A transient stability optimization method and system for ultra-high proportion new energy power grid

Abstract

The present invention discloses a transient stability optimization method and system for a super-high-proportion new energy power grid, comprising: determining the new energy access point and new energy installed capacity of a target power grid; establishing multiple sets of operating mode data of the DC receiving-end power grid of the target power grid under different operating conditions; calculating the node contraction admittance matrix of any new energy after accessing the target power grid based on the new energy installed capacity; performing power grid simulation based on the operating mode data to determine the dominant unstable equilibrium point; calculating the transient stability risk margin of any new energy under any fault after accessing the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point; and performing transient stability optimization of the target power grid based on the transient stability risk margin. The present invention 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.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and more particularly to a method and system for optimizing transient stability of 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 the access of ultra-large-scale renewable energy, for a specific power grid, due to the uneven distribution of traditional 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. Currently, time domain simulation methods are usually used to determine the transient stability characteristics of the system. However, it is difficult to quantitatively determine the transient stability margin of the system based on time domain simulation evaluation.

[0003] Therefore, a transient stability optimization method for ultra-high proportion of 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 method for optimizing transient stability of a power grid with an ultra-high proportion of new energy is provided, the method comprising:

[0006] Determine the target grid's renewable energy access points and installed capacity;

[0007] Establishing multiple sets of operating mode data of the DC receiving-end power grid of the target power grid under different operating 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 operating mode data to determine a dominant unstable equilibrium point;

[0010] Calculating the transient stability risk margin of any new energy source under any fault after connecting to the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point;

[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 installed capacity of the new energy source, including:

[0013]

[0014] Among them, Y s is the node contraction admittance matrix; Y q is the n-order full 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 row i and column i is Y ii =Y ii.0 +y i , Y ii.0 Matrix Y when new energy source i is not connected q The element in row i and column i; 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 the updated Y 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, the transient stability risk margin of any new energy source under any fault after being connected to the target power grid is calculated based on the node contraction admittance matrix and the dominant unstable equilibrium point, including:

[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 are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes in 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, 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; θ t To carry out fault simulation calculation for the power system after the integration of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and 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 new energy distribution and storage grid-forming transformation needs to be carried out in any new energy near the fault area; among which, if the transient stability risk margin is less than -1, the rated capacity of the grid-forming energy storage converter 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-forming energy storage converter 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, configured to establish multiple sets 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, configured to calculate a 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, based on the node contraction admittance matrix and the dominant unstable equilibrium point, a transient stability risk margin of any new energy source under any fault after being connected to the target power grid;

[0029] A transient stability optimization unit is configured 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-order full 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 row i and column i is Y ii =Y ii.0 +y i , Y ii.0 Matrix Y when new energy source i is not connected q The element in row i and column i; 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 the updated Y 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 determining 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 are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes in 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, 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; θ t To carry out fault simulation calculation for the power system after the integration of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and 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 new energy distribution and storage grid-forming transformation needs to be carried out in any new energy near the fault area; among which, if the transient stability risk margin is less than -1, the rated capacity of the grid-forming energy storage converter 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-forming energy storage converter 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 configured to execute the program in the computer-readable storage medium.

[0045] The present invention provides a method and system for transient stability optimization 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 sets of operating mode data of the DC receiving end power grid of the target power grid under different operating conditions; calculating the node contraction admittance matrix of any new energy after accessing the target power grid based on the new energy installed capacity; performing power grid simulation based on the operating mode data to determine the dominant unstable equilibrium point; calculating the transient stability risk margin of any new energy under any fault after accessing the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point; and performing transient stability optimization of the target power grid based on the transient stability risk margin. The present invention adopts the grid-forming transformation technology of electrochemical energy storage power stations to perform transient stability optimization 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 access of new energy, 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 Flowchart of a transient stability optimization method 100 for a super-high proportion of new energy power grid according to an embodiment of the present invention;

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

[0049] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to provide a thorough and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments shown in the accompanying drawings is not intended to limit the present invention. In the accompanying drawings, identical elements are denoted by the same reference numerals.

[0050] Unless otherwise specified, the terms used herein (including technical terms) have the meanings commonly understood by those skilled in the art. In addition, it is understood that 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 power grid with a very high proportion of new energy provided by an embodiment of the present invention uses electrochemical energy storage power station grid-based transformation technology to optimize the transient stability of the power grid. This method can provide technical support for the safe and stable operation of a power grid with a very high proportion of new energy, effectively avoid transient stability risks in the power system after new energy access, and thus ensure the safe and stable operation of a power grid with a very high proportion of new energy. The transient stability optimization method 100 for a power grid with a very high proportion of new energy provided by an embodiment of the present invention begins at step 101. In step 101, the new energy access points and new energy installed capacity of the target power grid are determined.

[0052] In step 102, multiple sets 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 research and collection. 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 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 installed capacity of the new energy source.

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

[0057]

[0058]

[0059] Among them, Y s is the node contraction admittance matrix; Y q is the n-order full 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 row i and column i is Y ii =Y ii.0 +yi , Y ii.0 Matrix Y when new energy source i is not connected q The element in row i and column i; 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 the updated Y q Calculate the node contraction admittance matrix.

[0060] In the present invention, for any node i (i=1, 2, ..., m) connected to a new energy source, 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 new energy i.

[0064] Then, the node contraction admittance matrix including all nodes in the conventional generator sets in the power grid and the new energy access point i 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 full 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, the matrix Y q The element in row i and column i.

[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 the matrix elements in formula (4) are the updated values ​​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 equilibrium 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, the 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, the failure of a certain important component is set as the basis for judgment. Generally, it can be set that an important transmission line or transformer has a three-phase permanent fault and is cut off.

[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 a specific fault, we first conduct fault simulation calculations on the power system after the new energy source i is connected, 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 the unstable units are numbered e and f, then θ u 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, the transient stability risk margin of any new energy source under any fault after being connected to the target power grid is calculated based on the node contraction admittance matrix and the dominant unstable equilibrium point, including:

[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 are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes in 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, 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; θ t To carry out fault simulation calculation for the power system after the integration of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and 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 is connected to the power grid to be studied is calculated in sequence, and the transient stability risk margin ΔV of the system after the new energy source is connected under the fault scenario is calculated based on the fault scenario.

[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 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 is cr It can be expressed as:

[0096]

[0097] For a specific fault, we first conduct a fault simulation calculation on the power system after the new energy source i is connected. 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 are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes in 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, 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; θ t To carry out fault simulation calculation for the power system after the integration of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and 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 new energy distribution and storage grid-forming transformation needs to be carried out in any new energy near the fault area; among which, if the transient stability risk margin is less than -1, the rated capacity of the grid-forming energy storage converter 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-forming energy storage converter is determined to be 3S0, and S0 is the original capacity configuration.

[0103] In this invention, a larger value for the transient stability risk margin ΔV indicates a lower risk of transient grid instability after the integration of renewable energy source i. Conversely, a smaller value for ΔV indicates a greater risk of transient grid instability. When ΔV is less than 0, it indicates that the system will experience transient instability under a specific fault. Therefore, by determining the value of the risk margin ΔV, the transient stability risk of the grid after the integration of renewable energy source i can be clearly determined.

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

[0105] The method of the present invention aims at the transient stability problem of the power grid after large-scale access to 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 grid-building transformation is adopted to propose a transient stability optimization method for the ultra-high proportion new energy power grid based on electrochemical energy storage grid-building transformation, which provides technical support for the safe and stable operation of the ultra-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 ultra-high proportion new energy power grid.

[0106] Figure 2 FIG. 2 is a structural diagram of a transient stability optimization system 200 for an ultra-high proportion new energy power 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 by 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 determining unit 201 is used to determine the new energy access points and new energy installed capacity of the target power grid.

[0108] Preferably, the operation mode data establishing unit 202 is configured to establish multiple sets 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 installed capacity of the new energy source.

[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-order full 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 row i and column i is Y ii =Y ii.0 +y i , Y ii.0 Matrix Y when new energy source i is not connected q The element in row i and column i; 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 the updated Y q Calculate the node contraction admittance matrix.

[0113] Preferably, the dominant unstable balance point determining unit 204 is configured to perform power grid simulation based on the operation mode data to determine a 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 determining unit 205 is 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.

[0118] Preferably, the transient stability risk margin determining 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 are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes in 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, 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; θ t To carry out fault simulation calculation for the power system after the integration of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained; and θ o t 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 new energy distribution and storage grid-forming transformation needs to be carried out in any new energy near the fault area; among which, if the transient stability risk margin is less than -1, the rated capacity of the grid-forming energy storage converter 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-forming energy storage converter is determined to be 3S0, and S0 is the original capacity configuration.

[0124] The transient stability optimization system 200 for a super-high proportion of new energy power grid according to an embodiment of the present invention corresponds to the transient stability optimization method 100 for a super-high proportion of 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 configured 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 herein. All references to "a / the [means, component, etc.]" are to be interpreted openly as referring to at least one instance of the means, component, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not necessarily need to be performed in the exact order disclosed, unless explicitly stated otherwise.

[0131] It will be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, 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 magnetic 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 flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, 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 flowcharts and / or block diagrams. 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 that can direct a computer or other programmable data processing device to work 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 The 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 operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function 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 and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the 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 by the scope of protection of the claims of the present invention.

Claims

1. A transient stability optimization method for an ultra-high proportion of new energy power grid, characterized in that: The method comprises: Determine the target grid's renewable energy access points and installed capacity; Establishing multiple sets of operating mode data of the DC receiving-end power grid of the target power grid under different operating 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 operating mode data to determine a 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 based on the node contraction admittance matrix and the dominant unstable equilibrium point; performing transient stability optimization of the target power grid based on the transient stability risk margin; The step of calculating the transient stability risk margin of any new energy source under any fault after connecting to the target power grid based on the node contraction admittance matrix and the dominant unstable equilibrium point includes: 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 o is the mechanical power of the oth generator; and are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes in 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, 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; θ t In order to carry out fault simulation calculation for the power system after the connection of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained.

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-order full 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 row i and column i is Y ii =Y ii.0 +y i , Y ii.0 Matrix Y when new energy source i is not connected q The element in row i and column i; 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 the updated Y q Calculate the node contraction admittance matrix.

3. The method according to claim 1, characterized in that The power grid simulation to determine the unstable units and the dominant unstable balance point includes: 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; are the rotor angles of the e-th and f-th conventional units under steady-state operation of the power grid, respectively.

4. The method according to claim 1, wherein Performing transient stability optimization of the target power grid based on the transient stability risk margin includes: 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 new energy distribution and storage grid-forming transformation needs to be carried out in any new energy near the fault area; among which, if the transient stability risk margin is less than -1, the rated capacity of the grid-forming energy storage converter 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-forming energy storage converter is determined to be 3S0, and S0 is the original capacity configuration.

5. 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, configured to establish multiple sets 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, configured to calculate a 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, based on the node contraction admittance matrix and the dominant unstable equilibrium point, a transient stability risk margin of any new energy source under any fault after being connected to the target power grid; a transient stability optimization unit, configured to perform transient stability optimization of the target power grid based on the transient stability risk margin; 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 o is the mechanical power of the oth generator; and are θ u and θ t The oth element in θ u is the dominant unstable equilibrium point; n is the number of nodes in 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, 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; θ t In order to carry out fault simulation calculation for the power system after the connection of renewable energy source i for a specific fault, the rotor angles of each generator at time t are obtained.

6. The system according to claim 5, 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-order full 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 row i and column i is Y ii =Y ii.0 +y i , Y ii.0 Matrix Y when new energy source i is not connected q The element in row i and column i; 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 the updated Y q Calculate the node contraction admittance matrix.

7. The system according to claim 5, 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 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; are the rotor angles of the e-th and f-th conventional units under steady-state operation of the power grid, respectively.

8. The system according to claim 5, wherein: 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 new energy distribution and storage grid-forming transformation needs to be carried out in any new energy near the fault area; among which, if the transient stability risk margin is less than -1, the rated capacity of the grid-forming energy storage converter 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-forming energy storage converter is determined to be 3S0, and S0 is the original capacity configuration.

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