阅读说明：本技术 一种风力机叶片双轴共振式疲劳加载响应相位关系的方法 (Method for double-shaft resonance type fatigue loading response phase relation of wind turbine blade ) 是由 石可重 宋娟娟 秦志文 张明明 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种风力机叶片双轴共振式疲劳加载响应相位关系的方法,针对现有在风力机叶片疲劳测试上大都采用单方向施加载荷,而在一些开展的双方向疲劳加载研究方面,尤其是采用共振激振的双方向疲劳加载研究与尝试方面,叶片在挥舞与摆振两个方向的振动相位关系难与控制,是制约着双方向疲劳加载在测试行业应用的一个瓶颈问题,通过在风电叶片挥舞或摆振方向安装阻尼调节装置,根据试验中挥舞与摆振方向的相位差值,对阻尼进行调整,实现挥舞与摆振方向的相位差保持在所需要的关系。(The invention discloses a method for responding to a phase relation of double-shaft resonance type fatigue loading of a wind turbine blade, which aims at solving the problem that the existing wind turbine blade fatigue test mostly adopts unidirectional applied load, and the vibration phase relation of the blade in the waving direction and the shimmy direction is difficult to control in the aspects of developing bidirectional fatigue loading research, particularly in the aspects of bidirectional fatigue loading research and trial by adopting resonance excitation, so that the bottleneck problem of restricting the application of the bidirectional fatigue loading in the test industry is solved.)

1. A method for adjusting the double-shaft resonance type fatigue loading response phase relation of a wind turbine blade based on damping is characterized by at least comprising the following steps:

SS1, installing the wind turbine blade to be tested on an experiment bench, and simultaneously applying load to the test load of corresponding amplitude, frequency and phase required by the test scheme in the blade flapping direction and the shimmy direction;

SS2, measuring and recording displacement response parameters of the blade vibrating in the flapping and shimmy directions;

SS3, after a period of initial vibration, recording phase values of displacement vibration parameters of the blade flapping and shimmy directions when stable vibration is achieved, and respectively calculating phase difference values between loads and displacement responses in the flapping directions and the shimmy directions and phase difference values of the vibration displacement responses of the flapping and the shimmy directions according to the load phase values given in the step SS 1;

SS4, evaluating according to the phase difference value calculated in the step SS3, and comparing whether the phase difference value between the vibration responses in the two directions is consistent with the requirement of the test scheme, if so, adjusting is not needed, and if not, subsequent adjustment is needed;

SS5, comparing the phase situation of the vibration displacement in the waving direction and the shimmy direction, and judging whether a damping adjusting device is installed in the waving direction or the shimmy direction, wherein the damping adjusting device is used for increasing or decreasing the damping value, if the phase value of the vibration object is expected to be increased in a certain direction, the damping value is increased in the certain direction, otherwise, if the phase value in the certain direction is expected to be decreased, the damping value is decreased in the certain direction;

SS6, after the damping adjusting device is installed, loading and measuring are carried out again, the vibration phase difference value in the waving and shimmying directions after the damping adjusting device is installed is recorded, the damping value of the damping adjusting device is adjusted according to the measuring result, and then measuring and adjusting are carried out again until the vibration phase difference value in the waving and shimmying directions meets the requirements of the test scheme;

and SS7, after the adjustment, under the condition that the blade simultaneously carries out flap loading and edgewise loading, the phase difference value of the vibration response of the blade in the flap and edgewise directions can meet the requirement expected by the test.

2. A method according to claim 1, characterised in that when it is desired to increase the damping value in a certain direction, the damping adjustment means is selected to mount a plate or similar structure on the blade with a wind resistance in a certain direction greater; when the damping value in a certain direction needs to be reduced, the damping adjusting device is selected to be a device which is installed on the blade and has a streamline shape in a certain direction.

3. Method according to the preceding claim, characterized in that the increase of the damping value is adjusted by increasing or decreasing the area of the plate or the decrease of the damping value is adjusted by increasing or decreasing the area of the streamlined outer profile.

4. Method according to the preceding claim, characterized in that for adjusting the displacement phase difference of the vibration response under the condition of dual-direction loading of flap and shimmy, the original vibration displacement phase difference under the condition of not installing the damping adjusting device is measured, and according to the difference and the test scheme, the evaluation is carried out to select which direction the damping adjusting device is installed on the blade, and whether the damping adjusting device is used for increasing the damping or reducing the damping.

5. Method according to the preceding claim, characterized in that, in order to achieve a satisfactory damping adjustment effect, it is necessary to perform a loading test again with the installation of the device, verify the effect of the damping adjustment device and perform a number of adjustments according to the effect until the requirements of the test protocol are met.

Technical Field

The invention relates to the technical field of wind power generation in the mechanical industry, in particular to a method for adjusting the double-shaft resonance type fatigue loading response phase relation of a wind turbine blade based on damping, which can meet the requirement that the vibration response phase difference of the blade in two directions meets a test scheme under the condition that the wind turbine blade is subjected to fatigue loading in the waving direction and the shimmy direction simultaneously.

Background

The fatigue performance evaluation of the wind power blade is an important content concerned by research and development and design of the wind power blade. In order to evaluate the fatigue performance of the blade, the fatigue test of the novel blade is generally carried out on a test bed after development and trial production. The main fatigue loads in the blade operation are considered to comprise the fatigue load spectrum in the flap direction and the fatigue load spectrum in the lag direction. The measured results will be more effective when performing fatigue tests, if both load spectra can be applied to the blade simultaneously.

However, fatigue loads are applied in the blade flapping and shimmy directions to measure the performance of the blade, and many difficulties also exist, which cause that the prior industry is difficult to effectively carry out biaxial fatigue tests, but unidirectional fatigue tests in the flapping direction and the shimmy direction are still mostly carried out respectively, which plays a role in restraining the development of the wind power industry. In order to achieve the goal of loading the blade in the flapping and shimmy directions simultaneously, it is necessary to research various difficulties faced. The method is developed aiming at the problem that the phase relation of the waving and the shimmy vibration response is difficult to control under the condition of double-shaft loading, and can solve the problem that the phase relation of the waving and the shimmy vibration response is not consistent with an expected value, thereby providing a technical and method support for developing the double-shaft fatigue test.

Disclosure of Invention

(I) technical problem to be solved

The blade fatigue test device aims at the problems that in the existing wind turbine blade fatigue test, the blade is mostly loaded in a waving or shimmy direction in a unidirectional mode, the blade cannot exert fatigue load in the waving and shimmy directions at the same time, the biaxial fatigue test is difficult to effectively carry out, and the evaluation of the fatigue resistance of the blade under the actual operation condition cannot be met. And the blade resonance type double-shaft fatigue test loading method can effectively evaluate the real fatigue resistance of the blade. However, to realize the biaxial fatigue test, many technical problems need to be solved. Under the simultaneous loading of two directions, the phase relation between the flapping and shimmy two-direction vibration responses can be influenced by the damping of the flapping and shimmy directions of the blades, so that the phase relation in the actual test is different from the expected phase relation. The existence of this difference will result in the fatigue test result failing to meet the desired test target. Therefore, there is a need to develop a technique and method for ensuring that the phase relationship in the actual test is consistent with the expected phase relationship in both flapwise and shimmy fatigue tests. According to the method, the reason causing the inconsistency is analyzed, and the reason causing the problem is found to be that the damping conditions of the flap direction and the shimmy direction are different, so that an additional damping device is added, and the damping value is adjusted, so that the aim that the phase relation is consistent with the expected phase relation in the actual test is achieved.

(II) technical scheme

The technical scheme adopted by the invention for realizing the technical purpose is as follows:

1. a method for adjusting a double-shaft resonance type fatigue loading response phase relation of a wind turbine blade based on damping mainly aims at the technical problem that the two-direction vibration phase difference caused by the difference of flap and shimmy direction damping conditions can not meet the experimental requirements under the condition of adjusting the double-shaft resonance fatigue loading of the wind turbine blade, and is characterized by at least comprising the following steps of:

SS1, installing the wind turbine blade to be tested on an experiment bench, and simultaneously applying load to the test load of corresponding amplitude, frequency and phase required by the test scheme in the blade flapping direction and the shimmy direction;

SS2, measuring and recording displacement response parameters of the blade vibrating in the flapping and shimmy directions;

SS3, after a period of initial vibration, recording phase values of blade flap and edgewise vibration displacement vibration parameters, and respectively calculating phase difference values between loads and displacement responses in the flap direction and the edgewise vibration direction and phase difference values of the flap and edgewise vibration displacement responses according to the load phase values given in the step SS1 when stable vibration is achieved;

SS4. since the blade structure and the influence of the ambient air during vibration have a certain phase difference between the vibration response and the vibration load due to the influence of vibration damping in both flapwise and edgewise directions, the influence of damping on this phase difference is not negligible in consideration of the tendency of blade enlargement. The vibration damping of the blade in the flapwise direction is different from that of the flapwise direction, so that the damping in the two directions has different influences on the phase between the load and the response in the two directions. Therefore, in the case of blade vibration, the phase relationship between the two vibration displacement responses in the flapping and edgewise directions cannot be accurately predicted due to the influence of damping, which causes the phase relationship between the two vibration displacement responses in the flapping and edgewise directions in an actual test to be different from the phase difference value between the two directions expected by the test scheme. Therefore, the phase difference value calculated according to the step SS3 is evaluated, whether the phase difference value between the two direction vibration responses is consistent with the requirement of the test scheme or not is compared, if so, no adjustment is needed, and if not, subsequent adjustment is needed;

SS5, comparing the phase conditions of the vibration displacement in the waving direction and the shimmy direction for the condition needing to be adjusted, and judging whether a damping adjusting device is installed in the waving direction or the shimmy direction, wherein the damping adjusting device is used for increasing or decreasing the damping value, and the principle of increasing the damping device to realize the damping adjustment is that if the phase value of the vibrating object is expected to be increased in a certain direction, the damping is required to be increased in the direction, otherwise, if the phase value in the certain direction is expected to be decreased, the damping is reduced in the direction;

SS6, after the damping adjusting device is installed, loading and measuring are carried out again, the vibration phase difference value in the waving and shimmying directions after the damping adjusting device is installed is recorded, the damping value of the damping adjusting device is adjusted according to the measuring result, and then measuring and adjusting are carried out again until the vibration phase difference value in the waving and shimmying directions meets the requirements of the test scheme;

and SS7, after the adjustment, under the condition that the blade simultaneously carries out flap loading and edgewise loading, the phase difference value of the vibration response of the blade in the flap and edgewise directions can meet the requirement expected by the test.

Preferably, when the damping value in a certain direction needs to be increased, the damping adjusting device is selected to be a flat plate or a similar structure body with larger wind resistance in a certain direction; when the damping value in a certain direction needs to be reduced, the damping adjusting device is selected to be a device which is installed on the blade and has a streamline shape in a certain direction.

Further, the increase amount of the damping value is adjusted by increasing or decreasing the area of the flat plate, or the decrease amount of the damping value is adjusted by increasing or decreasing the area of the streamline outer appearance.

Preferably, the method is developed to solve the problem that the phase difference value of the vibration response in two directions cannot meet the requirement of a test scheme when the blade exerts the fatigue load in both directions of the flapwise shimmy.

Preferably, in order to adjust the phase difference value of the vibration response under the condition of dual-direction loading of flapping and shimmy, the original phase difference under the condition that no additional damping device is installed needs to be measured, the difference value is evaluated according to the difference value and the difference value of the test scheme, the direction of the blade is selected to be provided with the damping device, and the damping device is selected to be a device for increasing the damping or reducing the damping.

Preferably, in order to achieve a satisfactory damping adjustment effect, a loading test needs to be performed under the condition of mounting the damping device, the influence effect of the damping device is verified, and multiple adjustments are performed according to the effect until the requirements of a test scheme are met.

According to the method for adjusting the waving and shimmy vibration phase relation based on damping, the damping device is added in the waving or shimmy direction to change the vibration damping condition in a certain direction, so that the waving and shimmy vibration phase relation in two directions is kept at an expected value, and the goal of bidirectional fatigue loading is met.

(III) advantageous effects

Compared with the prior art, the method for adjusting the swing oscillation vibration phase relation based on damping has the following obvious essential characteristics and remarkable advantages:

the existing industry mostly adopts unidirectional applied load on the fatigue test of the wind turbine blade, and in the aspect of developing bidirectional fatigue loading research, especially in the aspect of bidirectional fatigue loading research and attempt adopting resonance excitation, the vibration phase relation of the blade in the two directions of flapping and shimmy is difficult to control, which is a bottleneck problem restricting the application of the bidirectional fatigue loading in the test industry.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to specific embodiments below.

In this embodiment, taking the current mainstream MW-grade wind turbine blade as an example, when the method for adjusting the biaxial resonance fatigue loading response phase relationship of the wind turbine blade based on damping is implemented, the following steps are adopted:

1) installing the wind turbine blade to be tested on an experimental bench, and applying load to the test load of corresponding amplitude, frequency and phase required by the test scheme in the blade flapping direction and the shimmy direction;

2) measuring and recording response parameters of the blade in the flapping and shimmy directions;

3) after a period of initial vibration, when stable vibration is achieved, phase values of blade flap and shimmy directions are recorded, and phase difference values of load and response in the flap and shimmy directions and phase difference values of vibration response of the flap and shimmy directions are respectively calculated;

4) evaluating according to the phase difference value measured and recorded in the step 3), and judging whether the phase difference value between the vibration responses in the two directions is consistent with that required by the test scheme or not, if so, adjusting is not needed, and if not, subsequent adjustment is needed, wherein in the example, the phase difference value is assumed to be inconsistent, so the subsequent adjustment is needed;

5) comparing the phase conditions of the waving direction and the shimmy direction, and judging whether a damping adjusting device is installed in the waving direction or the shimmy direction, wherein the damping adjusting device is used for increasing or reducing a damping value;

6) in order to achieve the aim, a plurality of streamline outer covers made of foam materials are arranged on the blade, the length of each outer cover in the spanwise direction of the blade is 50 cm, the inner part of each outer cover is consistent with the profile of the blade so as to be sleeved on the blade, and the outer part of each outer cover has a streamline structure in the waving direction;

7) after the damping adjusting device is installed, loading and measuring are carried out again, the vibration phase difference value in the waving and shimmy directions after the additional damping device is installed is recorded, the position and the number of the damping adjusting device are adjusted according to the measuring result, for example, the number of outer covers is properly increased or reduced, and then loading and measuring are carried out again until the vibration phase difference value in the waving and shimmy directions meets the requirements of the testing scheme;

8) after the adjustment, the phase difference value of the vibration response of the blade in the flapping and shimmy directions can meet the requirement expected by the test under the conditions of simultaneous flapping loading and shimmy loading of the blade.

Through the implementation of the steps, the phase relation between the flapping and the shimmy direction vibration response during the blade resonance type fatigue bidirectional loading can meet the expected requirement.

The above-mentioned embodiments further explain the objects, technical solutions and advantages of the present invention in detail. It should be understood that the above-mentioned embodiments are only exemplary of the present invention, and are not intended to limit the present invention, and any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.