A new energy power station reactive power control performance evaluation method and system

Abstract

The application discloses a new energy power station reactive power control performance evaluation method and system, wherein the method comprises the following steps: building simulation data of a new energy direct current external transmission system and a new energy station; based on the simulation data, performing fault simulation simulation on the new energy direct current external transmission system; determining a voltage instability criterion, identifying a limiting fault leading to transient voltage instability of the new energy direct current external transmission system based on the voltage instability criterion, and positioning a station where the limiting fault occurs as a voltage sensitive station; calculating a first voltage instability index value of the voltage sensitive station of the new energy external transmission system under a plurality of reactive power compensation configuration schemes; calculating a second voltage instability index value of the voltage sensitive station of an equal-capacity conventional unit external transmission system; and determining a configuration scheme of reactive power compensation based on the first voltage instability index value and the second voltage instability index value.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and more specifically, to a method and system for evaluating the reactive power control performance of a new energy power plant. Background Technology

[0002] Most of my country's existing and planned new energy bases are located in remote areas such as the west and north, with relatively weak AC power grids. They also face challenges such as multiple DC transmission lines and a high proportion of new energy sources, leading to complex grid operation characteristics and features such as poor continuous grid connection capacity of new energy sources and low grid reliability, characteristic of DC-sending weak grids. In recent years, with the increase in the large-scale grid connection capacity of new energy sources such as wind and solar power, the dynamic support capacity of the sending-end system has been declining, and the problem of reactive power and voltage control in the grid has become increasingly prominent.

[0003] According to the technical regulations for grid connection of new energy power plants, new energy power plants must have corresponding high / low voltage ride-through capabilities; and to improve the dynamic reactive power regulation capability of new energy power plants, they are all equipped with reactive power regulation equipment such as synchronous condensers, SVCs, and STATCOMs. However, based on the analysis of actual operation data from a large-scale wind power base, it was found that the dynamic reactive power compensation devices in wind farms have problems such as low commissioning rate, low operational reliability, slow dynamic response speed, and insufficient dynamic reactive power margin.

[0004] Therefore, how to provide a reactive power control performance evaluation method for new energy power plants that meets the requirements of power grid safety and stability is an urgent problem to be solved by power planning and operation departments. It is necessary to carry out research on reactive power control performance evaluation of new energy power plants in combination with key voltage reactive power regulation indicators. Summary of the Invention

[0005] The present invention provides a method and system for evaluating the reactive power control performance of new energy power plants, in order to solve the problem of how to evaluate the reactive power control performance of new energy power plants.

[0006] To address the above problems, this invention provides a method for evaluating the reactive power control performance of new energy power plants, the method comprising:

[0007] Simulation data for building a new energy DC transmission system and new energy power plants;

[0008] Based on the simulation data, a fault simulation of the new energy DC transmission system is performed; a voltage instability criterion is determined; based on the voltage instability criterion, a limiting fault that causes transient voltage instability in the new energy DC transmission system is identified, and the site where the limiting fault occurs is located as a voltage-sensitive site.

[0009] Calculate the first voltage instability index value of voltage-sensitive sites in a new energy transmission system under various reactive power compensation configuration schemes;

[0010] Calculate the second voltage instability index value of voltage-sensitive sites in a conventional power transmission system of equal capacity;

[0011] The reactive power compensation configuration scheme is determined based on the first voltage instability index value and the second voltage instability index value.

[0012] Preferably, the method further includes:

[0013] Obtain parameter information of the new energy DC transmission system and new energy power plants, and build simulation data of the new energy DC transmission system and new energy power plants based on the parameter information;

[0014] The parameter information of the new energy DC transmission system includes: DC transmission project, AC grid structure, generator parameters, load parameters, line parameters, transformer parameters, and reactive power compensation configuration of each station;

[0015] The parameter information of the new energy power station includes: the installed capacity of the new energy generator group, the type and parameters of the new energy generator unit, the reactive power and voltage control mode of the new energy generator unit, the type and capacity of the dynamic reactive power compensation device, the grid connection design scheme of the new energy generator group, the output characteristics of the new energy, the parameters of the step-up transformer, and the parameters of the grid connection line.

[0016] Preferably, the fault simulation includes: AC line single-instantaneous or three-permanent N-1 fault, DC commutation failure fault, and DC single-pole blocking fault.

[0017] Preferably, the step of determining the voltage instability criterion, based on the voltage instability criterion, identifies limiting faults that cause transient voltage instability in the new energy DC transmission system, and locates the sites experiencing limiting faults as voltage-sensitive sites, includes:

[0018] After verifying the transient voltage level of each station's busbar after the fault, monitor whether the busbar voltage of each station exceeds the voltage instability criterion. Faults where the busbar voltage of a station exceeds the voltage instability criterion are identified as limiting faults, and stations with limiting faults are identified as voltage-sensitive stations.

[0019] Preferably, the calculation of the first voltage instability index value of the voltage-sensitive site of the new energy transmission system under various reactive power compensation configuration schemes includes:

[0020] Determine the primary voltage instability index for stations in a renewable energy transmission system:

[0021]

[0022] Among them, t s t is the fault start time. o To monitor the end time, ΔU is a piecewise function;

[0023]

[0024] Among them, U max U represents the upper limit of the bus voltage at each station. min Here, U represents the lower limit of the bus voltage at each station, and U is the bus voltage value at each station.

[0025] Determine the first voltage instability index value for voltage-sensitive sites in the new energy transmission system:

[0026]

[0027] Where i represents the i-th limiting fault in the new energy transmission system that causes transient voltage to exceed the limit, and j represents the j-th voltage-sensitive site under this limiting fault.

[0028] Preferably, the calculation of the second voltage instability index value for voltage-sensitive sites in the conventional power transmission system of equivalent capacity includes:

[0029] Obtain the installed capacity of the new energy power stations in the transmission system, replace the new energy power stations with thermal power units of the same installed capacity, configure the unit step-up transformers that match the capacity, and update the BPA power flow and stability calculation data of the new energy transmission system and thermal power units.

[0030] The voltage stability characteristics of the conventional unit's power transmission system under various limiting faults were simulated and analyzed. Based on the simulation results, the second voltage instability index value of the conventional unit's power transmission system was calculated.

[0031] Preferably, the configuration scheme for determining reactive power compensation based on the first voltage instability index value and the second voltage instability index value includes:

[0032] Using the second voltage instability index of a conventional power transmission system of equal capacity as a benchmark, the reactive power control performance evaluation index I of a new energy power plant is defined. RPC ,in:

[0033]

[0034] Wherein, NS is the first voltage instability index value, and CS is the second voltage instability index value;

[0035] The reactive power control performance evaluation index I RPC The reactive power compensation scheme that is closest to 1 is determined as the optimal configuration scheme.

[0036] According to one aspect of the present invention, the present invention provides a reactive power control performance evaluation system for new energy power plants, the system comprising:

[0037] The initial unit is used to build simulation data for new energy DC transmission systems and new energy power plants;

[0038] The positioning unit is used to perform fault simulation of the new energy DC transmission system based on the simulation data; determine the voltage instability criterion; and based on the voltage instability criterion, identify the limiting fault that causes transient voltage instability of the new energy DC transmission system, and locate the site with the limiting fault as a voltage-sensitive site.

[0039] The calculation unit is used to calculate the first voltage instability index value of the voltage-sensitive site of the new energy transmission system under various reactive power compensation configuration schemes; and to calculate the second voltage instability index value of the voltage-sensitive site of the conventional unit transmission system of equal capacity.

[0040] The result unit is used to determine the reactive power compensation configuration scheme based on the first voltage instability index value and the second voltage instability index value.

[0041] Preferably, the initial unit is further configured to:

[0042] Obtain parameter information of the new energy DC transmission system and new energy power plants, and build simulation data of the new energy DC transmission system and new energy power plants based on the parameter information;

[0043] The parameter information of the new energy DC transmission system includes: DC transmission project, AC grid structure, generator parameters, load parameters, line parameters, transformer parameters, and reactive power compensation configuration of each station;

[0044] The parameter information of the new energy power station includes: the installed capacity of the new energy generator group, the type and parameters of the new energy generator unit, the reactive power and voltage control mode of the new energy generator unit, the type and capacity of the dynamic reactive power compensation device, the grid connection design scheme of the new energy generator group, the output characteristics of the new energy, the parameters of the step-up transformer, and the parameters of the grid connection line.

[0045] Preferably, the fault simulation includes: AC line single-instantaneous or three-permanent N-1 fault, DC commutation failure fault, and DC single-pole blocking fault.

[0046] Preferably, the positioning unit is used to determine a voltage instability criterion, identify limiting faults causing transient voltage instability in the new energy DC transmission system based on the voltage instability criterion, locate the sites with limiting faults as voltage-sensitive sites, and is also used to:

[0047] After verifying the transient voltage level of each station's busbar after the fault, monitor whether the busbar voltage of each station exceeds the voltage instability criterion. Faults where the busbar voltage of a station exceeds the voltage instability criterion are identified as limiting faults, and stations with limiting faults are identified as voltage-sensitive stations.

[0048] Preferably, the calculation unit is used to calculate the first voltage instability index value of voltage-sensitive sites in the new energy transmission system under various reactive power compensation configuration schemes, and is also used to:

[0049] Determine the primary voltage instability index for sites in the renewable energy transmission system:

[0050]

[0051] Among them, t s t is the fault start time. o To monitor the end time, ΔU is a piecewise function;

[0052]

[0053] Among them, U max U represents the upper limit of the bus voltage at each station. min Here, U represents the lower limit of the bus voltage at each station, and U represents the bus voltage value at each station.

[0054] Determine the first voltage instability index value for voltage-sensitive sites in the new energy transmission system:

[0055]

[0056] Where i represents the i-th limiting fault in the new energy transmission system that causes transient voltage to exceed the limit, and j represents the j-th voltage-sensitive site under this limiting fault.

[0057] Preferably, the calculation unit is used to calculate the second voltage instability index value of voltage-sensitive sites in a conventional power transmission system of equal capacity, and is also used to:

[0058] Obtain the installed capacity of the new energy power stations in the transmission system, replace the new energy power stations with thermal power units of the same installed capacity, configure the unit step-up transformers that match the capacity, and update the BPA power flow and stability calculation data of the new energy transmission system and thermal power units.

[0059] The voltage stability characteristics of the conventional unit's power transmission system under various limiting faults were simulated and analyzed. Based on the simulation results, the second voltage instability index value of the conventional unit's power transmission system was calculated.

[0060] Preferably, the result unit is used to determine the reactive power compensation configuration scheme based on the first voltage instability index value and the second voltage instability index value, and is further used to:

[0061] Using the second voltage instability index of a conventional power transmission system of equal capacity as a benchmark, the reactive power control performance evaluation index I of a new energy power plant is defined. RPC ,in:

[0062]

[0063] Wherein, NS is the first voltage instability index value, and CS is the second voltage instability index value;

[0064] The reactive power control performance evaluation index I RPC The reactive power compensation scheme that is closest to 1 is determined as the optimal configuration scheme.

[0065] This invention provides a method and system for evaluating the reactive power control performance of new energy power plants. The method includes: building simulation data for a new energy DC transmission system and new energy power plants; performing fault simulation of the new energy DC transmission system based on the simulation data; determining voltage instability criteria; identifying limiting faults causing transient voltage instability in the new energy DC transmission system based on the voltage instability criteria, and locating the sites with limiting faults as voltage-sensitive sites; calculating the first voltage instability index value of the voltage-sensitive sites in the new energy transmission system under various reactive power compensation configuration schemes; calculating the second voltage instability index value of the voltage-sensitive sites in a conventional unit transmission system of equal capacity; and determining the reactive power compensation configuration scheme based on the first and second voltage instability index values. This invention fully leverages the active support capabilities of new energy power plants, effectively improves the transient voltage stability characteristics of the weak-sending end of the new energy system, and can simply and quickly optimize the reactive power compensation equipment configuration scheme for new energy power plants, possessing good practical guidance and application value. Attached Figure Description

[0066] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0067] Figure 1 This is a flowchart of a method for evaluating the reactive power control performance of a new energy power plant according to a preferred embodiment of the present invention.

[0068] Figure 2 This is a flowchart of a method for evaluating the reactive power control performance of a new energy power plant according to a preferred embodiment of the present invention.

[0069] Figure 3 This is a schematic diagram of the QH simulation structure of a new energy DC transmission system according to a preferred embodiment of the present invention;

[0070] Figure 4 This is a schematic diagram of the voltage change curve of the near-field new energy generator terminal after a 2+1 fault in the HNZ~YNH DC commutation failure according to a preferred embodiment of the present invention; and

[0071] Figure 5 This is a structural diagram of a reactive power control performance evaluation system for a new energy power plant according to a preferred embodiment of the present invention. Detailed Implementation

[0072] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0073] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0074] Figure 1 This is a flowchart illustrating a preferred embodiment of a reactive power control performance evaluation method for a new energy power plant according to the present invention. Addressing the shortcomings of existing technologies, this invention provides a method for evaluating the reactive power control performance of a new energy power plant. It comprehensively considers the regulation capabilities of new energy generating units and various reactive power compensation devices within the plant on the transient voltage of the system. Based on simulation analysis of the system voltage stability characteristics, it identifies key voltage and reactive power influencing factors. Using the voltage and reactive power regulation capabilities of conventional generating units as a benchmark, it compares the reactive power regulation differences between new energy power plants and conventional generating units, defines the reactive power control performance evaluation index for the new energy power plant, and evaluates the reactive power control performance index values ​​of the new energy power plant under a dynamic reactive power compensation scheme.

[0075] This invention fully leverages the active support capabilities of renewable energy power plants, effectively improves the transient voltage stability characteristics of renewable energy weak-sending systems, and can easily and quickly optimize the reactive power compensation equipment configuration scheme for renewable energy power plants, thus possessing good practical guidance and application value.

[0076] like Figure 1 As shown, this invention provides a method for evaluating the reactive power control performance of a new energy power plant, the method comprising:

[0077] Step 101: Build simulation data for the new energy DC transmission system and new energy power plants;

[0078] Preferably, the method further includes:

[0079] Obtain parameter information of the new energy DC transmission system and new energy power plants, and build simulation data of the new energy DC transmission system and new energy power plants based on the parameter information;

[0080] The parameter information of the new energy DC transmission system includes: DC transmission project, AC grid structure, generator parameters, load parameters, line parameters, transformer parameters, and reactive power compensation configuration of each station;

[0081] The parameter information of the new energy power station includes: the installed capacity of the new energy generator group, the type and parameters of the new energy generator unit, the reactive power and voltage control mode of the new energy generator unit, the type and capacity of the dynamic reactive power compensation device, the grid connection design scheme of the new energy generator group, the output characteristics of the new energy, the parameters of the step-up transformer, and the parameters of the grid connection line.

[0082] In the above steps, the present invention first investigates and collects relevant data on the sending-end system and new energy power stations, and builds a BPA data simulation model for the sending-end system and new energy power stations;

[0083] Step 101-1: Investigate the current status and planning data of the power transmission system, including: DC power transmission projects, AC grid structure, generator parameters, load parameters, line parameters, transformer parameters, reactive power compensation configuration of each site, etc.

[0084] Step 101-2: Investigate the reactive power compensation configuration and related grid connection data of the new energy power station, including: the installed capacity of the new energy generator group, the type and parameters of the new energy generator unit, the reactive power voltage control mode of the new energy generator unit, the type and capacity of the dynamic reactive power compensation device, the grid connection design scheme of the new energy generator group, the output characteristics of the new energy, the parameters of the step-up transformer, the parameters of the grid connection line, etc.

[0085] Step 101-3: Establish BPA power flow and stability calculation data for the transmission system and new energy power plants under typical conditions.

[0086] Step 102: Based on simulation data, conduct fault simulation of the new energy DC transmission system; determine the voltage instability criterion, and based on the voltage instability criterion, identify the limiting faults that cause transient voltage instability in the new energy DC transmission system, and locate the sites with limiting faults as voltage-sensitive sites.

[0087] Preferably, the fault simulation includes: AC line single-instantaneous or three-permanent N-1 fault, DC commutation failure fault, and DC single-pole blocking fault.

[0088] Preferably, a voltage instability criterion is determined, and based on the voltage instability criterion, limiting faults causing transient voltage instability in the new energy DC transmission system are identified. Sites experiencing limiting faults are then designated as voltage-sensitive sites, including:

[0089] After verifying the transient voltage level of each station's busbar after the fault, monitor whether the busbar voltage of each station exceeds the voltage instability criterion. Faults where the busbar voltage of a station exceeds the voltage instability criterion are identified as limiting faults, and stations with limiting faults are identified as voltage-sensitive stations.

[0090] In the above steps, this application determines the system voltage instability criterion, simulates the voltage stability characteristics of the new energy transmission system, identifies the limiting faults that cause transient voltage instability in the system, and locates voltage-sensitive sites.

[0091] Step 102-1: Based on the relevant requirements of the power planning and dispatching departments, determine the upper limit value U of the bus voltage at each station within the system. max and lower limit value U min ;

[0092] Step 102-2: Perform AC / DC fault simulation on the new energy transmission system. Fault types include: AC line single instantaneous or three permanent N-1 fault, DC commutation failure fault, DC single pole blocking fault, etc.

[0093] Step 102-3: Verify the transient voltage level of each station's bus after the fault, and monitor the bus voltage U at each station. i If a voltage limit violation occurs, the fault is classified as a limiting fault, and the station where the voltage exceeds the limit is classified as a sensitive station.

[0094] Step 103: Calculate the first voltage instability index value of voltage-sensitive sites in the new energy transmission system under various reactive power compensation configuration schemes;

[0095] Preferably, the calculation of the first voltage instability index value of the voltage-sensitive site of the new energy transmission system under various reactive power compensation configuration schemes includes:

[0096] Determine the primary voltage instability index for sites in the renewable energy transmission system:

[0097]

[0098] Among them, t s t is the fault start time. o To monitor the end time, ΔU is a piecewise function;

[0099]

[0100] Among them, U max U represents the upper limit of the bus voltage at each station. min Here, U represents the lower limit of the bus voltage at each station, and U represents the bus voltage value at each station.

[0101] Determine the first voltage instability index value for voltage-sensitive sites in the new energy transmission system:

[0102]

[0103] Where i represents the i-th limiting fault in the new energy transmission system that causes transient voltage to exceed the limit, and j represents the j-th voltage-sensitive site under this limiting fault.

[0104] In the above steps, this invention evaluates the voltage instability index value of sensitive sites in the new energy transmission system;

[0105] Step 103-1: Define the voltage instability index S of a certain station bus in the power transmission system.

[0106]

[0107] Among them, t s t is the fault start time. o To monitor the end time, ΔU is a piecewise function.

[0108]

[0109] Step 103-2: Based on the above definition, calculate the voltage instability index value NS of the new energy transmission system.

[0110]

[0111] Where i represents the i-th limiting fault in the new energy transmission system that causes transient voltage to exceed the limit, and j represents the j-th sensitive site under this limiting fault.

[0112] Step 104: Calculate the second voltage instability index value of the voltage-sensitive site in the power transmission system of conventional units of equal capacity;

[0113] Preferably, the calculation of the second voltage instability index value for voltage-sensitive sites in a conventional power transmission system of equal capacity includes:

[0114] Obtain the installed capacity of the new energy power stations in the transmission system, replace the new energy power stations with thermal power units of the same installed capacity, configure the unit step-up transformers that match the capacity, and update the BPA power flow and stability calculation data of the new energy transmission system and thermal power units.

[0115] The voltage stability characteristics of the conventional unit's power transmission system under various limiting faults were simulated and analyzed. Based on the simulation results, the second voltage instability index value of the conventional unit's power transmission system was calculated.

[0116] In the above steps, this invention evaluates the voltage instability index values ​​of sensitive sites in conventional power transmission systems of equal capacity.

[0117] Step 104-1: Obtain the installed capacity of the new energy power stations in the transmission system, replace the new energy power stations with thermal power units of the same installed capacity, configure the step-up transformers of the units with appropriate capacity, and update the BPA power flow and stability calculation data of the transmission system and thermal power units.

[0118] Step 104-2: Simulate and analyze the voltage stability characteristics of the conventional unit's power transmission system under various limiting faults, and based on the simulation results, refer to Step 103 to calculate the voltage instability index value CS of the conventional unit's power transmission system.

[0119] Step 105: Determine the reactive power compensation configuration scheme based on the first voltage instability index value and the second voltage instability index value.

[0120] Preferably, the reactive power compensation configuration scheme is determined based on the first voltage instability index value and the second voltage instability index value, including:

[0121] Using the second voltage instability index of a conventional power transmission system of equal capacity as a benchmark, the reactive power control performance evaluation index I of a new energy power plant is defined. RPC ,in:

[0122]

[0123] Wherein, NS is the first voltage instability index value, and CS is the second voltage instability index value;

[0124] The reactive power control performance evaluation index I RPC The reactive power compensation scheme that is closest to 1 is determined as the optimal configuration scheme.

[0125] In the above steps, this invention compares the reactive power regulation performance of conventional units of the same capacity and calculates the reactive power control performance evaluation index value of new energy power plants.

[0126] Step 105-1: Using the voltage instability index CS of a conventional power transmission system of equal capacity as the benchmark value, define the reactive power control performance evaluation index I of the new energy power plant. RPC ,in

[0127] Step 105-2: Based on the above definition, calculate the reactive power control performance evaluation index value I of the new energy power plant under the set dynamic reactive power compensation scheme. RPC If the value of this indicator is closer to 0, it means that the reactive power control performance of the new energy power plant under the set dynamic reactive power compensation scheme is worse, and the transient voltage instability problem of the transmission system is more serious. If the value of this indicator is closer to 1, it means that the reactive power control performance of the new energy power plant under the set dynamic reactive power compensation scheme is stronger, and in ideal cases it can be compared with the reactive power control performance of conventional thermal power units.

[0128] This invention uses the reactive power regulation performance of conventional thermal power units as a comparison standard, which can easily and accurately evaluate the reactive power control performance indicators of new energy power plants. It fully considers the role of various dynamic reactive power compensation devices in new energy power plants and can be used to select the optimal configuration scheme of dynamic reactive power compensation devices in new energy power plants. It effectively avoids the transient over / under voltage problem of the weak transmission end system of new energy and has good practical guidance and application value.

[0129] The present invention takes the QH power grid of a real renewable energy DC transmission system as an example to illustrate a method for evaluating the reactive power control performance of a renewable energy power plant and the implementation steps of the system:

[0130] (1) Establishing QH grid simulation data for new energy DC transmission system

[0131] In a certain year, the installed capacity of hydropower in the QH power grid is about 16,546 MW, thermal power is 3,926 MW, and new energy is about 25,000 MW, with a load of about 13,000 MW. The power transmitted through the DC HNZ~YNH channel in the grid is 8,000 MW, and the voltage is ±800kV.

[0132] (2) Voltage stability verification analysis of QH power grid under typical conditions

[0133] Using a voltage exceeding 1.3 pu on the converter bus and the new energy generator terminal bus in the new energy DC transmission system as the criterion for voltage instability, simulations were conducted for any AC line within the network under the following faults: Sanyong N-1 fault, HNZ~YNH DC blocking, and commutation failure. Verification results show that after the HNZ~YNH DC commutation failure fault, the voltage instability of the converter bus and the new energy generator terminal bus is the most severe, and this is considered a limiting fault. The stations where the bus voltage exceeds 1.3 pu after this fault are shown in the table below:

[0134] Table 1. Bus Voltage Sensitive Sites in QH System

[0135] Serial Number Site Name Post-fault terminal bus voltage (pu) 1 XY 1.437 2 XM 1.428 3 GH 1.428 4 XIY 1.411 5 NS 1.407 6 DJ 1.405 7 NAY 1.402 8 GM 1.391 9 DY 1.373 10 DM 1.352 11 ZY 1.335 12 HY 1.317

[0136] The above-mentioned sites are designated as bus voltage sensitive sites.

[0137] (3) Calculation of voltage instability index of new energy transmission system under various reactive power compensation configuration schemes

[0138] The first reactive power compensation configuration scheme is as follows: Each renewable energy power station is equipped with SVG (Static Var Generator) with 15% renewable energy installed capacity and distributed synchronous condensers with 5% renewable energy installed capacity.

[0139] The second reactive power compensation configuration scheme is as follows: Each new energy power station is equipped with SVG with 20% of the new energy installed capacity and distributed synchronous condensers with 8% of the new energy installed capacity.

[0140] The third reactive power compensation configuration scheme is as follows: Each new energy power station is equipped with SVG (Static Var Generator) with 25% of the new energy installed capacity and distributed synchronous condensers with 8% of the new energy installed capacity.

[0141] Fault verification was performed on the voltage stability of the QH power grid under three reactive power compensation configuration schemes.

[0142] Table 2. Voltage instability index values ​​of the QH system under various reactive power compensation configurations.

[0143]

[0144] (4) Calculation of voltage instability index of power transmission system of conventional units of equal capacity

[0145] Replacing the new energy power station with a thermal power unit of the same installed capacity, and without considering the impact of various reactive power compensations of the new energy power station, the voltage instability index CS of the power transmission system of the conventional unit of the same capacity is calculated to be 13678.94.

[0146] (5) Calculation of voltage and reactive power control performance evaluation index of new energy transmission system under each reactive power compensation configuration scheme.

[0147] According to the formula The voltage and reactive power control performance evaluation indicators of the new energy transmission system under various reactive power compensation configuration schemes are shown in the table below:

[0148] Table 3 Evaluation Indicators of Voltage and Reactive Power Control Performance of QH System under Various Reactive Power Compensation Configurations

[0149] plan Option 1 Option 2 Option 3 <![CDATA[Voltage instability index value I RPC > 0.25 0.29 0.27

[0150] Based on the above calculation results, it is recommended that Option 2 be selected as the more suitable option for the reactive power compensation configuration scheme of the QH system.

[0151] Figure 5 This is a structural diagram of a reactive power control performance evaluation system for a new energy power plant according to a preferred embodiment of the present invention.

[0152] like Figure 5 As shown, this invention provides a reactive power control performance evaluation system for new energy power plants, the system comprising:

[0153] Initial unit 501 is used to build simulation data for new energy DC transmission systems and new energy power plants;

[0154] Preferably, the initial unit 501 is further configured to:

[0155] Obtain parameter information of the new energy DC transmission system and new energy power plants, and build simulation data of the new energy DC transmission system and new energy power plants based on the parameter information;

[0156] The parameter information of the new energy DC transmission system includes: DC transmission project, AC grid structure, generator parameters, load parameters, line parameters, transformer parameters, and reactive power compensation configuration of each site;

[0157] The parameter information of the new energy power station includes: the installed capacity of the new energy generator group, the type and parameters of the new energy generator unit, the reactive power and voltage control mode of the new energy generator unit, the type and capacity of the dynamic reactive power compensation device, the grid connection design scheme of the new energy generator group, the output characteristics of the new energy, the parameters of the step-up transformer, and the parameters of the grid connection line.

[0158] The positioning unit 502 is used to perform fault simulation of the new energy DC transmission system based on simulation data; determine the voltage instability criterion; identify the limiting fault that causes transient voltage instability of the new energy DC transmission system based on the voltage instability criterion; and locate the site with the limiting fault as a voltage sensitive site. Preferably, the fault simulation includes: AC line single instantaneous or three permanent N-1 fault, DC commutation failure fault and DC single pole blocking fault.

[0159] Preferably, the positioning unit 502 is used to determine the voltage instability criterion, identify the limiting faults that cause transient voltage instability in the new energy DC transmission system based on the voltage instability criterion, locate the sites with limiting faults as voltage-sensitive sites, and is also used to:

[0160] After verifying the transient voltage level of each station's busbar after the fault, monitor whether the busbar voltage of each station exceeds the voltage instability criterion. Faults where the busbar voltage of a station exceeds the voltage instability criterion are identified as limiting faults, and stations with limiting faults are identified as voltage-sensitive stations.

[0161] Calculation unit 503 is used to calculate the first voltage instability index value of voltage-sensitive sites in the new energy transmission system under various reactive power compensation configuration schemes; and to calculate the second voltage instability index value of voltage-sensitive sites in the conventional unit transmission system of equal capacity.

[0162] Preferably, the calculation unit 503 is used to calculate the first voltage instability index value of the voltage-sensitive site of the new energy transmission system under various reactive power compensation configuration schemes, and is also used for:

[0163] Determine the primary voltage instability index for stations in a renewable energy transmission system:

[0164]

[0165] Among them, t s t is the fault start time. o To monitor the end time, ΔU is a piecewise function;

[0166]

[0167] Among them, U max U represents the upper limit of the bus voltage at each station. min Here, U represents the lower limit of the bus voltage at each station, and U represents the bus voltage value at each station.

[0168] Determine the first voltage instability index value for voltage-sensitive sites in the new energy transmission system:

[0169]

[0170] Where i represents the i-th limiting fault in the new energy transmission system that causes transient voltage to exceed the limit, and j represents the j-th voltage-sensitive site under this limiting fault.

[0171] Preferably, the calculation unit 503 is used to calculate the second voltage instability index value of voltage-sensitive sites in a conventional power transmission system of equal capacity, and is also used for:

[0172] Obtain the installed capacity of the new energy power stations in the transmission system, replace the new energy power stations with thermal power units of the same installed capacity, configure the unit step-up transformers that match the capacity, and update the BPA power flow and stability calculation data of the new energy transmission system and thermal power units.

[0173] The voltage stability characteristics of the conventional unit's power transmission system under various limiting faults were simulated and analyzed. Based on the simulation results, the second voltage instability index value of the conventional unit's power transmission system was calculated.

[0174] Result unit 504 is used to determine the reactive power compensation configuration scheme based on the first voltage instability index value and the second voltage instability index value.

[0175] Preferably, the result unit 504 is used to determine the reactive power compensation configuration scheme based on the first voltage instability index value and the second voltage instability index value, and is also used to:

[0176] Using the second voltage instability index of a conventional power transmission system of equal capacity as a benchmark, the reactive power control performance evaluation index I of a new energy power plant is defined. RPC ,in:

[0177]

[0178] Wherein, NS is the first voltage instability index value, and CS is the second voltage instability index value;

[0179] The reactive power control performance evaluation index I RPC The reactive power compensation scheme that is closest to 1 is determined as the optimal configuration scheme.

[0180] The preferred embodiment of the present invention provides a reactive power control performance evaluation system for a new energy power plant, which corresponds to the preferred embodiment of the present invention providing a reactive power control performance evaluation method for a new energy power plant. These will not be elaborated upon further here.

[0181] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0182] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, 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, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0183] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0184] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0185] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0186] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

[0187] The invention has been described with reference to a few embodiments. However, as will be known to those skilled in the art, and as defined in the appended claims, other embodiments besides those disclosed above fall equivalently within the scope of the invention.

[0188] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the art, unless otherwise expressly defined herein. All references to “a / the / the [device, component, etc.]” ​​are openly interpreted as at least one instance of said device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed unless explicitly stated otherwise.

Claims

1. A method for evaluating the reactive power control performance of a new energy power plant, the method comprising: Simulation data for building a new energy DC transmission system and new energy power plants; Based on the simulation data, a fault simulation of the new energy DC transmission system is performed. Determine the voltage instability criteria, identify the limiting faults that cause transient voltage instability in the new energy DC transmission system based on the voltage instability criteria, and locate the sites with limiting faults as voltage-sensitive sites. Calculate the first voltage instability index value of voltage-sensitive sites in a renewable energy transmission system under various reactive power compensation configuration schemes, including: Determine the primary voltage instability index for sites in the renewable energy transmission system: in, The fault start time. For the end time of monitoring, It is a piecewise function; in, This refers to the upper limit of the bus voltage at each station. These are the lower limits of bus voltage at each station. U This refers to the bus voltage value at the station. Determine the first voltage instability index value for voltage-sensitive sites in the new energy transmission system: in, i The first cause of transient voltage exceeding the limit in the new energy transmission system i One limiting fault, j For the first under this limiting fault j One voltage-sensitive site; Calculate the second voltage instability index value for voltage-sensitive sites in a conventional power transmission system of equal capacity, including: Obtain the installed capacity of the new energy power stations in the transmission system, replace the new energy power stations with thermal power units of the same installed capacity, configure the unit step-up transformers that match the capacity, and update the BPA power flow and stability calculation data of the new energy transmission system and thermal power units. The voltage stability characteristics of the conventional unit's power transmission system under various limiting faults were simulated and analyzed. Based on the simulation results, the second voltage instability index value of the conventional unit's power transmission system was calculated. The reactive power compensation configuration scheme is determined based on the first voltage instability index value and the second voltage instability index value, including: Using the second voltage instability index of a conventional power transmission system of equal capacity as a benchmark, the reactive power control performance evaluation index of a new energy power plant is defined. ,in: in, NS This is the first voltage instability index value. CS This is the second voltage instability index value; Evaluation indicators of reactive power control performance The reactive power compensation scheme that is closest to 1 is determined as the optimal configuration scheme.

2. The method according to claim 1, further comprising: Obtain parameter information of the new energy DC transmission system and new energy power plants, and build simulation data of the new energy DC transmission system and new energy power plants based on the parameter information; The parameter information of the new energy DC transmission system includes: DC transmission project, AC grid structure, generator parameters, load parameters, line parameters, transformer parameters, and reactive power compensation configuration of each station; The parameter information of the new energy power station includes: the installed capacity of the new energy generator group, the type and parameters of the new energy generator unit, the reactive power and voltage control mode of the new energy generator unit, the type and capacity of the dynamic reactive power compensation device, the grid connection design scheme of the new energy generator group, the output characteristics of the new energy, the parameters of the step-up transformer, and the parameters of the grid connection line.

3. The method according to claim 1, wherein the fault simulation includes: AC line single-moment or three-permanent N-1 fault, DC commutation failure fault, and DC single-pole blocking fault.

4. The method according to claim 1, wherein determining the voltage instability criterion, based on the voltage instability criterion, identifying limiting faults causing transient voltage instability in the new energy DC transmission system, and locating the sites experiencing limiting faults as voltage-sensitive sites, includes: After verifying the transient voltage level of each station's busbar after the fault, monitor whether the busbar voltage of each station exceeds the voltage instability criterion. Faults where the busbar voltage of a station exceeds the voltage instability criterion are identified as limiting faults, and stations with limiting faults are identified as voltage-sensitive stations.

5. A reactive power control performance evaluation system for a new energy power plant, the system comprising: The initial unit is used to build simulation data for new energy DC transmission systems and new energy power plants; The positioning unit is used to perform fault simulation of the new energy DC transmission system based on the simulation data; determine the voltage instability criterion; and based on the voltage instability criterion, identify the limiting fault that causes transient voltage instability of the new energy DC transmission system, and locate the site with the limiting fault as a voltage-sensitive site. The calculation unit is used to calculate the first voltage instability index value of voltage-sensitive sites in the new energy transmission system under various reactive power compensation configuration schemes, and is also used for: Determine the primary voltage instability index for sites in the renewable energy transmission system: in, The fault start time. For the end time of monitoring, It is a piecewise function; in, This refers to the upper limit of the bus voltage at each station. These are the lower limits of bus voltage at each station. U This refers to the bus voltage value at the station. Determine the first voltage instability index value for voltage-sensitive sites in the new energy transmission system: in, i The first cause of transient voltage exceeding the limit in the new energy transmission system i One limiting fault, j For the first under this limiting fault j One voltage-sensitive site; calculates the second voltage instability index value of the voltage-sensitive site in the power transmission system of a conventional unit of equal capacity, and is also used for: Obtain the installed capacity of the new energy power stations in the transmission system, replace the new energy power stations with thermal power units of the same installed capacity, configure the unit step-up transformers that match the capacity, and update the BPA power flow and stability calculation data of the new energy transmission system and thermal power units. The voltage stability characteristics of the conventional unit's power transmission system under various limiting faults were simulated and analyzed. Based on the simulation results, the second voltage instability index value of the conventional unit's power transmission system was calculated. The result unit is used to determine the reactive power compensation configuration scheme based on the first voltage instability index value and the second voltage instability index value, and is also used to: Using the second voltage instability index of a conventional power transmission system of equal capacity as a benchmark, the reactive power control performance evaluation index of a new energy power plant is defined. ,in: in, NS This is the first voltage instability index value. CS This is the second voltage instability index value; Evaluation indicators of reactive power control performance The reactive power compensation scheme that is closest to 1 is determined as the optimal configuration scheme.

6. The system according to claim 5, wherein the initial unit is further configured to: Obtain parameter information of the new energy DC transmission system and new energy power plants, and build simulation data of the new energy DC transmission system and new energy power plants based on the parameter information; The parameter information of the new energy DC transmission system includes: DC transmission projects, AC grid structure, generator parameters, load parameters, line parameters, transformer parameters, and reactive power compensation configuration at each site; The parameter information of the new energy power station includes: the installed capacity of the new energy generator group, the type and parameters of the new energy generator unit, the reactive power and voltage control mode of the new energy generator unit, the type and capacity of the dynamic reactive power compensation device, the grid connection design scheme of the new energy generator group, the output characteristics of the new energy, the parameters of the step-up transformer, and the parameters of the grid connection line.

7. The system according to claim 5, wherein the fault simulation includes: AC line single-moment or three-permanent N-1 fault, DC commutation failure fault, and DC single-pole blocking fault.

8. The system according to claim 5, wherein the positioning unit is configured to determine a voltage instability criterion, identify, based on the voltage instability criterion, a limiting fault causing transient voltage instability in the new energy DC transmission system, and locate the site experiencing the limiting fault as a voltage-sensitive site, and is further configured to: After verifying the transient voltage level of each station's busbar after the fault, monitor whether the busbar voltage of each station exceeds the voltage instability criterion. Faults where the busbar voltage of a station exceeds the voltage instability criterion are identified as limiting faults, and stations with limiting faults are identified as voltage-sensitive stations.

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