilibrium point; θ s is a stable equilibrium point; are the rotor angles of the first, second and mth conventional generator sets under steady-state operation of the power grid; m is the number of conventional generator sets in the power grid; the unstable generator sets are numbered as e and f; and are the rotor angles of the e-th, f-th and k-th conventional units under steady-state operation of the power grid.

[0077] In the present invention, based on the simulation data of the power grid to be studied, a time domain simulation method is used to determine the unstable unit and the dominant unstable equilibrium point θ u .

[0078] In the present invention, according to the actual situation of the power grid, a failure of a certain important component is set as the basis for judgment. Generally, a three-phase permanent fault of an important transmission line or transformer can be set and removed.

[0079] First, define θ s For a stable equilibrium point:

[0080]

[0081] in, is the rotor angle of the kth conventional unit under steady-state operation of the power grid.

[0082] For specific faults, we first conduct fault simulation calculations on the power system after the access of renewable energy source i, gradually extend the fault time until the system experiences transient power angle instability, count the power angle instability units, and obtain the dominant unstable equilibrium point θ of the system. uFor example, assuming that the unstable units are numbered e and f, then θ u It is expressed as:

[0083]

[0084] In step 105, based on the node contraction admittance matrix and the dominant unstable equilibrium point, the transient stability risk margin of any new energy source under any fault after being connected to the target power grid is calculated.

[0085] Preferably, based on the node contraction admittance matrix and the dominant unstable equilibrium point, calculating the transient stability risk margin of any new energy source under any fault after connecting to the target power grid includes:

[0086]

[0087] Where ΔV is the transient stability risk margin; m is the number of conventional generators in the power grid; M o and are the moment of inertia and angular velocity of the oth generator respectively; P mo is the mechanical power of the oth generator; and They are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes of the target power grid; C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of the oth generator and the pth generator, respectively, and B op and G op are the real and imaginary parts of the elements in the oth row and pth column of the node contraction matrix Ys, respectively; θ t To carry out fault simulation calculation for the power system after the access of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and They are θ u and θ t The oth element in C op =E o E p B op , D op =E o Ep G op , E o and E p are the internal potentials of generators o and p respectively.

[0088] In the present invention, the energy function method is adopted. For any new energy source, by scanning faults, the transient critical energy index under each fault scenario after the new energy source to be studied is calculated in turn, and the transient stability risk margin ΔV of the system after the new energy source is connected under the fault scenario is calculated.

[0089] The rotor motion equation of the n-machine system in the center of inertia (COI) reference coordinate is:

[0090]

[0091] Where: C op =E o E p B op , D op =E o E p G op , P mo is the mechanical power of the oth generator, M o is the moment of inertia of the generator o, θ o and are the power angle and angular velocity of the generator o relative to the center of inertia respectively.

[0092] From the above formula, the expression of the system transient energy function V can be deduced as:

[0093]

[0094] Where: is the angle of the generator o relative to the center of inertia at the stable equilibrium point of the system.

[0095] Assume that the dominant unstable equilibrium point of the system under a certain fault scenario is θ u , then the transient critical energy value V of the system under this fault scenario cr It can be expressed as:

[0096]

[0097] For specific faults, we first conduct fault simulation calculation on the power system after the access of renewable energy source i. The fault time is set to 0.1s, and the rotor angle θ of each generator at 0.1s is obtained. t , and then combined with the classical energy function theory, the transient stability risk index V is obtainedo . Thus we can deduce:

[0098]

[0099] Where ΔV is the transient stability risk margin; m is the number of conventional generators in the power grid; M o and are the moment of inertia and angular velocity of the oth generator respectively; P mo is the mechanical power of the oth generator; and They are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes of the target power grid; C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of the oth generator and the pth generator, respectively, and B op and G op are the real and imaginary parts of the elements in the oth row and pth column of the node contraction matrix Ys, respectively; θ t To carry out fault simulation calculation for the power system after the access of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and They are θ u and θ t The oth element in C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of generators o and p respectively.

[0100] In step 106, transient stability optimization of the target power grid is performed based on the transient stability risk margin.

[0101] Preferably, performing transient stability optimization of the target power grid based on the transient stability risk margin includes:

[0102] If the transient stability risk margin is greater than or equal to 0, the transient stability of the target power grid is determined; if the transient stability risk margin is less than 0, it is determined that it is necessary to carry out new energy distribution and storage grid-building transformation in any new energy near the fault area; among them, if the transient stability risk margin is less than -1, the rated capacity of the grid-building energy storage inverter is determined to be 5S0; if the transient stability risk margin is greater than or equal to -1 and less than 0, the rated capacity of the grid-building energy storage inverter is determined to be 3S0, and S0 is the original capacity configuration.

[0103] In the present invention, the larger the value of the transient stability risk margin ΔV, the smaller the risk of transient instability of the power grid after the new energy source i is connected; on the contrary, the smaller the value of ΔV, the greater the risk of transient instability of the power grid. When ΔV is less than 0, it indicates that the system will be transiently unstable under a specific fault. Therefore, by judging the value of the risk margin ΔV, the transient stability risk of the power grid after the new energy source is connected can be clearly determined.

[0104] Therefore, in the present invention, it is determined whether the transient stability risk margin ΔV after the new energy is connected is less than zero. If it is less than zero, the new energy storage grid-building transformation is carried out in the new energy near the fault area. Specifically, if ΔV is less than -1, the rated capacity of the grid-building energy storage converter is 5S0 (S0 is the original capacity configuration); if ΔV is greater than or equal to -1, the rated capacity of the grid-building energy storage converter is 3S0.

[0105] The method of the present invention aims at the transient stability problem of the power grid after large-scale access of new energy. Based on the transient stability risk assessment method of the power grid considering the access of new energy, by calculating and judging the value of the risk index V, a technical means of electrochemical energy storage power station networking transformation is adopted to propose a transient stability optimization method for a super-high proportion new energy power grid based on electrochemical energy storage networking transformation, which provides technical support for the safe and stable operation of the super-high proportion new energy power grid, can effectively avoid the transient stability risk of the power system after the access of new energy, thereby ensuring the safe and stable operation of the super-high proportion new energy power grid.

[0106] Figure 2 FIG. 2 is a schematic diagram of a transient stability optimization system 200 for a super-high-proportion new energy grid according to an embodiment of the present invention. Figure 2 As shown, the transient stability optimization system 200 for an ultra-high proportion of new energy power grid provided in an embodiment of the present invention includes: a new energy data determination unit 201, an operation mode data establishment unit 202, a node contraction admittance matrix calculation unit 203, a dominant unstable equilibrium point determination unit 204, a transient stability risk margin determination unit 205 and a transient stability optimization unit 206.

[0107] Preferably, the new energy data determination unit 201 is used to determine the new energy access point and new energy installed capacity of the target power grid.

[0108] Preferably, the operation mode data establishing unit 202 is used to establish multiple groups of operation mode data of the DC receiving-end power grid of the target power grid under different operation conditions.

[0109] Preferably, the node contraction admittance matrix calculation unit 203 is used to calculate the node contraction admittance matrix after any new energy source is connected to the target power grid based on the new energy installed capacity.

[0110] Preferably, the node contraction admittance matrix calculation unit 203 calculates the node contraction admittance matrix after any new energy source is connected to the target power grid based on the new energy installed capacity, including:

[0111]

[0112] Among them, Y s is the node contraction admittance matrix; Y q is the n-th order total admittance matrix of the target power grid; n is the number of nodes of the target power grid; Y m,m is the m-order matrix composed of nodes in the generator, Y w,w is the matrix composed of the nodes other than the nodes in the generator, Y m,w and Y w,m is the mutual admittance matrix; Y q The element in the i-th row and i-th column is Y ii =Y ii.0 +y i , Y ii.0 The matrix Y is when the new energy source i is not connected q The i-th row and i-th column element in y i is the constant admittance; S N.i is the installed capacity of new energy i; U N.i is the rated voltage of the new energy source i; Y w,w The inverse matrix of q Calculate the node contraction admittance matrix.

[0113] Preferably, the dominant unstable balance point determination unit 204 is used to perform power grid simulation based on the operation mode data to determine the dominant unstable balance point.

[0114] Preferably, the dominant unstable balance point determination unit 204 performs power grid simulation to determine the unstable units and the dominant unstable balance point, including:

[0115]

[0116] Among them, θ u is the dominant unstable equilibrium point; θ sis a stable equilibrium point; are the rotor angles of the first, second and mth conventional generator sets under steady-state operation of the power grid; m is the number of conventional generator sets in the power grid; the unstable generator sets are numbered as e and f; and are the rotor angles of the e-th, f-th and k-th conventional units under steady-state operation of the power grid.

[0117] Preferably, the transient stability risk margin determination unit 205 is used to calculate the transient stability risk margin of any new energy source under any fault after it is connected to the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point.

[0118] Preferably, the transient stability risk margin determination unit 205 calculates the transient stability risk margin of any new energy source under any fault after it is connected to the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point, including:

[0119]

[0120] Where ΔV is the transient stability risk margin; m is the number of conventional generators in the power grid; M o and are the moment of inertia and angular velocity of the oth generator respectively; P mo is the mechanical power of the oth generator; and They are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes of the target power grid; C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of the oth generator and the pth generator, respectively, and B op and G op are the real and imaginary parts of the elements in the oth row and pth column of the node contraction matrix Ys, respectively; θ t To carry out fault simulation calculation for the power system after the access of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and θ o t They are θ u and θ t The oth element in C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of generators o and p respectively.

[0121] Preferably, the transient stability optimization unit 206 is configured to perform transient stability optimization of the target power grid based on the transient stability risk margin.

[0122] Preferably, the transient stability optimization unit 206 performs transient stability optimization of the target power grid based on the transient stability risk margin, including:

[0123] If the transient stability risk margin is greater than or equal to 0, the transient stability of the target power grid is determined; if the transient stability risk margin is less than 0, it is determined that it is necessary to carry out new energy distribution and storage grid-building transformation in any new energy near the fault area; among them, if the transient stability risk margin is less than -1, the rated capacity of the grid-building energy storage inverter is determined to be 5S0; if the transient stability risk margin is greater than or equal to -1 and less than 0, the rated capacity of the grid-building energy storage inverter is determined to be 3S0, and S0 is the original capacity configuration.

[0124] The transient stability optimization system 200 for a super-high-ratio new energy power grid according to an embodiment of the present invention corresponds to the transient stability optimization method 100 for a super-high-ratio new energy power grid according to another embodiment of the present invention, and will not be described in detail here.

[0125] Based on another aspect of the present invention, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any step of a transient stability optimization method for an ultra-high proportion of new energy power grid.

[0126] According to another aspect of the present invention, the present invention provides an electronic device, including:

[0127] The computer-readable storage medium described above; and

[0128] One or more processors are used to execute the program in the computer-readable storage medium.

[0129] The invention has been described above with reference to a few embodiments. However, it is readily apparent to a person skilled in the art that other embodiments than the ones disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

[0130] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise therein. All references to "a / said / the [means, components, etc.]" are to be openly interpreted as at least one instance of said means, components, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily have to be performed in the exact order disclosed, unless explicitly stated otherwise.

[0131] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0132] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0133] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0134] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A transient stability optimization method for a super-high proportion of new energy power grid, characterized in that: The method comprises: Determine the new energy access points and new energy installed capacity of the target power grid; Establishing multiple groups of operation mode data of the DC receiving-end power grid of the target power grid under different operation conditions; Calculate the node contraction admittance matrix after any new energy source is connected to the target power grid based on the installed capacity of the new energy source; Performing power grid simulation based on the operation mode data to determine a dominant unstable balance point; Based on the node contraction admittance matrix and the dominant unstable equilibrium point, calculating the transient stability risk margin of any new energy source under any fault after being connected to the target power grid; The transient stability optimization of the target power grid is performed based on the transient stability risk margin.

2. The method according to claim 1, characterized in that Calculating a node contraction admittance matrix after any new energy source is connected to the target power grid based on the new energy installed capacity, including: Among them, Y s is the node contraction admittance matrix; Y q is the n-th order total admittance matrix of the target power grid; n is the number of nodes of the target power grid; Y m,m is the m-order matrix composed of nodes in the generator, Y w,w is the matrix composed of the nodes other than the nodes in the generator, Y m,w and Y w,m is the mutual admittance matrix; Y q The element in the i-th row and i-th column is Y ii =Y ii.0 +y i , Y ii.0 The matrix Y is when the new energy source i is not connected q The i-th row and i-th column element in y i is the constant admittance; S N.i is the installed capacity of new energy i; U N.i is the rated voltage of the new energy source i; Y w,w The inverse matrix of q Calculate the node contraction admittance matrix.

3. The method according to claim 1, characterized in that: The power grid simulation is performed to determine the unstable units and the dominant unstable balance point, including: Among them, θ u is the dominant unstable equilibrium point; θ s For a stable equilibrium point; are the rotor angles of the first, second and mth conventional generator sets under steady-state operation of the power grid; m is the number of conventional generator sets in the power grid; the unstable generator sets are numbered as e and f; and are the rotor angles of the e-th, f-th and k-th conventional units under steady-state operation of the power grid.

4. The method according to claim 1, characterized in that: Based on the node contraction admittance matrix and the dominant unstable equilibrium point, the transient stability risk margin of any new energy source under any fault after being connected to the target power grid is calculated, including: Where ΔV is the transient stability risk margin; m is the number of conventional generators in the power grid; M o and are the moment of inertia and angular velocity of the oth generator respectively; P mo is the mechanical power of the oth generator; and They are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes of the target power grid; C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of the oth generator and the pth generator, respectively, and B op and G op are the real and imaginary parts of the elements in the oth row and pth column of the node contraction matrix Ys, respectively; θ t To carry out fault simulation calculation for the power system after the access of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and They are θ u and θ t The oth element in C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of generators o and p respectively.

5. The method according to claim 1, characterized in that The method further comprises: performing transient stability optimization of the target power grid based on the transient stability risk margin, comprising: If the transient stability risk margin is greater than or equal to 0, the transient stability of the target power grid is determined; if the transient stability risk margin is less than 0, it is determined that it is necessary to carry out new energy distribution and storage grid-building transformation in any new energy near the fault area; among them, if the transient stability risk margin is less than -1, the rated capacity of the grid-building energy storage inverter is determined to be 5S0; if the transient stability risk margin is greater than or equal to -1 and less than 0, the rated capacity of the grid-building energy storage inverter is determined to be 3S0, and S0 is the original capacity configuration.

6. A transient stability optimization system for ultra-high-proportion new energy power grid, characterized in that: The system comprises: A new energy data determination unit, used to determine the new energy access point and new energy installed capacity of the target power grid; An operation mode data establishing unit, used to establish multiple groups of operation mode data of the DC receiving-end power grid of the target power grid under different operation conditions; A node contraction admittance matrix calculation unit, used for calculating the node contraction admittance matrix after any new energy source is connected to the target power grid based on the installed capacity of the new energy source; A dominant unstable balance point determination unit, configured to perform power grid simulation based on the operation mode data to determine a dominant unstable balance point; A transient stability risk margin determination unit, configured to calculate the transient stability risk margin of any new energy source under any fault after it is connected to the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point; A transient stability optimization unit is used to perform transient stability optimization of the target power grid based on the transient stability risk margin.

7. The system according to claim 6, characterized in that The node contraction admittance matrix calculation unit calculates the node contraction admittance matrix after any new energy source is connected to the target power grid based on the new energy installed capacity, including: Among them, Y s is the node contraction admittance matrix; Y q is the n-th order total admittance matrix of the target power grid; n is the number of nodes of the target power grid; Y m,m is the m-order matrix composed of nodes in the generator, Y w,w is the matrix composed of the nodes other than the nodes in the generator, Y m,w and Y w,m is the mutual admittance matrix; Y q The element in the i-th row and i-th column is Y ii =Y ii.0 +y i , Y ii.0 The matrix Y is when the new energy source i is not connected q The i-th row and i-th column element in y i is the constant admittance; S N.i is the installed capacity of new energy i; U N.i is the rated voltage of the new energy source i; Y w,w The inverse matrix of q Calculate the node contraction admittance matrix.

8. The system according to claim 6, characterized in that The dominant unstable balance point determination unit performs power grid simulation to determine the unstable units and the dominant unstable balance point, including: Among them, θ u is the dominant unstable equilibrium point; θ s For a stable equilibrium point; are the rotor angles of the first, second and mth conventional generator sets under steady-state operation of the power grid; m is the number of conventional generator sets in the power grid; the unstable generator sets are numbered as e and f; and are the rotor angles of the e-th, f-th and k-th conventional units under steady-state operation of the power grid.

9. The system according to claim 6, characterized in that The transient stability risk margin determination unit calculates the transient stability risk margin of any new energy source under any fault after it is connected to the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point, including: Where ΔV is the transient stability risk margin; m is the number of conventional generators in the power grid; M o and are the moment of inertia and angular velocity of the oth generator respectively; P mo is the mechanical power of the oth generator; and They are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes of the target power grid; C op =E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of the oth generator and the pth generator, respectively, and B op and G op are the real and imaginary parts of the elements in the oth row and pth column of the node contraction matrix Ys, respectively; θ t To carry out fault simulation calculation for the power system after the access of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and They are θ u and θ t The oth element in C op = E o E p B op , D op =E o E p G op , E o and E p are the internal potentials of generators o and p respectively.

10. The system according to claim 6, characterized in that The transient stability optimization unit performs transient stability optimization of the target power grid based on the transient stability risk margin, including: If the transient stability risk margin is greater than or equal to 0, the transient stability of the target power grid is determined; if the transient stability risk margin is less than 0, it is determined that it is necessary to carry out new energy distribution and storage grid-building transformation in any new energy near the fault area; among them, if the transient stability risk margin is less than -1, the rated capacity of the grid-building energy storage inverter is determined to be 5S0; if the transient stability risk margin is greater than or equal to -1 and less than 0, the rated capacity of the grid-building energy storage inverter is determined to be 3S0, and S0 is the original capacity configuration.

11. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 1 to 5.

12. An electronic device, characterized in that: include: The computer readable storage medium as claimed in claim 11; as well as One or more processors are used to execute the program in the computer-readable storage medium.

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