阅读说明：本技术 一种风电场电磁暂态分析方法及系统 (Wind power plant electromagnetic transient analysis method and system ) 是由 杨朋威 范佳琪 郑博文 万玉良 窦宇宇 苏鹏 陈财福 白玉竹 陈更 于 2021-06-11 设计创作，主要内容包括：本公开公开的一种风电场电磁暂态分析方法及系统,包括：获取风电场各设备参数及各输电线路参数；根据获取的参数,对限定好边界条件的风电场电磁暂态仿真模型进行仿真,获取风电场电磁暂态仿真结果,其中,边界条件的确定过程为：确定单影响因素的边界条件,判断影响因素间的关联性,根据关联性对单影响因素的边界条件进行调整,确定最终的边界条件；根据风电场电磁暂态仿真结果,判断风电场的电磁暂态是否过限。通过单因素敏感性分析和多因素耦合敏感性分析,确定了电磁暂态分析合理的边界条件,提高了电磁暂态仿真分析的准确率。(The utility model discloses a wind-powered electricity generation field electromagnetism transient state analysis method and system, including: acquiring parameters of each device and each power transmission line of a wind power plant; simulating the wind power plant electromagnetic transient simulation model with the defined boundary conditions according to the obtained parameters, and obtaining a wind power plant electromagnetic transient simulation result, wherein the boundary conditions are determined in the following process: determining the boundary condition of the single influence factor, judging the relevance among the influence factors, adjusting the boundary condition of the single influence factor according to the relevance, and determining the final boundary condition; and judging whether the electromagnetic transient of the wind power plant is over-limit or not according to the electromagnetic transient simulation result of the wind power plant. Through single-factor sensitivity analysis and multi-factor coupling sensitivity analysis, the reasonable boundary condition of electromagnetic transient analysis is determined, and the accuracy of electromagnetic transient simulation analysis is improved.)

1. A wind power plant electromagnetic transient analysis method is characterized by comprising the following steps:

acquiring parameters of each device and each power transmission line of a wind power plant;

simulating the wind power plant electromagnetic transient simulation model with the defined boundary conditions according to the obtained parameters, and obtaining a wind power plant electromagnetic transient simulation result, wherein the boundary conditions are determined in the following process: determining the boundary condition of the single influence factor, judging the relevance among the influence factors, adjusting the boundary condition of the single influence factor according to the relevance, and determining the final boundary condition;

and judging whether the electromagnetic transient of the wind power plant is over-limit or not according to the electromagnetic transient simulation result of the wind power plant.

2. The wind farm electromagnetic transient analysis method of claim 1, characterized by determining wind farm electromagnetic transient influencing factors; and performing single-factor sensitivity analysis on all influence factors of the electromagnetic transient state of the wind power plant, and determining the boundary conditions of the single influence factors.

3. The wind farm electromagnetic transient analysis method according to claim 2, characterized in that the process of performing single factor sensitivity analysis on the influencing factors is as follows:

selecting one of the influencing factors to change, and keeping the other influencing factors unchanged;

calculating the magnitude variable quantity of the power frequency overvoltage when one influence factor is changed and the other factors are kept unchanged;

and determining the boundary condition of the single influence factor according to the magnitude variation of the power frequency overvoltage.

4. The wind farm electromagnetic transient analysis method according to claim 3, characterized in that the influence factors with the coupling relationship are subjected to multi-factor coupling sensitivity analysis to judge the relevance among the influence factors.

5. The wind farm electromagnetic transient analysis method according to claim 4, characterized in that the multi-factor coupling sensitivity analysis specifically comprises:

selecting two influence factors from the influence factors with the coupling relation at will;

one of the influencing factors is kept unchanged, and the other influencing factor is changed;

determining the magnitude variation of the power frequency overvoltage when one influencing factor is kept unchanged and the other influencing factor is changed;

comparing the magnitude variation of the power frequency overvoltage with the magnitude variation of the power frequency overvoltage obtained when single-factor sensitivity analysis is carried out on the unchanged influence factors;

and determining the relevance of the two influence factors according to the comparison result.

6. The wind farm electromagnetic transient analysis method according to claim 1, characterized in that the wind farm electromagnetic transient influencing factors comprise a series compensation operation mode, a direct current operation mode, a wind farm production time sequence, a thermal power plant group starting mode and a wind farm output, wherein a coupling relation exists among the thermal power plant group starting mode, the wind farm processing, the direct current operation mode and the wind farm production time sequence.

7. The wind farm electromagnetic transient analysis method of claim 1, characterized in that when it is determined that there is a correlation between the two influencing factors, a set margin is reserved when analyzing and calculating the power frequency overvoltage.

8. A wind farm electromagnetic transient analysis system, comprising:

the data acquisition module is used for acquiring parameters of each device and each power transmission line of the wind power plant;

the electromagnetic transient simulation module is used for simulating a wind power plant electromagnetic transient simulation model with well-defined boundary conditions according to the obtained parameters to obtain a wind power plant electromagnetic transient simulation result, wherein the boundary conditions are determined in the following process: determining the boundary condition of the single influence factor, judging the relevance among the influence factors, adjusting the boundary condition of the single influence factor according to the relevance, and determining the final boundary condition;

and the electromagnetic transient judgment module is used for judging whether the electromagnetic transient of the wind power plant is over-limit or not according to the electromagnetic transient simulation result of the wind power plant.

9. An electronic device comprising a memory and a processor and computer instructions stored on the memory and executed on the processor, the computer instructions, when executed by the processor, performing the steps of a method of electromagnetic transient analysis of a wind farm according to any of claims 1-7.

10. A computer readable storage medium storing computer instructions which, when executed by a processor, perform the steps of a method of electromagnetic transient analysis of a wind farm according to any of claims 1 to 7.

Technical Field

The invention relates to the technical field of electromagnetic simulation, in particular to a method and a system for analyzing electromagnetic transient of a wind power plant.

Background

The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art.

At present, with the rapid development of new energy power generation grid connection, flexible direct current transmission, direct current power grids and the like, power electronics are applied more and more in a power system, and electromagnetic transient simulation analysis is indispensable for accurately analyzing complex transient characteristics in the system and the device.

When electromagnetic transient simulation analysis is performed on a power generation system containing clean energy, because the influence factors influencing electromagnetic transient are more, in order to obtain an accurate electromagnetic transient simulation analysis result, boundary conditions during electromagnetic transient simulation analysis need to be reasonably determined.

Disclosure of Invention

In order to solve the problems, the invention provides a wind power plant electromagnetic transient analysis method and system, and when the boundary condition of the electromagnetic transient is determined, the coupling among different influence factors is considered, so that the determined boundary condition is more accurate, and the accuracy of electromagnetic transient simulation analysis is improved.

In order to achieve the purpose, the following technical scheme is adopted in the disclosure:

in a first aspect, a wind farm electromagnetic transient analysis method is provided, including:

acquiring parameters of each device and each power transmission line of a wind power plant;

simulating the wind power plant electromagnetic transient simulation model with the defined boundary conditions according to the obtained parameters, and obtaining a wind power plant electromagnetic transient simulation result, wherein the boundary conditions are determined in the following process: determining the boundary condition of the single influence factor, judging the relevance among the influence factors, adjusting the boundary condition of the single influence factor according to the relevance, and determining the final boundary condition;

and judging whether the electromagnetic transient of the wind power plant is over-limit or not according to the electromagnetic transient simulation result of the wind power plant.

In a second aspect, a wind farm electromagnetic transient analysis system is provided, including:

the data acquisition module is used for acquiring parameters of each device and each power transmission line of the wind power plant;

the electromagnetic transient simulation module is used for simulating a wind power plant electromagnetic transient simulation model with well-defined boundary conditions according to the obtained parameters to obtain a wind power plant electromagnetic transient simulation result, wherein the boundary conditions are determined in the following process: determining the boundary condition of the single influence factor, judging the relevance among the influence factors, adjusting the boundary condition of the single influence factor according to the relevance, and determining the final boundary condition;

and the electromagnetic transient judgment module is used for judging whether the electromagnetic transient of the wind power plant is over-limit or not according to the electromagnetic transient simulation result of the wind power plant.

In a third aspect, an electronic device is provided, which includes a memory and a processor, and computer instructions stored in the memory and executed on the processor, wherein the computer instructions, when executed by the processor, perform the steps of a wind farm electromagnetic transient analysis method.

In a fourth aspect, a computer-readable storage medium is provided for storing computer instructions which, when executed by a processor, perform the steps of a method for electromagnetic transient analysis of a wind farm.

Compared with the prior art, the beneficial effect of this disclosure is:

1. when the boundary condition of electromagnetic transient simulation analysis is determined, firstly, single-factor sensitivity analysis is carried out on the influence factors of the electromagnetic transient, then multi-factor coupling sensitivity analysis is carried out on the influence factors, the boundary condition of the electromagnetic transient is determined according to the single-factor sensitivity analysis result and the multi-factor coupling sensitivity analysis result, and when the electromagnetic transient simulation analysis is carried out according to the boundary condition, the accuracy of the electromagnetic transient simulation result is ensured.

Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.

FIG. 1 is a flow chart of a method disclosed in example 1 of the present disclosure;

fig. 2 is a schematic structural diagram of a wind farm disclosed in embodiment 1 of the present disclosure.

The specific implementation mode is as follows:

the present disclosure is further described with reference to the following drawings and examples.

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

Example 1

In order to ensure the accuracy of the electromagnetic transient analysis result of the wind farm, the embodiment discloses a wind farm electromagnetic transient analysis method, which comprises the following steps:

acquiring parameters of each device and each power transmission line of a wind power plant;

simulating the wind power plant electromagnetic transient simulation model with the defined boundary conditions according to the obtained parameters, and obtaining a wind power plant electromagnetic transient simulation result, wherein the boundary conditions are determined in the following process: determining the boundary condition of the single influence factor, judging the relevance among the influence factors, adjusting the boundary condition of the single influence factor according to the relevance, and determining the final boundary condition;

and judging whether the electromagnetic transient of the wind power plant is over-limit or not according to the electromagnetic transient simulation result of the wind power plant.

Further, single-factor sensitivity analysis is carried out on all influence factors of the electromagnetic transient state of the wind power plant, and the boundary condition of the single influence factor is determined.

Further, the process of analyzing the single factor sensitivity of the influencing factors is as follows:

selecting one of the influencing factors to change, and keeping the other influencing factors unchanged;

calculating the magnitude variable quantity of the power frequency overvoltage when one influence factor is changed and the other factors are kept unchanged;

and determining the boundary condition of the single influence factor according to the magnitude variation of the power frequency overvoltage.

Further, multi-factor coupling sensitivity analysis is carried out on the influence factors with the coupling relation, and the relevance among the influence factors is judged.

Further, the analysis of the multi-factor coupling sensitivity specifically comprises:

selecting two influence factors from the influence factors with the coupling relation at will;

one of the influencing factors is kept unchanged, and the other influencing factor is changed;

determining the magnitude variation of the power frequency overvoltage when one influencing factor is kept unchanged and the other influencing factor is changed;

comparing the magnitude variation of the power frequency overvoltage with the magnitude variation of the power frequency overvoltage obtained when single-factor sensitivity analysis is carried out on the unchanged influence factors;

and determining the relevance of the two influence factors according to the comparison result.

Further, the influence factors of the electromagnetic transient state of the wind power plant comprise a series compensation operation mode, a direct current operation mode, a wind power plant production time sequence, a thermal power plant group starting mode and wind power plant output, wherein a coupling relation exists among the thermal power plant group starting mode, wind power plant processing, the direct current operation mode and the wind power plant production time sequence.

Furthermore, when the two influence factors are judged to have relevance, a set margin is reserved when the power frequency overvoltage is analyzed and calculated.

The wind farm electromagnetic transient analysis method disclosed in the embodiment is explained in detail by combining a tin union 'five stations and five lines' and a matched wind farm.

The sending end of the tin union extra-high voltage transmission channel is matched with 36 wind power with the total capacity of 700 ten thousand kilowatts, the wind power is collected and sent out in a five-station five-wire mode, and the wind power is respectively collected to Baoli root, Bayangzhou cover, other power ancient table, white sound checking and Alshan fig. 5 500kV collection stations and is connected to a tin forest extra-high converter station, a Shengli extra-high voltage station and a tin union extra-high voltage station, as shown in fig. 2. A tin union 'five-station five-wire' and a matched project newly build 5 500kV transformer substations, the transformation capacity is 800 ten thousand kilovolt-ampere, a 500kV power transmission line is newly built for 1166.1km, and a 220kV wind power plant sending-out line is newly built for 401.3 km.

The project scale of the wind power output matched with the five stations and the five lines is as follows:

(1) new energy delivery project in Xilinhaote City

The new Baoli root 500kV collecting station and the matched 220kV sending-out project are provided with 1 newly-built 500kV transformer substation, the transformation capacity is 2 multiplied by 750MVA, the newly-built Baoli root collecting station-the cylinder Haote converter station is provided with a 500kV line 67km, and the newly-built 220kV wind power plant sending-out line is 98.8 km. The project sends out wind power from 5 wind power plants such as Harragia and North Udar, and the total installed capacity of the wind power is 1300 MW.

(2) Abagaqi new energy delivery engineering

The power ancient platform 500kV collection station and the matched 220kV sending-out project newly build 1 500kV transformer substation, the transformation capacity is 2 multiplied by 750MVA, the power ancient platform collection station-victory ultra-high voltage station 500kV line is newly built for 106km, and the 220kV wind power plant sending-out line is newly built for 96.1 km. The engineering is that 9 wind power stations such as middle-energy forehead Torton and Huanennaren send out wind power, and the total installed capacity of the wind power is 1300 MW.

(3) Blue flag new energy delivery project

The Alexan map 500kV collection station and the matched 220kV sending-out project newly build 1 of 500kV transformer substations with the transformation capacity of 2 x 750MVA, the Alexan map collection station-Sn alliance extra-high voltage station 500kV line 119km and the new 220kV collection line 126 km. The engineering is that wind power is sent out by 7 wind power stations such as south beam in Huarun and field in Datang schools, and the total installed capacity of the wind power is 1225 MW.

(4) Project for sending new energy of white flag

The white sound dry-check 500kV collection station and the matched 220kV sending-out project build 1 new 500kV transformer substation with the transformation capacity of 2 multiplied by 1000MVA, the white sound dry-check collection station-tin union extra-high voltage station 500kV line 208km, and the new 220kV wind power plant sending-out line 96.9 km. The project sends out wind power for 9 wind power stations such as deep energy New Sumo, Hua-elymph and the like, and the total installed amount of the wind power is 1800 MW.

(5) Dongshu flag new energy delivery project

Bayangzhou cover 500kV collection station and matched 220kV outlet project are provided with 1 seat of newly-built 500kV transformer substation, the transformation capacity is 2 x 750MVA, newly-built Bayangzhou cover collection station-cylinder Haote converter station 500kV line is 200km, and newly-built 220kV wind power station outlet line with length of 52.486 km. The engineering is that 6 wind power stations such as special wind tripod, Mongolian Bayan and Jing Nengdu send out wind power, and the total amount of wind power installation is 1375 MW.

The electromagnetic transient research content of the five-station five-line and matched wind power plants comprises the following steps: 500kV line operation overvoltage; power frequency overvoltage of a 500kV line; secondary current and recovery voltage of 500kV lines; the 500kV line is not a full-phase resonance overvoltage; and (3) charging main transformer operation overvoltage at 500kV side.

The PSCAD/EMTDC 4.6 version is adopted to construct a five-station five-line electromagnetic transient simulation model of equipment including lines, transformers, lightning arresters, circuit breakers and the like and a matched wind power plant, and parameters of the simulation model are set according to the five-station five-line electromagnetic transient simulation model and parameters of equipment and power transmission lines of the matched wind power plant. The equipment parameters comprise equipment delivery parameters and design parameters; the transmission line parameters comprise parameters such as line tower parameters and excitation curves.

The concrete five-station five-line and equipment parameters and transmission line parameters of the matched wind power plant comprise:

the Alexan 500kV collection station scale is as follows:

main transformation parameters: the ODFSZ-250000/500 type oil-immersed air-cooled transformer has a power transformation capacity of 2 x 750MVA and a transformation ratio of 525/230 +/-8 x 1.25%/35 kV.

Parameters of the low-voltage capacitor: each main transformer 35kV side is equipped with 1 group of low-voltage capacitors, and the rated capacity is 60 Mvar.

(var generator) SVG parameters: each main transformer 35kV side is equipped with 1 group of SVG, and the rated capacity is +/-60 Mvar.

The white sound dry check 500kV collection station has the following scales:

main transformation parameters: the ODFSZ-334000/500 type oil-immersed air-cooled transformer has a power transformation capacity of 2 x 1000MVA and a transformation ratio of 525/230 +/-8 x 1.25%/35 kV.

Parameters of the low-voltage capacitor: each main transformer 35kV side is equipped with 4 groups of low-voltage capacitors, and the rated capacity is 60 Mvar.

SVG parameters: each main transformer 35kV side is equipped with 1 group of SVG, and the rated capacity is +/-60 Mvar.

The Bayangzhou cover 500kV collecting station has the following scale:

main transformation parameters: the ODFSZ-250000/500 type oil-immersed air-cooled transformer has a power transformation capacity of 2 x 750MVA and a transformation ratio of 525/230 +/-8 x 1.25%/35 kV.

Parameters of the low-voltage capacitor: each main transformer 35kV side is equipped with 3 groups of low-voltage capacitors, and the rated capacity is 60 Mvar.

SVG parameters: each main transformer 35kV side is equipped with 1 group of SVG, and the rated capacity is +/-60 Mvar.

The scale of the 500kV collection station of the ancient platform is as follows:

main transformation parameters: the ODFSZ-250000/500 type oil-immersed air-cooled transformer has a power transformation capacity of 2 x 750MVA and a transformation ratio of 525/230 +/-8 x 1.25%/35 kV.

Parameters of the low-voltage capacitor: each main transformer 35kV side is equipped with 1 group of low-voltage capacitors, and the rated capacity is 60 Mvar.

SVG parameters: each main transformer 35kV side is equipped with 1 group of SVG, and the rated capacity is +/-60 Mvar.

The berk 500kV collection station has the following scales:

main transformation parameters: the ODFSZ-250000/500 type oil-immersed air-cooled transformer has a power transformation capacity of 2 x 750MVA and a transformation ratio of 525/230 +/-8 x 1.25%/35 kV.

Parameters of the low-voltage capacitor: each main transformer 35kV side is equipped with 1 group of low-voltage capacitors, and the rated capacity is 60 Mvar.

SVG parameters: each main transformer 35kV side is equipped with 1 group of SVG, and the rated capacity is +/-60 Mvar.

Parameters of a 500kV power transmission line:

the method comprises the following steps of tin alliance extra-high voltage station-Alshan map gathering station (first-grade tin), wire model 4 XJL/G1A-630/45-45/7, line length 121.481km, single-circuit erection of the whole line and transposition for 3 times in the whole process.

The method comprises the following steps of tin union extra-high voltage station-Baiyin inspection trunk gathering station (tin trunk first line), wire model 4 XJL/G1A-630/45-45/7, line length 209.409km, single-circuit erection of the whole line and six transposition times in the whole process.

The model of wire is 4 XJL/G1A-630/45-45/7, the length of wire is 199.743km, the whole wire is set up in a single loop, and the whole transposition is five times.

The super high voltage station for victory, the foreign ancient station collection station (victory first line), the wire model 4 XJL/G1A-630/45-45/7, the line length 103.791km, the whole line is erected in a single loop, and the whole process is transposed for three times.

The system comprises a cylinder Haote converter station-Baoli root collecting station (Lingen first line), a lead model of 4 multiplied by JL/G1A-630/45-45/7, a line length of 66.094km, single-circuit erection of the whole line and no transposition.

High impedance and neutral point small impedance parameters:

the 500kV dry tin wire is provided with 1 group of lines with high resistance, rated voltage of 525kV and rated capacity of 150 Mvar. The high impedance is provided with 1 group of neutral point small impedance, the rated capacity is 900kvar, and no tap joint is arranged.

The 500kV forest-type first line is equipped with 1 group of lines with high impedance, rated voltage 550kV and rated capacity 180 Mvar. The high impedance is provided with 1 group of neutral point small impedance, the rated capacity is 900kvar, and no tap joint is arranged.

Circuit breaker closing resistance parameters:

the 500kV Sn-rich one-line two-side Sn-allied extra-high voltage station and the Alshan station side circuit breaker are not provided with a closing resistor.

The 500kV tin dry wire tin union extra-high voltage station side circuit breaker has no switching-on resistor, the switching-on resistor is installed on the 500kV line side circuit breaker of the white sound inspection dry collection station, the switching-on resistor is 400 omega, the access time is 10ms, the switching-on different-phase time of the three-phase circuit breaker is not more than 5ms, and the switching-off different-phase time is not more than 3 ms.

The circuit breaker on one line of the great current converting station side of the forest of 500kV is equipped with a closing resistor, the closing resistor is 400 omega, the access time is 10ms, the closing off time of the three-phase circuit breaker is not more than 5ms, and the opening off time is not more than 3 ms. The Bayangzhou lid station side 500kV line side circuit breaker installs closing resistance, and closing resistance is 425 omega, and the access time is 10ms, and three-phase circuit breaker closing off not in-phase time is not more than 5ms, and the separating off not in-phase time is not more than 3 ms.

The circuit breakers on the two sides of the 500kV victory extra-high voltage station and the other ancient station are not provided with a closing resistor.

A circuit breaker on the 500kV forest root one-line cylinder wide converter station side is provided with a closing resistor, the closing resistor is 400 omega, the access time is 10ms, the closing non-synchronous time of the three-phase circuit breaker is not more than 5ms, and the opening non-synchronous time is not more than 3 ms. The 500kV line side circuit breaker of the Baoli root station is not provided with a closing resistor.

Parameters of the lightning arrester:

the rated voltage of a 500kV line side arrester (MOA) of a tin alliance extra-high voltage station is 444kV, and the rated voltage of a line side arrester of an Alshan station is 444 kV.

The rated voltage of a 500kV line side arrester (MOA) of a tin alliance extra-high voltage station is 444kV, and the rated voltage of a line side arrester of a white sound check trunk station is 444 kV.

The rated voltage of 500kV line side arrester (MOA) in the Xilinhaote converter station is 420kV, and the rated voltage of line side arrester in the Bayangzhou station is 444 kV.

The rated voltage of a 500kV line side arrester (MOA) of the super-high voltage station is 444kV, and the rated voltage of a foreign station side arrester is 444 kV.

The rated voltage of 500kV line side arrester (MOA) of the Xilinhaote converter station is 420kV, and the rated voltage of the line side arrester of the Baoli root station is 444 kV.

Other technical parameters are as follows:

(1) according to the regulations of the national standard GB/T50064-2014 'design specifications for overvoltage protection and insulation matching of alternating current electrical devices', the power frequency overvoltage level of a 500kV system should not exceed the transformer substation side of the line breaker by 1.3p.u., and the line side of the line breaker by 1.4p.u.

(2) The operating overvoltage level of a 500kV system should not exceed 2.0 p.u.according to the provisions of the national standard GB/T50064-2014 "specifications for overvoltage protection and insulation coordination of alternating current electrical devices".

When carrying out electromagnetic transient simulation analysis on a tin union extra-high voltage power transmission system consisting of five-station five-wire and a matched wind power plant, the boundary condition of an electromagnetic transient simulation model needs to be reasonably determined, and electromagnetic transient calculation is ensured under the reasonable boundary condition.

The specific process for determining the boundary condition of the electromagnetic transient simulation model comprises the following steps:

s1: determining influencing factors influencing the electromagnetic transient.

As the tin union extra-high voltage power transmission system is used as a wind-fire power source to bundle an alternating current-direct current hybrid power grid which is delivered through series compensation, factors such as a live-fire power group, a wind power plant, series compensation, a direct current operation mode, a five-station five-line production time sequence and the like have certain influence on the condition of starting and debugging overvoltage. The influence factors of the electromagnetic transient state comprise a series compensation operation mode, a direct current operation mode, a wind power plant production time sequence, a thermal power plant group starting mode and wind power plant output, wherein a coupling relation exists among the thermal power plant group starting mode, wind power plant processing, the direct current operation mode and the wind power plant production time sequence.

S2: the method is used for carrying out single-factor sensitivity analysis on the influence factors of the electromagnetic transient, and specifically comprises the following steps: selecting one of the influencing factors to change, and keeping the other influencing factors unchanged except the influencing factor; calculating the magnitude variation of the power frequency overvoltage of the power transmission line when one of the influencing factors changes and the other influencing factors remain unchanged; and determining the boundary condition of the single influence factor according to the magnitude variable quantity of the power frequency overvoltage of the power transmission line.

A power frequency overvoltage calculation model is built in the PSCAD, and a fault-free load shedding and single-phase grounding three-phase load shedding fault is set to calculate the power frequency overvoltage.

Single factor sensitivity analysis included:

(1) under the condition that factors such as a starting mode of a thermal power unit group, the output of a wind power plant, a direct current operation mode, a five-station five-line production time sequence and the like are not changed, single-factor sensitivity analysis of a series compensation operation mode is carried out by changing the series compensation operation mode.

The power frequency overvoltage calculation result is shown in the following table, and before the fault, the 500kV bus voltage of the upper-level extra-high voltage station is 530 kV.

Through calculation and analysis, the variation of the power frequency overvoltage of the same 500kV line is not more than 0.005p.u. under different operation modes of the augmentation series compensation station, and the overvoltage condition is more serious than the operation of the augmentation series compensation station under the exit mode of the augmentation series compensation, so that the boundary condition of the operation mode of the augmentation series compensation is set as that the augmentation series compensation station is not put into use.

(2) Under the condition that factors such as a starting mode of a thermal power engine group, the output of a wind power plant, a series compensation operation mode, a five-station five-line production time sequence and the like are not changed, a direct current operation mode is changed to carry out single-factor sensitivity analysis, the power frequency overvoltage calculation result is shown in the following table, and the 500kV bus voltage of a higher-level extra-high voltage station is 530kV before a fault.

Through calculation and analysis, the variation of the power frequency overvoltage of the same 500kV line is not more than 0.01p.u. under different direct current operation modes, the overvoltage condition is more serious than that of direct current operation under the direct current shutdown mode, and the direct current transmission 1000MW is more serious than that of other conditions, so that the direct current shutdown overvoltage condition is the most serious, and the boundary condition under the direct current operation mode is set as direct current shutdown.

(3) The engineering start-up debugging is divided into two stages. In the first stage, the upper-level extra-high voltage station charges the 500kV wind power collection station through a 500kV line. And in the second stage, wind power fields connected with the 500kV wind power collecting station are sequentially connected to the grid. Because the production time sequence of the five-station five-line engineering has the possibility of changing at any time, the influence of the production time sequence of the five-station five-line engineering on the overvoltage needs to be researched. And under the condition that factors such as a starting mode of a thermal power unit group, the output of a wind power plant, series compensation and a direct current running mode are unchanged, single-factor sensitivity analysis of an engineering production time sequence is carried out by changing the production time sequence. The power frequency overvoltage calculation result is shown in the following table, and before the fault, the 500kV bus voltage of the upper-level extra-high voltage station is 530 kV.

Through calculation and analysis, under different 'five-station five-line' engineering production time sequences, the power frequency overvoltage of the same 500kV line has the variation not exceeding 0.002p.u., and the capacity rise of the head end and the tail end of the 500kV line is basically kept unchanged, so that the influence of the 'five-station five-line' engineering production time sequence on the overvoltage is small, the change of the engineering production time sequence does not influence the overvoltage calculation conclusion, and the boundary condition under the production time sequence is determined according to the actual production time sequence because the production time sequence does not influence the power frequency overvoltage.

(4) In order to research the influence of the starting-up combination of different fire motor groups connected with a cylinder great current converter station and a victory extra-high voltage station on the overvoltage, the starting-up combination is divided into 3 fire motor groups: a converter station cluster: the Wulan power plant, the Runqing power plant; victory 1000kV fleet: hana power plant, horse-city power plant; victory 500kV fleet: en and power plants. In consideration of a more serious situation, taking 5 machines which are opened in 5 thermal power plants at a sending end as an example, under the condition that factors such as output of a wind power plant, series compensation, a direct current operation mode, a five-station five-line project production time sequence and the like are not changed, the thermal power group starting mode is changed to carry out single-factor sensitivity analysis on the thermal power group starting mode. The power frequency overvoltage calculation result is shown in the following table, and before the fault, the 500kV bus voltage of the upper-level extra-high voltage station is 530 kV.

Through calculation and analysis, under different starting combination modes of the thermal power unit group, the power frequency overvoltage of the same 500kV circuit has the variation not exceeding 0.01p.u., and the capacity rise of the head end and the tail end of the 500kV circuit is basically kept unchanged, so that the different starting combination modes of the thermal power unit group have small influence on the overvoltage result, and the boundary conditions under the starting mode of the thermal power unit group are determined according to the actual operation condition of a power grid because the different starting combination modes have small influence on the overvoltage.

(5) Factors influencing power frequency overvoltage are in power flow transmission of a line before fault, particularly the size of reactive power flow transmitted to the line, the size of the sending end equivalent power supply potential E 'is determined, the larger the line transmission reactive power is, the higher the sending end equivalent potential E' is, and the power frequency overvoltage is relatively high. The capacity rise of a 500kV line is basically maintained after the wind power plant fan outputs power, but the fan control strategy has certain regulating capacity on the system voltage and certain inhibiting capacity on the power frequency overvoltage. Meanwhile, the size of reactive power flow of a line can be reduced after the wind turbine of the wind power plant outputs power, so that the equivalent potential of a sending end is reduced, and the power frequency overvoltage is correspondingly reduced. Therefore, the single-factor sensitivity analysis of the output of the wind power plant is carried out under the condition that the factors such as the starting mode, the series compensation mode, the direct-current operation mode, the five-station five-line production time sequence and the like of the thermal power plant group are not changed. A wind power plant is selected from 500kV collection stations connected with a Union extra-high voltage station, a victory extra-high voltage station and a Xilinhaoto converter station respectively, the power frequency overvoltage calculation result is shown in the following table, and the 500kV bus voltage of the superior extra-high voltage station is 530kV before a fault occurs.

Through calculation and analysis, under the condition that the output of the wind power plant is changed, the power frequency overvoltage of the same 500kV line has the variation not exceeding 0.003p.u., and the overvoltage condition is serious when the output of a wind power plant fan is not output, so that the boundary condition under the output of the wind power plant is determined to be that all the wind power plant fans do not output.

S3: the influence factors influencing the overvoltage magnitude include multi-factor coupling of a starting mode of a fire power generation group, the output of a wind power plant, a direct current operation mode and a production time sequence, so that the sensitivity analysis of the multi-factor coupling relation is necessary to find out strong-correlation and weak-correlation influence factors so as to determine the final boundary condition. Carrying out multi-factor coupling sensitivity analysis on the influence factors with the coupling relation, determining the relevance among the influence factors, adjusting the boundary condition of a single influence factor according to the relevance, and determining the final boundary condition, wherein the multi-factor coupling sensitivity analysis comprises the following steps: selecting two influence factors from the influence factors with the coupling relation at will; one of the influencing factors is kept unchanged, and the other influencing factor is changed; determining the magnitude variation of the power frequency overvoltage when one influencing factor is kept unchanged and the other influencing factor is changed; comparing the magnitude variation of the power frequency overvoltage with the magnitude variation of the power frequency overvoltage obtained when single-factor sensitivity analysis is carried out on the unchanged influence factors; according to the comparison result, determining the relevance of the two influence factors, including:

(1) and the power output of the wind power plant and the power on coupling relationship of the thermal power generating unit are considered, the power output of the wind power plant and the power on coupling of the thermal power generating unit are considered, the power output and the non-power output of the wind power plant are selected, and the high, medium and low schemes are selected for the power on of the thermal power generating unit according to the preorder calculation results to analyze the coupling relationship. The power frequency overvoltage calculation result is shown in the following table, and before the fault, the 500kV bus voltage of the upper-level extra-high voltage station is 530 kV.

Through calculation and analysis, when a wind power plant is changed from no power output to power output and a thermal power unit is changed from a high scheme to a low scheme during starting, the size variation of the power frequency overvoltage calculation result is not more than 0.009p.u., and the difference of the power frequency overvoltage calculation result and the single-factor sensitivity analysis result is 0.001p.u. Therefore, the two factors of the wind power plant output and the thermal power unit starting combination are weakly related to each other, and can be decoupled for analysis.

(2) The coupling relation between the output of the wind power plant and the direct current operation mode is considered, the output of the wind power plant and the direct current operation mode are coupled in pairs and mutually influenced, the output and the non-output of the wind power plant are selected, and the direct current operation mode selects three conditions of direct current shutdown, 1000MW and 3000MW to analyze the coupling relation. The power frequency overvoltage calculation result is shown in the following table, and before the fault, the 500kV bus voltage of the upper-level extra-high voltage station is 530 kV.

Through calculation and analysis, when the wind power plant is changed from no output to output and the direct current operation mode is changed from shutdown to 3000MW power transmission, the variation of the power frequency overvoltage calculation result is not more than 0.008p.u., and the difference of the power frequency overvoltage calculation result and the direct current operation mode single-factor sensitivity analysis result is 0.002p.u. Therefore, the two factors of the wind power plant output and the direct current operation mode are weakly related to each other, and can be decoupled for analysis.

(3) Coupling relation between wind power plant output and engineering production time sequence

And (3) considering the coupling between the output of the wind power plant and the project operation time sequence in pairs and the mutual influence, selecting the output and non-output of the wind power plant, selecting the local station as the first station to operate and selecting the local station as the fifth station to operate in the project operation time sequence, and analyzing the coupling relation. The power frequency overvoltage calculation result is shown in the following table, and before the fault, the 500kV bus voltage of the upper-level extra-high voltage station is 530 kV.

Through calculation and analysis, when the local station is changed from operation as a first station to operation as a fifth station, and the wind power plant is changed from no output to output, the variation of the power frequency overvoltage calculation result is not more than 0.003p.u., and is consistent with the previous single-factor sensitivity analysis result of the wind power plant output. Therefore, the two factors of the project production time sequence and the wind power plant output are weakly related to each other, and can be decoupled for analysis.

(4) Engineering production time sequence and thermal power generating unit startup coupling relation

Considering the mutual influence between the project production time sequence and the starting of the thermal power unit, selecting the station as the first station for operation and selecting the station as the fifth station for operation, and selecting a high scheme, a medium scheme and a low scheme for the starting of the thermal power unit according to the preorder calculation result to analyze the coupling relation. The power frequency overvoltage calculation result is shown in the following table, and before the fault, the 500kV bus voltage of the upper-level extra-high voltage station is 530 kV.

Through calculation and analysis, when the station is changed from operation as a first station to operation as a fifth station and the starting of the thermal power unit group is changed from a high scheme to a low scheme, the variation of the power frequency overvoltage calculation result is not more than 0.01p.u., and is consistent with the single-factor sensitivity analysis result of the previous thermal power unit group in different starting combination modes. Therefore, the two factors of the engineering production time sequence and the starting combination of the thermal power generating unit are weakly related to each other, and can be decoupled for analysis.

(5) Engineering production time sequence and direct current operation mode coupling relation

Considering the mutual influence between the coupling between the project production time sequence and the direct current operation mode, selecting the station as the first station for operation and the station as the fifth station for operation, and selecting the direct current shutdown, 1000MW and 3000MW for the direct current operation mode to analyze the coupling relation. The power frequency overvoltage calculation result is shown in the following table, and before the fault, the 500kV bus voltage of the upper-level extra-high voltage station is 530 kV.

Through calculation and analysis, when the station is changed from operation as a first station to operation as a fifth station and the direct current operation mode is changed from shutdown to 3000MW power transmission, the variation of the power frequency overvoltage calculation result is not more than 0.01p.u., and is consistent with the single-factor sensitivity analysis result of the previous direct current operation mode. Therefore, two factors of the engineering production time sequence and the direct current operation mode are weakly correlated, and can be decoupled for analysis.

(6) Starting and direct-current operation mode coupling relation of thermal power generating unit

Considering the mutual influence between the starting-up and direct-current operation modes of the thermal power unit, selecting three conditions of direct-current shutdown, 1000MW and 3000MW in the direct-current operation mode, and selecting three schemes of high, medium and low for the starting-up of the thermal power unit according to the preorder calculation result to analyze the coupling relation. The power frequency overvoltage calculation result is shown in the following table, and before the fault, the 500kV bus voltage of the upper-level extra-high voltage station is 530 kV.

Through calculation and analysis, when the direct current operation mode is changed from direct current shutdown to 1000MW and 3000MW, and when the thermal power unit group is started from a high scheme to a low scheme, the power frequency overvoltage calculation result has a variation range of 0.002-0.02 p.u., so that two factors of the direct current operation mode and the thermal power unit starting combination have certain relevance with each other, and when the direct current operation mode is compared with a standard required value in the calculation process, a 0.02 P.U.margin needs to be reserved.

In summary, the influence of single factor and multi-factor coupling on the overvoltage in the starting mode of the thermal power plant, the output of the wind power plant, the direct current operation mode and the production time sequence is shown in the following table:

results of one-factor sensitivity analysis

Results of multifactor coupling sensitivity analysis

As can be seen from the above table, the above factors are weak correlation, and can be decoupled for independent analysis, and the obtained conclusion has the same applicability when coupling multiple factors, wherein a certain margin is considered between the two factors of the starting and direct current operation modes of the thermal power plant. And selecting one machine and a direct current outage mode of each of Enhe, Wulan, Runqing, Hana and Madu power plants as boundary conditions by combining the actual operation condition of a power grid, and reserving a margin of 0.02p.u. in a power frequency overvoltage calculation conclusion. The final boundary conditions determined are therefore as follows:

(1) no investment is made in the augmentation bunch filling station;

(2) the busbar of the Silvery convertor station has high resistance to running;

(3) the Wulan power plant bus has high resistance to quit operation;

(4) running Enhe 1 machine, running Wulan 1 machine, running Runqing 1 machine, running Hana 1 machine and running Madu 1 machine;

(5) stopping direct current operation of the stannate;

(6) the production timing sequence is Alzhen diagram → white sound checking stem → Bayangzhou lid → yili old platform → Baoli root;

(7) when the gathering station is researched, all wind power field fans connected with the preorder gathering station do not output power;

(8) the phase modifier is taken out of operation.

Performing electromagnetic transient simulation analysis according to the final boundary condition to obtain an electromagnetic transient simulation analysis result, wherein the electromagnetic transient simulation analysis result comprises the following steps: and simulation analysis results of operation overvoltage, power frequency overvoltage, secondary arc current, recovery voltage and non-full-phase resonance overvoltage.

And judging whether the electromagnetic transient state is over-limit or not according to the acquired electromagnetic transient state simulation analysis result.

Example 2

In this embodiment, a wind farm electromagnetic transient analysis system is disclosed, including:

the data acquisition module is used for acquiring parameters of each device and each power transmission line of the wind power plant;

the electromagnetic transient simulation module is used for simulating a wind power plant electromagnetic transient simulation model with well-defined boundary conditions according to the obtained parameters to obtain a wind power plant electromagnetic transient simulation result, wherein the boundary conditions are determined in the following process: determining the boundary condition of the single influence factor, judging the relevance among the influence factors, adjusting the boundary condition of the single influence factor according to the relevance, and determining the final boundary condition;

and the electromagnetic transient judgment module is used for judging whether the electromagnetic transient of the wind power plant is over-limit or not according to the electromagnetic transient simulation result of the wind power plant.

Example 3

In this embodiment, an electronic device is disclosed, which includes a memory and a processor, and computer instructions stored in the memory and executed on the processor, wherein the computer instructions, when executed by the processor, perform the steps of the wind farm electromagnetic transient analysis method disclosed in embodiment 1.

Example 4

In this embodiment, a computer readable storage medium is disclosed for storing computer instructions which, when executed by a processor, perform the steps of a method for electromagnetic transient analysis of a wind farm as disclosed in embodiment 1.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.