A wind turbine blade clearance control method and system

Abstract

The application relates to the technical field of wind turbine units, in particular to a wind turbine unit blade clearance control method and system. The method comprises the following steps: constructing multiple adjustment periods, and generating a wind speed prediction curve in the current adjustment period according to a preset wind speed prediction model; setting a pitch angle control strategy and a clearance value threshold curve in the current adjustment period according to the wind speed prediction curve; establishing multiple monitoring points according to wind turbine equipment parameters, and acquiring real-time monitoring data collected by each monitoring point; judging whether to generate a compensation instruction according to the real-time monitoring data, and correcting the pitch angle control strategy in the current adjustment period according to the compensation instruction. Through the establishment of the adjustment period, the real-time clearance state of the fan blade is monitored, the clearance value threshold is dynamically adjusted according to the wind speed change and other parameters, the problem of insufficient clearance of the wind turbine unit blade is timely warned, and through the active compensation mechanism, the tower clearance is improved, and the safe operation of the wind turbine unit is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind turbine, in particular to a wind turbine blade clearance control method and system. BACKGROUND

[0002] With the increasing demand for clean energy worldwide, wind turbine installations are increasing year by year, and as an important renewable energy technology, it has developed rapidly. Wind turbine design is getting higher and longer, as the core equipment of wind power, its safe and stable operation is crucial. The wind turbine tower clearance is a key parameter. It not only relates to the structural safety of the unit itself, but also has an important influence on the operation efficiency and economic benefit of the entire wind farm.

[0003] At present, wind resource development is gradually shifting to low wind speed and high turbulence wind resource areas. Such wind farms are mostly complex mountainous terrain, and there are more extreme gusts. The characteristics of gusts are that wind speed and direction change greatly in a short time, and extreme turbulence and extreme wind shear are easy to occur. At this time, wind turbines face the problem of insufficient clearance, and there have been many tower sweeping accidents in the industry. SUMMARY

[0004] The purpose of the present application is to solve the above technical problems, the present application provides a wind turbine blade clearance control method and system, which aims to improve the efficiency of wind turbine blade clearance control and ensure the safe operation of wind turbine.

[0005] In some embodiments of the present application, by establishing an adjustment period, the real-time clearance state of the wind turbine blade is monitored, the clearance value threshold is dynamically adjusted according to the wind speed change and other parameters, the problem of insufficient clearance of the wind turbine blade is timely warned, and through the active compensation mechanism, the tower clearance is improved, the control efficiency of the wind turbine clearance is improved, and the safe operation of the wind turbine is ensured.

[0006] In some embodiments of the present application, multiple time intervals are constructed within a single adjustment period, so as to periodically monitor the original pitch angle control strategy, and dynamically optimize according to the real-time deviation evaluation value, improve the efficiency of wind turbine clearance control, and reduce the probability of blade tower sweeping accidents.

[0007] In some embodiments of the present application, a wind turbine blade clearance control method is provided, comprising:

[0008] A plurality of adjustment periods are constructed, and a wind speed prediction curve in the current adjustment period is generated according to a preset wind speed prediction model;

[0009] The pitch angle control strategy and the clearance value threshold curve in the current adjustment period are set according to the wind speed prediction curve;

[0010] According to the wind turbine equipment parameters, a plurality of monitoring points are established, and real-time monitoring data collected by each monitoring point is obtained;

[0011] According to the real-time monitoring data, it is judged whether to generate a compensation instruction, and the pitch angle control strategy in the current adjustment period is corrected according to the compensation instruction.

[0012] In some embodiments of the application, when the plurality of adjustment periods are constructed, the following steps are included:

[0013] Obtain historical environmental data and wind turbine equipment parameters, and generate a historical evaluation value a;

[0014]

[0015] Wherein, e1 is a preset first fixed coefficient; e2 is a preset second fixed coefficient; Q1 is a preset first weight coefficient; Q2 is a preset second weight coefficient; θ1 is the number of environmental evaluation indexes; βi is the influence factor of the ith environmental evaluation index; ji is the reference value of the ith environmental evaluation index based on historical environmental data; θ2 is the number of equipment evaluation indexes; αi is the influence factor of the ith equipment evaluation index; pi is the reference value of the ith equipment evaluation index based on wind turbine equipment parameters;

[0016] According to the historical evaluation value a, the duration t of the adjustment period is set, and a plurality of adjustment periods are constructed.

[0017] In some embodiments of the application, when the duration t of the adjustment period is set, the following steps are included:

[0018] A preset first historical evaluation value interval (A1, A2), a second historical evaluation value interval (A2, A3) and a third historical evaluation value interval (A3, A4) are set;

[0019] If a is in the preset first historical evaluation interval, set the duration t as a preset first duration T1, i.e. t = T1;

[0020] If a is in the preset second historical evaluation interval, set the duration t as a preset second duration T2, i.e. t = T2;

[0021] If a is in the preset third historical evaluation interval, set the duration t as a preset first duration T3, i.e. t = T3; and T1 < T2 < T3.

[0022] In some embodiments of the application, when the pitch angle control strategy and the clearance threshold curve in the current adjustment period are set, the following steps are included:

[0023] According to the wind speed prediction curve, a plurality of time intervals are set in the current adjustment period;

[0024] establish a time interval sequence B of the current adjustment period, B=(b1, b2…bi…bn), wherein bi is the i th time interval in the current adjustment time interval; n is the number of time intervals in the current adjustment period;

[0025] generate an expected wind rate change value in each time interval according to the wind speed prediction curve, and set a clearance value threshold in each time interval according to all expected wind rate change values;

[0026] establish a clearance value threshold sequence C, C=(c1, c2…ci…cn), wherein ci is the clearance value threshold in the i th time interval;

[0027] generate a clearance value threshold curve in the current adjustment period according to the clearance value threshold sequence C;

[0028] set a pitch angle control strategy in the current adjustment period according to the wind speed prediction curve and the clearance value threshold curve.

[0029] In some embodiments of the present application, when determining whether to generate a compensation instruction according to real-time monitoring data, the following steps are included:

[0030] a plurality of feedback time nodes are preset in the current adjustment period;

[0031] monitoring data collected by each monitoring point at the current feedback time node is obtained, and an actual clearance value c' and a deviation evaluation value f of the current feedback time node are generated;

[0032] determine whether to generate a correction instruction according to the deviation evaluation value f, and set a correction coefficient r;

[0033] obtain the clearance value threshold Δc of the time interval corresponding to the current feedback time node;

[0034] if c' < r* Δc, a compensation instruction is generated at the current feedback time node, and the pitch angle control strategy in the current adjustment period is corrected according to the compensation instruction.

[0035] In some embodiments of the present application, when generating the deviation evaluation value f of the current feedback time node, the following steps are included:

[0036]

[0037] wherein e3 is a preset third weight coefficient; e4 is a preset fourth weight coefficient; Q3 is a preset third fixed coefficient; Q4 is a preset fourth fixed coefficient; n1 is the number of time intervals between the start time node of the current adjustment period and the current feedback time node; di is the actual wind rate change value in the i th time interval of the current adjustment period; d' i is the expected wind rate change value in the i th time interval of the current adjustment period; d n1This represents the actual wind rate change at the current feedback time point; d' n1 Y is the expected wind rate change value within the time interval corresponding to the current feedback time node; Y is the selection function, if (d n1 -d' n1) If ≤0, then Y=0; if (d n1 -d' n1) If Y > 0, then Y = 1.

[0038] In some embodiments of this application, when determining whether to generate a correction instruction based on the deviation evaluation value f, the following are included:

[0039] A first deviation evaluation value threshold F1 and a second deviation evaluation value threshold F2 are preset, and F1 < F2;

[0040] If f < F1, no correction instruction is generated within the current feedback time node, and r = 1 is set;

[0041] If F1≤f<F2, a first-level correction instruction is generated at the current feedback time point, and a correction coefficient r is set according to the deviation from the evaluation value f;

[0042] If f > F2, a secondary correction instruction is generated at the current feedback time node, and the wind speed prediction curve within the current adjustment cycle is updated according to the secondary correction instruction. The correction coefficient r is set according to the update result.

[0043] In some embodiments of this application, a wind turbine blade clearance control system is provided, including:

[0044] The central control unit is used to construct multiple adjustment cycles and establish multiple monitoring points based on the wind turbine equipment parameters;

[0045] The monitoring unit is used to collect real-time monitoring data from each monitoring point;

[0046] The central control unit includes:

[0047] The first processing module is used to generate the wind speed prediction curve for the current adjustment cycle based on the preset wind speed prediction model.

[0048] The second processing module is used to set the pitch angle control strategy and the clearance threshold curve for the current adjustment cycle based on the wind speed prediction curve.

[0049] The compensation module is used to determine whether to generate a compensation command based on real-time monitoring data, and to correct the pitch angle control strategy within the current adjustment cycle based on the compensation command.

[0050] The third processing module is used to acquire historical environmental data and wind turbine equipment parameters, and generate historical evaluation value a;

[0051]

[0052] wherein e1 is a preset first fixed coefficient; e2 is a preset second fixed coefficient; Q1 is a preset first weight coefficient; Q2 is a preset second weight coefficient; θ1 is the number of environmental evaluation indexes; βi is the influence factor of the i-th environmental evaluation index; ji is the reference value of the i-th environmental evaluation index generated based on historical environmental data; θ2 is the number of equipment evaluation indexes; αi is the influence factor of the i-th equipment evaluation index; pi is the reference value of the i-th equipment evaluation index based on the wind turbine equipment parameter setting;

[0053] The length t of the adjustment period is set according to the historical evaluation value a, and a plurality of adjustment periods are constructed.

[0054] In some embodiments of the present application, the second processing module is further configured to:

[0055] A plurality of time intervals are set in the current adjustment period according to the wind speed prediction curve;

[0056] A time interval sequence B of the current adjustment period is established, B=(b1, b2…bi…bn), wherein bi is the i-th time interval in the current adjustment time interval; and n is the number of time intervals in the current adjustment period.

[0057] The expected wind rate change value in the time interval is generated according to the wind speed prediction curve, and the clearance value threshold in each time interval is set according to all expected wind rate change values;

[0058] A clearance value threshold sequence C is established, C=(c1, c2…ci…cn), wherein ci is the clearance value threshold in the i-th time interval.

[0059] A clearance value threshold curve in the current adjustment period is generated according to the clearance value threshold sequence C.

[0060] The pitch angle control strategy in the current adjustment period is set according to the wind speed prediction curve and the clearance value threshold curve.

[0061] In some embodiments of the present application, the compensation module is further configured to:

[0062] A plurality of feedback time nodes are preset in the current adjustment period.

[0063] The monitoring data collected by each monitoring point at the current feedback time node is obtained, and the actual clearance value c' and the deviation evaluation value f of the current feedback time node are generated.

[0064] Whether to generate a correction instruction is determined according to the deviation evaluation value f, and a correction coefficient r is set.

[0065] The clearance value threshold Δc of the time interval corresponding to the current feedback time node is obtained.

[0066] If c' < r*Ac, the current feedback time node generates a compensation instruction, and modifies the pitch angle control strategy in the current adjustment period according to the compensation instruction.

[0067] Compared with the prior art, the wind turbine blade clearance control method and system provided in the embodiments of the present application has the beneficial effects that:

[0068] By establishing an adjustment period, the real-time clearance state of the wind turbine blade is monitored, the clearance threshold value is dynamically adjusted according to the wind speed change and other parameters, the problem of insufficient clearance of the wind turbine blade is timely warned, and the tower clearance is improved through the active compensation mechanism, the control efficiency of the wind turbine clearance is improved, and the safe operation of the wind turbine is ensured.

[0069] In a single adjustment period, multiple time intervals are constructed, so that the original pitch angle control strategy is periodically monitored, and is dynamically optimized according to the real-time deviation evaluation value, the clearance control efficiency of the wind turbine is improved, and the probability of the blade tower scanning accident is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0070] Figure 1 is a flowchart of a wind turbine blade clearance control method in a preferred embodiment of the present application. DETAILED DESCRIPTION

[0071] The specific embodiments of the present application will be further described in detail below in combination with the drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application.

[0072] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0073] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.

[0074] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, can be electrically connected; can be directly connected, can be indirectly connected through an intermediate medium, and can be internal communication of two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0075] As Figure 1 shown, the wind turbine blade clearance control method of the preferred embodiment of the present application comprises:

[0076] S101: Constructing a plurality of adjustment periods, and generating a wind speed prediction curve in the current adjustment period according to a preset wind speed prediction model;

[0077] S102: Setting a pitch angle control strategy and a clearance value threshold curve in the current adjustment period according to the wind speed prediction curve;

[0078] S103: Establishing a plurality of monitoring points according to wind turbine equipment parameters, and acquiring real-time monitoring data collected by each monitoring point;

[0079] S104: Determining whether to generate a compensation instruction according to the real-time monitoring data, and correcting the pitch angle control strategy in the current adjustment period according to the compensation instruction.

[0080] Specifically, laser clearance monitoring devices are arranged at part of the monitoring points, and when the blade rotates to the monitoring point, the laser beam can quickly collect the distance from the blade tip monitoring point to the laser clearance monitoring device. After coordinate transformation, the tower clearance value is calculated. Laser wind radar is arranged at part of the monitoring points, which can measure the wind shear and wind speed variation rate of the incoming flow direction in real time.

[0081] Specifically, a wind speed prediction model is constructed according to historical monitoring parameters, the real-time clearance value threshold is dynamically adjusted according to the predicted wind speed, and the early warning efficiency for potential blade tower scanning risk is improved. Ensure the safe operation of the wind turbine.

[0082] Specifically, when constructing a plurality of adjustment periods, it comprises:

[0083] Acquire historical environmental data and wind turbine equipment parameters, and generate a historical evaluation value a;

[0084]

[0085] Wherein, e1 is a preset first fixed coefficient; e2 is a preset second fixed coefficient; Q1 is a preset first weight coefficient; Q2 is a preset second weight coefficient; θ1 is the number of environmental evaluation indexes; βi is the influence factor of the i th environmental evaluation index; j i is the reference value of the i th environmental evaluation index generated based on historical environmental data; θ2 is the number of equipment evaluation indexes; αi is the influence factor of the i th equipment evaluation index; p i is the reference value of the i th equipment evaluation index based on the wind turbine equipment parameter setting;

[0086] The length t of the adjustment period is set according to the historical evaluation value a, and a plurality of adjustment periods are constructed.

[0087] Specifically, by setting the first fixed coefficient and the second fixed coefficient, all parameters in the model are normalized, so that each parameter is in the same value range.

[0088] Specifically, the environmental evaluation indexes include but are not limited to historical wind speed average, wind speed variation frequency, temperature, wind direction variation frequency and other parameters that may affect the clearance value, and the equipment evaluation indexes include but are not limited to blade parameters, wind turbine historical operation time, blade tower scanning failure frequency and other parameters. The greater the historical evaluation value is, the smaller the possibility of current wind turbine operation fluctuation and tower scanning risk is.

[0089] Specifically, when setting the length t of the adjustment period, it includes:

[0090] The preset first historical evaluation value interval (A1, A2), the second historical evaluation value interval (A2, A3) and the third historical evaluation value interval (A3, A4) are set.

[0091] If a is in the preset first historical evaluation interval, the length t is set to the preset first length T1, that is, t=T1;

[0092] If a is in the preset second historical evaluation interval, the length t is set to the preset second length T2, that is, t=T2;

[0093] If a is in the preset third historical evaluation interval, the length t is set to the preset first length T3, that is, t=T3; and T1

[0094] It can be understood that in the above embodiment, the length of a single adjustment period is dynamically adjusted, thereby improving the accuracy of the control strategy in a single adjustment period, improving the adjustment efficiency of the clearance compensation, and avoiding that the expected data deviates greatly from the actual data due to the too long single adjustment period, thereby affecting the clearance control efficiency.

[0095] In the preferred embodiment of the present application, when setting the pitch angle control strategy and the clearance value threshold curve in the current adjustment period, it includes:

[0096] a plurality of time intervals are set according to the wind speed prediction curve in the current adjustment period;

[0097] a time interval sequence B of the current adjustment period is established, B=(b1, b2…bi…bn), wherein bi is the i-th time interval in the current adjustment time interval; n is the number of time intervals in the current adjustment period;

[0098] expected wind rate change values in the time intervals are generated according to the wind speed prediction curve, and the clearance value threshold in each time interval is set according to all expected wind rate change values;

[0099] a clearance value threshold sequence C is established, C=(c1, c2…ci…cn), wherein ci is the clearance value threshold in the i-th time interval;

[0100] a clearance value threshold curve in the current adjustment period is generated according to the clearance value threshold sequence C;

[0101] a pitch angle control strategy in the current adjustment period is set according to the wind speed prediction curve and the clearance value threshold curve.

[0102] Specifically, the clearance value threshold refers to the minimum safe clearance value allowed by the fan blade in the current time interval, and when the actual clearance value is less than the clearance value threshold, there is a great possibility of tower scanning failure.

[0103] Specifically, the wind speed prediction curve is processed, and the number of time intervals is set according to the average wind speed change rate. The greater the average wind speed change rate, the more the number of time intervals.

[0104] Specifically, expected wind rate change values in each time interval are generated according to the wind speed prediction curve, and safe clearance values in each time interval are generated in combination with the average wind speed in each time interval and historical operation parameters, and the safe clearance values are set as the clearance value thresholds. Thus, the clearance value threshold sequence is constructed.

[0105] Specifically, when determining whether to generate a compensation instruction according to real-time monitoring data, it includes:

[0106] a plurality of feedback time nodes are preset in the current adjustment period;

[0107] monitoring data collected by each monitoring point at the current feedback time node is obtained, and an actual clearance value c' and a deviation evaluation value f of the current feedback time node are generated;

[0108] whether to generate a correction instruction is determined according to the deviation evaluation value f, and a correction coefficient r is set;

[0109] the clearance value threshold Δc of the time interval corresponding to the current feedback time node is obtained;

[0110] If c' < r * Δc, the current feedback time node generates a compensation instruction, and modifies the pitch angle control strategy in the current adjustment period according to the compensation instruction.

[0111] Specifically, when the real-time clearance value is less than the clearance value threshold, it indicates that the possibility of tower scanning risk in the current time interval is relatively large, and a compensation value needs to be superimposed on the original pitch angle control strategy to reduce the thrust of the wind wheel surface, improve the tower clearance, and at the time node when the current time interval ends, the pitch angle compensation value exits at a ramp rate.

[0112] It can be understood that in the above embodiment, by constructing multiple time intervals in a single adjustment period, the original pitch angle control strategy is periodically monitored, and dynamically optimized according to the real-time deviation evaluation value, thereby improving the clearance control efficiency of the wind turbine and reducing the probability of blade tower scanning accidents.

[0113] In the preferred embodiment of the present application, when the deviation evaluation value f of the current feedback time node is generated, it includes:

[0114]

[0115] Wherein e3 is a preset third weight coefficient; e4 is a preset fourth weight coefficient; Q3 is a preset third fixed coefficient; Q4 is a preset fourth fixed coefficient; n1 is the number of time intervals between the start time node of the current adjustment period and the current feedback time node; di is the actual wind rate change value in the i th time interval of the current adjustment period; d' i is the expected wind rate change value in the i th time interval of the current adjustment period; d' n1 is the actual wind rate change value at the current feedback time node; d' n1 is the expected wind rate change value in the time interval corresponding to the current feedback time node; Y is a selection function, if (d n1 -d' n1) ≤0, Y=0; if (d n1 -d' n1) >0, Y=1.

[0116] Specifically, by setting the third fixed coefficient and the fourth fixed coefficient, all parameters in the model are normalized, so that each parameter is in the same value range.

[0117] Specifically, by periodically generating the deviation evaluation value, the original wind speed prediction curve is monitored, and the corresponding clearance value threshold is adjusted in a timely manner according to the deviation value, so as to avoid misjudgment of real-time tower scanning risk caused by deviation of expected data.

[0118] Specifically, when judging whether to generate a correction instruction according to the deviation evaluation value f, it includes:

[0119] a first deviation evaluation value threshold F1 and a second deviation evaluation value threshold F2 are preset, and F1 < F2;

[0120] If f < F1, no correction instruction is generated in the current feedback time node, and r = 1 is set;

[0121] If F1 ≤ f < F2, a first-level correction instruction is generated in the current feedback time node, and a correction coefficient r is set according to the deviation evaluation value f;

[0122] If f > F2, a second-level correction instruction is generated in the current feedback time node, and the wind speed prediction curve in the current adjustment period is updated according to the second-level correction instruction, and a correction coefficient r is set according to the update result.

[0123] Specifically, in the first-level correction instruction, the greater the deviation evaluation value, the greater the corresponding correction coefficient r, and in the second-level correction instruction, the original wind speed prediction curve needs to be corrected, and the clearance value threshold in the current time interval is updated according to the corrected wind speed prediction curve, and the correction coefficient r is set as the ratio between the updated clearance value threshold and the original clearance value threshold.

[0124] It can be understood that in the above embodiment, the original wind speed prediction curve is continuously optimized and corrected by monitoring the operation data of the wind turbine in real time, thereby improving the early warning efficiency of potential tower-sweeping failure, improving the clearance control efficiency of the wind turbine, and reducing the probability of tower-sweeping accident of the blade.

[0125] Based on any one of the wind turbine blade clearance control methods in the above preferred embodiments, another preferred embodiment of the wind turbine blade clearance control system in the preferred embodiment comprises:

[0126] The central control unit is configured to construct a plurality of adjustment periods and establish a plurality of monitoring points according to the wind turbine equipment parameters;

[0127] The monitoring unit is configured to collect real-time monitoring data of each monitoring point;

[0128] The central control unit comprises:

[0129] The first processing module is configured to generate a wind speed prediction curve in the current adjustment period according to a preset wind speed prediction model;

[0130] The second processing module is configured to set a pitch angle control strategy and a clearance value threshold curve in the current adjustment period according to the wind speed prediction curve;

[0131] The compensation module is configured to determine whether to generate a compensation instruction according to the real-time monitoring data, and correct the pitch angle control strategy in the current adjustment period according to the compensation instruction;

[0132] The third processing module is configured to acquire historical environmental data and wind turbine equipment parameters, and generate a historical evaluation value a;

[0133]

[0134] wherein e1 is a preset first fixed coefficient; e2 is a preset second fixed coefficient; Q1 is a preset first weight coefficient; Q2 is a preset second weight coefficient; θ1 is the number of environmental evaluation indexes; βi is an influence factor of the i-th environmental evaluation index; ji is a reference value of the i-th environmental evaluation index generated based on historical environmental data; θ2 is the number of equipment evaluation indexes; αi is an influence factor of the i-th equipment evaluation index; and pi is a reference value of the i-th equipment evaluation index set based on wind turbine equipment parameters;

[0135] The length t of the adjustment period is set according to the historical evaluation value a, and a plurality of adjustment periods are constructed.

[0136] Specifically, the monitoring unit includes a laser light clearance monitoring device and a laser wind radar. The laser light clearance monitoring device is arranged at part of the monitoring points. When the blade rotates to the monitoring point, the laser beam can quickly collect the distance from the blade tip monitoring point to the laser light clearance monitoring device. After coordinate transformation, the tower clearance value is converted. The laser wind radar is arranged at part of the monitoring points, and can measure the wind shear and wind speed variation rate of the incoming flow direction in real time.

[0137] In the preferred embodiment of the present application, the second processing module is further configured to:

[0138] A plurality of time intervals are set in the current adjustment period according to the wind speed prediction curve;

[0139] A time interval sequence B of the current adjustment period is established, B=(b1, b2…bi…bn), wherein bi is the i-th time interval in the current adjustment time interval, and n is the number of time intervals in the current adjustment period.

[0140] The expected wind rate change value in the time interval is generated according to the wind speed prediction curve, and the clearance value threshold in each time interval is set according to all expected wind rate change values;

[0141] A clearance value threshold sequence C is established, C=(c1, c2…ci…cn), wherein ci is the clearance value threshold in the i-th time interval;

[0142] The clearance value threshold curve in the current adjustment period is generated according to the clearance value threshold sequence C;

[0143] The pitch angle control strategy in the current adjustment period is set according to the wind speed prediction curve and the clearance value threshold curve.

[0144] In the preferred embodiment of the present application, the compensation module is further configured to:

[0145] presetting a plurality of feedback time nodes in the current adjustment period;

[0146] obtaining monitoring data collected by each monitoring point at the current feedback time node, and generating an actual clearance value c' and a deviation evaluation value f of the current feedback time node;

[0147] judging whether to generate a correction instruction according to the deviation evaluation value f, and setting a correction coefficient r;

[0148] obtaining a clearance value threshold Δc of the time interval corresponding to the current feedback time node;

[0149] if c' < r* Δc, generating a compensation instruction at the current feedback time node, and correcting the pitch angle control strategy in the current adjustment period according to the compensation instruction.

[0150] According to the first concept of the present application, the real-time clearance state of the fan blade is monitored by establishing an adjustment period, the clearance value threshold is dynamically adjusted according to the wind speed change and other parameters, the problem of insufficient clearance of the wind turbine blade is timely warned, the tower clearance is improved through the active compensation mechanism, the control efficiency of the wind turbine clearance is improved, and the safe operation of the wind turbine is ensured.

[0151] According to the second concept of the present application, a plurality of time intervals are constructed in a single adjustment period, so that the original pitch angle control strategy is periodically monitored, and dynamically optimized according to the real-time deviation evaluation value, the clearance control efficiency of the wind turbine is improved, and the probability of blade tower scanning accident is reduced.

[0152] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and replacements can be made, which should be considered as the protection scope of the present application.

Claims

1. A method for controlling the clearance of wind turbine blades, characterized in that, include: Multiple adjustment cycles are constructed, and the wind speed prediction curve for the current adjustment cycle is generated based on the preset wind speed prediction model. Set the pitch angle control strategy and clearance threshold curve for the current adjustment cycle based on the wind speed prediction curve; Multiple monitoring points were established based on the equipment parameters of the wind turbine, and real-time monitoring data collected from each monitoring point was obtained. The system determines whether to generate a compensation command based on real-time monitoring data, and corrects the pitch angle control strategy within the current adjustment cycle based on the compensation command. When constructing multiple adjustment cycles, the following are included: Acquire historical environmental data and wind turbine equipment parameters, and generate historical evaluation value 'a'; a=e1*Q1+ (βi*ji)]+e2*Q2* (αi*pi)]; Where e1 is the preset first fixed coefficient; e2 is the preset second fixed coefficient; Q1 is the preset first weight coefficient; Q2 is the preset second weight coefficient; θ1 is the number of environmental assessment indicators; βi is the influence factor of the i-th environmental assessment indicator; ji is the reference value of the i-th environmental assessment indicator generated based on historical environmental data; θ2 is the number of equipment assessment indicators; αi is the influence factor of the i-th equipment assessment indicator; and pi is the reference value of the i-th equipment assessment indicator set based on the wind turbine equipment parameters. The duration t of the adjustment cycle is set based on the historical evaluation value 'a', and multiple adjustment cycles are constructed. When setting the pitch angle control strategy and clearance threshold curve for the current adjustment cycle, the following are included: Multiple time intervals are set within the current adjustment cycle based on the wind speed prediction curve; Establish a time interval sequence B for the current adjustment cycle, B=(b1, b2, ..., bi, ..., bn), where bi is the i-th time interval in the current adjustment time interval; n is the number of time intervals in the current adjustment cycle. The expected wind rate change value is generated within the time interval based on the wind speed prediction curve, and the net air value threshold is set within each time interval based on all expected wind rate change values. Establish a net air value threshold sequence C, C=(c1, c2…ci…cn), where ci is the net air value threshold in the i-th time interval; Generate the net air value threshold curve for the current adjustment period based on the net air value threshold sequence C; The pitch angle control strategy for the current adjustment cycle is set based on the wind speed prediction curve and the airspace threshold curve.

2. The wind turbine blade clearance control method as described in claim 1, characterized in that, When setting the duration t of the adjustment period, it includes: The first historical evaluation value range (A1, A2), the second historical evaluation value range (A2, A3), and the third historical evaluation value range (A3, A4) are preset. If a is within the preset first historical evaluation interval, the set duration t is the preset first duration T1, i.e., t=T1; If a is within the preset second historical evaluation interval, the set duration t is the preset second duration T2, i.e., t=T2; If a is within the preset third historical evaluation interval, the set duration t is the preset first duration T3, i.e., t=T3; and T1 <T2<T3。 3. The wind turbine blade clearance control method as described in claim 2, characterized in that, When determining whether to generate a compensation command based on real-time monitoring data, the following are included: Multiple feedback time points are preset within the current adjustment cycle; Acquire the monitoring data collected from each monitoring point at the current feedback time point, and generate the actual net air value c' and deviation evaluation value f at the current feedback time point; Based on the deviation from the evaluation value f, determine whether to generate a correction instruction and set the correction coefficient r; Obtain the clearance value threshold ∆c corresponding to the current feedback time node within the time interval; If c' < r * ∆c, generate a compensation instruction at the current feedback time node, and correct the pitch angle control strategy within the current adjustment period according to the compensation instruction.

4. The wind turbine blade clearance control method as described in claim 3, characterized in that, When generating the deviation evaluation value f of the current feedback time node, it includes: f=e3*Q3* (d i -d' i) 2 ]+e4*Q4*Y*(d n1 -d' n1 ); Where e3 is the preset third weighting coefficient; e4 is the preset fourth weighting coefficient; Q3 is the preset third fixed coefficient; Q4 is the preset fourth fixed coefficient; n1 is the number of time intervals between the start time node and the current feedback time node of the current adjustment cycle; di is the actual wind rate change value in the i-th time interval of the current adjustment cycle; d' i d represents the expected wind rate change within the i-th time interval of the current adjustment cycle; n1 This represents the actual wind rate change at the current feedback time point; d' n1 Y is the expected wind rate change value within the time interval corresponding to the current feedback time node; Y is the selection function, if (d n1 -d' n1） If ≤0, then Y=0; if (d n1 -d' n1） If the value is greater than 0, then Y = 1.

5. The wind turbine blade clearance control method as described in claim 4, characterized in that, When judging whether to generate a correction instruction according to the deviation evaluation value f, it includes: Preset the first deviation evaluation value threshold F1 and the second deviation evaluation value threshold F2, and F1 < F2; If f < F1, no correction instruction is generated within the current feedback time node, and set r = 1; If F1 ≤ f < F2, generate a first-level correction instruction at the current feedback time node, and set the correction coefficient r according to the deviation evaluation value f; If f > F2, generate a second-level correction instruction at the current feedback time node, update the wind speed prediction curve within the current adjustment period according to the second-level correction instruction, and set the correction coefficient r according to the update result.

6. A wind turbine blade clearance control system, employing the wind turbine blade clearance control system described in any one of claims 1-5, characterized in that, It includes: The central control unit is used to construct multiple adjustment periods and establish multiple monitoring points according to the wind turbine equipment parameters; The monitoring unit is used to collect the real-time monitoring data of each monitoring point; The central control unit includes: The first processing module is used to generate the wind speed prediction curve within the current adjustment period according to the preset wind speed prediction model; The second processing module is used to set the pitch angle control strategy and the clearance value threshold curve within the current adjustment period according to the wind speed prediction curve; The compensation module is used to judge whether to generate a compensation instruction according to the real-time monitoring data, and correct the pitch angle control strategy within the current adjustment period according to the compensation instruction; The third processing module is used to obtain the historical environmental data and the wind turbine equipment parameters, and generate the historical evaluation value a; a=e1*Q1+ (βi*ji)]+e2*Q2* (αi*pi)]; Among them, e1 is the preset first fixed coefficient; e2 is the preset second fixed coefficient; Q1 is the preset first weight coefficient; Q2 is the preset second weight coefficient; θ1 is the number of environmental evaluation indicators; βi is the influence factor of the i-th environmental evaluation indicator; ji is the reference value of the i-th environmental evaluation indicator generated based on the historical environmental data; θ2 is the number of equipment evaluation indicators; αi is the influence factor of the i-th equipment evaluation indicator; pi is the reference value of the i-th equipment evaluation indicator set based on the wind turbine equipment parameters; Set the duration t of the adjustment period according to the historical evaluation value a, and construct multiple adjustment periods.

7. The wind turbine blade clearance control system as described in claim 6, characterized in that, The second processing module is also used for: Set multiple time intervals within the current adjustment period according to the wind speed prediction curve; Establish the time interval sequence B of the current adjustment period, B = (b1, b2…bi…bn), where bi is the i-th time interval within the current adjustment time interval; n is the number of time intervals within the current adjustment period; Generate the expected wind rate change value within the time interval according to the wind speed prediction curve, and set the clearance value threshold within each time interval according to all the expected wind rate change values; Establish the clearance value threshold sequence C, C = (c1, c2…ci…cn), where ci is the clearance value threshold of the i-th time interval; Generate the clearance value threshold curve within the current adjustment period according to the clearance value threshold sequence C; Set the pitch angle control strategy within the current adjustment period according to the wind speed prediction curve and the clearance value threshold curve.

8. The wind turbine blade clearance control system as described in claim 7, characterized in that, The compensation module is further configured to: Preset a plurality of feedback time nodes within the current adjustment period; Obtain the monitoring data collected at each monitoring point at the current feedback time node, and generate the actual clearance value c' and the deviation evaluation value f at the current feedback time node; Judge whether to generate a correction instruction according to the deviation evaluation value f, and set the correction coefficient r; Obtain the clearance value threshold ∆c for the time interval corresponding to the current feedback time node; If c' < r * ∆c, a compensation instruction is generated at the current feedback time node, and the pitch angle control strategy within the current adjustment period is corrected according to the compensation instruction.

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