A method, system and electronic device for measuring imbalance based on simulation model

Abstract

The present invention relates to the technical field of overhead transmission line design, and more particularly to a simulation model-based imbalance measurement method, system, and electronic device. The method comprises: establishing a simulation model of a double-circuit transmission line on a same tower; calculating an impedance matrix corresponding to the simulation model of the double-circuit transmission line on a same tower; calculating a coefficient of variation based on elements in the impedance matrix, and determining the coefficient of variation as the imbalance corresponding to the simulation model of the double-circuit transmission line on a same tower. The imbalance of the double-circuit transmission line on a same tower can be calculated without requiring complex admittance matrix calculations or phase sequence transformations, resulting in accurate, simple, and efficient calculations.

Description

Technical Field

[0001] The present invention relates to the technical field of overhead power transmission line design, and in particular to a method, system and electronic equipment for measuring imbalance based on a simulation model. Background Art

[0002] With the rapid development of power generation and the increasing scarcity of land resources, an increasing number of multi-circuit transmission lines are being installed on the same tower. Due to the large number of conductors, close distances between conductors, no transposition throughout the entire line, and strong electromagnetic coupling between circuits, these lines pose a growing threat of three-phase imbalance. Different researchers have employed different models to address these issues, but current models for multi-circuit transmission lines on the same tower differ significantly from actual lines. Furthermore, calculating current imbalance is complex, requiring the calculation of an impedance matrix based on line parameters. This matrix is ​​then inverted to obtain an admittance matrix, from which the phase current vectors are derived. These current vectors are then subjected to phase sequence transformation to ultimately determine current imbalance. Calculating the admittance matrix is ​​a significant undertaking for single-circuit lines, and even more so for multi-circuit lines, such as double-circuit and quadruple-circuit lines, with no guaranteed accuracy.

[0003] Therefore, how to propose a simple, practical, and fast-calculating imbalance measurement method to provide accurate guidance for actual line imbalance calculation is an urgent problem that those skilled in the art need to solve. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the deficiencies of the prior art and provide a method, system and electronic device for measuring imbalance based on a simulation model.

[0005] The technical solution of the imbalance degree measurement method based on the simulation model of the present invention is as follows:

[0006] Establish a simulation model of double-circuit transmission lines on the same tower;

[0007] Calculating the impedance matrix corresponding to the same-tower double-circuit transmission line simulation model;

[0008] The coefficient of variation is calculated according to the elements in the impedance matrix, and the coefficient of variation is determined as the unbalance degree of the three-phase current of the double-circuit transmission line simulation model on the same tower.

[0009] The beneficial effects of the imbalance degree measurement method based on the simulation model of the present invention are as follows:

[0010] The unbalance degree of the three-phase current of the double-circuit transmission line simulation model on the same tower can be calculated without complicated admittance matrix calculation and phase sequence transformation. The calculation is accurate, simple and efficient.

[0011] On the basis of the above solution, the imbalance degree measurement method based on the simulation model of the present invention can be further improved as follows.

[0012] Furthermore, the same-tower double-circuit transmission line simulation model includes a double-circuit transmission line model, a reactive compensation device model, a high-voltage series reactor model, and two equivalent power supply models;

[0013] The first equivalent power model is connected to the first bus;

[0014] The second equivalent power source model and the reactive power compensation device model are respectively connected to the second bus;

[0015] One end of the high-voltage series reactor model is connected to the second busbar, and the other end of the high-voltage series reactor model is connected to the first busbar through the double-circuit transmission line model.

[0016] Furthermore, it also includes:

[0017] Based on the distributed parameter model and in combination with the overhead ground wire and earth loop resistance, a double-circuit transmission line model is established.

[0018] Furthermore, it also includes:

[0019] According to Thevenin's theorem, the equivalent power supply model is established.

[0020] Furthermore, the calculation of the coefficient of variation based on the elements in the impedance matrix includes:

[0021] The coefficient of variation CV is calculated using a first formula, which is: The elements in the impedance matrix include: the mutual impedance Z between the e-th phase and the f-th phase of the double-circuit transmission line simulation model on the same tower ef , It represents the expected value of the mutual impedance element in the impedance matrix of the double-circuit transmission line simulation model on the same tower, phase e is any phase among the three phases A, B, and C in the double-circuit transmission line model, and phase f is any phase among the three phases a, b, and c in the double-circuit transmission line model.

[0022] The technical solution of the imbalance measurement system based on the simulation model of the present invention is as follows:

[0023] It includes an establishment module, a calculation module and a determination module;

[0024] The establishment module is used to: establish a simulation model of a double-circuit transmission line on the same tower;

[0025] The calculation module is used to calculate the impedance matrix corresponding to the same-tower double-circuit transmission line simulation model;

[0026] The determination module is used to calculate the coefficient of variation according to the elements in the impedance matrix, and determine the coefficient of variation as the imbalance degree of the three-phase current of the double-circuit transmission line simulation model on the same tower.

[0027] The beneficial effects of the imbalance measurement system based on the simulation model of the present invention are as follows:

[0028] The unbalance degree of the three-phase current of the double-circuit transmission line simulation model on the same tower can be calculated without complicated admittance matrix calculation and phase sequence transformation. The calculation is accurate, simple and efficient.

[0029] Furthermore, the same-tower double-circuit transmission line simulation model includes a double-circuit transmission line model, a reactive compensation device model, a high-voltage series reactor model, and two equivalent power supply models;

[0030] The first equivalent power model is connected to the first bus;

[0031] The second equivalent power source model and the reactive power compensation device model are respectively connected to the second bus;

[0032] One end of the high-voltage series reactor model is connected to the second busbar, and the other end of the high-voltage series reactor model is connected to the first busbar through the double-circuit transmission line model.

[0033] Furthermore, the establishment module is further specifically used to establish a double-circuit transmission line model based on a distributed parameter model and in combination with overhead ground wire and earth loop resistance.

[0034] Furthermore, the establishing module is further specifically used to establish the equivalent power supply model according to Thevenin's theorem.

[0035] Furthermore, the determining module is specifically configured to:

[0036] The coefficient of variation CV is calculated using a first formula, which is: The elements in the impedance matrix include: the mutual impedance Z between the e-th phase and the f-th phase of the double-circuit transmission line simulation model on the same tower ef , It represents the expected value of the mutual impedance element in the impedance matrix of the double-circuit transmission line simulation model on the same tower, phase e is any phase among the three phases A, B, and C in the double-circuit transmission line model, and phase f is any phase among the three phases a, b, and c in the double-circuit transmission line model.

[0037] The technical solution of an electronic device of the present invention is as follows:

[0038] The system comprises a memory, a processor and a program stored in the memory and running on the processor, wherein when the processor executes the program, the steps of the imbalance degree measurement method based on the simulation model as described in any one of the above items are implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of a flow chart of a method for measuring imbalance based on a simulation model according to an embodiment of the present invention;

[0040] Figure 2 This is a structural diagram of the simulation model of a double-circuit transmission line on the same tower;

[0041] Figure 3 It is the structural diagram of the double-circuit transmission line model;

[0042] Figure 4 It is the structural diagram of the equivalent power supply model;

[0043] Figure 5 It is a structural diagram of the reactive power compensation device model;

[0044] Figure 6 It is the structural diagram of the high-voltage series reactor model;

[0045] Figure 7 The figure is a structural diagram of an imbalance measurement system based on a simulation model according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] To clearly illustrate the solutions of the present invention, preferred embodiments are given below and described in detail with reference to the accompanying drawings.

[0047] like Figure 1 As shown, a method for measuring imbalance based on a simulation model according to an embodiment of the present invention includes the following steps:

[0048] S1. Establish a simulation model of a double-circuit transmission line on the same tower;

[0049] S2. Calculate the impedance matrix corresponding to the simulation model of the double-circuit transmission line on the same tower;

[0050] S3. Calculate the coefficient of variation based on the elements in the impedance matrix, and determine the coefficient of variation as the unbalance degree of the three-phase current of the double-circuit transmission line simulation model on the same tower.

[0051] The unbalance degree of the three-phase current of the double-circuit transmission line simulation model on the same tower can be calculated without complicated admittance matrix calculation and phase sequence transformation. The calculation is accurate, simple and efficient.

[0052] Optionally, in the above technical solution, the following is further included:

[0053] S4. When the unbalance degree of the three-phase current of the double-circuit transmission line on the same tower simulation model exceeds the preset unbalance degree threshold, it indicates that there is a problem with the conductor arrangement in the double-circuit transmission line on the same tower simulation model. The arrangement of the transmission line conductors in the double-circuit transmission line on the same tower simulation model is adjusted. This is also applicable to the case of multiple circuits on the same tower, such as 4 circuits and 8 circuits, to obtain a new double-circuit transmission line on the same tower simulation model.

[0054] The specific technical approach for adjusting the conductor arrangement of the transmission line in the simulation model of a double-circuit transmission line on the same tower is similar to the existing method for adjusting the phase sequence arrangement of conductors for three-phase current imbalance in a substation transmission line, and is not detailed here. In the embodiment, the arrangement can be a dual-circuit, or a multi-circuit arrangement such as a four-circuit, eight-circuit, or similar arrangement.

[0055] S5. Use the new same-tower double-circuit transmission line simulation model as the same-tower double-circuit transmission line simulation model of the same-tower double-circuit transmission line simulation model in S2, return to execute S2, until the same-tower double-circuit transmission line simulation model that reaches the preset imbalance threshold is obtained, and construct the same-tower double-circuit transmission line according to the conductor sorting method in the same-tower double-circuit transmission line simulation model that reaches the preset imbalance threshold.

[0056] Optionally, in the above technical solution, if Figure 2 As shown, the same-tower double-circuit transmission line simulation model includes a double-circuit transmission line model 5, a reactive compensation device model 4, a high-voltage series reactor model 2 and two equivalent power supply models; wherein, the Thevenin equivalence is one of the commonly used circuit equivalence methods, specifically, the Thevenin equivalence is performed on the system outside the busbar on both sides of the double-circuit transmission line model 5.

[0057] The first equivalent power source model 1 is connected to the first bus 20;

[0058] The second equivalent power source model 3 and the reactive power compensation device model 4 are respectively connected to the second bus 21;

[0059] One end of the high-voltage series reactor model 2 is connected to the second bus 21, and the other end of the high-voltage series reactor model 2 is connected to the first bus 20 through the double-circuit transmission line model 5, wherein high voltage generally refers to a voltage level of 220kV and above.

[0060] Among them, based on the distributed parameter model of the double-circuit transmission line on the same tower, based on this distributed parameter model and combined with the overhead ground wire and earth loop resistance, the double-circuit transmission line model 5 is established. The establishment process includes formula 1 and formula 2; Figure 3 As shown, Figure 3In the figure, U represents an overhead ground wire in the double-circuit transmission line model 5 (i.e., the model corresponding to the double circuits on the same tower), W represents the other overhead ground wire in the double-circuit transmission line model 5, A, B, and C represent the three-phase conductors of one circuit in the double-circuit transmission line model 5, and a, b, and c represent the three-phase conductors of the other circuit in the double-circuit transmission line model 5; d represents the earth circuit; i U Indicates the current of overhead ground wire U, i W represents the current of overhead ground wire W, i A Represents the current of phase line A, i B represents the current of phase line B, i C Represents the current of phase line C, i a represents the current of phase line a, i b represents the current of phase b, i c represents the current of phase line c, i d Indicates the current in the earth loop, u U Indicates the voltage of the overhead ground wire U, u W Indicates the voltage of the overhead ground wire W, u A Indicates the voltage of phase line A, u B Indicates the voltage of phase line B, u C Indicates the voltage of phase line C, u a Indicates the voltage of phase line a, u b represents the voltage of phase b, u c Indicates the voltage of phase line c, u d Represents the voltage of the earth loop. x represents any position on the double-circuit transmission line, dx represents a microelement, R U dx represents the resistance per unit length of the overhead ground wire U, R W dx represents the resistance per unit length of the overhead ground wire W, R A dx represents the resistance per unit length of phase line A, R B dx represents the resistance per unit length of phase line B, R C dx represents the resistance per unit length of the phase line C, R a dx represents the resistance per unit length of the conductor of phase a, R b dx represents the resistance per unit length of the phase b conductor, R c dx represents the resistance per unit length of the phase line c, C U dx represents the capacitance per unit length of the overhead ground wire U, C W dx represents the capacitance per unit length of the overhead ground wire W, C A dx represents the capacitance per unit length of phase line A, C B dx represents the capacitance per unit length of phase line B, C C dx represents the capacitance per unit length of the phase line C, Ca dx represents the capacitance per unit length of phase line a, C b dx represents the capacitance per unit length of phase b, C c dx represents the capacitance per unit length of the phase line c, G U dx represents the conductance per unit length of the overhead ground wire U, G W dx represents the conductivity per unit length of the overhead ground wire W, G A dx represents the conductance per unit length of phase line A, G B dx represents the conductance per unit length of phase line B, G C dx represents the conductance per unit length of the phase line C, G a dx represents the conductance per unit length of phase line a, G b dx represents the conductance per unit length of phase line b, G c dx represents the conductance per unit length of the phase line c, L U dx represents the inductance per unit length of the overhead ground wire U, L W dx represents the inductance per unit length of the overhead ground wire W, L A dx represents the inductance per unit length of phase line A, L B dx represents the inductance per unit length of phase line B, L C dx represents the inductance per unit length of the phase line C, L a dx represents the inductance per unit length of the phase line a, L b dx represents the inductance per unit length of the phase line b, L c dx represents the inductance per unit length of the phase line c.

[0061] For the double-circuit transmission line model 5, the voltage and current at any position x on the transmission line at a certain time t (the x position from the transmission line head end is the same x position for all lines) are taken. For the double-circuit transmission line model 5, the x position includes the voltage and current of 8 lines, which can be expressed as a vector. The following relationship is satisfied, where the transmission line head end refers to the first busbar 20, that is, the following equations (1) and (2) are satisfied:

[0062]

[0063]

[0064] In formula (1) and formula (2): X=[u A ,u B ,u C ,u a ,u b ,u c ,u U ,uW ] T , is the voltage column vector of 8 lines; Y=[i A ,i B ,i C ,i a ,i b ,i c ,i U ,i W ] T , is the current column vector of the 8 lines; R=diag(R g ), is the resistance diagonal matrix of 8 lines; H=(M gh ) 8×8 , is the inductance matrix of 8 lines; C=(C gh ) 8×8 , is the capacitance matrix of 8 lines. R g Represents the total resistance of wire g. M gh Represents the mutual inductance between wires g and h. gh represents the mutual capacitance between wires g and h. Here, g, h = A, B, C, a, b, c, U, W.

[0065] Among them, according to Thevenin's theorem, according to Figure 2 The components represented by the first power supply equivalent model 1 or the second power supply equivalent model 3 in the example are used to establish a third equivalent power supply model ( Figure 4 power supply equivalent model), such as Figure 4 As shown, Figure 4 where Es, Rs, and Xs are the equivalent voltage source, equivalent resistance, and equivalent reactance, respectively. V and I are the voltage and current amplitudes at the connected buses, namely, first bus 20 and second bus 21, respectively. Φ is the power factor angle of second bus 21, and δ is the power angle of the equivalent voltage source.

[0066] The equivalent power source model includes the equivalent voltage source Es, its power angle δ, the equivalent resistance Rs, and the equivalent reactance Xs. The values ​​of these components are calculated using the Thevenin equivalence theorem. Their function is to provide busbar voltage and current for a double-circuit transmission line.

[0067] The voltage on the second bus 21 is measured for the first time V1 , measure the voltage on the second bus 21 for the second time V2 , first measure the current at the second bus 21 I1 , measure the current at the second bus 21 for the second time I2 , the phase angles are as follows: I1∠0, I2∠0, in and Through actual measurement, is the power factor angle between the voltage and current at the second bus 21 obtained by the first measurement, is the power factor angle between the voltage and current at the second bus 21 obtained by the second measurement, which can be expressed as follows:

[0068] The following equation can be written:

[0069]

[0070] Then, according to formula (3), the model parameter E is obtained s and Z s Among them, Zs is the external system (such as Figure 2 The equivalent impedance is obtained by equating the other systems (not shown) connected to the two buses in the figure.

[0071] Among them, the reactive compensation device model 4 is as follows Figure 5 As shown, a model represented by a static VAR compensator is shown, where the second bus 21 is connected to six TSCs through transformers, the six TSCs are connected in parallel with each other, and the other ends of the six TSCs are grounded;

[0072] Among them, TSC is a thyristor controlled capacitor (TSC is also called thyristor switched capacitor), which is composed of a capacitor connected in series with two reverse thyristors, and its control elements are all thyristors.

[0073] The two opposing thyristors in the TSC disconnect or connect the capacitor to the grid, controlling the capacitor switching. There are two operating states: on and off. In the on state, one of the two opposing thyristors conducts, allowing the capacitor to function and generate capacitive reactive power. In the off state, the two opposing thyristors are blocked and do not function, outputting any reactive power.

[0074] The function of the reactive power compensation device model 4 is to compensate for the reactive power of the double-circuit transmission line model 5 and stabilize the bus voltage. Reactive power compensation affects the inductance and capacitance parameters of the double-circuit transmission line model 5, which in turn changes the element values ​​of the impedance matrix.

[0075] The reactive power generated by the reactive compensation device model 4 (SVC) is:

[0076]

[0077] Where Q svc is the reactive power generated by the SVC, α is the thyristor triggering delay angle of the TSC, L0 is the reactor inductance of the TSC, C0 is the capacitor capacity of the TSC, U0 is the voltage of the second bus 21, and ω is the angular frequency of the equivalent power supply model 3.

[0078] Among them, the high-voltage series reactor model 2 is as follows Figure 6 As shown, the high-voltage series reactor model 2 adopts a uniform distribution method. The uniform distribution method is an existing technology, which generally means that the reactance value of the connected reactor of each phase line connected in series at the end is the same, specifically:

[0079] Connected in series between the double-circuit transmission line model 5 and the second busbar 21, the high-voltage series reactor model 2 includes 6 resistors and 6 inductors. The 6 resistors are A-phase series resistor R A1 , B phase series resistance R B1 、C phase series resistance R C1 、Phase a series resistance R a1 , b-phase series resistance R b1 , c-phase series resistance R c1 ; The 6 inductors are A phase series inductor L A1 , B phase series inductor L B1 , C phase series inductor L C1 , a-phase series inductor L a1 , b-phase series inductor L b1 , c-phase series inductor L c1 . R A1 and L A1 Connect in series and then ground, R B1 and L B1 Connect in series and then ground, R C1 and L C1 Connect in series and then ground, R a1 and L a1 Connect in series and then ground, R b1 and L b1 Connect in series and then ground, R c1 and L c1 They are connected in series and then grounded, and then connected in parallel, arranged in sequence, M A1B1 Indicates the mutual inductance between phase lines A and B caused by the series reactor, M A1C1 Indicates the mutual inductance between phase lines A and C caused by the series reactor, M B1C1 Indicates the mutual inductance between phase lines B and C caused by the series reactor, M a1b1 The mutual inductance between phase lines a and c caused by the series reactor is M b1c1 Indicates the mutual inductance between phase lines b and c caused by the series reactor, M a1c1 Indicates the mutual inductance between phase lines a and c caused by the series reactor, M Ⅰ_Ⅱ It represents the mutual inductance between two circuits caused by the series reactor.

[0080] The main function of high-voltage series reactor model 2 is inductance, which increases the impedance of the transmission line and limits the short-circuit current of the double-circuit transmission line.

[0081] Considering the impact of the remaining modules, equivalent power modules 1 and 3 primarily provide voltage for busbars 1 and 2. The contributions of high-voltage series reactor model 2 and the reactive power compensation device module to the overall simulation model are primarily reflected in their contributions to the impedance matrix.

[0082] Based on the double-circuit transmission line model 5, the corresponding impedance matrix Z is calculated.

[0083] Among them, Z mm represents the self-impedance of phase line m, Z mn (m≠n) represents the mutual impedance between phase line m and phase line n, where m=A, B, C, a, b or c, and n=A, B, C, a, b or c.

[0084] The self-impedance calculation formula is: R m is the total resistance of phase line m, which can be found from the relevant manual according to the wire model. e is the earth's equivalent resistance, r e =9.87f×10 -4 (Ω / km). f is the frequency of the second equivalent power model 3. D e is the equivalent depth of the virtual wire in the ground, When calculating impedance, it is assumed that there is a virtual wire loop in the earth, ρ (Ω·m) represents the earth resistivity, and f is the frequency of the second equivalent power model 3. s D is the geometric mean distance of the conductor of the phase line m, s =0.779r, r is the wire radius, which can be found in the relevant manual according to the wire model.

[0085] Mutual impedance calculation formula:

[0086] Wherein, ω is the angular frequency of the second equivalent power model 3, k is a constant, l is the length of the double-circuit transmission line model 5, D mn is the distance between the mth and nth phase conductors of the double-circuit transmission line model 5, where m = A, B, C, a, b, or c, and n = A, B, C, a, b, or c.

[0087] The contribution of the high-voltage series reactor module to the impedance matrix is:

[0088]

[0089] Among them, R A1 is the series resistance of phase A, R B1 is the series resistance of phase B, R C1 is the series resistance of phase C, R a1 is the series resistance of phase a, R b1 is the series resistance of phase b, R c1is the series resistance of phase c; L A1 is the series inductor of phase A, L B1 is the B phase series inductor, L C1 is the C phase series inductor, L a1 is the series inductance of phase a, L b1 is the series inductance of phase b, L c1 is the series inductance of phase c. M A1B1 Indicates the mutual inductance between phase lines A and B caused by the series reactor, M A1C1 Indicates the mutual inductance between phase lines A and C caused by the series reactor, M B1C1 Indicates the mutual inductance between phase lines B and C caused by the series reactor, M a1b1 The mutual inductance between phase lines a and c caused by the series reactor is M b1c1 Indicates the mutual inductance between phase lines b and c caused by the series reactor, M a1c1 Indicates the mutual inductance between phase lines a and c caused by the series reactor, M Ⅰ_Ⅱ represents the mutual inductance between the two circuits of the series reactor caused by the series reactor. ω is the angular frequency of the equivalent power supply model 3.

[0090] Overall, the double-circuit transmission line model 5 forms the core framework of the on-tower double-circuit transmission line simulation model, reflecting the basic line parameters of the on-tower double-circuit transmission line. The equivalent power source model provides busbar voltage and current for the double-circuit transmission line model 5; the high-voltage series reactor model 2 limits short-circuit currents that may occur during operation; and the reactive power compensation device model 4 provides reactive power losses during operation and stabilizes the busbar voltage. The inclusion of the series reactor and reactive power compensation device is solely to ensure that the model is closer to the actual line and to enhance the accuracy of the simulation results.

[0091] The contribution of the reactive compensation device module to the impedance matrix is:

[0092] ω is the angular frequency of the second equivalent power model 3. , C1, C2, C3, C4, C5, and C6 are the reactive compensation capacitance values ​​of phase A, phase B, phase C, phase a, phase b, and phase c, respectively.

[0093] Then the impedance matrix of the double-circuit transmission line model on the same tower is: Z'=Z+Z1'+Z2'.

[0094]

[0095] Optionally, in the above technical solution, the coefficient of variation is calculated based on the elements in the impedance matrix Z', including: (Zef is a general term, and the matrix is ​​specific)

[0096] The coefficient of variation CV is calculated using a first formula, which is: The elements in the impedance matrix include: the mutual impedance Z between the e-th phase and the f-th phase of the double-circuit transmission line simulation model on the same tower ef , The above operation can also be achieved by representing the expected value of the mutual impedance element in the impedance matrix of the double-circuit transmission line simulation model on the same tower, phase e is any one of the three phases A, B, and C in the double-circuit transmission line model, and phase f is any one of the three phases a, b, and c in the double-circuit transmission line model, or vice versa.

[0097] The present invention discloses a method for measuring imbalance based on a precise simulation model of a double-circuit transmission line on a same tower. The simulation model of the double-circuit transmission line on a same tower includes: a double-circuit transmission line model 5 established based on a distributed parameter model; an equivalent power source model established according to the Thevenin theorem; a reactive compensation device model 4 that considers centralized busbar compensation; and a high-voltage series reactor model 2 based on a uniform distribution method. A precise simulation model of the double-circuit transmission line system on a same tower is established taking into account the specific conditions of the actual line, with the simulation results of relevant parameters within 1% of the actual line error. The impedance matrix variation coefficient is calculated based on the double-circuit transmission line model on a same tower. The impedance matrix variation coefficient is introduced to measure the three-phase current imbalance of the transmission line. This not only allows the three-phase current imbalance of the line to be directly calculated using line parameters, but also eliminates the need for complex admittance matrix calculations and phase sequence transformations, resulting in accurate, simple, and efficient calculations.

[0098] In the above embodiments, although the steps are numbered S1, S2, etc., these are only specific embodiments given in this application. Those skilled in the art can adjust the execution order of S1, S2, etc. according to actual conditions, which is also within the scope of protection of the present invention. It can be understood that in some embodiments, some or all of the above embodiments may be included.

[0099] like Figure 7 As shown, an imbalance degree measurement system based on a simulation model according to an embodiment of the present invention includes an establishment module 210, a calculation module 220 and a determination module 230;

[0100] The establishment module 210 is used to: establish a simulation model of a double-circuit transmission line on the same tower;

[0101] The calculation module 220 is used to calculate the impedance matrix corresponding to the simulation model of the double-circuit transmission line on the same tower;

[0102] The determination module 230 is used to calculate the coefficient of variation according to the elements in the impedance matrix, and determine the coefficient of variation as the unbalance degree of the three-phase current of the double-circuit transmission line simulation model on the same tower.

[0103] Without the need for complex matrix calculations and phase sequence transformations, the unbalance of the three-phase currents in the simulation model of a double-circuit transmission line on the same tower can be calculated accurately, simply and efficiently.

[0104] Optionally, in the above technical solution, a judgment module and a repeated calling module are further included;

[0105] The judgment module is used to: when the imbalance degree of the three-phase current of the double-circuit transmission line simulation model on the same tower exceeds a preset imbalance degree threshold, it indicates that there is a problem with the double-circuit transmission line simulation model on the same tower, and adjust the arrangement of the transmission line conductors in the double-circuit transmission line simulation model on the same tower to obtain a new double-circuit transmission line simulation model on the same tower;

[0106] The repeated calling module is used to: use the new same-tower double-circuit transmission line simulation model as the same-tower double-circuit transmission line simulation model of the same-tower double-circuit transmission line simulation model in S2, return to call the calculation module 220, the determination module 230 and the judgment module until the same-tower double-circuit transmission line simulation model that reaches the preset imbalance threshold is obtained, and construct the same-tower double-circuit transmission line according to the same-tower double-circuit transmission line simulation model that reaches the preset imbalance threshold.

[0107] Optionally, in the above technical solution, the same-tower double-circuit transmission line simulation model includes a double-circuit transmission line model 5, a reactive compensation device model 4, a high-voltage series reactor model 2 and two equivalent power supply models;

[0108] The first equivalent power source model 1 is connected to the first bus 20;

[0109] The second equivalent power source model 3 and the reactive power compensation device model 4 are respectively connected to the second bus 21;

[0110] One end of the high-voltage series reactor model 2 is connected to the second bus 21 , and the other end of the high-voltage series reactor model 2 is connected to the first bus 20 through the double-circuit transmission line model 5 .

[0111] Optionally, in the above technical solution, the establishing module 210 is further specifically used to establish a double-circuit transmission line model 5 based on the distributed parameter model and in combination with the overhead ground wire and earth loop resistance.

[0112] Optionally, in the above technical solution, the establishing module 210 is further specifically used to establish an equivalent power supply model according to the Thevenin theorem.

[0113] Optionally, in the above technical solution, the determination module 230 is specifically configured to:

[0114] The coefficient of variation CV is calculated using a first formula, which is: The elements in the impedance matrix include: the mutual impedance Z between the e-th phase and the f-th phase of the double-circuit transmission line simulation model on the same tower ef , The above operation can also be achieved by representing the expected value of the mutual impedance element in the impedance matrix of the double-circuit transmission line simulation model on the same tower, phase e is any one of the three phases A, B, and C in the double-circuit transmission line model, and phase f is any one of the three phases a, b, and c in the double-circuit transmission line model, or vice versa.

[0115] For the above-mentioned parameters and steps for each unit module to implement corresponding functions in the imbalance measurement system based on a simulation model of the present invention, reference can be made to the parameters and steps in the embodiment of the imbalance measurement method based on a simulation model above, and no further details will be given here.

[0116] An electronic device according to an embodiment of the present invention includes a memory, a processor, and a program stored in the memory and running on the processor. When the processor executes the program, the steps of any of the above-mentioned methods for measuring imbalance based on a simulation model are implemented.

[0117] Among them, the electronic device can be a computer, a mobile phone, etc., and correspondingly, its program is computer software or a mobile phone APP, etc., and the above-mentioned parameters and steps in an electronic device of the present invention can refer to the parameters and steps in the embodiment of the imbalance measurement method based on the simulation model above, and will not be repeated here.

[0118] Those skilled in the art will appreciate that the present invention may be implemented as a system, method or computer program product.

[0119] Therefore, the present disclosure may be embodied in the following forms: entirely in hardware, entirely in software (including firmware, resident software, microcode, etc.), or in a combination of hardware and software, generally referred to herein as a "circuit," "module," or "system." Furthermore, in some embodiments, the present disclosure may be embodied in the form of a computer program product embodied in one or more computer-readable media, wherein the computer-readable media contains computer-readable program code.

[0120] Any combination of one or more computer-readable media can be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device, or device.

[0121] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for measuring imbalance based on a simulation model, characterized in that: include: Establish a simulation model of double-circuit transmission lines on the same tower; Calculating the impedance matrix corresponding to the same-tower double-circuit transmission line simulation model; Calculating a coefficient of variation based on elements in an impedance matrix, and determining the coefficient of variation as an unbalance degree of three-phase current of the double-circuit transmission line simulation model on the same tower; The double-circuit transmission line simulation model on the same tower includes a double-circuit transmission line model, a reactive compensation device model, a high-voltage series reactor model and two equivalent power supply models; The first equivalent power model is connected to the first bus; The second equivalent power source model and the reactive power compensation device model are respectively connected to the second bus; One end of the high-voltage series reactor model is connected to the second busbar, and the other end of the high-voltage series reactor model is connected to the first busbar through the double-circuit transmission line model; Calculating the coefficient of variation based on the elements in the impedance matrix includes: The coefficient of variation is calculated using the first formula CV , the first formula is: The elements in the impedance matrix include: e Phase and Di f Mutual impedance between phases Z ef , It represents the expected value of the mutual impedance element in the impedance matrix of the double-circuit transmission line simulation model on the same tower, phase e is any phase among the three phases A, B, and C in the double-circuit transmission line model, and phase f is any phase among the three phases a, b, and c in the double-circuit transmission line model.

2. The method for measuring imbalance based on a simulation model according to claim 1, wherein: Also includes: Based on the distributed parameter model and in combination with the overhead ground wire and earth loop resistance, a double-circuit transmission line model is established.

3. The method for measuring imbalance based on a simulation model according to claim 1, wherein: Also includes: According to Thevenin's theorem, the equivalent power supply model is established.

4. An imbalance measurement system based on a simulation model, characterized in that: It includes an establishment module, a calculation module and a determination module; The establishment module is used to: establish a simulation model of a double-circuit transmission line on the same tower; The calculation module is used to calculate the impedance matrix corresponding to the same-tower double-circuit transmission line simulation model; The determining module is used to calculate the coefficient of variation according to the elements in the impedance matrix, and determine the coefficient of variation as the unbalance degree of the three-phase current of the double-circuit transmission line simulation model on the same tower; The double-circuit transmission line simulation model on the same tower includes a double-circuit transmission line model, a reactive compensation device model, a high-voltage series reactor model and two equivalent power supply models; The first equivalent power model is connected to the first bus; The second equivalent power source model and the reactive power compensation device model are respectively connected to the second bus; One end of the high-voltage series reactor model is connected to the second busbar, and the other end of the high-voltage series reactor model is connected to the first busbar through the double-circuit transmission line model; Calculating the coefficient of variation based on the elements in the impedance matrix includes: The coefficient of variation is calculated using the first formula CV , the first formula is: The elements in the impedance matrix include: e Phase and Di f Mutual impedance between phases Z ef , It represents the expected value of the mutual impedance element in the impedance matrix of the double-circuit transmission line simulation model on the same tower, phase e is any phase among the three phases A, B, and C in the double-circuit transmission line model, and phase f is any phase among the three phases a, b, and c in the double-circuit transmission line model.

5. The imbalance measurement system based on a simulation model according to claim 4, characterized in that: The establishment module is further specifically used for: Based on the distributed parameter model and in combination with the overhead ground wire and earth loop resistance, a double-circuit transmission line model is established.

6. The imbalance measurement system based on a simulation model according to claim 4, characterized in that: The establishment module is further specifically used for: According to Thevenin's theorem, the equivalent power supply model is established.

7. An electronic device comprising a memory, a processor, and a program stored in the memory and running on the processor, characterized in that: When the processor executes the program, the steps of the imbalance measurement method based on a simulation model as described in any one of claims 1 to 3 are implemented.

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