Power flow controller site selection method and system considering line transmission power margin distribution balance degree

Abstract

The invention provides a power flow controller site selection method and system considering line transmission power margin distribution balance, and the method comprises the steps: setting a fault in a target power grid to determine a load rate average value of all heavy load lines under each working condition, calculating a power flow entropy, and forming a target power grid operation capability evaluation factor; a typical working condition set is screened out; based on the line load rates and node voltage information under all typical working conditions, and in combination with the real-time safety margin under each typical working condition, constructing a target power grid operation capability safety margin balance degree index set of the heavy load line load rates and the voltages at the two ends under the steady state and transient state conditions; and determining comprehensive evaluation factors of the load rates of the heavy load lines and the operation safety margins of the voltages at the two ends, screening the comprehensive evaluation factors of all the heavy load lines, and obtaining the optimal configuration point of the power flow controller according to actual demands. According to the method, reasonable configuration of the power flow controller is better realized under the complex power grid condition, and the operation safety and efficiency of the power grid are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible AC transmission, and particularly relates to a method and system for locating a power flow controller considering the balance degree of the power transmission margin distribution of lines. Background Art

[0002] With the expansion of the scale of the power system and the improvement of the complexity of power grid operation, as an important power grid regulation device, the power flow controller is widely used in the power system to optimize the power flow distribution and relieve the overload problem of transmission lines. The existing power flow controllers mainly include unified power flow controllers, phase shifters, inter-line power flow controllers, etc., which can effectively improve the utilization rate of transmission lines and optimize the power flow direction under steady-state conditions. However, in the existing research on the location method of power flow controllers, it mainly relies on a single index such as line load rate, and the comprehensive impact on the transient and steady-state performance of the system is insufficiently evaluated, unable to fully reflect the complexity and diversity of the power grid operation ability. This limitation is particularly prominent when facing the dynamic changes of complex power grid structures and their operating states, and it is difficult to meet the requirements of modern power grids for high reliability and efficient utilization.

[0003] At present, some studies have tried to improve the power flow controller location technology through different methods, such as simple models based on fault scanning, load rate optimization, or system operation margin, but there are still deficiencies in practical applications. The existing methods usually fail to systematically consider the balance of the power transmission margin distribution of lines under multiple working conditions and the coordinated optimization of steady-state and transient conditions, resulting in deficiencies in the comprehensive performance of the power flow controller configuration scheme across the network. Therefore, there is an urgent need to propose a more comprehensive and scientific location method to better realize the reasonable configuration of power flow controllers under complex power grid conditions and improve the safety and efficiency of power grid operation. Summary of the Invention

[0004] The present invention provides a method and system for locating a power flow controller considering the balance degree of the power transmission margin distribution of lines to better realize the reasonable configuration of power flow controllers under complex power grid conditions and improve the safety and efficiency of power grid operation.

[0005] In a first aspect, the present invention provides a method for locating a power flow controller considering the balance degree of the power transmission margin distribution of lines, including:

[0006] Setting N-1 faults under a first disturbance and node power fluctuation faults under the first disturbance in the target power grid to determine the average load rate of all overloaded lines and the power flow entropy of the target power grid under each working condition;

[0007] Determining multiple typical working conditions under each disturbance according to the average load rate of all overloaded lines and the power flow entropy of the target power grid under each working condition;

[0008] Obtain the load rates and node voltages of heavy-load lines under all typical operating conditions;

[0009] Determine the active power safety margin transfer ratio and voltage safety margin transfer ratio of the target heavy-load line under the target typical operating condition based on the load rates and node voltages of heavy-load lines under all typical operating conditions;

[0010] Determine the load rate transfer balance degree and voltage deviation transfer balance degree of the target heavy-load line considering the safety margin based on the active power safety margin transfer ratio and voltage safety margin transfer ratio of the target heavy-load line under the target typical operating condition;

[0011] Determine the comprehensive evaluation factor of the operating safety margin of the target heavy-load line under steady-state and transient conditions based on the load rate transfer balance degree and voltage deviation transfer balance degree of the target heavy-load line considering the safety margin;

[0012] Obtain the comprehensive evaluation factors of the operating safety margins of all heavy-load lines in the target power grid under steady-state and transient conditions;

[0013] In the target power grid, determine the installation branches of the power flow controller for the heavy-load lines corresponding to the comprehensive evaluation factors exceeding the preset evaluation factor threshold.

[0014] Optionally, setting the N-1 fault under the first disturbance and the node power fluctuation fault under the first disturbance in the target power grid to determine the average load rate of all heavy-load lines and the power flow entropy of the target power grid under each operating condition, including:

[0015] Calculate the average load rate of all lines under each operating condition according to the following formula:

[0016]

[0017] where, μ aver,t is the average load rate of all heavy-load lines under operating condition t; μ i,t is the load rate of heavy-load line i under operating condition t; L t is the total number of heavy-load lines under operating condition t; N is the total number of transmission lines in the target power grid; M is the total number of nodes in the target power grid;

[0018] Calculate the power flow entropy of the target power grid under each operating condition according to the following formula:

[0019]

[0020] where, H p,t is the power flow entropy of the target power grid under operating condition t; P(k) tis the probability that the line load rate under condition t is in the range of (kc1, kc1 + c1); k is the load rate interval number without considering the safety margin; c1 is the value of a single load rate interval without considering the safety margin; K is the total number of load rate intervals without considering the safety margin; ln represents the natural logarithm operator; α is a preset first constant coefficient.

[0021] Optionally, the average load rate of all heavy-load lines and the target power grid flow entropy under each condition are used to determine multiple typical conditions under each disturbance, including:

[0022] Calculate the target power grid operation ability evaluation factor under the target condition according to the following formula:

[0023] C t = α1·μ aver,t + α2·H p,t ;

[0024] where C t is the target power grid operation ability evaluation factor under condition t; α1 is a preset second constant coefficient; μ aver,t is the average load rate of all heavy-load lines under condition t; α2 is a preset third constant coefficient; H p,t is the power grid flow entropy of the target power grid under condition t;

[0025] Obtain all the operation ability evaluation factors of the target power grid under the first disturbance and all the operation ability evaluation factors under the second disturbance, and use them as the first evaluation factor set and the second evaluation factor set respectively;

[0026] Determine the conditions corresponding to the evaluation factors exceeding the first evaluation factor threshold in the first evaluation factor set as typical conditions;

[0027] Determine the conditions corresponding to the evaluation factors exceeding the second evaluation factor threshold in the second evaluation factor set as typical conditions.

[0028] Optionally, the determination of the active power safety margin transfer ratio and the voltage safety margin transfer ratio of the target heavy-load line under the target typical condition according to the heavy-load line load rate and node voltage under all typical conditions includes:

[0029] Calculate the active power safety margin transfer ratio of the target heavy-load line under the target typical condition according to the following formula: <http: / / www.example.com /

[0030]

[0031] where is the active power safety margin transfer ratio of the heavy-load line pq under the typical condition f; Δμ pq,f is the load rate fluctuation of the heavy-load line pq under the typical condition f; Δμ pqs,fis the active power transfer margin of the load rate of the heavy-load line pq under the typical condition f; n is the total number of typical conditions under the first disturbance; m is the total number of typical conditions under the second disturbance;

[0032] Calculate the voltage security margin transfer ratio of the target heavy-load line under the target typical condition according to the following formula:

[0033]

[0034] where η pq, f is the voltage security margin transfer ratio of the heavy-load line pq under the typical condition f; ΔU p,f is the voltage fluctuation amount of the p-terminal node of the heavy-load line pq under the typical condition f; ΔU q,f is the voltage fluctuation amount of the q-terminal node of the heavy-load line pq under the typical condition f; ΔU ps,f is the operable margin of the voltage of the p-terminal node of the heavy-load line pq under the typical condition f; ΔU qs,f is the operable margin of the voltage of the q-terminal node of the heavy-load line pq under the typical condition f.

[0035] Optionally, determining the load rate transfer balance degree and voltage offset transfer balance degree of the target heavy-load line considering the safety margin according to the active power security margin transfer ratio and voltage security margin transfer ratio of the target heavy-load line under the target typical condition includes:

[0036] Calculate the load rate transfer balance degree and voltage offset transfer balance degree of the target heavy-load line considering the safety margin according to the following formula:

[0037]

[0038] where, is the load rate transfer balance degree of the heavy-load line pq considering the safety margin; ω1 is a preset fourth constant coefficient; P(g) is the probability that the active power security margin transfer ratio of the heavy-load line pq after normalization is in (gc2, gc2 + c2); g is the interval number of the load rate considering the safety margin; c2 is the value of a single load rate interval considering the safety margin; ln represents the natural logarithm operator; A is the total number of load rate intervals considering the safety margin; H η,pq is the voltage offset transfer balance degree of the heavy-load line pq considering the safety margin; ω2 is a preset fifth constant coefficient; P(h) is the probability that the voltage security margin transfer ratio of the heavy-load line pq after normalization is in (hc3, hc3 + c3); h is the interval number of the voltage offset considering the safety margin; c3 is the value of a single voltage offset interval considering the safety margin; B is the total number of voltage offset intervals considering the safety margin.

[0039] Optionally, the comprehensive evaluation factor for the operating safety margin of the target heavy-load line under steady-state and transient conditions is determined based on the load rate transfer balance degree and voltage deviation transfer balance degree of the target heavy-load line considering the safety margin, including:

[0040] Calculate the comprehensive evaluation factor H for the operating safety margin of the heavy-load line pq under steady-state and transient conditions according to the following formula pq :

[0041]

[0042] where β1 is a preset sixth constant coefficient; is the load rate transfer balance degree of the heavy-load line pq considering the safety margin; β2 is a preset seventh constant coefficient; H η,pq is the voltage deviation transfer balance degree of the heavy-load line pq considering the safety margin.

[0043] In a second aspect, the present invention provides a power flow controller location system considering the balance degree of line transmission power margin distribution, including:

[0044] A first determination module, configured to set N-1 faults under a first disturbance and node power fluctuation faults under the first disturbance in the target power grid to determine the average load rate of all heavy-load lines and the power flow entropy of the target power grid under each working condition;

[0045] A second determination module, configured to determine multiple typical working conditions under each disturbance according to the average load rate of all heavy-load lines and the power flow entropy of the target power grid under each working condition;

[0046] A first acquisition module, configured to acquire the load rate of the heavy-load line and the node voltage under all typical working conditions;

[0047] A third determination module, configured to determine the active power safety margin transfer ratio and voltage safety margin transfer ratio of the target heavy-load line under the target typical working condition according to the load rate of the heavy-load line and the node voltage under all typical working conditions;

[0048] A fourth determination module, configured to determine the load rate transfer balance degree and voltage deviation transfer balance degree of the target heavy-load line considering the safety margin according to the active power safety margin transfer ratio and voltage safety margin transfer ratio of the target heavy-load line under the target typical working condition;

[0049] A fifth determination module, configured to determine the comprehensive evaluation factor for the operating safety margin of the target heavy-load line under steady-state and transient conditions according to the load rate transfer balance degree and voltage deviation transfer balance degree of the target heavy-load line considering the safety margin;

[0050] A second acquisition module, configured to acquire a comprehensive evaluation factor of the operating safety margin of all overloaded lines in the target power grid under steady-state and transient conditions;

[0051] A sixth determination module, configured to determine, in the target power grid, the overloaded lines corresponding to the comprehensive evaluation factors exceeding a preset evaluation factor threshold as the installation branches of the power flow controller.

[0052] In a third aspect, the present invention provides a computer device, including a processor and a memory; wherein, when the processor executes the computer program stored in the memory, the steps of the power flow controller location selection method considering the balance degree of the line transmission power margin distribution described in the first aspect are implemented.

[0053] In a fourth aspect, the present invention provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, the steps of the power flow controller location selection method considering the balance degree of the line transmission power margin distribution described in the first aspect are implemented.

[0054] In a fifth aspect, the present invention provides a computer program product, including computer-executable instructions or a computer program, and when the computer-executable instructions or the computer program are executed by a processor, the steps of the power flow controller location selection method considering the balance degree of the line transmission power margin distribution described in the first aspect are implemented.

[0055] The present invention provides a power flow controller location selection method and system considering the balance degree of the line transmission power margin distribution. In the method, first, N-1 faults and node power fluctuations are set in the target power grid to determine the average load rate of all overloaded lines under each working condition and calculate the power flow entropy, forming an evaluation factor of the target power grid operation ability, and screening out a set of typical working conditions according to the evaluation factor of the target power grid operation ability; secondly, based on the line load rates and node voltage information obtained under all typical working conditions, combined with the real-time safety margin under each typical working condition, a set of target power grid operation ability safety margin balance degree indexes of the overloaded line load rates and the voltages at both ends under steady-state and transient conditions is constructed; finally, a comprehensive evaluation factor of the operating safety margin of the load rates and the voltages at both ends of the overloaded lines in the target power grid under steady-state and transient conditions is determined, the comprehensive evaluation factors of all overloaded lines are screened, and the optimal configuration points of the power flow controller are obtained according to actual requirements. The present invention better realizes the reasonable configuration of the power flow controller under complex power grid conditions, and improves the operation safety and efficiency of the power grid. Description of the Drawings

[0056] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only the embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0057] Figure 1 Schematic flow diagram of a method for locating a power flow controller considering the balance degree of line transmission power margin distribution provided by an embodiment of the present invention;

[0058] Figure 2 Schematic structural diagram of a system for locating a power flow controller considering the balance degree of line transmission power margin distribution provided by an embodiment of the present invention. Detailed implementation manners

[0059] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0060] Embodiment 1

[0061] As Figure 1 shown, an embodiment of the present invention provides a method for locating a power flow controller considering the balance degree of line transmission power margin distribution, including:

[0062] Step 101, set the N-1 fault under the first disturbance and the node power fluctuation fault under the first disturbance in the target power grid to determine the average load rate of all heavy-load lines and the power flow entropy of the target power grid under each working condition.

[0063] In this step, the disturbance degree of the first disturbance is greater than that of the second disturbance.

[0064] The first disturbance fault is that the target power grid has an N-1 fault. The target power grid includes N transmission lines and M nodes. The first disturbance fault set D T The expression is D T ={D T1 , D T2 ,..., D TN}; D T1 , D T2 and D TN are respectively the N-1 faults of the first line, the second line, and the Nth line in the target power grid.

[0065] The second disturbance fault is that each node in the target power grid has the same power fluctuation. The second disturbance fault set D S The expression is D S ={D S1 , D S2 ,..., D SM}; D S1 , DS2 and D SN are disturbances of power fluctuations occurring at the first node, the second node, and the Mth node in the target power grid, respectively.

[0066] Therefore, the N-1 fault scan under the first disturbance and the fault set of node power fluctuations under the second disturbance (i.e., the set of all faults) D can be expressed as D = {D1, D2,..., D N+M}; D1, D2, and D N+M are the first fault, the second fault, and the (N + M)th fault in the target power grid, respectively.

[0067] Record the average load rates of all heavily loaded lines (e.g., transmission lines with transmission power exceeding 80% of their rated power) under different disturbance levels; exemplarily, calculate the average load rate of all lines under each working condition according to the following formula:

[0068]

[0069] where, μ aver,t is the average load rate of all heavily loaded lines under working condition t; μ i,t is the load rate of heavily loaded line i under working condition t; L t is the total number of heavily loaded lines under working condition t; N is the total number of transmission lines in the target power grid; M is the total number of nodes in the target power grid.

[0070] Calculate the power flow entropy of the target power grid under each working condition according to the following formula:

[0071]

[0072] where, H p,t is the power flow entropy of the target power grid under working condition t; P(k) t is the probability that the line load rate is in the interval (kc1, kc1 + c1) under working condition t; k is the load rate interval number without considering the safety margin; c1 is the value of a single load rate interval without considering the safety margin; K is the total number of load rate intervals without considering the safety margin; ln represents the natural logarithm operator; α is a preset first constant coefficient.

[0073] Step 102: Determine multiple typical working conditions under each disturbance according to the average load rates of all heavily loaded lines and the power flow entropy of the target power grid under each working condition.

[0074] In this step, exemplarily, calculate the evaluation factor of the target power grid operation ability under the target working condition according to the following formula:

[0075] C t = α1·μ aver,t + α2·H p,t .

[0076] Among them, C t is the target power grid operation ability evaluation factor under condition t; α1 is a preset second constant coefficient; μ aver,t is the average load rate of all heavily loaded lines under condition t; α2 is a preset third constant coefficient; H p,t is the power flow entropy of the target power grid under condition t. To save computing resources, μ aver,t and H p,t can be normalized and then substituted into C t .

[0077] Obtain all the operation ability evaluation factors of the target power grid under the first disturbance and all the operation ability evaluation factors under the second disturbance, and use them as the first evaluation factor set and the second evaluation factor set respectively.

[0078] Determine the conditions corresponding to the evaluation factors exceeding the first evaluation factor threshold in the first evaluation factor set as typical conditions.

[0079] Determine the conditions corresponding to the evaluation factors exceeding the second evaluation factor threshold in the second evaluation factor set as typical conditions.

[0080] Exemplarily, the expression of the target power grid operation ability evaluation factor set under different types of disturbances is:

[0081] C T ={C T1 , C T2 , …, C TN}.

[0082] C S ={C S1 , C S2 , …, C SM}.

[0083] Among them, C T and C S are the sets of target power grid operation ability evaluation factors under the first disturbance and the second disturbance respectively; C T,N is the value of the target power grid operation ability evaluation factor under condition N under the first disturbance; C S,M is the value of the target power grid operation ability evaluation factor under condition M under the second disturbance.

[0084] Arrange all the elements in the sets C T and C S in descending order, and select the conditions corresponding to the top 5% of the elements as the typical conditions for each disturbance, that is:

[0085] TD T ={TD T1 , TDT2 , …, TD Tn}。

[0086] TD S ={TD S1 , TD S2 , …, TD Sm}。

[0087] Among them, TD T is the set of typical operating conditions under the first perturbation fault; TD T1 , TD T2 and TD Tn are the 1st, 2nd, and nth typical operating conditions in the set of typical operating conditions under the first perturbation fault respectively; TD S is the set of typical operating conditions under the second perturbation fault; TD S1 , TD S2 and TD Sm are the 1st, 2nd, and mth typical operating conditions in the set of typical operating conditions under the second perturbation fault respectively.

[0088] Step 103, obtain the heavy - load line load ratios and node voltages under all typical operating conditions.

[0089] Step 104, determine the active power safety margin transfer ratio and voltage safety margin transfer ratio of the target heavy - load line under the target typical operating condition according to the heavy - load line load ratios and node voltages under all typical operating conditions.

[0090] In this step, exemplarily, calculate the active power safety margin transfer ratio of the target heavy - load line under the target typical operating condition according to the following formula:

[0091]

[0092] Among them, is the active power safety margin transfer ratio of the heavy - load line pq under the typical operating condition f; Δμ pq,f is the load ratio fluctuation amount of the heavy - load line pq under the typical operating condition f; Δμ pqs,f is the active power transmission margin of the load ratio of the heavy - load line pq under the typical operating condition f; n is the total number of typical operating conditions under the first perturbation; m is the total number of typical operating conditions under the second perturbation.

[0093] Calculate the voltage safety margin transfer ratio of the target heavy - load line under the target typical operating condition according to the following formula:

[0094]

[0095] Among them, η pq, f is the voltage safety margin transfer ratio of the heavy - load line pq under the typical operating condition f; ΔUp,f is the voltage fluctuation of the p - end node of the overloaded line pq under the typical operating condition f; ΔU q,f is the voltage fluctuation of the q - end node of the overloaded line pq under the typical operating condition f; ΔU ps,f is the operable margin of the voltage at the p - end node of the overloaded line pq under the typical operating condition f; ΔU qs,f is the operable margin of the voltage at the q - end node of the overloaded line pq under the typical operating condition f.

[0096] Step 105: Determine the load rate transfer balance degree and voltage offset transfer balance degree of the target overloaded line considering the safety margin according to the active power safety margin transfer ratio and voltage safety margin transfer ratio of the target overloaded line under the target typical operating condition.

[0097] According to the sum η in Step 104 pq,f , construct a matrix of line power flow and node voltage change considering line safety margin under all typical operating conditions:

[0098]

[0099] where Φ is the line power flow matrix considering line safety margin; Γ is the matrix of node voltage change considering line safety margin.

[0100] The row vectors of the above matrices Φ and Γ represent the load rate and voltage offset of a certain line considering safety margin under all typical operating conditions, which can be used as the original data for balance degree calculation. Combining with the theoretical concept of entropy, calculate the balance degree of each line considering safety margin under all typical operating conditions, that is, the load rate transfer balance degree and voltage offset transfer balance degree considering safety margin.

[0101] Exemplarily, calculate the load rate transfer balance degree and voltage offset transfer balance degree of the target overloaded line considering safety margin according to the following formula:

[0102]

[0103] where is the load rate transfer balance degree of the overloaded line pq considering safety margin; ω1 is a preset fourth constant coefficient; P(g) is the probability that the active power safety margin transfer ratio of the overloaded line pq after normalization is in (gc2, gc2 + c2); g is the interval number of the load rate considering safety margin; c2 is the value of a single load rate interval considering safety margin; ln represents the natural logarithm operator; A is the total number of load rate intervals considering safety margin; H η,pqis the voltage offset transfer balance degree of the overloaded line pq considering the safety margin; ω2 is the preset fifth constant coefficient; P(h) is the probability that the voltage safety margin transfer ratio of the overloaded line pq after normalization is in the range of (hc3, hc3 + c3); h is the interval number of the voltage offset considering the safety margin; c3 is the value of a single voltage offset interval considering the safety margin; B is the total number of voltage offset intervals considering the safety margin.

[0104] Step 106: Determine the comprehensive evaluation factor of the operating safety margin of the target overloaded line under steady-state and transient conditions according to the load rate transfer balance degree and voltage offset transfer balance degree of the target overloaded line considering the safety margin.

[0105] In this step, exemplarily, calculate the comprehensive evaluation factor H of the operating safety margin of the overloaded line pq under steady-state and transient conditions according to the following formula pq :

[0106]

[0107] where β1 is the preset sixth constant coefficient, that is, the weight of; is the load rate transfer balance degree of the overloaded line pq considering the safety margin; β2 is the preset seventh constant coefficient, that is, the weight of H η,pq ; H η,pq is the voltage offset transfer balance degree of the overloaded line pq considering the safety margin.

[0108] Step 107: Obtain the comprehensive evaluation factors of the operating safety margins of all overloaded lines in the target power grid under steady-state and transient conditions.

[0109] Step 108: In the target power grid, determine the installation branches of the power flow controller for the overloaded lines corresponding to the comprehensive evaluation factors exceeding the preset evaluation factor threshold.

[0110] In Steps 107 - 108, sort the elements in the formed comprehensive evaluation factor set in descending order. This sequence can reflect the load rate and voltage fluctuation characteristics of the overloaded lines in the target circuit under steady-state and transient conditions. The larger the element, the worse the balance of the corresponding power flow fluctuation of the overloaded line.

[0111] The number of power flow controllers can be configured according to the actual engineering needs, and the corresponding number of overloaded lines is selected from the comprehensive evaluation factor set sorted in descending order to configure the power flow controller.

[0112] In summary, this embodiment provides a method for locating a power flow controller considering the balance degree of the power transfer margin distribution of a line, which conducts location selection in a more comprehensive and scientific manner, better realizes the reasonable configuration of the power flow controller under complex power grid conditions, and improves the operation safety and efficiency of the power grid.

[0113] Embodiment 2

[0114] Based on the same inventive concept as Embodiment 1, this embodiment further provides a system for locating a power flow controller considering the balance degree of the power transfer margin distribution of a line. Since the principle of this system for solving problems is similar to the method for locating a power flow controller considering the balance degree of the power transfer margin distribution of a line described above, the implementation of this system can refer to the implementation of the method for locating a power flow controller considering the balance degree of the power transfer margin distribution of a line.

[0115] As Figure 2 shown, the system for locating a power flow controller considering the balance degree of the power transfer margin distribution of a line includes:

[0116] The first determination module 10 is configured to set the N-1 fault under the first disturbance and the node power fluctuation fault under the first disturbance in the target power grid to determine the average load rate of all heavy-load lines and the power flow entropy of the target power grid under each working condition.

[0117] The second determination module 20 is configured to determine multiple typical working conditions under each disturbance according to the average load rate of all heavy-load lines and the power flow entropy of the target power grid under each working condition.

[0118] The first acquisition module 30 is configured to acquire the load rate of heavy-load lines and the node voltage under all typical working conditions.

[0119] The third determination module 40 is configured to determine the active power safety margin transfer ratio and the voltage safety margin transfer ratio of the target heavy-load line under the target typical working condition according to the load rate of heavy-load lines and the node voltage under all typical working conditions.

[0120] The fourth determination module 50 is configured to determine the load rate transfer balance degree and the voltage offset transfer balance degree of the target heavy-load line considering the safety margin according to the active power safety margin transfer ratio and the voltage safety margin transfer ratio of the target heavy-load line under the target typical working condition.

[0121] The fifth determination module 60 is configured to determine the comprehensive evaluation factor of the operation safety margin of the target heavy-load line under steady-state and transient conditions according to the load rate transfer balance degree and the voltage offset transfer balance degree of the target heavy-load line considering the safety margin.

[0122] The second acquisition module 70 is configured to acquire the comprehensive evaluation factors of the operation safety margins of all heavy-load lines in the target power grid under steady-state and transient conditions.

[0123] The sixth determination module 80 is configured to determine, in a target power grid, a heavy-load line corresponding to a comprehensive evaluation factor exceeding a preset evaluation factor threshold as an installation branch of a power flow controller.

[0124] For a more specific working process of each of the above modules, reference may be made to the corresponding content disclosed in Embodiment 1, and details are not described herein again.

[0125] Embodiment 3

[0126] This embodiment provides a computer device, including a processor and a memory; wherein, when the processor executes a computer program stored in the memory, the steps of the power flow controller location selection method considering the balance degree of line transmission power margin distribution described in Embodiment 1 are implemented.

[0127] For a more specific process of the above method, reference may be made to the corresponding content disclosed in Embodiment 1, and details are not described herein again.

[0128] Embodiment 4

[0129] This embodiment provides a computer-readable storage medium for storing a computer program; when the computer program is executed by a processor, the steps of the power flow controller location selection method considering the balance degree of line transmission power margin distribution described in Embodiment 1 are implemented.

[0130] For a more specific process of the above method, reference may be made to the corresponding content disclosed in Embodiment 1, and details are not described herein again.

[0131] Embodiment 5

[0132] This embodiment provides a computer program product, including computer-executable instructions or a computer program, when the computer-executable instructions or the computer program are executed by a processor, the steps of the power flow controller location selection method considering the balance degree of line transmission power margin distribution described in Embodiment 1 are implemented.

[0133] For a more specific process of the above method, reference may be made to the corresponding content disclosed in Embodiment 1, and details are not described herein again.

[0134] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference may be made to each other. For the systems, devices, storage media, and computer program products disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and reference may be made to the description of the method part for relevant parts.

[0135] Those skilled in the art can clearly understand that the technologies in the embodiments of the present invention can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solutions in the embodiments of the present invention, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disc, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

[0136] In some embodiments, the computer-executable instructions can be in the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and can be deployed in any form, including being deployed as an independent program or being deployed as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0137] As an example, the computer-executable instructions may or may not correspond to files in a file system, and may be stored as part of a file that stores other programs or data. For example, they can be stored in one or more scripts in a Hyper Text Markup Language (HTML) document, stored in a single file dedicated to the program being discussed, or stored in multiple cooperating files (e.g., files that store one or more modules, subroutines, or code portions).

[0138] As an example, the computer-executable instructions can be deployed to be executed on one electronic device, or on multiple electronic devices located at one location, or on multiple electronic devices distributed at multiple locations and interconnected through a communication network.

[0139] The present invention has been described in detail above in conjunction with specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art understand that without departing from the spirit and scope of the present invention, various equivalent substitutions, modifications, or improvements can be made to the technical solutions and their implementation manners of the present invention, and these all fall within the scope of the present invention. The protection scope of the present invention is subject to the appended claims.

Claims

1. A method for locating a power flow controller considering the balance degree of the power transfer margin distribution of a line, characterized in that Including: Set the N-1 fault under the first disturbance and the node power fluctuation fault under the first disturbance in the target power grid to determine the average load rate of all heavily loaded lines and the power flow entropy of the target power grid under each working condition; Determine multiple typical working conditions under each disturbance according to the average load rate of all heavily loaded lines and the power flow entropy of the target power grid under each working condition; Obtain the load rates of heavily loaded lines and the node voltages under all typical working conditions; Determine the active power safety margin transfer ratio and the voltage safety margin transfer ratio of the target heavily loaded line under the target typical working condition according to the load rates of heavily loaded lines and the node voltages under all typical working conditions; Determine the load rate transfer balance degree and the voltage offset transfer balance degree of the target heavily loaded line considering the safety margin according to the active power safety margin transfer ratio and the voltage safety margin transfer ratio of the target heavily loaded line under the target typical working condition; Determine the comprehensive evaluation factor of the operating safety margin of the target heavily loaded line under steady-state and transient conditions according to the load rate transfer balance degree and the voltage offset transfer balance degree of the target heavily loaded line considering the safety margin; Obtain the comprehensive evaluation factors of the operating safety margins of all heavily loaded lines in the target power grid under steady-state and transient conditions; In the target power grid, determine the installation branch of the power flow controller for the heavily loaded line corresponding to the comprehensive evaluation factor exceeding the preset evaluation factor threshold.

2. The method for locating a power flow controller according to claim 1, characterized in that, The setting of the N-1 fault under the first disturbance and the node power fluctuation fault under the first disturbance in the target power grid to determine the average load rate of all heavily loaded lines and the power flow entropy of the target power grid under each working condition includes: Calculate the average load rate of all lines under each working condition according to the following formula: Among them, μ aver,t is the average load rate of all heavy-load lines under condition t; μ i,t is the load rate of heavy-load line i under condition t; L t is the total number of heavy-load lines under condition t; N is the total number of transmission lines in the target power grid; M is the total number of nodes in the target power grid; Calculate the power flow entropy of the target power grid under each working condition according to the following formula: Among them, H p,t is the power flow entropy of the target power grid under condition t; P(k) t is the probability that the line load rate is in (kc1, kc1 + c1) under condition t; k is the load rate interval number without considering the safety margin; c1 is the value of a single load rate interval without considering the safety margin; K is the total number of load rate intervals without considering the safety margin; ln represents the natural logarithm operator; α is a preset first constant coefficient.

3. The method for locating a power flow controller according to claim 1, characterized in that, The determination of multiple typical working conditions under each disturbance according to the average load rate of all heavily loaded lines and the power flow entropy of the target power grid under each working condition includes: Calculate the operating capacity evaluation factor of the target power grid under the target working condition according to the following formula: C t = α1·μ aver,t + α2·H p,t ; Among them, C t is the target power grid operation ability evaluation factor under condition t; α1 is a preset second constant coefficient; μ aver,t is the average load rate of all heavily loaded lines under condition t; α2 is a preset third constant coefficient; H p,t is the power flow entropy of the target power grid under condition t; Obtain all the operating capacity evaluation factors of the target power grid under the first disturbance and all the operating capacity evaluation factors of the target power grid under the second disturbance, and use them as the first evaluation factor set and the second evaluation factor set respectively; Determine the working conditions corresponding to the evaluation factors exceeding the first evaluation factor threshold in the first evaluation factor set as typical working conditions; Determine the working conditions corresponding to the evaluation factors exceeding the second evaluation factor threshold in the second evaluation factor set as typical working conditions.

4. The method for locating a power flow controller according to claim 1, characterized in that The determination of the active power safety margin transfer ratio and the voltage safety margin transfer ratio of the target heavily loaded line under the target typical working condition according to the load rates of heavily loaded lines and the node voltages under all typical working conditions includes: Calculate the active power safety margin transfer ratio of the target heavily loaded line under the target typical working condition according to the following formula: Among them, is the active power safety margin transfer ratio of the heavy-load line pq under the typical condition f; Δμ pq,f is the load rate fluctuation of the heavy-load line pq under the typical condition f; Δμ pqs,f is the active power transmission margin of the load rate of the heavy-load line pq under the typical condition f; n is the total number of typical conditions under the first disturbance; m is the total number of typical conditions under the second disturbance; Calculate the voltage safety margin transfer ratio of the target heavily loaded line under the target typical working condition according to the following formula: Among them, η pq, f is the voltage security margin transfer ratio of the heavy-load line pq under the typical operating condition f; ΔU p,f is the voltage fluctuation of the p-end node of the heavy-load line pq under the typical operating condition f; ΔU q,f is the voltage fluctuation of the q-end node of the heavy-load line pq under the typical operating condition f; ΔU ps,f is the operable margin of the voltage of the p-end node of the heavy-load line pq under the typical operating condition f; ΔU qs,f is the operable margin of the voltage of the q-end node of the heavy-load line pq under the typical operating condition f.

5. The method for locating a power flow controller according to claim 1, wherein The determination of the load rate transfer balance degree and the voltage offset transfer balance degree of the target heavily loaded line considering the safety margin according to the active power safety margin transfer ratio and the voltage safety margin transfer ratio of the target heavily loaded line under the target typical working condition includes: Calculate the load rate transfer balance degree and the voltage offset transfer balance degree of the target heavily loaded line considering the safety margin according to the following formula: Among them, is the load rate transfer balance degree of the overloaded line pq considering the safety margin; ω1 is a preset fourth constant coefficient; P(g) is the probability that the active power safety margin transfer ratio of the overloaded line pq after normalization is in the range (gc2, gc2 + c2); g is the interval number of the load rate considering the safety margin; c2 is the single load rate interval value considering the safety margin; ln represents the natural logarithm operator; A is the total number of load rate intervals considering the safety margin; H η,pq is the voltage deviation transfer balance degree of the overloaded line pq considering the safety margin; ω2 is a preset fifth constant coefficient; P(h) is the probability that the voltage safety margin transfer ratio of the overloaded line pq after normalization is in the range (hc3, hc3 + c3); h is the interval number of the voltage deviation considering the safety margin; c3 is the single voltage deviation interval value considering the safety margin; B is the total number of voltage deviation intervals considering the safety margin.

6. The method for locating a power flow controller according to claim 1, wherein Determining a comprehensive evaluation factor for the operating safety margin of the target heavy-load line under steady-state and transient conditions according to the load rate transfer balance degree and voltage deviation transfer balance degree of the target heavy-load line considering the safety margin, including: Calculate the comprehensive evaluation factor H of the operation safety margin of the heavy-load line pq under steady-state and transient conditions according to the following formula pq : Among them, β1 is a preset sixth constant coefficient; is the load rate transfer balance degree of the overloaded line pq considering the safety margin; β2 is a preset seventh constant coefficient; H η,pq is the voltage deviation transfer balance degree of the overloaded line pq considering the safety margin.

7. A power flow controller location system considering the balance degree of line transmission power margin distribution, characterized in that Including: A first determination module, configured to set an N-1 fault under a first disturbance and a node power fluctuation fault under the first disturbance in the target power grid to determine the average load rate of all heavy-load lines and the power grid flow entropy of the target power grid under each operating condition; A second determination module, configured to determine multiple typical operating conditions under each disturbance according to the average load rate of all heavy-load lines and the power grid flow entropy of the target power grid under each operating condition; A first acquisition module, configured to acquire the heavy-load line load rate and node voltage under all typical operating conditions; A third determination module, configured to determine the active power safety margin transfer ratio and voltage safety margin transfer ratio of the target heavy-load line under the target typical operating condition according to the heavy-load line load rate and node voltage under all typical operating conditions; A fourth determination module, configured to determine the load rate transfer balance degree and voltage deviation transfer balance degree of the target heavy-load line considering the safety margin according to the active power safety margin transfer ratio and voltage safety margin transfer ratio of the target heavy-load line under the target typical operating condition; A fifth determination module, configured to determine a comprehensive evaluation factor for the operating safety margin of the target heavy-load line under steady-state and transient conditions according to the load rate transfer balance degree and voltage deviation transfer balance degree of the target heavy-load line considering the safety margin; A second acquisition module, configured to acquire the comprehensive evaluation factors for the operating safety margins of all heavy-load lines in the target power grid under steady-state and transient conditions; A sixth determination module, configured to determine, in the target power grid, the heavy-load line corresponding to the comprehensive evaluation factor exceeding the preset evaluation factor threshold as the installation branch of the power flow controller.

8. A computer device, characterized in that, Including a processor and a memory; wherein, when the processor executes the computer program stored in the memory, the steps of the power flow controller location selection method considering the line transmission power margin distribution balance degree according to any one of claims 1-6 are implemented.

9. A computer-readable storage medium, characterized in that, For storing a computer program; when the computer program is executed by the processor, the steps of the power flow controller location selection method considering the line transmission power margin distribution balance degree according to any one of claims 1-6 are implemented.

10. A computer program product, characterized in that, Including computer-executable instructions or a computer program, when the computer-executable instructions or the computer program are executed by the processor, the steps of the power flow controller location selection method considering the line transmission power margin distribution balance degree according to claims 1-6 are implemented.

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