A method for fine equivalence and automatic verification of new energy station topology

Abstract

The present invention relates to the technical field of new energy power station modeling, and provides a method for fine topology equivalence and automatic verification of new energy power stations. The present invention includes the following steps. Step 1: Construct structured modeling data for new energy power stations. Step 2: Use an RPA tool to operate the PSASP software to complete automatic modeling of new energy power stations. Step 3: Calculate the collector line loss, transformer substation loss, and topology equivalent impedance based on the power flow calculation results of the PSASP software. Step 4: According to different verification conditions for high / low voltage ride-through, iteratively modify the values of the grounding fault R and X in the transient stability fault card of the PSASP software until the grid connection point voltage U of the new energy power station during the fault ride-through fault is consistent with the set verification condition voltage U set According to the solution of the present invention, the combined modeling based on the RPA tool and the PSASP software greatly improves the quality and efficiency of the modeling work of new energy power stations, thereby ensuring the stable operation and optimal dispatching of the new energy power system.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy power station modeling, and particularly relates to a method for fine equivalent and automatic verification of new energy power station topology. Background Technique

[0002] The high proportion of new energy connected to the system squeezes the power generation space of conventional units. Traditional rotating synchronous equipment is gradually replaced by large-scale power electronic equipment, and the operating characteristics of the power grid have changed profoundly. Conducting large-scale power system simulation analysis is an important means to enhance the understanding of the characteristics of new power systems, guide the arrangement of power grid operation modes, and ensure the safe and stable operation of the system. However, different from the simulation of traditional synchronous machine-dominated AC power grids, new energy power stations and their internal components are numerous, and the control process of power electronic devices is complex, which severely restricts the simulation calculation efficiency of new energy power systems. The equivalent modeling of new energy power stations is an effective method that takes into account both the simulation calculation efficiency of large-scale power systems and the dynamic response characteristics of new energy power stations.

[0003] The single-unit multiplication model uses a single new energy unit to equivalent the entire power station to make its external characteristics tend to be the same. Currently, this model is generally used for new energy power stations in large power grid simulations. Although this simplification can reduce the model order and simulation calculation amount of new energy power stations, this model does not consider the characteristic differences between different single-unit types and cannot reflect the impedance distribution within the power station. For multiple new energy units connected by long-distance collector lines, due to the different terminal voltage distributions along the line, the response characteristics of each unit during low-voltage ride-through are not the same. Summary of the Invention

[0004] The present invention provides a method for fine equivalent and automatic verification of new energy power station topology, which can improve the technical problems of low modeling efficiency and insufficient equivalent accuracy in the new energy power station modeling technology in related technologies.

[0005] The present invention provides a method for fine equivalent and automatic verification of new energy power station topology, including the following steps:

[0006] Step 1: Construct structured modeling data of a new energy power station: Construct structured modeling data of a new energy power station including unit parameters, line parameters, box transformer parameters, bus modeling, unit modeling, box transformer modeling, and collector line modeling;

[0007] Step 2: Design an automatic modeling process for a new energy power station based on an RPA tool: Use the RPA tool to operate the PSASP software to complete the new construction of a new energy power station project, read the structured modeling data of the new energy power station, automatically model the bus, automatically model the AC line, automatically model the transformer, and automatically model the generator;

[0008] Step 3: Calculate the topological equivalent impedance based on the PSASP power flow result report: Calculate the collector line loss, box transformer loss, and topological equivalent impedance based on the power flow calculation results of the PSASP software;

[0009] The specific steps are as follows: Run the power flow calculation program of the PSASP software to generate power flow results, export the result report data of physical buses and two-winding transformers respectively, and calculate the collector line loss, box transformer loss, and topological equivalent impedance based on the result report data;

[0010] Step 4: According to the different verification conditions of high / low voltage ride-through, iteratively modify the values of the grounding fault R and X of the transient stability fault card in the PSASP software until the grid connection point voltage U of the new energy power station during the fault ride-through fault is consistent with the set verification condition voltage U set ; where R is the grounding resistance and X is the grounding reactance.

[0011] A new energy power station topological fine equivalence and automatic verification method provided by the present invention has at least the following technical effects: By constructing structured modeling data for new energy power stations, designing an automatic modeling process for new energy power stations based on RPA tools, calculating topological equivalent impedance based on PSASP power flow result reports, and automatically verifying the impedance of verification conditions based on loop calls of the PSASP software, efficient modeling and accurate equivalence verification of new energy power stations are achieved through joint modeling of RPA tools and PSASP software, significantly improving the quality and efficiency of the modeling work of new energy power stations, thereby ensuring the stable operation and optimal dispatching of the new energy power system.

[0012] Further, the said Step 1 includes the following steps:

[0013] Step 101: Construct a structured modeling data group that can be read by the RPA tool: Obtain the single-machine modeling parameters of the new energy power station, including the type and capacity of new energy single machines, box transformer parameters, and measured parameters of the converter fault ride-through characteristics; and obtain the topological modeling parameters of the new energy power station, including the primary system diagram of the new energy power station, the cable routing diagram of the collector line, and the step-up transformer parameters;

[0014] Among them, the said box transformer parameters include capacity, short-circuit voltage percentage, short-circuit loss, no-load loss, and no-load current percentage, the cable routing diagram of the collector line includes the type and length of the collector line, and the step-up transformer parameters include capacity, short-circuit voltage percentage, short-circuit loss, no-load loss, and no-load current percentage;

[0015] Step 102: Construct a structured modeling data group for unit parameters, including generator index, generator rated capacity, generator model type, and parameter group number;

[0016] Step 103: Construct a structured modeling data group for line parameters, including line index, line type, positive sequence resistance per unit length, positive sequence reactance per unit length, positive sequence susceptance per unit length, zero sequence resistance per unit length, zero sequence reactance per unit length, and zero sequence susceptance per unit length;

[0017] Step 104: Construct a structured modeling data group for box transformer parameters, including transformer index, rated capacity of the transformer, short-circuit loss, percentage of short-circuit voltage, no-load loss, and percentage of no-load current;

[0018] Step 105: Construct a structured modeling data group for busbar modeling, including busbar index, base voltage, upper voltage limit, and lower voltage limit;

[0019] Step 106: Construct a structured modeling data group for unit modeling, including unit name, connected busbar, and generator type, where the generator type is consistent with the generator index number in Step 102;

[0020] Step 107: Construct a structured modeling data group for collector line modeling, including collector line name, I-side busbar, J-side busbar, line index, and line length, where the line type is consistent with the line index number in Step 103;

[0021] Step 108: Construct a structured modeling data group for box transformer modeling, including box transformer name, high-voltage side busbar, low-voltage side busbar, and box transformer type, where the box transformer type is consistent with the transformer index number in Step 104.

[0022] Further, Step 2 includes the following steps:

[0023] Step 2 includes the following steps:

[0024] Step 201: New construction of new energy power station project: Use the RPA tool to open the application, name and save after creating a new new energy power station project;

[0025] Step 202: Reading structured modeling data of new energy power station: Use the RPA tool to read the structured modeling data of the new energy power station constructed in Step 1 and store it in variables such as line parameters, generator parameters, transformer parameters, busbar modeling, generator modeling, transformer modeling, and collector line modeling;

[0026] Step 203: Automatic busbar modeling: Open the component data busbar, use the RPA tool to loop through the busbar modeling variables one by one, and fill in the busbar name, base voltage, upper voltage limit, and lower voltage limit;

[0027] Step 204: Automatic AC line modeling: Open the component data AC line, use the RPA tool to loop through the collector line modeling variables one by one, and fill in the collector line name, I-side busbar, and J-side busbar;

[0028] Among them, the line parameter reading line parameter variable per unit length calculates the AC line impedance phasor as: [R 1L , X 1L , B 1L , R 0L , X 0L , B 1L = [R 1 , X 1 , B 1 , R 0 , X 0 , B 0 × L;

[0029] In the formula: R 1L , X 1L , B 1L , R 0L , X 0L and B 1L are the total positive sequence resistance, total positive sequence reactance, total positive sequence susceptance, total zero sequence resistance, total zero sequence reactance and total zero sequence susceptance of the AC line respectively; R 1 , X 1 , B 1 , R 0 , X 0 and B 0 are the positive sequence resistance per unit length, positive sequence reactance per unit length, positive sequence susceptance per unit length, zero sequence resistance per unit length, zero sequence reactance per unit length and zero sequence susceptance per unit length of the AC line respectively; L is the length of each line segment;

[0030] Step 205: Automatic transformer modeling: Open the component data two-winding transformer, and use the RPA tool to loop through the transformer modeling variables one by one to fill in the box transformer name, high-voltage side bus, low-voltage side bus and box transformer capacity;

[0031] Calculate the transformer resistance R T , transformer reactance X T , transformer conductance G T and transformer susceptance B T ;

[0032] It is expressed as:

[0033] R T = P k / 1000 * U N 2 / S N 2 ;

[0034] In the formula: R T is the transformer resistance, P k is the transformer short-circuit loss, U N is the rated voltage of the transformer and SN is the rated capacity of the transformer; and,

[0035] X T = U k % / 100*U N 2 / S N ;

[0036] Where: X T is the reactance of the transformer, U k % is the percentage of the short-circuit voltage of the transformer, U N is the rated voltage of the transformer and S N is the rated capacity of the transformer; and,

[0037] G T = ΔP 0 / U N 2 ×10 -3 ;

[0038] Where: G T is the conductance of the transformer, ΔP 0 is the no-load loss of the transformer and U N is the rated voltage of the transformer; and,

[0039] B T = I 0 % / 100*S N / U N 2 ;

[0040] Where: B T is the susceptance of the transformer, I 0 % is the percentage of the no-load current of the transformer, U N is the rated voltage of the transformer and S N is the rated capacity of the transformer;

[0041] Step 206: Automatic modeling of the generator: Open the component data of the generator and the regulator, and use the RPA tool to loop through the generator modeling variables one by one to fill in the unit name, connected bus, generator type, generator rated capacity, generator model type, and parameter group number.

[0042] Further, the said step 3 includes the following steps:

[0043] Step 301: Divide the units G of the new energy power station into M groups according to the differences in unit type, capacity, and control performance of the new energy power station, and set them as: G={G 1 ,G 2 ,...,G i ,...,G M}, G iFor the i-th group, where i = {1, 2,..., M}, the corresponding distribution transformer T is set as: T = {T 1 , T 2 ,..., T i ,..., T M}; where there are N units in the i-th group, set as: G i = {G i1 , G i2 ,..., G ij ,..., G iN}, G ij is the j-th unit in the i-th group, where j = {1, 2,..., N}, and the corresponding distribution transformer T i is set as: T i = {T i1 , T i2 ,..., T ij ,..., T iN};

[0044] Step 302: According to the result report data of the physical bus, read the bus voltage phasor U BusPOIL of the low-voltage side of the grid connection point, the bus voltage U ij of the 35 kV side of the unit G Busij , the high-side power S ij of the distribution transformer T H-Busij and the low-side power S ij of the distribution transformer T L-Busij ;

[0045] Calculate the sharing loss generated when the power generated by the unit G ij flows through the collector line to the grid connection point as: ;

[0046] In the formula: U Busij is the bus voltage of the 35 kV side of the unit G ij , U BusPOIL is the bus voltage phasor of the low-voltage side of the grid connection point, and S H-Busij is the high-side power of the distribution transformer T ij ;

[0047] The loss generated by the distribution transformer T ij is: ;

[0048] In the formula: S L-Busij is the low-side power of the distribution transformer T ij , and S H-Busij is the high-side power of the distribution transformer T ij ;

[0049] Step 303: After accumulating the losses of each collector line in the unit group i, the total collector line loss of the unit group i is: ;

[0050] Wherein: is the total collector line loss of the i-th fleet, k is the k-th unit in the i-th fleet, and is the loss of the power of the k-th unit in the i-th fleet on the collector line;

[0051] After summing up the losses of each transformer substation in the i-th fleet, the total transformer substation loss of the i-th fleet is: ;

[0052] Wherein, is the total transformer substation loss of the i-th fleet; k is the k-th transformer substation in the i-th fleet, and is the loss of the k-th transformer substation in the i-th fleet;

[0053] Step 304: Calculate the equivalent collector line impedance of the i-th fleet as: ;

[0054] Wherein, is the equivalent collector line impedance of the i-th fleet, is the total collector line loss of the i-th fleet, U BusPOIL is the bus voltage phasor at the low-voltage side of the grid connection point, and is the sum of the powers at the low-voltage side of the transformer substation T ij ;

[0055] Calculate the equivalent transformer substation impedance of the i-th fleet as: ;

[0056] Wherein, is the equivalent transformer substation impedance of the i-th fleet, is the total transformer substation loss of the i-th fleet, U BusPOIL is the bus voltage phasor at the low-voltage side of the grid connection point, and is the sum of the powers at the low-voltage side of the transformer substation T ij ;

[0057] Furthermore, the said Step 4 includes the following steps:

[0058] Step 401: Given the initial values of the grounding impedance R and X of the fault card as 0, where R is the grounding resistance and X is the grounding reactance, obtain the fault response curve of the new energy power station through transient simulation, and read the voltage U fault during the fault;

[0059] Step 402: If |U fault -U set |>ɛ U , ɛ U is the allowable voltage deviation;

[0060] Wherein, U fault is the voltage during the fault and U set is the voltage under the verification condition;

[0061] Then continue to increase the grounding impedance value according to the ΔR and ΔX step lengths as follows:

[0062] R nxt = R pre + ΔR;

[0063] In the formula: R nxt is the grounding resistance for the next transient simulation, R pre is the grounding resistance for the current transient simulation, and ΔR is the resistance change step length; and,

[0064] X nxt = X pre + ΔX;

[0065] In the formula: X nxt is the grounding reactance for the next transient simulation, X pre is the grounding reactance for the current transient simulation, and ΔX is the reactance change step length. Description of the Drawings

[0066] The exemplary embodiments of the present invention can be more fully understood by referring to the following drawings:

[0067] Figure 1 is a flowchart of the new energy power station topology fine equivalence and automatic verification method provided by the embodiment of the present invention. Detailed Embodiments

[0068] In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0069] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs; the terms used herein are only for the purpose of describing specific embodiments and do not limit the present invention.

[0070] In order to improve the technical problems of low modeling efficiency and insufficient equivalence accuracy in the new energy power station modeling technology in the related art, the embodiments of the present invention provide the following solutions.

[0071] As Figure 1 shown, the embodiments of the present invention provide a new energy power station topology fine equivalence and automatic verification method, including the following steps:

[0072] Step 1: Construct structured modeling data for the new energy power station: Construct structured modeling data for the new energy power station including unit parameters, line parameters, box transformer parameters, bus modeling, unit modeling, box transformer modeling, and collector line modeling;

[0073] Step 2: Design an automatic modeling process for new energy power stations based on RPA tools: Use RPA tools to operate PSASP software to complete the new construction of new energy power station projects, read structured modeling data of new energy power stations, automatically model busbars, automatically model AC lines, automatically model transformers, and automatically model generators;

[0074] Step 3: Calculate the topological equivalent impedance based on the PSASP power flow result report: Calculate the collector line loss, box transformer loss, and topological equivalent impedance based on the power flow calculation results of PSASP software;

[0075] Step 4: According to the different verification conditions of high / low voltage ride-through, iteratively modify the values of grounding fault R and X in the transient stability fault card of PSASP software until the grid connection point voltage U of the new energy power station during the fault ride-through fault is consistent with the set verification condition voltage U set ; where R is the grounding resistance and X is the grounding reactance.

[0076] It can be understood that to balance the simulation calculation accuracy and calculation efficiency of new energy power stations, it is necessary to reasonably group according to the response characteristics differences of each unit, and consider the equivalent parameters of each cluster in the network topology calculation.

[0077] By constructing structured modeling data for new energy power stations, designing an automatic modeling process for new energy power stations based on RPA tools, calculating the topological equivalent impedance based on the PSASP power flow result report, and automatically verifying the impedance of the verification conditions based on the loop call of PSASP software, the efficient modeling and accurate equivalent verification of new energy power stations are realized based on the joint modeling of RPA tools and PSASP software, greatly improving the quality and efficiency of the modeling work of new energy power stations, thereby ensuring the stable operation and optimal dispatching of the new energy power system.

[0078] Specifically, in some embodiments, the specific steps of Step 3 are: Run the power flow calculation program of PSASP software to generate power flow results, respectively export the result report data of physical busbars and two-winding transformers, and calculate the collector line loss, box transformer loss, and topological equivalent impedance based on the result report data.

[0079] Specifically, in some embodiments, Step 1 includes the following steps:

[0080] The said Step 1 includes the following steps:

[0081] Step 101: Construct a structured modeling data group that can be read by RPA tools: Obtain the single-unit modeling parameters of the new energy power station, including the type and capacity of new energy single units, box transformer parameters, and measured parameters of the converter fault ride-through characteristics; and obtain the topological modeling parameters of the new energy power station, including the primary system diagram of the new energy power station, the cable routing diagram of the collector line, and the booster transformer parameters;

[0082] It can be understood that the box-type transformer parameters include capacity, short-circuit voltage percentage, short-circuit loss, no-load loss, and no-load current percentage. The collector line cable routing diagram includes the collector line model and length. The step-up transformer parameters include capacity, short-circuit voltage percentage, short-circuit loss, no-load loss, and no-load current percentage;

[0083] Step 102: Construct a structured modeling data group for unit parameters, including generator index, generator rated capacity, generator model type, and parameter group number;

[0084] It can be understood that the generator model types are 12-type doubly-fed wind turbines, 13-type direct-drive wind turbines, and 14-type centralized photovoltaics;

[0085] Step 103: Construct a structured modeling data group for line parameters, including line index, line type, positive-sequence resistance per unit length, positive-sequence reactance per unit length, positive-sequence susceptance per unit length, zero-sequence resistance per unit length, zero-sequence reactance per unit length, and zero-sequence susceptance per unit length;

[0086] Step 104: Construct a structured modeling data group for box-type transformer parameters, including transformer index, transformer rated capacity, short-circuit loss, short-circuit voltage percentage, no-load loss, and no-load current percentage;

[0087] Step 105: Construct a structured modeling data group for bus modeling, including bus index, base voltage, voltage upper limit, and voltage lower limit;

[0088] Step 106: Construct a structured modeling data group for unit modeling, including unit name, connected bus, and generator type, where the generator type is consistent with the generator index number in Step 102;

[0089] Step 107: Construct a structured modeling data group for collector line modeling, including collector line name, side-I bus, side-J bus, line index, and line length, where the line type is consistent with the line index number in Step 103;

[0090] Step 108: Construct a structured modeling data group for box-type transformer modeling, including box-type transformer name, high-voltage side bus, low-voltage side bus, and box-type transformer type, where the box-type transformer type is consistent with the transformer index number in Step 104.

[0091] Specifically, in some embodiments, Step 2 includes the following steps:

[0092] Step 201: New construction of a new energy power station project: Use the RPA tool to open the application, name and save the new energy power station project after creation;

[0093] Step 202: Reading Structured Modeling Data of New Energy Power Station: Use the RPA tool to read the structured modeling data of the new energy power station constructed in Step 1 and store it in variables such as line parameters, generator parameters, transformer parameters, bus modeling, generator modeling, transformer modeling, and collector line modeling;

[0094] Step 203: Automatic Bus Modeling: Open the component data bus, and use the RPA tool to loop through the bus modeling variables one by one to fill in the bus name, base voltage, voltage upper limit, and voltage lower limit;

[0095] Step 204: Automatic AC Line Modeling: Open the component data AC line, and use the RPA tool to loop through the collector line modeling variables one by one to fill in the collector line name, I-side bus, and J-side bus;

[0096] Among them, the unit length line parameters read the line parameter variables, and the calculated AC line impedance phasor is: [R 1L ,X 1L ,B 1L ,R 0L ,X 0L ,B 1L = [R 1 ,X 1 ,B 1 ,R 0 ,X 0 ,B 0 ×L;

[0097] In the formula: R 1L , X 1L , B 1L , R 0L , X 0L and B 1L are the total positive sequence resistance, total positive sequence reactance, total positive sequence susceptance, total zero sequence resistance, total zero sequence reactance, and total zero sequence susceptance of the AC line respectively; R 1 , X 1 , B 1 , R 0 , X 0 and B 0 are the positive sequence resistance per unit length, positive sequence reactance per unit length, positive sequence susceptance per unit length, zero sequence resistance per unit length, zero sequence reactance per unit length, and zero sequence susceptance per unit length of the AC line respectively; L is the length of each line segment;

[0098] Step 205: Automatic Transformer Modeling: Open the component data two-winding transformer, and use the RPA tool to loop through the transformer modeling variables one by one to fill in the box transformer name, high-voltage side bus, low-voltage side bus, and box transformer capacity;

[0099] Calculate the transformer resistance R T , the transformer reactance X T, the conductance G of the transformer T and the susceptance B of the transformer T ;

[0100] are expressed as:

[0101] R T = P k / 1000*U N 2 / S N 2 ;

[0102] In the formula: R T is the resistance of the transformer, P k is the short-circuit loss of the transformer, U N is the rated voltage of the transformer, and S N is the rated capacity of the transformer; and,

[0103] X T = U k % / 100*U N 2 / S N ;

[0104] In the formula: X T is the reactance of the transformer, U k % is the percentage of the short-circuit voltage of the transformer, U N is the rated voltage of the transformer, and S N is the rated capacity of the transformer; and,

[0105] G T = ΔP 0 / U N 2 ×10 -3 ;

[0106] In the formula: G T is the conductance of the transformer, ΔP 0 is the no-load loss of the transformer, and U N is the rated voltage of the transformer; and,

[0107] B T = I 0 % / 100*S N / U N 2 ;

[0108] In the formula: B T is the susceptance of the transformer, I 0 % is the percentage of the no-load current of the transformer, U N is the rated voltage of the transformer, and S N is the rated capacity of the transformer;

[0109] Step 206: Automatic modeling of generators: Open the component data of generators and regulators, and use the RPA tool to loop through the generator modeling variables one by one, filling in the unit name, connected bus, generator type, generator rated capacity, generator model type, and parameter group number.

[0110] Specifically, in some embodiments, step 3 includes the following steps:

[0111] Step 301: Divide the new energy power station units G into M groups according to the differences in unit types, capacities, and control performances of the new energy power station, and set them as: G = {G 1 , G 2 ,..., G i ,..., G M}, where G i is the i-th group, i = {1, 2,..., M}, and the corresponding transformer substations T are set as: T = {T 1 , T 2 ,..., T i ,..., T M}; among them, there are N units in the i-th group, set as: G i = {G i1 , G i2 ,..., G ij ,..., G iN}, where G ij is the j-th unit in the i-th group, j = {1, 2,..., N}, and the corresponding transformer substation T i is set as: T i = {T i1 , T i2 ,..., T ij ,..., T iN};

[0112] Step 302: According to the result report data of the physical bus, read the low-voltage side bus voltage phasor U BusPOIL of the grid connection point, the 35 kV side bus voltage U ij of the unit G Busij , the high-side power S ij of the transformer substation T H-Busij and the low-side power S ij of the transformer substation T L-Busij ;

[0113] Calculate the apportioned loss generated when the power generated by the unit G ij flows through the collector line to the grid connection point as: ;

[0114] In the formula: U Busij is the 35 kV side bus voltage of the unit G ij , UBusPOIL is the phasor sum S of the low-voltage side bus voltages at the grid connection point H-Busij is the box-type transformer T ij High-side power;

[0115] Box-type transformer T ij The losses generated are: ;

[0116] In the formula: S L-Busij is the box-type transformer T ij Low-side power sum S H-Busij is the box-type transformer T ij High-side power;

[0117] Step 303: After accumulating the losses of each collector line in cluster i, the total collector line loss of cluster i is: ;

[0118] In the formula: is the total collector line loss of cluster i, k is the kth unit in cluster i, and is the loss of the power of the kth unit in cluster i on the collector line;

[0119] After accumulating the losses of each box-type transformer in cluster i, the total box-type transformer loss of cluster i is: ;

[0120] In the formula, is the total box-type transformer loss of cluster i; k is the kth box-type transformer in cluster i, and is the loss of the kth box-type transformer in cluster i;

[0121] Step 304: Calculate the equivalent collector line impedance of cluster i as: ;

[0122] In the formula, is the equivalent collector line impedance of cluster i, is the total collector line loss of cluster i, U BusPOIL is the phasor sum of the low-voltage side bus voltages at the grid connection point is the box-type transformer T ij Sum of low-side powers;

[0123] Calculate the equivalent box-type transformer impedance of cluster i as: ;

[0124] In the formula, is the equivalent box-type transformer impedance of cluster i, is the total box-type transformer loss of cluster i, U BusPOIL is the phasor sum of the low-voltage side bus voltages at the grid connection point is the box-type transformer T ij Sum of low-side powers.

[0125] Specifically, in some embodiments, step 4 includes the following steps:

[0126] Step 401: Given the initial values of the grounding impedance R and X of the fault card as 0, where R is the grounding resistance and X is the grounding reactance, obtain the fault response curve of the new energy power station through transient simulation, and read the voltage U during the fault fault ;

[0127] Step 402: If |U fault -U set |>ɛ U , ɛ U is the allowable voltage deviation;

[0128] In the formula, U fault is the voltage during the fault and U set is the voltage of the verification condition;

[0129] Then continue to increase the grounding impedance value according to the step sizes of ΔR and ΔX as:

[0130] R nxt =R pre +ΔR;

[0131] In the formula: R nxt is the grounding resistance for the next transient simulation, R pre is the grounding resistance for the current transient simulation, and ΔR is the resistance change step size; and,

[0132] X nxt =X pre +ΔX;

[0133] In the formula: X nxt is the grounding reactance for the next transient simulation, X pre is the grounding reactance for the current transient simulation, and ΔX is the reactance change step size.

[0134] Embodiment 1

[0135] The actual wind farm topology includes 6 collector lines. Each collector line is radial and connects 7 - 10 2.5 MW or 3.2 MW wind turbines. All the electricity is collected through a 35 kV busbar and then stepped up and sent out. The structured modeling information of the unit parameters is shown in Table 1, the structured modeling information of the line parameters is shown in Table 2, the structured modeling information of the box transformer parameters is shown in Table 3, the structured modeling information of the busbar modeling is shown in Table 4, the structured modeling information of the unit modeling is shown in Table 5, the structured modeling information of the box transformer modeling is shown in Table 6, and the structured modeling information of the collector line modeling is shown in Table 7.

[0136] Table 1 Structured Modeling Data Group of Unit Parameters

[0137]

[0138] Table 2 Structured Modeling Data Group of Line Parameters

[0139]

[0140] Table 3 Structured Modeling Data Group of Box-Type Transformer Parameters

[0141]

[0142] Table 4 Structured Modeling Data Group of Bus Modeling

[0143]

[0144] Table 5 Structured Modeling Data Group of Generator Set Modeling

[0145]

[0146] Table 6 Structured Modeling Data Group of Box-Type Transformer Modeling

[0147]

[0148] Table 7 Structured Modeling Data Group of Collector Line Modeling

[0149]

[0150] The PSASP software is operated through the RPA tool to complete the new construction of the new energy power station project, the reading of structured modeling data of the new energy power station, the automatic modeling of the bus, the automatic modeling of the AC line, the automatic modeling of the transformer, and the automatic modeling of the generator.

[0151] After the automatic modeling is completed, the power flow result report is exported, and the 51 units of the power station are divided into 2 groups. The numbers G91~G122 are the first group, with the active power loss of the collector line being 2.61 MW, the reactive power loss of the collector line being 5.30 Mvar, the active power loss of the box-type transformer being 0.65 MW, the reactive power loss of the box-type transformer being 4.62 Mvar, the equivalent resistance of the collector line being 0.0423 p.u., the equivalent reactance of the collector line being 0.0861 p.u., the short-circuit loss of the box-type transformer being 812.60 kW, and the percentage of the short-circuit voltage of the box-type transformer being 6.60%; the numbers G123~G141 are the second group, with the active power loss of the collector line being 0.57 MW, the reactive power loss of the collector line being 1.02 Mvar, the active power loss of the box-type transformer being 0.48 MW, the reactive power loss of the box-type transformer being 3.85 Mvar, the equivalent resistance of the collector line being 0.016 p.u., the equivalent reactance of the collector line being 0.0281 p.u., the short-circuit loss of the box-type transformer being 569.90 kW, and the percentage of the short-circuit voltage of the box-type transformer being 6.93%.

[0152] Set the low voltage ride-through verification condition to 0.1 p.u., and through cyclic iteration, the grounding resistance is obtained as 0.031 p.u., the grounding reactance is 0.031 p.u., and the comparison error is 3×10e -4 .

[0153] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A new energy station topology fine equivalence and automatic verification method, characterized in that: The following steps are involved: Step 1: Construct new energy station structured modeling data including unit parameters, line parameters, box transformer parameters, busbar modeling, unit modeling, box transformer modeling and collector line modeling; Step 2: Use the RPA tool to operate the PSASP software to complete the construction of new energy station projects, read the structured modeling data of new energy stations, and automatically model the busbars, AC lines, transformers, and generators. The specific steps are as follows: Step 201: Create a new energy station project: Use the RPA tool to open the PSASP software, create a new energy station project, name it, and save it; Step 202: Reading structured modeling data of new energy stations: Using the RPA tool to read the structured modeling data of new energy stations constructed in step 1, and storing it in line parameters, generator parameters, transformer parameters, busbar modeling, generator modeling, transformer modeling, and collector modeling variables; Step 203: Automatic bus modeling: Open the component data bus, use the RPA tool to loop through the bus modeling variables one by one, and fill in the bus name, reference voltage, upper voltage limit, and lower voltage limit; Step 204: Automatic modeling of AC lines: Open the component data AC line, use the RPA tool to loop through the collector line modeling variables one by one, and fill in the collector line name, I-side busbar, and J-side busbar; The unit length line parameter reads the line parameter variable, and the AC line impedance phasor is calculated as: [R 1L ,X 1L ,B 1L ,R 0L ,X 0L ,B 1L ] = [R1,X1,B1,R0,X0,B0]×L; Where: R 1L , X 1L , B 1L , R 0L , X 0L and B 1L They are the total positive-sequence resistance, total positive-sequence reactance, total positive-sequence susceptance, total zero-sequence resistance, total zero-sequence reactance and total zero-sequence susceptance of the AC line respectively; R1, X1, B1, R0, X0 and B0 are the positive-sequence resistance per unit length, positive-sequence reactance per unit length, positive-sequence susceptance per unit length, zero-sequence resistance per unit length, zero-sequence reactance per unit length and zero-sequence susceptance per unit length of the AC line respectively; L is the length of each line section; Step 205: Automatic transformer modeling: Open the two-winding transformer in the component data, use the RPA tool to loop through the transformer modeling variables one by one, and fill in the name of the box transformer, the high-voltage side bus, the low-voltage side bus, and the box transformer capacity; Calculate the transformer resistance R T , Transformer Reactance X T , Transformer conductivity G T And transformer susceptance B T ; It is expressed as: R T = P k / 1000*U N 2 / S N 2 ; Where: R T is the transformer resistance, P k is the transformer short-circuit loss, U N is the transformer rated voltage and S N is the rated capacity of the transformer; and, X T = U k % / 100*U N 2 / S N ; Where: X T is the transformer reactance, U k % is the transformer short-circuit voltage percentage, U N is the transformer rated voltage and S N is the rated capacity of the transformer; and, G T = ΔP0 / U N 2 ×10 -3 ; Where: G T is the transformer conductance, ΔP0 is the transformer no-load loss and U N is the rated voltage of the transformer; and, B T = I0% / 100*S N / U N 2 ; Where: B T is the transformer susceptance, I0% is the transformer no-load current percentage, U N is the transformer rated voltage and S N is the rated capacity of the transformer; Step 206: Automatic generator modeling: Open the component data generator and regulator, use the RPA tool to loop through the generator modeling variables one by one, and fill in the unit name, access bus, generator type, generator rated capacity, generator model type and parameter group number; Step 3: Based on the power flow calculation results of PSASP software, calculate the collector line loss, box transformer loss and topological equivalent impedance; Step 4: According to the different high / low voltage ride-through verification conditions, iteratively modify the values ​​of ground fault R and X of the transient stability fault card of the PSASP software until the voltage U of the grid connection point of the new energy station during the fault ride-through period is fault Verification condition voltage U set consistent; where R is the grounding resistance and X is the grounding reactance; the specific steps are: Step 401: Given the initial values ​​of the fault card grounding impedance R and X as 0, where R is the grounding resistance and X is the grounding reactance, obtain the fault response curve of the new energy station through transient simulation, and read the voltage U during the fault period fault ; Step 402: If |U fault -U set |>ɛ U , ɛ U That is the allowable voltage deviation; Where U fault is the voltage during the fault and U set To verify the working voltage; Then continue to increase the ground impedance value according to the ΔR and ΔX steps: R nxt =R pre +ΔR; Where: R nxt For the next transient simulation ground resistance, R pre is the ground resistance of this transient simulation and ΔR is the resistance change step; and, X nxt =X pre +ΔX; Where: X nxt Simulate the grounding reactance, X for the next transient pre is the grounding reactance for this transient simulation and ΔX is the reactance change step.

2. The new energy station topology fine equivalence and automatic verification method according to claim 1 is characterized in that: The step 1 comprises the following steps: Step 101: Construct a structured modeling data group that can be read by the RPA tool: obtain the modeling parameters of the new energy station, including the type and capacity of the new energy station, the parameters of the box transformer, and the measured parameters of the converter fault ride-through characteristics; and obtain the topology modeling parameters of the new energy station, including the primary system diagram of the new energy station, the cable direction diagram of the collector line, and the parameters of the step-up transformer; Step 102: constructing a unit parameter structured modeling data group, including generator index, generator rated capacity, generator model type and parameter group number; Step 103: constructing a line parameter structured modeling data group, including line index, line type, unit length positive sequence resistance, unit length positive sequence reactance, unit length positive sequence susceptance, unit length zero sequence resistance, unit length zero sequence reactance and unit length zero sequence susceptance; Step 104: construct a structured modeling data set of box-type transformer parameters, including transformer index, transformer rated capacity, short-circuit loss, short-circuit voltage percentage, no-load loss and no-load current percentage; Step 105: construct a busbar modeling structured modeling data group, including a busbar index, a reference voltage, a voltage upper limit, and a voltage lower limit; Step 106: constructing a unit modeling structured modeling data group, including the unit name, access bus and generator type, wherein the generator type is consistent with the generator index number of step 102; Step 107: constructing a structured modeling data group for collector line modeling, including the collector line name, I-side busbar, J-side busbar, line index and line length, wherein the line type is consistent with the line index number of step 103; Step 108: construct a structured modeling data group for the box-type transformer modeling, including the box-type transformer name, high-voltage side bus, low-voltage side bus, and box-type transformer type. The box-type transformer type is consistent with the transformer index number of step 104.

3. The new energy station topology fine equivalence and automatic verification method according to claim 2 is characterized by: In step 101, the box transformer parameters include capacity, short-circuit voltage percentage, short-circuit loss, no-load loss and no-load current percentage, the collector line cable route diagram includes the collector line model and length, and the step-up transformer parameters include capacity, short-circuit voltage percentage, short-circuit loss, no-load loss and no-load current percentage.

4. The new energy station topology fine equivalence and automatic verification method according to claim 1 is characterized in that: The specific steps of step 3 are: running the power flow calculation program of the PSASP software to generate power flow results, exporting the result report data of the physical bus and the two-winding transformer respectively, and calculating the collector line loss, box transformer loss and topological equivalent impedance based on the result report data.

5. The new energy station topology fine equivalence and automatic verification method according to claim 4 is characterized in that: The step 3 comprises the following steps: Step 301: Divide the renewable energy station units G into M groups according to the types, capacities and control performance differences of the renewable energy station units, and set them as: G={G1,G2,...,G i ,...,G M }, G i For the i-th group, i={1,2,...,M}, the corresponding box transformer T is set to: T={T1,T2,...,T i ,...,T M }; There are N units in the i-th group, set as: G i ={G i1 ,G i2 ,...,G ij ,...,G iN }, G ij The i-th group has j units, j={1,2,...,N}, and the corresponding box transformer T i Set to: T i ={T i1 ,T i2 ,...,T ij ,...,T iN }; Step 302: Read the bus voltage phasor U at the low voltage side of the grid connection point according to the result report data of the physical bus BusPOIL , Unit G ij 35 kV bus voltage U Busij 、Box Transformer T ij High voltage side power S H-Busij And box transformer T ij Low voltage side power S L-Busij ; Calculate the unit G ij The generated power flows through the collection line to the grid connection point, and the apportioned loss is: ; Where: U Busij For unit G ij 35 kV bus voltage, U BusPOIL is the bus voltage phase quantity on the low voltage side of the grid connection point and S H-Busij For box transformer T ij High voltage side power; Box transformer T ij The resulting loss is: ; Where: S L-Busij For box transformer T ij Low voltage side power and S H-Busij For box transformer T ij High voltage side power; Step 303: After accumulating the losses of each collector line of cluster i, the total collector line loss of cluster i is obtained as follows: ; Where: is the total collector line loss of group i, k is the kth unit in group i and is the power loss of the kth unit in the cluster i on the collector circuit; After accumulating the losses of each box transformer in cluster i, the total box transformer loss of cluster i is: ; In the formula, is the total transformer loss of cluster i; k is the sum of the kth transformer in cluster i is the loss of the kth box transformer in cluster i; Step 304: The equivalent collector line impedance of computer group i is: ; In the formula, is the equivalent collector line impedance of cluster i, is the total collection line loss of cluster i, U BusPOIL is the bus voltage phase quantity and For box transformer T ij The sum of the power on the low voltage side; The equivalent transformer impedance of computer group i is: ; In the formula, is the equivalent box transformer impedance of cluster i, is the total box transformer loss of cluster i, U BusPOIL is the bus voltage phase quantity and For box transformer T ij The sum of the low voltage side powers.

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