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Han H.,Chongqing University | Zhang G.,Chongqing University | Yang W.,CSIC Chongqing Haizhuang Wind Power Equipment Co.
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | Year: 2015

Through analyzing the influence of turbulence intensity on statistical power curve of wind turbine, the correction method for output power curve of wind turbine was put forward according to turbulence intensity. By comparing with the measured statistic results of the same wind turbine according to IEC standard, the measurement results by using correction method has lower uncertainty than standard statistical method, which can accurately reflect actual operation situation of wind turbine, and provide reliable basis on normal maintenance, operation optimization of wind turbine, as well as preliminary power estimation of wind farm construction. ©, 2015, Science Press. All right reserved. Source

Jin X.,Chongqing University | Zhong X.,Chongqing University | He Y.-L.,Chongqing University | Han H.-L.,CSIC Chongqing Haizhuang Wind Power Equipment Co.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2013

With the increasing power of wind turbine, the structure is growing larger and larger, vibration problems have gradually emerged in domestic wind turbine. In view of this, based on the traditional method of pitch control, an individual pitch control strategy is proposed by combining the Linear Quadratic Regulator (LQR) with the Disturbance Accommodating Control (DAC). Then this control strategy is simulated under the environment of FAST and Matlab/Simulink software. The theory research and engineering application of a 5 MW wind turbines show the superiority of individual pitch control in vibration control of large scale wind turbine, which can effectively reduce the vibration of wind turbines, and then improve the equipment reliability, extend equipment's service life, and reduce maintenance costs. Source

Li H.,Chongqing University | Liu S.,Chongqing University | Li Y.,Chongqing University | Yang D.,Chongqing University | And 2 more authors.
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2016

In order to more correctly describe the junction temperature of the parallel chips on the converter IGBT module of large wind-power unit, an improved junction temperature evaluation model considering the effect of multi-thermal coupling is proposed. Based on the internal structure and the material parameters of the converter IGBT module of 2 MW DFIG (Doubly Fed Induction Generator), the junction temperature distribution and the steady-state effect of multi-thermal coupling are analyzed with FEM (Finite Element Method). The concept of equivalent thermal coupling impedance is introduced to deduce the thermal impedance relation matrix among chips of power module and establish an improved thermal network model considering the effect of multi-thermal coupling. With H93-2MW DFIG as an example, the calculated chip junction temperatures are compared among the improved thermal network model, the FEM model and the traditional thermal network model for different power losses. Results show the necessity and effectiveness of the internal junction temperature calculation considering the effect of multi-thermal coupling for the power module of wind-power converter. The effect of multi-thermal coupling is closely related to the interval between chips and great attention should be paid to the thermal distribution of chips in the middle of module. © 2016, Electric Power Automation Equipment Press. All right reserved. Source

Yang D.,Chongqing University | Li H.,Chongqing University | Hu Y.,Chongqing University | Zhao J.,Chongqing University | And 2 more authors.
Renewable Energy | Year: 2016

A noise suppression method for feature frequency extraction that is supplemented with multi-point data fusion was investigated in consideration of issues involving wind turbine vibration signals subject to high noise disturbance. The difficulty of extracting early weak fault features was examined as well. First, a de-noising and feature extraction method that uses EMD-Correlation was developed by adding empirical mode decomposition (EMD) and autocorrelation de-noising to the wavelet package transform under the effects of white noise and short-term disturbance noise in wind turbine vibration signals. Second, an EMD-Correlation analysis model for feature frequency extraction supplemented with multi-point data fusion was established with reference to adaptive resonance theory-2 to highlight the feature frequency of a possible early weak fault. Third, the results obtained with the actual and simulated fault vibration signals of wind turbine bearing faults and the outcomes of comparing the different feature frequency extraction methods show that the proposed method of EMD-Correlation that is supplemented with multi-point data fusion can not only effectively reduce white noise and short-term disturbance noise but can also extract the feature frequency of early weak faults. Finally, prototype hardware and software were developed for a wind turbine condition monitoring system based on the aforementioned fault feature extraction algorithms and tested in an actual wind turbine generation system. © 2016 Elsevier Ltd. Source

Wang C.,Chongqing University of Technology | Li Q.,CSIC Chongqing Haizhuang Wind Power Equipment Co. | Zhao W.,Chongqing University of Technology
Gongneng Cailiao/Journal of Functional Materials | Year: 2015

Electro-brush plating were operated on the base material of ADC12 aluminum with alkaline copper primer, respectively fast nickel solution and fast nickel solution + rare earth La2O3 as the working layer. The results showed that adding the appropriate amount of rare earth La2O3 can obtain better properties than without adding rare earth La2O3 into the plating solution, comparing the microstructure, component and hardness, the binding force of the coating and the matrix, corrosion resistance, friction and wear behavior of two kinds of coatings by SEM, XRD, micro hardness tester, utomatic scratch tester, constant potential instrument, abrasion tester, etc. ©, 2015, Journal of Functional Materials. All right reserved. Source

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