CN117726020A - Wind turbine running state prediction method and device - Google Patents

Wind turbine running state prediction method and device Download PDF

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Publication number
CN117726020A
CN117726020A CN202311474187.4A CN202311474187A CN117726020A CN 117726020 A CN117726020 A CN 117726020A CN 202311474187 A CN202311474187 A CN 202311474187A CN 117726020 A CN117726020 A CN 117726020A
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China
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wind turbine
turbine generator
overvoltage
representing
power grid
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Inventor
李长宇
尚若愚
谢欢
刘昕宇
卢文清
娄云天
梁倍华
辛焕海
李善颖
梁浩
夏雪
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State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Jibei Electric Power Co Ltd
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State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Jibei Electric Power Co Ltd
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Priority to CN202311474187.4A priority Critical patent/CN117726020A/en
Publication of CN117726020A publication Critical patent/CN117726020A/en
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/70—Wind energy
    • Y02E10/76—Power conversion electric or electronic aspects

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Abstract

The invention provides a method and a device for predicting the running state of a wind turbine, wherein the method comprises the following steps: responding to an event that a target power grid fails, and acquiring network parameters of the target power grid; calculating the output current of each wind turbine generator in the target power grid according to the network parameters and the first target formula; according to the network parameters, the output current of each wind turbine and the second target formula, calculating the overvoltage of each wind turbine; comparing the overvoltage of each wind turbine generator with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator; predicting the running state of each wind turbine according to the overvoltage risk assessment result of each wind turbine; and selecting a preset adjustment strategy corresponding to the running state to adjust the equipment of the target power grid. The invention provides a method for quantitatively calculating overvoltage of each wind turbine generator, which predicts the running state of the wind turbine generator according to the overvoltage, adjusts a power grid in advance and reduces the influence of the stop operation of the wind turbine generator on the stable operation of the power grid.

Description

Wind turbine running state prediction method and device
Technical Field
The invention relates to the field of power grids, in particular to a method and a device for predicting the running state of a wind turbine.
Background
With the rapid development of renewable energy sources, a large-scale doubly-fed wind generating set and a direct-driven wind generating set are integrated into a power grid, and meanwhile, the duty ratio of a synchronous machine in the power grid is reduced, so that the sensitivity of node voltage to reactive power in a power system is obviously increased. Thus, the risk of overvoltage is more easily induced after surplus reactive power in the grid. The control delay generated by the actual wind farm centralized voltage control strategy and the voltage amplitude detection algorithm under large disturbance (such as overvoltage) is generally about 30 ms. Under the influence of control delay, the wind generating set in the power grid generates surplus reactive power during fault recovery, and overvoltage phenomenon can occur at the grid connection point.
In order to solve the overvoltage phenomenon at the grid connection point, the grid connection rule provides that when the voltage of the grid connection point is larger than 1.3 times of rated voltage, the wind generating set related to the grid connection point is allowed to stop running. However, the method easily causes a large number of wind generating sets to be separated from the power grid, and the stable operation of the power grid is seriously threatened. Therefore, how to predict the overvoltage level of the wind power generation system containing two types of wind generating sets has important significance for the safe and stable operation of the power grid.
At present, the research on the power frequency transient overvoltage is mainly focused on qualitative analysis, for example, the influence of each parameter on the overvoltage is analyzed by using a sensitivity analysis method in combination with simulation, or the influence of each link parameter on the overvoltage is analyzed by using a phasor analysis method in combination with simulation. However, the lack of quantitative analysis on the power frequency transient overvoltage (hereinafter referred to as overvoltage) cannot calculate the power frequency transient overvoltage, and the overvoltage level of the wind power generation system (the wind power generation system can be understood as a system comprising multiple types of wind power generation sets, for example, two types of wind power generation sets can be respectively a doubly-fed wind power generation set and a direct-driven wind power generation set) cannot be predicted, so that the influence of the stop operation of the wind power generation set on the power grid cannot be effectively controlled.
Disclosure of Invention
Aiming at the problems in the prior art, the method and the device for predicting the running state of the wind turbine can provide a method for quantitatively calculating the overvoltage of each wind turbine, predict the running state of each wind turbine according to the overvoltage, and adjust equipment in a power grid in advance according to an adjustment strategy corresponding to the running state, thereby effectively reducing the influence on the safe and stable running of the power grid due to the stop of the wind turbine in fault.
In order to solve the technical problems, the invention provides the following technical scheme:
in a first aspect, the present invention provides a method for predicting an operation state of a wind turbine, where the method includes: responding to an event that a target power grid fails, and acquiring network parameters of the target power grid; calculating the output current of each wind turbine generator in the target power grid according to the network parameters and a first target formula; calculating overvoltage of each wind turbine generator according to the network parameters, the output current of each wind turbine generator and a second target formula; comparing the overvoltage of each wind turbine generator with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator; predicting the operation state of each wind turbine according to the overvoltage risk assessment result of each wind turbine, wherein the operation state comprises a maintenance operation state and a stop operation state; and selecting a preset adjustment strategy corresponding to the running state to adjust the equipment of the target power grid.
Optionally, the network parameter includes any one or more of stator leakage reactance of the doubly-fed wind turbine in the target power grid, rotor leakage reactance of the doubly-fed wind turbine, stator resistance of the doubly-fed wind turbine, rotor resistance of the doubly-fed wind turbine, coupling reactance of the doubly-fed wind turbine, voltage of each point of common coupling of each wind turbine when a fault occurs, filter capacitance of each point of common coupling of each wind turbine when a fault occurs, filter inductance of each wind turbine when a fault occurs, control delay time of the power grid, reactive output coefficient, filter time constant, slip ratio, rated voltage, line impedance, line inductance ratio, rated voltage, rated frequency, rated capacity, rated output current of the wind turbine, model of each wind turbine when a fault occurs, number of wind turbines in the target power grid, mutual impedance between wind turbines, voltage of each circuit node when a fault occurs, total number of circuit nodes in the target power grid and short-circuit capacity of grid connection points in the target power grid.
Optionally, the calculating the output current of each wind turbine generator in the target power grid according to the network parameter and the first target formula includes: determining the type of each wind turbine according to the network parameters, wherein the type of each wind turbine comprises a first type wind turbine and a second type wind turbine; selecting the first target formula corresponding to the type of the wind turbine, wherein the first target formula of the first type wind turbine comprises:
I v ＝k(0.9-U tf )+I vq0
the first target formula of the second type wind turbine generator includes:
I r1 ＝I s1 ＝I v
U t ＝U tf
wherein I is v The output current of the side converter of the first type wind turbine generator system is represented, k represents the gain coefficient of reactive voltage, U tf Representing the voltage of the public coupling point of the wind turbine generator when a fault occurs, I vq0 Representing rated output current of first type wind turbine generator system, I r1 Representing the output current of the second type wind turbine generator when the rotor-side converter is not saturated, I s1 Representing the output current of the second type wind turbine generator when the stator-side converter is not saturated, I r2 Representing the output current X of the second type wind turbine generator when the rotor-side converter is saturated s Representing the stator reactance, X, of a second type wind turbine m Representing the coupling reactance of a second type wind turbine generator system, I s2 The output current of the second type wind turbine generator when the stator-side converter is saturated is represented; substituting the network parameters into the first target formula to obtain the output current of each wind turbine in the target power grid.
Optionally, the second target formula includes:
ΔI qj ＝I v or DeltaI qj ＝I r1 Or DeltaI qj ＝I s1 Or DeltaI qj ＝I r2 Or DeltaI qj ＝I s2
In TOV of i M represents a wind turbine generator in a power grid, Z ij Representing the transimpedance of wind turbine j to wind turbine I, ΔI qj Output current of wind turbine generator system is represented, U 0i And the voltage of the wind turbine generator i when the fault occurs is represented.
Optionally, the risk assessment result includes that the wind turbine generator has an overvoltage risk and the wind turbine generator does not have an overvoltage risk, and the comparing the overvoltage of each wind turbine generator with a preset maximum overvoltage tolerance value to determine the overvoltage risk assessment result of each wind turbine generator includes: calculating the overvoltage short-circuit ratio of each wind turbine generator set through the overvoltage of each wind turbine generator set; calculating a critical overvoltage short-circuit ratio according to the preset maximum overvoltage tolerance value; judging whether the overvoltage short-circuit ratio of each wind turbine generator is larger than the critical overvoltage short-circuit ratio, if so, determining that the wind turbine generator does not have overvoltage risk, and if not, determining that the wind turbine generator has overvoltage risk.
Optionally, the calculating the overvoltage short-circuit ratio of each wind turbine generator set by using the overvoltage of each wind turbine generator set and calculating the critical overvoltage short-circuit ratio by using the preset maximum overvoltage tolerance value includes: substituting the overvoltage of each wind turbine into a third target formula to obtain the overvoltage short-circuit ratio of each wind turbine; substituting the preset maximum overvoltage tolerance value into the third target formula to obtain the critical overvoltage short-circuit ratio; the third target formula includes:
MIFIF ij ＝α if ·MIIF ij
MIIF ij ＝|Z ij |/|Z ii |
S aci ＝1/|Z ii |
in gSCR TOV Representing the overvoltage short-circuit ratio of each wind turbine generator, S aci Represents the short-circuit capacity of the point of the parallel connection i, MIFIF ij Representing multi-feed fault interaction factor, S eqj Representing the equivalent transient capacity of a new energy station j under a fault, f representing a fault node, m representing the number of wind turbines in a target power grid, and k lj The reactive voltage gain coefficient Z of the new energy station j under fault mff Correction impedance matrix for representing fault node f of new energy station f under fault, Z mjf The method comprises the steps that a correction impedance matrix of a fault node f of a new energy station j under a fault is represented, the correction impedance matrix is determined according to overvoltage of each wind turbine generator set, output current of each wind turbine generator set and reactance of each wind turbine generator set when the fault occurs, the reactance of a first type wind turbine generator set is 1/k, k represents a reactive voltage gain coefficient, and the reactance of a second type wind turbine generator set is X s ，X s Representing the stator reactance, k, of a second type of wind turbine ln Representing the reactive voltage gain coefficient, Z, of node n mjn Correction impedance matrix Z representing failure node n of new energy station j under failure mnf Modified impedance matrix representing failure node f of new energy station n under failure, S n Represents the per unit of the node n capacity, S j Representing the per unit of node j capacity, alpha if Representing the failure coefficient, MIIF ij Representing multi-feed interaction factor, |Z ij I represents the transimpedance between nodes i, j, |z ii I represents the self-impedance of node i.
Optionally, the third objective formula further includes:
or->
U tf1 ＝0.9-I max1 /k
I max1 ＝I max -I vq0i
U tf2 ＝0.9-(I max2 +0.1)/(kX s -1)
I max2 ＝X m I rmax -I vq0i X s -1
ΔU ti ＝Z m ΔI
ΔI q ＝S(K l Z m ΔI+I eq )
Wherein k is lj Reactive voltage gain coefficient k representing wind turbine generator node j i Representing the reactive voltage gain coefficient, k, before correction l1i 、k l2i Respectively representing the reactive voltage gain coefficient of the first type wind turbine generator node I and the reactive voltage gain coefficient of the second type wind turbine generator node I, I max Representing maximum output current of a first type wind turbine generator system side converter during fault occurrence, I max1 Representing maximum output current of first type wind turbine generator set during fault occurrence, I vq0i Indicating rated output current DeltaU of first type wind turbine generator system node i during fault occurrence ti Indicating the voltage variation of node i, U tfi Representing the voltage amplitude during the fault of node i, U tf1 Represents the voltage amplitude limit of the first type wind turbine generator system, S Gi Representing per unit capacity, U, of second type wind turbine generator set where node i is located tf2 Representing the voltage amplitude limit of the second type wind turbine generator system, I rmax Representing maximum output current of rotor-side converter of second type wind turbine generator during fault occurrence, I max2 Represents the maximum output current of the second type wind turbine generator set during the fault occurrence period, delta I represents the vector of the output current of the wind turbine generator set, Z m Representing a modified impedance matrix according to the overvoltage of each wind turbine generator set and the output of each wind turbine generator setThe current and the reactance of each wind turbine generator are determined, the reactance of the first type wind turbine generator is 1/k, k represents the reactive voltage gain coefficient, and the reactance of the second type wind turbine generator is X s ，ΔI q Representing the current vector, I q ＝[I q1 ,…I qj ,…] T S represents the per unit node capacity, K l Representing a matrix of reactive-voltage gain coefficients, I eq Representing an equivalent current source, wherein the equivalent current source of the first type wind turbine generator is I vq0 +k and-0.1 k, wherein the equivalent current source of the second type wind turbine generator is E q /X s ，E q Representing the electromotive force excited by the rotor current.
Optionally, the calculation formula of the electromotive force includes: e (E) q ＝jX m I r ＝jX s I s +U t ，U t ＝U tf 。
Optionally, predicting the operation state of each wind turbine according to the overvoltage risk assessment result of each wind turbine includes: if the risk assessment result indicates that the wind turbine generator does not have overvoltage risk, predicting the running state of the wind turbine generator to be a maintenance running state; and if the risk assessment result indicates that the wind turbine generator has an overvoltage risk, predicting that the running state of the wind turbine generator is a stop running state.
Optionally, the method for predicting the running state of the wind turbine generator provided by the invention further comprises the following steps: the formula for calculating the weighted sensitivity matrix includes:
in the formula, SE represents,an inverse matrix representing the system admittance matrix after the kran reduction, S B Representing per-unit device capacity matrix, diag -1 (Z m ) Representing an inverse matrix after diagonal elements of the modified impedance matrix are taken to form a diagonal matrix; from the saidAnd identifying dangerous nodes in the weighted sensitivity matrix so that the power grid can pre-control the dangerous nodes, wherein the dangerous nodes comprise the node with the largest overvoltage after the fault and the node which is most likely to cause the overvoltage risk after the fault.
Optionally, the identifying the dangerous node from the weighted sensitivity matrix includes: identifying a node corresponding to a row number of a row where the maximum element is located from the weighted sensitivity matrix as a node with the maximum overvoltage after the fault occurs; and identifying a node corresponding to the column number of the column where the maximum element is located from the weighted sensitivity matrix as the node which is most likely to cause overvoltage risk after the fault occurs.
In a second aspect, the present invention provides a wind turbine generator system operation state prediction apparatus, the apparatus comprising: the parameter acquisition module is suitable for responding to the event that the target power grid fails and acquiring network parameters of the target power grid; the output current calculation module is suitable for calculating the output current of each wind turbine generator in the target power grid according to the network parameters and a first target formula; the overvoltage calculation module is suitable for calculating the overvoltage of each wind turbine generator according to the network parameters, the output current of each wind turbine generator and a second target formula; the overvoltage risk assessment result determining module is suitable for comparing the overvoltage of each wind turbine generator with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator; the wind turbine generator running state determining module is suitable for predicting the running state of each wind turbine generator according to the overvoltage risk assessment result of each wind turbine generator, and the running state comprises a maintaining running state and a stopping running state; and the power grid equipment adjusting module is suitable for selecting a preset adjusting strategy corresponding to the running state to adjust equipment of the target power grid.
In a third aspect, the invention provides an electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the method described above when the program is executed by the processor.
In a fourth aspect, the present invention provides a computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of the above method.
As can be seen from the above description, according to the wind turbine running state prediction method provided by the invention, when a power grid fails, the transient overvoltage of each wind turbine is calculated through the network parameters and the target formula when the power grid fails, so that the transient overvoltage of the wind turbine is rapidly and quantitatively calculated. And comparing the voltage with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator, and providing a theoretical basis for overvoltage safety assessment of the fan grid-connected system. And predicting whether the operation state of each wind turbine is stopped according to the overvoltage risk assessment result of each wind turbine, and selecting a corresponding adjustment strategy according to the operation state of each wind turbine so as to adjust equipment in the power grid in advance according to the adjustment strategy, thereby effectively reducing the influence on the safe and stable operation of the power grid caused by the stop operation of the wind turbine during faults, ensuring the safe and stable operation of the power grid during the faults, realizing the automatic regulation and control of the power grid equipment during the stop operation of the wind turbine, and improving the convenience of the regulation and control of the power grid.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a flowchart of a method for predicting an operation state of a wind turbine generator system according to a first embodiment of the present invention;
FIG. 2 is a flow chart of step 300 in an embodiment of the invention;
FIG. 3 is a flow chart of step 500 in an embodiment of the invention;
FIG. 4 is a flowchart of a method for predicting the running state of a wind turbine generator system according to a second embodiment of the present invention;
FIG. 5 is a flow chart of step 900 in an embodiment of the present invention;
FIG. 6 is a network diagram of a wind turbine system in accordance with one embodiment of the present invention;
fig. 7 is a waveform diagram of the point of common coupling voltage EMT in one embodiment of the invention;
FIG. 8 is a block diagram illustrating a wind turbine operating state prediction apparatus according to an embodiment of the present invention;
fig. 9 is a schematic structural diagram of an electronic device in an embodiment of the invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Before the technical scheme of the invention is described in detail, the technical scheme of the invention has the advantages that the acquisition, storage, use, processing and the like of the data meet the relevant regulations of national laws and regulations.
In order to solve the technical problem that the overvoltage level of a wind power generation system cannot be predicted in the prior art, the embodiment of the invention provides a method and a device for predicting the running state of a wind turbine generator, so as to solve the technical problem.
The wind turbine running state prediction method provided by the embodiment of the invention is applied to risk assessment of power frequency transient state (which can be understood as when faults occur) overvoltage of the wind turbine in a power grid comprising multiple types of wind turbines, and the power frequency transient state overvoltage is simply called overvoltage in the follow-up.
Referring to fig. 1, the method for predicting the running state of the wind turbine provided by the embodiment of the invention specifically comprises the following steps:
step 100: and monitoring the fault occurrence of the target power grid. When the failure information sent by the target instance is received, which corresponds to the event that the failure of the target network is detected, step 200 is executed at this time.
Step 200: and acquiring network parameters of the target power grid.
Taking a doubly-fed wind turbine generator as an example, one type of wind turbine generator included in the power grid, and the network parameters include one or more of stator leakage reactance of the doubly-fed wind turbine generator in the target power grid, rotor leakage reactance of the doubly-fed wind turbine generator, stator resistance of the doubly-fed wind turbine generator, rotor resistance of the doubly-fed wind turbine generator, coupling reactance of the doubly-fed wind turbine generator, voltage of each point of common coupling of each wind turbine generator when a fault occurs, filter capacitance of each point of common coupling of each wind turbine generator when the fault occurs, filter inductance of each wind turbine generator when the fault occurs, control delay time of the power grid, reactive output coefficient, filter time constant, slip ratio, rated voltage, line impedance, line inductance ratio, rated voltage, rated frequency, rated capacity, rated output current of the wind turbine generator, model of each wind turbine generator, injection current of each wind turbine generator when the fault occurs, number of wind turbine generator in the target power grid, mutual impedance between wind turbine generator, voltage of each circuit node when the fault occurs, total number of circuit nodes in the target power grid, and short circuit capacity of grid parallel nodes in the target power grid.
And 300, calculating the output current of each wind turbine in the target power grid according to the network parameters and the first target formula.
The first target formula here is a calculation formula of output current of a wind turbine, and since the embodiment of the invention is applicable to a power grid including wind turbines of multiple types, the calculation formulas of calculated output current corresponding to wind turbines of different types are different, and will be described in detail below.
It should be noted that the calculation formulas for calculating the output currents corresponding to different types of wind turbines are different, and it can be understood that the modeling modes of different types of wind turbines are different. The specific type of the wind turbine generator can be set according to the actual application scene, and the method is not limited.
By the type of wind turbine generatorThe method comprises the steps of taking a first type wind turbine and a second type wind turbine as an example, wherein the first type can be a direct-drive wind turbine and the second type can be a doubly-fed wind turbine, and in the embodiment of the invention, the first type wind turbine is equivalently modeled into two independent current sources and a virtual parallel reactance, and the sizes of the current sources are respectively I vq0 +k and-0.1 k, the virtual reactance is 1/k, and k represents the reactive voltage gain factor. The modeling mode of the second type wind turbine generator when the rotor side is unsaturated is the same as that of the first type wind turbine generator, namely, the second type wind turbine generator is equivalently modeled into two independent current sources and a virtual parallel reactance, and the sizes of the current sources are respectively I vq0 +k and-0.1 k, the virtual reactance is 1/k. When the second type wind turbine generator is saturated at the rotor side, the second type wind turbine generator can be equivalently modeled as a parallel circuit of a current source and a reactance, wherein the current source is E in size q /X s Reactance of size X s ，E q An electromotive force excited by the rotor current is represented, a calculation formula of the electromotive force will be described hereinafter, X s Representing the stator reactance of the second type of wind turbines.
Step 400: and calculating the overvoltage of each wind turbine according to the network parameters, the output current of each wind turbine and the second target formula, so that the rapid quantitative calculation of the temporary overvoltage of the wind turbine is realized.
The second target formula here is a calculation formula of the overvoltage of the wind turbine generator, and is described in detail below.
Step 500: and comparing the overvoltage of each wind turbine generator with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator.
The risk assessment result comprises the risk of overvoltage of the wind turbine generator and the risk of no overvoltage.
Step 600: and predicting the operation state of each wind turbine according to the overvoltage risk assessment result of each wind turbine, wherein the operation state comprises a maintenance operation state and a stop operation state.
Step 700: and selecting a preset adjustment strategy corresponding to the running state to adjust the equipment of the target power grid.
As can be seen from the above description, according to the wind turbine running state prediction method provided by the embodiment of the invention, when a power grid fails, the transient overvoltage of each wind turbine is calculated through the network parameters and the target formula when the power grid fails, so that the transient overvoltage of the wind turbine is rapidly and quantitatively calculated. And comparing the voltage with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator, and providing a theoretical basis for overvoltage safety assessment of the fan grid-connected system. And predicting whether the operation state of each wind turbine is stopped according to the overvoltage risk assessment result of each wind turbine, and selecting a corresponding adjustment strategy according to the operation state of each wind turbine so as to adjust equipment in the power grid in advance according to the adjustment strategy, thereby effectively reducing the influence on the safe and stable operation of the power grid caused by the stop operation of the wind turbine during faults, ensuring the safe and stable operation of the power grid during the faults, realizing the automatic regulation and control of the power grid equipment during the stop operation of the wind turbine, and improving the convenience of the regulation and control of the power grid.
The following describes the operation state prediction method of the wind turbine shown in fig. 1 in detail:
in some embodiments, as shown in fig. 2, step 300 may specifically include:
step 310: and determining the type of each wind turbine according to the network parameters. Further, the type of each wind turbine can be determined according to the model of the wind turbine in the network parameters.
The types of the wind turbines comprise a first type wind turbine and a second type wind turbine, wherein the first type can be a direct-driven wind turbine, the second type can be a double-fed wind turbine, and of course, the two types of wind turbines are only exemplary, and the wind turbines can also be other types of wind turbines with performances similar to those of the direct-driven wind turbine and the double-fed wind turbine.
Step 320: selecting a first target formula corresponding to the type of the wind turbine, wherein the first target formula of the first type wind turbine comprises:
I v ＝k(0.9-U tf )+I vq0
the first target formula of the second type wind turbine generator includes:
I r1 ＝I s1 ＝I v
U t ＝U tf
wherein I is v The output current of the side converter of the first type wind turbine generator system is represented, k represents the gain coefficient of reactive voltage, U tf Representing the voltage of the public coupling point of the wind turbine generator when a fault occurs, I vq0 Representing the rated output current (=0) of a first type wind turbine generator, I r1 Representing the output current of the second type wind turbine generator when the rotor-side converter is not saturated, I s1 Representing the output current of the second type wind turbine generator when the stator-side converter is not saturated, I r2 Representing the output current X of the second type wind turbine generator when the rotor-side converter is saturated s Representing the stator reactance, X, of a second type wind turbine m Representing the coupling reactance of a second type wind turbine generator system, I s2 The output current of the second type wind turbine generator when the stator-side converter is saturated is represented;
step 330: substituting the related data in the network parameters into a first target formula to obtain the output current of each wind turbine in the target power grid.
From the above, it can be seen that the embodiment of the invention is equivalent to setting the calculation formulas of the output currents of the wind turbines of different types respectively, so that the calculation formulas of the output currents are more in line with the actual conditions of the wind turbines, and the accuracy of the output currents of each wind turbine can be improved when a fault occurs.
In some implementations, the second target formula includes:
ΔI qj ＝I v or DeltaI qj ＝I r1 Or DeltaI qj ＝I s1 Or DeltaI qj ＝I r2 Or DeltaI qj ＝I s2
In TOV of i M represents a wind turbine generator in a power grid, Z ij Representing the transimpedance of wind turbine j to wind turbine I, ΔI qj Output current of wind turbine generator system is represented, U 0i And the voltage of the wind turbine generator i when the fault occurs is represented.
At this time, step 400 may specifically include: substituting partial parameters in the network parameters and the output current of each wind turbine into a second target formula to calculate the overvoltage of each wind turbine, thereby realizing the rapid quantitative calculation of the temporary overvoltage of the wind turbine when the fault occurs and providing a calculation method for the rapid quantitative calculation of the temporary overvoltage of the wind turbine when the fault occurs.
In some embodiments, as shown in fig. 3, step 500 may specifically include:
step 510: and calculating the overvoltage short-circuit ratio of each wind turbine generator set through the overvoltage of each wind turbine generator set.
Step 520: and calculating the critical overvoltage short-circuit ratio through a preset maximum overvoltage tolerance value.
Specific: the step of calculating the overvoltage short-circuit ratio of each wind turbine generator by the overvoltage of each wind turbine generator, and the step of calculating the critical overvoltage short-circuit ratio by the preset maximum overvoltage tolerance value comprises the following steps: firstly substituting overvoltage of each wind turbine into a third target formula to obtain an overvoltage short-circuit ratio of each wind turbine, and secondly substituting a preset maximum overvoltage tolerance value into the third target formula to obtain the critical overvoltage short-circuit ratio.
Wherein the third target formula comprises:
MIFIF ij ＝α if ·MIIF ij
MIIF ij ＝|Z ij |/|Z ii |
S aci ＝1/|Z ii |
Or->
U tf1 ＝0.9-I max1 /k
I max1 ＝I max -I vq0i
U tf2 ＝0.9-(I max2 +0.1)/(kX s -1)
I max2 ＝X m I rmax -I vq0i X s -1
ΔU ti ＝Z m ΔI
ΔI q ＝S(K l Z m ΔI+I eq )
In gSCR TOV S represents the overvoltage short-circuit ratio of each wind turbine generator aci Represents the short-circuit capacity of the point of the parallel connection i, MIFIF ij Representing multi-feed fault interaction factor, S eqj Representing the equivalent transient capacity of a new energy station j under a fault, f representing a fault node, m representing the number of wind turbines in a target power grid, and k lj The reactive voltage gain coefficient Z of the new energy station j under fault mff Correction impedance matrix for representing fault node f of new energy station f under fault, Z mjf The correction impedance matrix representing the fault node f of the new energy station j under the fault is based on the overvoltage of each wind turbine generator set, the output current of each wind turbine generator set and each wind turbine generator set during the faultThe reactance of the wind turbine generator system is determined, the reactance of the wind turbine generator system of the first type is 1/k, k represents the reactive voltage gain coefficient, and the reactance of the wind turbine generator system of the second type is X s ，X s Representing the stator reactance, k, of a second type of wind turbine ln Representing the reactive voltage gain coefficient, Z, of node n mjn Correction impedance matrix Z representing failure node n of new energy station j under failure mnf Modified impedance matrix representing failure node f of new energy station n under failure, S n Represents the per unit of the node n capacity, S j Representing the per unit of node j capacity, alpha if Representing the failure coefficient, MIIF ij Representing multi-feed interaction factor, |Z ij I represents the transimpedance between node i and node j, |z ii I represents the self-impedance of node i, k lj Reactive voltage gain coefficient k representing wind turbine generator node j i Representing the reactive voltage gain coefficient, k, before correction l1i 、k l2i Respectively representing the reactive voltage gain coefficient of the first type wind turbine generator node I and the reactive voltage gain coefficient of the second type wind turbine generator node I, I max Representing maximum output current of a first type wind turbine generator system side converter during fault occurrence, I max1 Representing maximum output current of first type wind turbine generator set during fault occurrence, I vq0i Indicating rated output current DeltaU of first type wind turbine generator system node i during fault occurrence ti Indicating the voltage variation of node i, U tfi Representing the voltage amplitude during the fault of node i, U tf1 Represents the voltage amplitude limit of the first type wind turbine generator system, S Gi Representing per unit capacity, U, of second type wind turbine generator set where node i is located tf2 Representing the voltage amplitude limit of the second type wind turbine generator system, I rmax Representing maximum output current of rotor-side converter of second type wind turbine generator during fault occurrence, I max2 Represents the maximum output current of the second type wind turbine generator set during the fault occurrence period, delta I represents the vector of the output current of the wind turbine generator set, Z m Representing the modified impedance matrix, ΔI q Representing the current vector, I q ＝[I q1 ,…I qj ,…] T S represents the per unit node capacity，K l Representing a matrix of reactive-voltage gain coefficients, I eq Representing an equivalent current source, wherein the equivalent current source of the first type wind turbine generator is I vq0 +k and-0.1 k, wherein the equivalent current source of the second type wind turbine generator is E q /X s ，E q Representing the electromotive force excited by the rotor current.
It is worth noting that the correction impedance matrix is determined according to the overvoltage of each wind turbine generator set, the output current of each wind turbine generator set and the reactance of each wind turbine generator set when a fault occurs, and the correction impedance matrix is reconstructed when the fault occurs, so that the correction impedance matrix is more in line with the actual condition of the power grid when the fault occurs at present, the accuracy of the overvoltage short-circuit ratio obtained through the correction impedance matrix and the overvoltage of each wind turbine generator set can be improved, the accuracy of the overvoltage risk assessment result of each wind turbine generator set is improved, and the accuracy of the running state prediction of the wind turbine generator set is improved. And, the reactance of the first type wind turbine may be set to 1/k, and the reactance of the second type wind turbine may be set to X s 。
In the embodiment of the invention, the current instruction of the rotor side converter of the second type wind turbine generator is not changed when the fault is cleared, so that the output current of the second type wind turbine generator when the rotor side converter is saturated after the fault is cleared is kept unchanged, and the second type wind turbine generator can be regarded as a voltage source with constant electromotive force. And the calculation formula of the electromotive force comprises: e (E) q ＝jX m I r ＝jX s I s +U t Under the influence of control delay, it can be considered U t ＝U tf Then combine
I.e. E q I in (a) r Replaced by I r2 Is available in the form of
E q ＝(0.9k+I vq0 )X s +U tf (1-kX s )。
Step 530: and judging whether the overvoltage short-circuit ratio of each wind turbine generator is larger than the critical overvoltage short-circuit ratio, if so, executing step 540, and if not, executing step 550.
Step 540: and determining that the wind turbine generator set does not have overvoltage risk.
Step 550: and determining that the wind turbine generator has overvoltage risk.
According to the method, the device and the system, the actual situation of the power grid when the faults occur is more met through the overvoltage of each wind turbine, the output current of each wind turbine and the reactance correction impedance matrix of each wind turbine, so that the accuracy of the overvoltage short-circuit ratio obtained through the correction impedance matrix and the overvoltage of each wind turbine can be improved, the accuracy of the overvoltage risk assessment result of each wind turbine is improved, and the accuracy of the running state prediction of the wind turbine is improved.
As can be seen from the above description, the operation state includes a hold operation state and a stop operation state, and in some embodiments, if the operation state is the stop operation state, the step 600 may specifically include: and when the risk assessment result is that the wind turbine generator has overvoltage risk, predicting the running state of the wind turbine generator to be a stop running state. Because the operation stop of the wind turbine generator system can bring influence to the safe and stable operation of the power grid, corresponding adjustment of equipment in the power grid is needed to reduce the influence of the operation stop of the wind turbine generator system on the power grid as much as possible.
In this case, step 700 may specifically include: when the running state of the wind turbine generator is predicted to be the running stop state, a corresponding preset strategy can be selected to adjust the equipment in the power grid. Taking an example that 20 wind turbines in a power grid are included, 10 wind turbines in the power grid are predicted to have overvoltage risks under the influence of faults, and at the moment, the preset strategy can start the wind turbines numbered 1-10 in the standby wind turbines to work.
In addition, in some embodiments, if the operation state is the inactive operation state, the step 600 may specifically include: when the risk assessment result indicates that the wind turbine generator does not have an overvoltage risk, predicting that the running state of the wind turbine generator is a maintaining running state, where step 700 may specifically include: because the wind turbine generator is not stopped, the power grid is not affected by the running state of the wind turbine generator, and the preset strategy can be that equipment in the power grid is not required to be adjusted at the moment.
Of course, the above-mentioned preset strategy is only exemplary, and the preset strategy may be set according to an actual application scenario, which is not limited by the present invention.
In order to better control the power grid to reduce the impact of faults on safe and stable operation of the power grid, in some embodiments, as shown in fig. 4, the method further includes:
Step 800: calculating a weighted sensitivity matrix, wherein the formula for calculating the weighted sensitivity matrix includes:
in the formula, SE represents,an inverse matrix representing the system admittance matrix after the kran reduction, S B Representing per-unit device capacity matrix, diag -1 (Z m ) Representing the inverse of the modified impedance matrix after diagonal elements are taken to form the diagonal matrix.
Step 900: dangerous nodes are identified from the weighted sensitivity matrix so that the power grid can pre-control the dangerous nodes.
Dangerous nodes here include the node where the overvoltage is greatest after a fault has occurred and the node where the risk of overvoltage is most likely to be caused after a fault has occurred. Therefore, dangerous nodes can be rapidly determined through the weighted sensitivity matrix, and the fault position of the power grid can be conveniently found in time, so that the overvoltage risk of the wind turbine generator at the fault position can be rapidly judged, and the stable operation of the power grid can be better protected.
In some embodiments, as shown in fig. 5, step 900 may specifically include:
step 910: and identifying the node corresponding to the row number of the row where the maximum element is located from the weighted sensitivity matrix as the node with the maximum overvoltage after the fault occurs.
Step 920: and identifying the node corresponding to the column number of the column where the largest element is located from the weighted sensitivity matrix as the node which is most likely to cause overvoltage risk after the fault occurs.
An example of verifying the validity of the overvoltage calculation method is given below.
In order to verify the effectiveness of the method for calculating the overvoltage of the wind turbine generator in the new energy power grid, a system model shown in fig. 6 is built based on a PSCAD platform, the DFIG in fig. 6 represents a direct-driven wind turbine generator, the PMSG represents a double-fed wind turbine generator, and the PV represents a photovoltaic generator. Based on an IEEE New England 39 node test system, all stations adopt full-power new energy equipment. A test system may be understood as a tested wind power system comprising wind turbines of various types. Wherein the simulated device capacities are shown in table 1.
Table 1 simulation parameter setting table
In order to evaluate the overvoltage risk of the wind power system comprising the multi-type wind power generation set, a weighted sensitivity matrix of the test system is calculated, and the most serious faults and the weakest new energy nodes are found out. The calculation result shows that the maximum element of the weighted sensitivity matrix is 0.23 at row 3 and column 16. Thus, the least disadvantageous temporary overvoltage will occur at the new energy node 3 and a corresponding fault at node 16. Meanwhile, the overvoltage short-circuit ratio and the critical overvoltage short-circuit ratio are respectively that the overvoltage short-circuit ratio is minus 0.861 and the critical overvoltage short-circuit ratio is minus 2.469, and the overvoltage short-circuit ratio is smaller than the critical overvoltage short-circuit ratio, which indicates that the system has temporary overvoltage risk.
To verify the effectiveness of the proposed overvoltage evaluation method, it is assumed that a metal three-phase fault applied to node 16 occurs at t=1 s and clears at t=1.1 s. The EMT simulation results of the a-phase instantaneous values (Uti) of the PCC voltage at each point of common coupling are shown in fig. 7, and are consistent with the analytical evaluation results described above.
Based on the same conception as the wind turbine running state prediction method, the embodiment of the application also provides a wind turbine running state prediction device which can be used for realizing the wind turbine running state prediction method described in the embodiment, and the embodiment is as follows. Because the principle of solving the problem of the wind turbine running state prediction device is similar to that of the wind turbine running state prediction method, the implementation of the wind turbine running state prediction device can be implemented by the wind turbine running state prediction method, and repeated parts are not repeated. As used below, the term "unit" or "module" may be a combination of software and/or hardware that implements the intended function. While the system described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and contemplated.
The embodiment of the invention provides a specific implementation manner of a wind turbine running state prediction device, referring to fig. 8, the device specifically comprises the following contents:
The parameter acquisition module 10 is adapted to acquire network parameters of a target power grid in response to an event of a failure of the target power grid.
The output current calculation module 20 is adapted to calculate the output current of each wind turbine generator in the target power grid according to the network parameters and the first target formula.
The overvoltage calculation module 30 is adapted to calculate the overvoltage of each wind turbine generator according to the network parameters, the output current of each wind turbine generator and a second target formula.
The risk assessment result determining module 40 is adapted to compare the overvoltage of each wind turbine generator with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator.
The wind turbine running state determining module 50 is adapted to predict the running state of each wind turbine according to the overvoltage risk assessment result of each wind turbine.
The grid device adjustment module 60 is adapted to select a preset adjustment strategy corresponding to the operation state to adjust the device of the target grid.
Therefore, when the power grid fails, the transient overvoltage of each wind turbine generator is calculated through the network parameters and the target formula when the power grid fails, so that the transient overvoltage of the wind turbine generator is rapidly and quantitatively calculated. And comparing the voltage with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator, and providing a theoretical basis for overvoltage safety assessment of the fan grid-connected system. And predicting whether the operation state of each wind turbine is stopped according to the overvoltage risk assessment result of each wind turbine, and selecting a corresponding adjustment strategy according to the operation state of each wind turbine so as to adjust equipment in the power grid in advance according to the adjustment strategy, thereby effectively reducing the influence on the safe and stable operation of the power grid caused by the stop operation of the wind turbine during faults, ensuring the safe and stable operation of the power grid during the faults, realizing the automatic regulation and control of the power grid equipment during the stop operation of the wind turbine, and improving the convenience of the regulation and control of the power grid.
The embodiment of the present application further provides a specific implementation manner of an electronic device capable of implementing all the steps in the wind turbine generator running state prediction method in the foregoing embodiment, and referring to fig. 9, the electronic device specifically includes the following contents:
a processor (processor) 901, a memory (memory) 902, a communication interface (Communications Interface) 903, and a communication bus 904;
wherein the processor 901, the memory 902, and the communication interface 903 perform communication with each other through the communication bus 904; the communication interface 903 is used to implement information transmission among related devices such as a server device, a parameter acquisition device, and a client device.
The processor 901 is configured to invoke a computer program in the memory 902, where the processor executes the computer program to implement all the steps in the method for predicting an operation state of a wind turbine in the foregoing embodiment, for example, the processor executes the computer program to implement the following steps:
step 100: and monitoring the fault occurrence of the target power grid. When the failure information sent by the target instance is received, which corresponds to the event that the failure of the target network is detected, step 200 is executed at this time.
Step 200: and acquiring network parameters of the target power grid.
And 300, calculating the output current of each wind turbine in the target power grid according to the network parameters and the first target formula.
Step 400: and calculating the overvoltage of each wind turbine according to the network parameters, the output current of each wind turbine and the second target formula, so that the rapid quantitative calculation of the temporary overvoltage of the wind turbine is realized.
Step 500: and comparing the overvoltage of each wind turbine generator with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator.
Step 600: and predicting the running state of each wind turbine according to the overvoltage risk assessment result of each wind turbine.
Step 700: and selecting a preset adjustment strategy corresponding to the running state to adjust the equipment of the target power grid.
As can be seen from the above description, the electronic device in the embodiments of the present application provides a method for predicting an operation state of a wind turbine, where when a power grid fails, transient overvoltage of each wind turbine is calculated through network parameters and a target formula when the power grid fails, so that the transient overvoltage of the wind turbine is rapidly and quantitatively calculated. And comparing the voltage with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator, and providing a theoretical basis for overvoltage safety assessment of the fan grid-connected system. And predicting whether the operation state of each wind turbine is stopped according to the overvoltage risk assessment result of each wind turbine, and selecting a corresponding adjustment strategy according to the operation state of each wind turbine so as to adjust equipment in the power grid in advance according to the adjustment strategy, thereby effectively reducing the influence on the safe and stable operation of the power grid caused by the stop operation of the wind turbine during faults, ensuring the safe and stable operation of the power grid during the faults, realizing the automatic regulation and control of the power grid equipment during the stop operation of the wind turbine, and improving the convenience of the regulation and control of the power grid.
The embodiments of the present application further provide a computer readable storage medium capable of implementing all the steps in the wind turbine running state prediction method in the above embodiments, where a computer program is stored on the computer readable storage medium, and when the computer program is executed by a processor, the computer program implements all the steps in the wind turbine running state prediction method in the above embodiments, for example, when the processor executes the computer program, the following steps are implemented:
step 100: and monitoring the fault occurrence of the target power grid. When the failure information sent by the target instance is received, which corresponds to the event that the failure of the target network is detected, step 200 is executed at this time.
Step 200: and acquiring network parameters of the target power grid.
And 300, calculating the output current of each wind turbine in the target power grid according to the network parameters and the first target formula.
Step 400: and calculating the overvoltage of each wind turbine according to the network parameters, the output current of each wind turbine and the second target formula, so that the rapid quantitative calculation of the temporary overvoltage of the wind turbine is realized.
Step 500: and comparing the overvoltage of each wind turbine generator with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator.
Step 600: and predicting the running state of each wind turbine according to the overvoltage risk assessment result of each wind turbine.
Step 700: and selecting a preset adjustment strategy corresponding to the running state to adjust the equipment of the target power grid.
As can be seen from the above description, the computer readable storage medium in the embodiments of the present application provides a method for predicting an operation state of a wind turbine, when a power grid fails, transient overvoltage of each wind turbine is calculated through network parameters and a target formula when the power grid fails, so that the transient overvoltage of the wind turbine is rapidly and quantitatively calculated. And comparing the voltage with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator, and providing a theoretical basis for overvoltage safety assessment of the fan grid-connected system. And predicting whether the operation state of each wind turbine is stopped according to the overvoltage risk assessment result of each wind turbine, and selecting a corresponding adjustment strategy according to the operation state of each wind turbine so as to adjust equipment in the power grid in advance according to the adjustment strategy, thereby effectively reducing the influence on the safe and stable operation of the power grid caused by the stop operation of the wind turbine during faults, ensuring the safe and stable operation of the power grid during the faults, realizing the automatic regulation and control of the power grid equipment during the stop operation of the wind turbine, and improving the convenience of the regulation and control of the power grid.
In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for a hardware+program class embodiment, the description is relatively simple, as it is substantially similar to the method embodiment, as relevant see the partial description of the method embodiment.
The foregoing describes specific embodiments of the present disclosure. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.
Although the present application provides method operational steps as an example or flowchart, more or fewer operational steps may be included based on conventional or non-inventive labor. The order of steps recited in the embodiments is merely one way of performing the order of steps and does not represent a unique order of execution. When implemented by an actual device or client product, the instructions may be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment) as shown in the embodiments or figures.
It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention 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 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 flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations 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.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The principles and embodiments of the present invention have been described in detail with reference to specific examples, which are provided to facilitate understanding of the method and core ideas of the present invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.

Claims (14)

1. A method for predicting an operational state of a wind turbine, the method comprising:
responding to an event that a target power grid fails, and acquiring network parameters of the target power grid;
calculating the output current of each wind turbine generator in the target power grid according to the network parameters and a first target formula;
calculating overvoltage of each wind turbine generator according to the network parameters, the output current of each wind turbine generator and a second target formula;
comparing the overvoltage of each wind turbine generator with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator;
predicting the operation state of each wind turbine according to the overvoltage risk assessment result of each wind turbine, wherein the operation state comprises a maintenance operation state and a stop operation state;
and selecting a preset adjustment strategy corresponding to the running state to adjust the equipment of the target power grid.
2. The method of claim 1, wherein the network parameters include any one or more of stator leakage reactance of a doubly-fed wind turbine in a target power grid, rotor leakage reactance of a doubly-fed wind turbine, stator resistance of a doubly-fed wind turbine, rotor resistance of a doubly-fed wind turbine, coupling reactance of a doubly-fed wind turbine, voltage of various points of common coupling of wind turbines at the time of a fault, filter capacitance of various points of common coupling of wind turbines at the time of a fault, filter inductance of various wind turbines at the time of a fault, control delay time of a power grid, reactive output coefficient, filter time constant, slip ratio, rated voltage, line impedance, line inductance ratio, rated voltage, rated frequency, rated capacity, rated output current of a motor, model number of wind turbines at the time of a fault, injection current of various wind turbines in a target power grid, number of wind turbines, mutual impedance between wind turbines, voltage of various circuit nodes at the time of a fault, total number of circuit nodes in a target power grid, and short circuit capacity of grid points in a target power grid.
3. The method of claim 1, wherein calculating the output current of each wind turbine in the target grid according to the network parameters and the first target formula comprises:
determining the type of each wind turbine according to the network parameters, wherein the type of each wind turbine comprises a first type wind turbine and a second type wind turbine;
selecting the first target formula corresponding to the type of the wind turbine, wherein the first target formula of the first type wind turbine comprises:
I v ＝k(0.9-U tf )+I vq0
the first target formula of the second type wind turbine generator includes:
I r1 ＝I s1 ＝I v
U t ＝U tf
wherein I is v The output current of the side converter of the first type wind turbine generator system is represented, k represents the gain coefficient of reactive voltage, U tf Representing the voltage of the public coupling point of the wind turbine generator when a fault occurs, I vq0 Representing rated output current of first type wind turbine generator system, I r1 Representing the output current of the second type wind turbine generator when the rotor-side converter is not saturated, I s1 Representing the output current of the second type wind turbine generator when the stator-side converter is not saturated, I r2 Representing the output current X of the second type wind turbine generator when the rotor-side converter is saturated s Representing the stator reactance, X, of a second type wind turbine m Representing the coupling reactance of a second type wind turbine generator system, I s2 The output current of the second type wind turbine generator when the stator-side converter is saturated is represented;
substituting the network parameters into the first target formula to obtain the output current of each wind turbine in the target power grid.
4. The method of claim 1, wherein the second target formula comprises:
ΔI qj ＝I v or DeltaI qj ＝I r1 Or DeltaI qj ＝I s1 Or DeltaI qj ＝I r2 Or DeltaI qj ＝I s2
In TOV of i M represents a wind turbine generator in a power grid, Z ij Representing the transimpedance of wind turbine j to wind turbine I, ΔI qj Output current of wind turbine generator system is represented, U 0i And the voltage of the wind turbine generator i when the fault occurs is represented.
5. The method for predicting an operation state according to claim 3, wherein the risk assessment result includes that a wind turbine has an overvoltage risk and that the wind turbine does not have an overvoltage risk, and the comparing the overvoltage of each wind turbine with a preset maximum overvoltage tolerance value to determine the overvoltage risk assessment result of each wind turbine includes:
calculating the overvoltage short-circuit ratio of each wind turbine generator set through the overvoltage of each wind turbine generator set;
Calculating a critical overvoltage short-circuit ratio according to the preset maximum overvoltage tolerance value;
judging whether the overvoltage short-circuit ratio of each wind turbine generator is larger than the critical overvoltage short-circuit ratio, if so, determining that the wind turbine generator does not have overvoltage risk, and if not, determining that the wind turbine generator has overvoltage risk.
6. The method of claim 5, wherein calculating the overvoltage short-circuit ratio of each of the wind turbines from the overvoltage of each of the wind turbines and calculating the critical overvoltage short-circuit ratio from the preset maximum overvoltage tolerance value comprises:
substituting the overvoltage of each wind turbine into a third target formula to obtain the overvoltage short-circuit ratio of each wind turbine;
substituting the preset maximum overvoltage tolerance value into the third target formula to obtain the critical overvoltage short-circuit ratio;
the third target formula includes:
MIFIF ij ＝α if ·MIIF ij
MIIF ij ＝|Z ij |/|Z ii |
S aci ＝1/|Z ii |
in gSCR TOV Representing the overvoltage short-circuit ratio of each wind turbine generator, S aci Represents the short-circuit capacity of the point of the parallel connection i, MIFIF ij Representing multi-feed fault phasesInteraction factor, S eqj Representing the equivalent transient capacity of a new energy station j under a fault, f representing a fault node, m representing the number of wind turbines in a target power grid, and k lj The reactive voltage gain coefficient Z of the new energy station j under fault mff Correction impedance matrix for representing fault node f of new energy station f under fault, Z mjf The method comprises the steps that a correction impedance matrix of a fault node f of a new energy station j under a fault is represented, the correction impedance matrix is determined according to overvoltage of each wind turbine generator set, output current of each wind turbine generator set and reactance of each wind turbine generator set when the fault occurs, the reactance of a first type wind turbine generator set is 1/k, k represents a reactive voltage gain coefficient, and the reactance of a second type wind turbine generator set is X s ，X s Representing the stator reactance, k, of a second type of wind turbine ln Representing the reactive voltage gain coefficient, Z, of node n mjn Correction impedance matrix Z representing failure node n of new energy station j under failure mnf Modified impedance matrix representing failure node f of new energy station n under failure, S n Represents the per unit of the node n capacity, S j Representing the per unit of node j capacity, alpha if Representing the failure coefficient, MIIF ij Representing multi-feed interaction factor, |Z ij I represents the transimpedance between nodes i, j, |z ii I represents the self-impedance of node i.
7. The method of claim 6, wherein the third target formula further comprises:
Or->
U tf1 ＝0.9-I max1 /k
I max1 ＝I max -I vq0i
U tf2 ＝0.9-(I max2 +0.1)/(kX s -1)
I max2 ＝X m I rmax -I vq0i X s -1
ΔU ti ＝Z m ΔI
ΔI q ＝S(K l Z m ΔI+I eq )
Wherein k is lj Reactive voltage gain coefficient k representing wind turbine generator node j i Representing the reactive voltage gain coefficient, k, of the node i before correction l1i 、k l2i Respectively representing the reactive voltage gain coefficient of the first type wind turbine generator node I and the reactive voltage gain coefficient of the second type wind turbine generator node I, I max Representing maximum output current of a first type wind turbine generator system side converter during fault occurrence, I max1 Representing maximum output current of first type wind turbine generator set during fault occurrence, I vq0i Indicating rated output current DeltaU of first type wind turbine generator system node i during fault occurrence ti Indicating the voltage variation of node i, U tfi Representing the voltage amplitude during the fault of node i, U tf1 Represents the voltage amplitude limit of the first type wind turbine generator system, S Gi Representing per unit capacity, U, of second type wind turbine generator set where node i is located tf2 Representing the voltage amplitude limit of the second type wind turbine generator system, I rmax Representing maximum output current of rotor-side converter of second type wind turbine generator during fault occurrence, I max2 Represents the maximum output current of the second type wind turbine generator set during the fault occurrence period, delta I represents the vector of the output current of the wind turbine generator set, Z m Representing a modified impedance matrix, wherein the modified impedance matrix is determined according to overvoltage of each wind turbine generator, output current of each wind turbine generator and reactance of each wind turbine generator, the reactance of the first type wind turbine generator is 1/k, k represents a reactive voltage gain coefficient, and the reactance of the second type wind turbine generator is X s ，ΔI q Representing the current vector, I q ＝[I q1 ,…I qj ,…] T S represents the per unit node capacity, K l Representing a matrix of reactive-voltage gain coefficients, I eq Represents an equivalent current source, the firstThe equivalent current source of the type wind turbine generator is I vq0 +k and-0.1 k, wherein the equivalent current source of the second type wind turbine generator is E q /X s ，E q Representing the electromotive force excited by the rotor current.
8. The operation state prediction method according to claim 7, wherein the calculation formula of the electromotive force includes: e (E) q ＝jX m I r ＝jX s I s +U t ，U t ＝U tf 。
9. The method for predicting an operational state of each wind turbine according to claim 5, wherein predicting the operational state of each wind turbine based on the overvoltage risk assessment result of each wind turbine comprises:
if the risk assessment result indicates that the wind turbine generator does not have overvoltage risk, predicting the running state of the wind turbine generator to be a maintenance running state;
and if the risk assessment result indicates that the wind turbine generator has an overvoltage risk, predicting that the running state of the wind turbine generator is a stop running state.
10. The method of operating state prediction according to claim 1, characterized in that the method further comprises:
the formula for calculating the weighted sensitivity matrix includes:
in the formula, SE represents, An inverse matrix representing the system admittance matrix after the kran reduction, S B Representing per-unit device capacity matrix, diag -1 (Z m ) Representing an inverse matrix after diagonal elements of the modified impedance matrix are taken to form a diagonal matrix;
and identifying dangerous nodes from the weighted sensitivity matrix so as to enable the power grid to pre-control the dangerous nodes, wherein the dangerous nodes comprise the node with the largest overvoltage after the fault and the node which is most likely to cause the overvoltage risk after the fault.
11. The method of claim 10, wherein identifying dangerous nodes from the weighted sensitivity matrix comprises:
identifying a node corresponding to a row number of a row where the maximum element is located from the weighted sensitivity matrix as a node with the maximum overvoltage after the fault occurs;
and identifying a node corresponding to the column number of the column where the maximum element is located from the weighted sensitivity matrix as the node which is most likely to cause overvoltage risk after the fault occurs.
12. A wind turbine generator system operating condition prediction apparatus, the apparatus comprising:
the parameter acquisition module is suitable for responding to the event that the target power grid fails and acquiring network parameters of the target power grid;
The output current calculation module is suitable for calculating the output current of each wind turbine generator in the target power grid according to the network parameters and a first target formula;
the overvoltage calculation module is suitable for calculating the overvoltage of each wind turbine generator according to the network parameters, the output current of each wind turbine generator and a second target formula;
the overvoltage risk assessment result determining module is suitable for comparing the overvoltage of each wind turbine generator with a preset maximum overvoltage tolerance value to determine an overvoltage risk assessment result of each wind turbine generator;
the wind turbine generator running state determining module is suitable for predicting the running state of each wind turbine generator according to the overvoltage risk assessment result of each wind turbine generator, and the running state comprises a maintaining running state and a stopping running state;
and the power grid equipment adjusting module is suitable for selecting a preset adjusting strategy corresponding to the running state to adjust equipment of the target power grid.
13. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the steps of the wind turbine operating state prediction method of any one of claims 1 to 11 when the program is executed.
14. A computer readable storage medium having stored thereon a computer program, characterized in that the computer program, when executed by a processor, implements the steps of the wind turbine running state prediction method of any of claims 1 to 11.
CN202311474187.4A 2023-11-07 2023-11-07 Wind turbine running state prediction method and device Pending CN117726020A (en)

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CN202311474187.4A CN117726020A (en) 2023-11-07 2023-11-07 Wind turbine running state prediction method and device

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CN117726020A true CN117726020A (en) 2024-03-19

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