Wind turbine icing and grid-trip risk warning method and system based on relative humidity

Abstract

The present invention relates to the field of wind power generation prediction and control technology, and discloses a relative humidity-based wind turbine icing and grid-trip risk warning method and system. The method comprises: obtaining weather forecast information for each forecast time point; for any forecast time point where the forecast temperature is less than zero degrees, substituting the forecast humidity information into a first calculation model fitted according to historical data to obtain visibility at the forecast time point; then substituting the solved visibility into a second calculation model fitted according to historical data to obtain liquid water content at the forecast time point; substituting the calculated liquid water content into a third calculation model fitted according to historical data to obtain the maximum number of wind turbine blades in the wind farm corresponding to the forecast time point that are iced and grid-tripped; and simultaneously substituting the calculated liquid water content into a fourth calculation model fitted according to historical data to obtain the expected number of wind turbines in the wind farm corresponding to the forecast time point that are iced and grid-tripped.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation prediction and control, and in particular to a method and system for early warning of wind turbine icing and grid disconnection risks based on relative humidity. Background Art

[0002] Wind turbines in southern my country are mostly located in mountainous areas at high altitudes. Winter cold snaps expose these turbines to freezing fog, often with high levels of supercooled liquid water. This fog can easily cause ice to form on turbine blades. The increased load from ice on the blades alters aerodynamic characteristics, forcing turbines to shut down. This can easily cause widespread disconnection of wind turbines from the grid, significantly increasing wind power output volatility and leading to unstable power supply.

[0003] Currently, research and technical approaches to address wind turbine blade icing hazards focus primarily on indirect monitoring and early warning of ice thickness, lacking a method for early warning of the risks and impacts of blade icing on wind farms. Therefore, a method for early warning of the risk of grid disconnection caused by blade icing in wind farms is urgently needed, capable of calculating the impact of blade icing and providing early warning. Summary of the Invention

[0004] The purpose of the present invention is to disclose a relative humidity-based wind turbine icing and disconnection risk warning method and system to solve the technical problems in the prior art of the risks and impacts of wind turbine blade icing on wind farms due to lack of warning means.

[0005] To achieve the above-mentioned purpose, the present invention discloses a relative humidity-based wind turbine icing and disconnection risk early warning method, which includes:

[0006] Obtaining weather forecast information for each predicted time point, wherein the weather forecast information includes at least temperature and relative humidity information;

[0007] For any forecast time point where the predicted temperature is less than zero degrees, the forecasted humidity information is substituted into a first calculation model fitted based on historical data to obtain the visibility at that forecast time point. The obtained visibility is then substituted into a second calculation model fitted based on historical data to obtain the liquid water content at that forecast time point.

[0008] The calculated liquid water content is substituted into the third calculation model fitted according to historical data to obtain the maximum number of wind turbine blades in the wind farm that are iced and off the grid corresponding to the predicted time point; at the same time, the calculated liquid water content is substituted into the fourth calculation model fitted according to historical data to obtain the expected number of wind turbines in the wind farm that are iced and off the grid corresponding to the predicted time point.

[0009] Preferably, the specific calculation formula of the first calculation model is:

[0010]

[0011] Where VIS is the observed visibility, c1 and c2 are the first and second parameters of visibility calculated based on historical data, and RH is the observed humidity.

[0012] Preferably, the specific calculation formula of the second calculation model is:

[0013]

[0014] Where LWC is the observed liquid water content, and c3, c4, c5, and c6 are the third, fourth, fifth, and sixth parameters fitted based on historical data, respectively.

[0015] Preferably, the specific calculation formula of the third calculation model is:

[0016]

[0017] in, is the number of wind turbines that are offline in time period t under scenario ω when the liquid water content LWC is s; S is the set of all possible situations of liquid water content; Ω s is the scenario set consisting of the number of possible wind turbines off-grid when the liquid water content is s; T is the analysis period set; t∈T; N t,max The maximum number of wind farm shutdowns and disconnections.

[0018] Preferably, the specific calculation formula of the fourth calculation model is:

[0019]

[0020] Among them, π s is the probability that the liquid water content is s; π ω is the probability of scenario ω, is the expected number of wind turbines that will be disconnected from the grid due to icing.

[0021] To achieve the above-mentioned purpose, the present invention also discloses a relative humidity-based wind turbine icing and grid-off risk warning system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method when executing the computer program.

[0022] The present invention has the following beneficial effects:

[0023] It is simple, practical, logically sound and reliable, and can provide effective early warning for the risk of grid disconnection caused by icing on wind turbine blades in wind farms.

[0024] The present invention will be described in further detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 The present invention is a flowchart of a method for early warning of wind turbine icing and grid disconnection risk based on relative humidity disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0028] Example 1

[0029] This embodiment discloses a method for early warning of wind turbine icing and grid disconnection risk based on relative humidity, the method comprising:

[0030] (1) Collect basic information of the wind farm, i.e. the total number of wind turbines in the wind farm and other data.

[0031] (2) Collect relevant records of wind turbine shutdown and startup during the historical icing process of the wind farm as the basic data of icing shutdown, and collect meteorological data such as visibility VIS, temperature T, relative humidity RH, liquid water content LWC collected by the wind farm during the icing process.

[0032] (3) Based on the data collected in (2), the visibility sequence {vis1, vis2, vis3, ... visn} and the relative humidity sequence {rh1, rh2, rh3, ... rhn} data when the temperature T is less than 0°C at the observation time and the fan is shut down due to icing are taken out. The calculation formula of visibility and relative humidity is constructed by using the exponential function fitting method:

[0033]

[0034] Where VIS is the observed visibility in km; c1 is the first parameter for visibility calculation in km; RH is the observed relative humidity in %; and c2 is the second parameter for visibility calculation, a dimensionless quantity.

[0035] Where c1 and c2 can be obtained by fitting the visibility sequence {vis1, vis2, vis3, …, visn} and the relative humidity sequence {rh1, rh2, rh3, …, rhn}.

[0036] (4) Based on the data collected in (2), the visibility sequence {vis1, vis2, vis3, ... visn} and the liquid water content sequence {lwc1, lwc2, lwc3, ... lwcn} data when the temperature T is less than 0 °C at the observation time and the fan is shut down due to icing are taken out. The calculation formula of visibility and liquid water content is constructed by using the exponential function fitting method:

[0037]

[0038] Where LWC is the observed liquid water content, in g / m3; VIS is the observed visibility, in km; c3 is the first parameter for liquid water content calculation, in g / m3; c4 is the second parameter for liquid water content calculation, in km; c5 is the third parameter for liquid water content calculation, which is a dimensionless quantity; and c6 is the fourth parameter for liquid water content calculation, which is a dimensionless quantity.

[0039] Where c3, c4, c5, and c6 can be obtained by fitting according to the visibility sequence {vis1, vis2, vis3, …, visn} and the relative humidity sequence {lwc1, lwc2, lwc3, …, lwcn}.

[0040] (5) The maximum number of wind turbines that are disconnected from the grid due to ice and the expected value of wind turbines disconnected from the grid due to ice are used as the risk of wind turbines disconnected from the grid due to ice in the wind farm.

[0041] (6) Based on the wind turbine icing shutdown and grid disconnection data and liquid water content data collected in (2), the maximum number of wind farm shutdowns and grid disconnections is calculated:

[0042]

[0043] Where, is the number of wind turbines that are offline in time period t under scenario ω when the liquid water content LWC is s; S is the set of all possible situations of liquid water content; Ω s is the scenario set consisting of the number of possible wind turbines off-grid when the liquid water content is s; T is the analysis period set; t∈T; N t,max The maximum number of wind farm shutdowns and disconnections.

[0044] (7) Based on the wind turbine icing shutdown and off-grid data and liquid water content data collected in (2), the expected number of wind turbines off-grid due to icing is calculated as follows:

[0045]

[0046] Where, π s is the probability that the liquid water content is s; π ω is the probability of scenario ω, is the expected number of wind turbines that will be disconnected from the grid due to icing.

[0047] (8) Obtain hourly weather forecast information for the next three days, including temperature T P , and relative humidity RH P .

[0048] (9) corresponds to a certain time t in the future P , the visibility VIS at that moment can be calculated according to formula 1 P , and then according to formula 2, the liquid water content LWC at that moment can be calculated P .

[0049] (10) LWC P Input them into formula 3 respectively to get t P The maximum number of wind turbine blades covered with ice and disconnected from the grid at the moment

[0050] (11) LWC P Input them into formula 4 respectively to get t P The expected number of wind turbines in the wind farm at the time of wind turbine blade ice accretion and disconnection from the grid

[0051] In summary, the method of the embodiment of the present invention can be summarized as follows: Figure 1 The following steps are shown:

[0052] Step S1: Obtain weather forecast information at each predicted time point, wherein the weather forecast information at least includes temperature and relative humidity information.

[0053] Step S2: For any predicted time point when the predicted temperature is less than zero degrees, the predicted humidity information is substituted into a first calculation model fitted according to historical data to obtain the visibility at the predicted time point, and then the visibility obtained by the solution is substituted into a second calculation model fitted according to historical data to obtain the liquid water content at the predicted time point.

[0054] Step S3: Substitute the calculated liquid water content into a third calculation model fitted based on historical data to obtain the maximum number of wind turbine blades in the wind farm that are iced and off-grid at the predicted time point; at the same time, substitute the calculated liquid water content into a fourth calculation model fitted based on historical data to obtain the expected number of wind turbines in the wind farm that are iced and off-grid at the predicted time point.

[0055] Example 2

[0056] This embodiment discloses a relative humidity-based wind turbine icing and grid-off risk warning system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method when executing the computer program.

[0057] Preferably, the system may specifically include:

[0058] Data collection module: used to collect the basic data required to carry out wind turbine blade icing risk calculation.

[0059] Risk calculation module: Constructs the relationship between relative humidity and visibility, and visibility and liquid water content, and calculates the risk of wind turbine blades being iced and disconnected from the grid.

[0060] Risk warning module: Based on the calculation results, it displays and warns of the possible risk of wind farm wind turbine blades being iced and disconnected from the grid.

[0061] Storage module: stores the calculated warning values ​​of wind turbine icing and grid-trip risk.

[0062] In summary, the method and system disclosed in the embodiments of the present invention are simple, practical, logically reasonable and reliable, and can provide effective early warning of the risk of grid disconnection caused by icing on wind turbine blades in wind farms.

[0063] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A relative humidity-based wind turbine icing and grid-off risk early warning method, characterized in that: include: Obtaining weather forecast information for each predicted time point, wherein the weather forecast information includes at least temperature and relative humidity information; For any forecast time point where the predicted temperature is less than zero degrees, the forecasted humidity information is substituted into a first calculation model fitted based on historical data to obtain the visibility at that forecast time point. The obtained visibility is then substituted into a second calculation model fitted based on historical data to obtain the liquid water content at that forecast time point. The calculated liquid water content is substituted into a third calculation model fitted based on historical data to obtain the maximum number of wind turbine blades in the wind farm that are iced and off-grid at the predicted time point. At the same time, the calculated liquid water content is substituted into a fourth calculation model fitted based on historical data to obtain the expected number of wind turbines in the wind farm that are iced and off-grid at the predicted time point. The specific calculation formula of the first calculation model is: Where VIS is the observed visibility, c1 and c2 are the first and second parameters of visibility calculated based on historical data, and RH is the observed humidity. The specific calculation formula of the second calculation model is: Where LWC is the observed liquid water content, c3, c4, c5, and c6 are the third, fourth, fifth, and sixth parameters fitted based on historical data, respectively; The specific calculation formula of the third calculation model is: in, is the number of wind turbines that are offline in time period t under scenario ω when the liquid water content LWC is s; S is the set of all possible situations of liquid water content; Ω s is the scenario set consisting of the number of possible wind turbines off-grid when the liquid water content is s; T is the analysis period set; t∈T; N t,max The maximum number of wind farm shutdowns and disconnections; The specific calculation formula of the fourth calculation model is: Among them, π s is the probability that the liquid water content is s; π ω is the probability of scenario ω, E(N t ) is the expected number of wind turbines that are disconnected from the grid due to icing.

2. A relative humidity-based wind turbine icing and grid-trip risk warning system, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to claim 1 is implemented.

Images