The Experts below are selected from a list of 11256 Experts worldwide ranked by ideXlab platform
Lizhong Zhang - One of the best experts on this subject based on the ideXlab platform.
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data driven method for wind turbine Yaw Angle sensor zero point shifting fault detection
Energies, 2018Co-Authors: Zheng Qian, Bo Jing, Dahai Kang, Lizhong ZhangAbstract:Wind turbine Yaw control plays an important role in increasing the wind turbine production and also in protecting the wind turbine. Accurate measurement of Yaw Angle is the basis of an effective wind turbine Yaw controller. The accuracy of Yaw Angle measurement is affected significantly by the problem of zero-point shifting. Hence, it is essential to evaluate the zero-point shifting error on wind turbines on-line in order to improve the reliability of Yaw Angle measurement in real time. Particularly, qualitative evaluation of the zero-point shifting error could be useful for wind farm operators to realize prompt and cost-effective maintenance on Yaw Angle sensors. In the aim of qualitatively evaluating the zero-point shifting error, the Yaw Angle sensor zero-point shifting fault is firstly defined in this paper. A data-driven method is then proposed to detect the zero-point shifting fault based on Supervisory Control and Data Acquisition (SCADA) data. The zero-point shifting fault is detected in the proposed method by analyzing the power performance under different Yaw Angles. The SCADA data are partitioned into different bins according to both wind speed and Yaw Angle in order to deeply evaluate the power performance. An indicator is proposed in this method for power performance evaluation under each Yaw Angle. The Yaw Angle with the largest indicator is considered as the Yaw Angle measurement error in our work. A zero-point shifting fault would trigger an alarm if the error is larger than a predefined threshold. Case studies from several actual wind farms proved the effectiveness of the proposed method in detecting zero-point shifting fault and also in improving the wind turbine performance. Results of the proposed method could be useful for wind farm operators to realize prompt adjustment if there exists a large error of Yaw Angle measurement.
Ken Nakano - One of the best experts on this subject based on the ideXlab platform.
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Effect of Yaw Angle misalignment on brake noise and brake time in a pad-on-disc-type apparatus with unidirectional compliance for pad support
Tribology International, 2014Co-Authors: Naohiro Kado, Naoya Sato, Chiharu Tadokoro, Antonin Skarolek, Ken NakanoAbstract:A pad-on-disc-type brake apparatus was constructed based on a theoretical principle for suppressing frictional vibration. The pad for this apparatus was supported by parallel leaf springs with a unidirectional compliance. Braking tests were conducted using the apparatus under a constant normal load. It has been found that a Yaw Angle misalignment between the directions of the pad and disc motions provides a positive damping to suppress the frictional vibration and brake noise. In addition, it has been also found that when an appropriate misalignment Angle is selected, a low-noise performance and a good braking performance can be achieved simultaneously.
Wenhui Yue - One of the best experts on this subject based on the ideXlab platform.
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Ground-based phase wind-up and its application in Yaw Angle determination
Journal of Geodesy, 2016Co-Authors: Miaomiao Cai, Wen Chen, Danan Dong, Zhengqi Zheng, Feng Zhou, Minghua Wang, Wenhui YueAbstract:Ground-based phase wind-up effect (GPWU) is caused by the rotation of receiving antenna. It had been studied and applied in rapidly rotation platforms, such as sounding rocket, guided missile and deep space exploration. In Global Navigation Satellite System high accuracy positioning applications, however, most studies treated it as an error source and focused on eliminating this effect in Precision Point Positioning and Real Time Kinematic (RTK) positioning. The GPWU effect is also sensitive to the rotational status of the antenna, in particular the Yaw Angle variations. In this paper we explore the feasibility of Yaw Angle determination of relatively slow rotation platforms based on the GPWU effect. We use the geometry-free carrier phase observations from a RTK base and a moving station receivers to estimate the cumulative Yaw Angle of the moving platform. Several experiments, including rotating platform tests, vehicle and shipborne tests were carried out. The cumulative errors of rotating platform tests are under 0.38\(^{\circ }\), indicating good long-term accuracy of the GPWU determined Yaw Angle. But the RMS are in a range of 11.98\(^{\circ }\)and 17.39\(^{\circ }\), indicating the errors, such as multipath effect, are not negligible and should be further investigated. The RMS of vehicle and shipborne tests using a base station of 9–11 km are 24.77\(^{\circ }\) and 23.66\(^{\circ }\). In order to evaluate the influence of the differential ionospheric delay, another vehicle test was carried out using a base station located less than 1 km to the vehicle. The RMS reduces to 15.11\(^{\circ }\), which gains 39.00 % improvement than before, and demonstrates that the differential ionospheric delay even from a few kilometers long baseline still cannot be neglected. These tests validate the feasibility of GPWU for real-time Yaw Angle determination. Since this method is able to determine the Yaw Angle with a minimum one satellite, such a unique feature provides potential applications for attitude determination in the environment with poor sky visibility.
Zheng Qian - One of the best experts on this subject based on the ideXlab platform.
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data driven method for wind turbine Yaw Angle sensor zero point shifting fault detection
Energies, 2018Co-Authors: Zheng Qian, Bo Jing, Dahai Kang, Lizhong ZhangAbstract:Wind turbine Yaw control plays an important role in increasing the wind turbine production and also in protecting the wind turbine. Accurate measurement of Yaw Angle is the basis of an effective wind turbine Yaw controller. The accuracy of Yaw Angle measurement is affected significantly by the problem of zero-point shifting. Hence, it is essential to evaluate the zero-point shifting error on wind turbines on-line in order to improve the reliability of Yaw Angle measurement in real time. Particularly, qualitative evaluation of the zero-point shifting error could be useful for wind farm operators to realize prompt and cost-effective maintenance on Yaw Angle sensors. In the aim of qualitatively evaluating the zero-point shifting error, the Yaw Angle sensor zero-point shifting fault is firstly defined in this paper. A data-driven method is then proposed to detect the zero-point shifting fault based on Supervisory Control and Data Acquisition (SCADA) data. The zero-point shifting fault is detected in the proposed method by analyzing the power performance under different Yaw Angles. The SCADA data are partitioned into different bins according to both wind speed and Yaw Angle in order to deeply evaluate the power performance. An indicator is proposed in this method for power performance evaluation under each Yaw Angle. The Yaw Angle with the largest indicator is considered as the Yaw Angle measurement error in our work. A zero-point shifting fault would trigger an alarm if the error is larger than a predefined threshold. Case studies from several actual wind farms proved the effectiveness of the proposed method in detecting zero-point shifting fault and also in improving the wind turbine performance. Results of the proposed method could be useful for wind farm operators to realize prompt adjustment if there exists a large error of Yaw Angle measurement.
Ledong Zhu - One of the best experts on this subject based on the ideXlab platform.
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tsing ma bridge deck under skew winds part i aerodynamic coefficients
Journal of Wind Engineering and Industrial Aerodynamics, 2002Co-Authors: Feng-liang Zhang, Ledong Zhu, Haifan XiangAbstract:Abstract This paper aims to measure six static aerodynamic coefficients, while a companion paper addresses the measurement of eight flutter derivatives, of a typical oblique strip of the Tsing Ma suspension bridge deck under skew winds. The wind tunnel test technique developed for the aerodynamic coefficient measurement includes the design of oblique sectional models, the development of a test rig and a measurement system, and the analysis of test results. The effects of model end Angle on the aerodynamic coefficients are investigated and found to be very small on lift, drag and pitching moment coefficients. The measured results are then fitted to obtain the six aerodynamic coefficient curves as functions of both wind inclination and Yaw Angle, which will be used in a later comparison of buffeting response of the bridge between field measurement and analysis. The measurement results reveal that the drag, lift and pitching moment coefficients are much larger than the crosswind force, rolling moment and Yawing moment coefficients. The variation of lift coefficient with wind Yaw Angle is small, but the value of drag coefficient decreases with increasing wind Yaw Angle and the value of pitching moment coefficient increases with increasing wind Yaw Angle. The obtained six aerodynamic coefficient curves are also used to examine the currently used cosine rule for buffeting analysis of a bridge under Yaw winds. It is found that the traditional cosine rule is generally inadequate, particularly in the cases of large wind Yaw Angle.
