Adjustable concentric towers to vary tower shadow effect on flicker in wind turbine
01 Aug 2017-
TL;DR: In this article, the authors developed a facility to find the impact of tower shadow effect on voltage flicker initiated in the wind turbine output, where a tubular tower is formed using pipes.
Abstract: In this paper the facility to find the impact of tower shadow effect on voltage flicker initiated in the wind turbine output is developed. Concentric towers are developed using steel any suitable material pipe. The length of the pipe can be adjusted using sliding the pipe. Nut and bolts are used to fix the length of the pipe. There is a provision to fix the turbine on the tower. Tubular tower are formed using pipes. Pipes with different diameters are provided in the test set up. As length and height of the towers is varied the tower shadow effect is also varied. Artificial wind is created using blower fans. The impact of tower shadow effect on the voltage flicker output of the wind turbine is observed on digital storage oscilloscope. There is a provision to fix various types of generators on the towers. The experiment is conducted on the wind turbine scaled down models. The result can be scaled to the actual dimensions of the wind tower.
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TL;DR: In this article, the validity of the standard method in IEC 61400-21 for assessing the flicker emission from multiple wind turbines was investigated, which is based on the data from two wind farms, one with fixed-speed wind turbines and one with variable speed wind turbines.
Abstract: This paper studies the validity of the standard method in IEC 61400-21 for assessing the flicker emission from multiple wind turbines. The standard method is based on testing a single wind turbine and then using the results of this test to assess the flicker emission from a number of wind turbines. This study is based on the data from two wind farms, one with fixed-speed wind turbines and one with variable-speed wind turbines. The data are: a type test at the terminals of a wind turbine, and measurements at the connection of a collection line to the substation. The type test data are used to assess the flicker emission at the collection line; this assessment is then compared to the actual measurements in order to study the accuracy of the estimation. It was observed in both wind farms, that the assessment based on the standard method is statistically conservative compared to the measurements. The reason for this is the statistical characteristics of flicker emission.
57 citations
TL;DR: In this article, the authors demonstrate the effect of tower shadow and wind turbulence on the influence control performance of power system stabilizer (PSS) loops for doubly-fed induction generators (DFIGs).
Abstract: The aim of the paper is to demonstrate the way in which mechanical power variations, due to tower shadow and wind turbulence, influence control performance of power system stabilizer (PSS) loops for doubly-fed induction generators (DFIGs). The PSS auxiliary loops are applied on a specific DFIG control scheme, the flux magnitude and angle controller (FMAC). However, since the PSS signal is applied at the output of the basic controller, the PSS performance characteristics displayed are deemed typical for DFIG control schemes in general. The relative capabilities of PSS controllers based on stator power, rotor speed, and network frequency, when the DFIG turbine is subjected to aerodynamic torque variations, are investigated via simulation studies. A two-generator aggregate model of a wind farm is introduced, which enables the influence of tower shadow and wind turbulence on both an individual turbine and on the overall wind farm itself to be assessed.
53 citations
15 Oct 2013
TL;DR: In this paper, a new parameter vertical wind shear is also considered while computing the flicker emission severity and experimental results are of a turbine installed at Village Nimgaon Mhalungi, Tal. Shirur, District Pune, India.
Abstract: Scarcity of electric power, in developing countries like India, demands more generation of electric power. The conventional means of generating power are much time consuming and hence it is necessary to utilize renewable energy sources like wind, solar etc. Wind is intermittent in nature. It is not possible to predict exact wind speed because of the continuously changing climatic conditions. So flicker i.e. change in voltage is produced because of change in wind speed. It creates nuisance to the consumers. Consumers observe flicker in light of the incandescent lamp. So it is very difficult to read in that light source. So it is necessary to quantify and reduce the flicker emission severity produced by wind turbine. Now a days while computing flicker emission severity, only wind speed and grid impedance phase angle are considered. In this paper new parameter vertical wind shear is also considered while computing the flicker emission severity. Experimental results are of a turbine installed at Village Nimgaon Mhalungi, Tal. Shirur, District Pune, India.
36 citations
24 Mar 2011
TL;DR: Simulation results show that the proposed method can detect ice accumulation, related vibrations and electromagnetic torque pulsations independent from any pre-defined geometry.
Abstract: This paper introduces a novel method for detecting ice accumulation on wind turbines. The proposed detection method is based on utilizing a multi-resolution analysis to extract specific frequency components present in the direct and quadrature components of the electric current flowing out of a wind generator. The basis of the proposed method lies in the fact that ice accumulation leads to a slow increase in the mass of the wind turbine, which demands higher electromagnetic torque to overcome the iced rotor and blades at each wind speed. The Daubechies db6 basis functions are used to construct the desired multi-resolution analysis for analyzing the current signals. The proposed method has been implemented for simulation tests using MAT-LAB/SIMULINK software. Simulation results show that the proposed method can detect ice accumulation, related vibrations and electromagnetic torque pulsations independent from any pre-defined geometry.
33 citations
20 Mar 2014
TL;DR: In this paper, the impact of turbulence on the flicker produced in a wind turbine which is sited on a hill surface is examined in a laboratory wind tunnel with small models of hills with different slopes and wind turbines.
Abstract: This paper bequeaths particulars of impact of turbulence on the flicker produced in the wind turbine which is sited on that surface. This is achieved in a laboratory wind tunnel with small models of hills with different slopes and wind turbine. Different shapes of models of hills placed in a laboratory wind tunnel. Wind turbines are tested for those conditions. The paper provides an empirical model to find flicker in terms of hill topography. The exquisiteness of the model is that, it is expedient to sundry types hills on which the turbine is sited. Validation of model is carried out with comparative graphs revealed with readings recorded on a turbine in tunnel.
31 citations