Wind Turbine Interference Research Articles

Processing of weather radar raw IQ-data towards the identification and correction of wind turbine interference – Project RIWER: Removing the Influence of Wind Park Echoes in Weather Radar Measurements

Abstract. In recent years, the fast construction, expansion and repowering of wind parks have been a major source of concern for the weather radar community and meteorological services. Among others because wind turbines are extremely tall, reflective, and moving objects, which make them a source of interference that is hard to distinguish from meteorological echoes and therefore difficult to filter and even more difficult to correct. Polarimetric C-Band Doppler weather radar measurements enable us to analyse and understand the impact of wind turbine interference on meteorological weather radar echoes and to build up knowledge. The main idea is to analyse the raw IQ-data in order to quantify the behaviour of wind turbine interference with meteorological scattering. As a first step in this direction, this paper will focus on the derivation and analysis of radar moments such as Reflectivity (Z), Differential Reflectivity (ZDR), Differential Propagation Phase (PHIDP), Mean Doppler Velocity (V), and Correlation Coefficient (RHOHV). We will consider two cases: (i) events with precipitation, and (ii) events without precipitation, in order to understand and model the impact of wind turbine interference (WTI). For this purpose, weather radar measurements from Deutscher Wetterdienst (DWD), recorded under the aegis of the project RIWER (Removing the Influence of Wind Park Echoes in Weather Radar Measurements), are presented, analysed and discussed in detail.

A coupled turbine-interaction wind farm parameterization in the Weather Research and Forecasting model

The wind farm parameterization in the mesoscale numerical weather prediction (NWP) model is a valuable approach to exploring the performance and atmospheric impact of the large-scale wind farm. However, the sub-grid interactions between turbines are not resolved in the current parameterization method. In this study, we propose an improved wind farm parameterization by coupling a novel sub-grid wind turbine interference model. It is incorporated in the state-of-the-art Weather Research and Forecasting (WRF) model. To verify the model, the coupled model is applied in a real offshore wind farm in China for comparing the model performances with the original parameterization. The findings demonstrate that the proposed approach improves the wind simulation and has minimal sensitivity to horizontal grid resolution, hence strengthening the model’s robustness. Additionally, it is discovered that the sub-grid interaction reduces the turbine-produced turbulence and shortens the wake length by more than 30% compared to the original parameterization. Importantly, the power output prediction of turbine cells is modified, approximately resulting in a 1 % reduction of the entire wind farm relative to the original model. The effects of sub-grid turbine interaction are effectively captured in the proposed model and it is recommended for further wind farm simulations.

Configuration of wind farm in Kaberten region: wind potential and optimal capacity

The configuration of a wind farm depends mainly on the wind potential and the disposition of the wind turbines in this park. The windiest site is the most favorable for a future installation of wind turbines for the production of electricity, also, in this same site, a too dense arrangement would lead to considerable of power losses under the effect of wake. In this context, it is presented a research work that consists of determining the installation conditions of a wind farm; evaluating the wind farm through measurements of wind speed and the location of wind turbines in the park to minimize the effect of wind turbine interference. In order to do this, an evaluation study of the wind potential for the implementation of a wind farm based on the quantification of the wind in speed and directions firstly proposed. Secondly, a method for optimizing the positioning of wind turbines in a wind power farm is used based on the introduction of the Jensen wake model and the application of the iterative pseudo-random distribution approach of the turbines in the site. Simulation results are presented and discussed using data from the Kaberten site in Algeria and the characteristics of the GAMESA G52 wind turbine.

Wind Turbine Interference Mitigation Using a Waveform Diversity Radar

Interference from the proliferation of wind turbines is becoming a problem for ground-based medium-to-high pulse repetition frequency (PRF) pulsed–Doppler air surveillance radars. This paper demonstrates that randomizing some parameters of the transmit waveform from pulse to pulse, a filter can be designed to suppress both the wind turbine interference and the ground clutter. Furthermore, a single coherent processing interval (CPI) is sufficient to make an unambiguous range measurement. Therefore, multiple CPIs are not needed for range disambiguation, as in the staggered PRFs techniques. First, we consider a waveform with fixed PRF but diverse (random) initial phase applied to each transmit pulse. Second, we consider a waveform with diverse (random) PRF. The theoretical results are validated through simulations and analysis of experimental data. Clutter-plus-interference suppression and range disambiguation in a single CPI may be attractive to the Federal Aviation Administration and coastal radars.

The Oklahoma Wind Energy Development Act, as Amended. The Impact of the Amendments; Comparing and Contrasting Multiple Guidelines and, Other Persuasive Jurisdictions with Specific Emphasis to Oklahoma

Wind Law is a relatively new subject area specialization here in the United States, and around the world. The State of Oklahoma, is the second windiest place in the United States, after Texas. This essay brings into light how the wind business regulated in Oklahoma, by attempts to look at the short comings of the newly amended Oklahoma Wind Energy Development Act. We attempts here to delve into questions the Act has no answers for. This essay also looks at causes of actions, defenses, and remedies that may arise in the use of Wind Turbine business, from both the plaintiffs' and defendants' views; we deal with the questions on setbacks, the distances set between the wind turbine and other human habitable facilities like homes, schools, airports, and hospitals. The wind turbine interference of airports' equipment (radars) and what the next generation of radars and wind turbines will do, have been explained here. While this essay may be of interest to those studying Wind Law, wind developers and researchers, town and zoning planners, renewable energy enthusiasts, will equally be of interest in this discussion.

Some Effects of Efficiency on Wind Turbine Interference and Maximum Power Production

The effects of finite efficiency on wake interference and power output are studied for identical horizontal-axis wind turbines in line with the wind. Interference occurs whenever turbines reduce the power available to any turbines downwind of them. The analysis uses wake models that are commonly employed in wind farm layout design. The aerodynamic efficiency is varied from 75% to 100% for six identical hypothetical turbines in line parallel to the wind direction with spacing from four to six rotor diameters. Selfish optimization of the power output of individual turbines and co-operative optimization of the total power are considered. For selfish control, all turbines operate at the maximum possible local C P, based on the aerodynamic efficiency. For co-operative optimization, each turbine operates at a C P value between zero and the selfish value, and the total power is optimized numerically. The results show that at low efficiency, there is little difference in total power output between the two strategies. As efficiency increases, co-operative optimization produces increasingly more power. As turbine spacing increases, the difference between the strategies decreases. There is, however, a realistic range of efficiencies and spacing over which more power is delivered by co-operative optimization. The simplest form of co-operative optimization requires reducing the power output of the most upwind turbine to allow increased performance from those downwind. This should be an easy strategy to implement in wind farm control.

Wind farms' interference effects on the error performance of wireless line-of-sight communications using binary digital modulations

The main objective of this paper is to examine the deterioration on the average error performance of military and civilian wireless communications systems (WCSs) that are in the vicinity of wind farms. By treating the total interference signal caused by any wind turbine (WT) as the ensemble of scattering signal replicas over the uniformly segmented parts of the WT that face different Doppler frequency shifts, path loss factors, etc., the time-varying characteristics of the total signal have been investigated by means of the varying configuration parameters. To expose the degrading effects of the wind farms on the received signal and the overall error performance of the WCSs, the scattering signal contribution of the segments of the mast and blades have been evaluated analytically by also taking physical optics-based radar cross-section (RCS) estimation method into account. Average bit error rate performances of digital modulation schemes have been examined theoretically and numerically via Monte Carlo simulations through the entire rotation period of the blades. With the aim of providing useful insights on the assessment of the performance degradation caused by the WT interference, this paper exposes miscellaneous numerical results related to different configurations and settlings.

Explicit Solutions for Simple Models of Wind Turbine Interference

Wind turbine interference - the reduction in output power of a turbine downwind of any others - is a major problem for wind farm optimization and control. With interference, it is well-known for specific cases that co-operative optimization of power output yields more power than does the selfish optimization of individual turbines. This paper develops explicit solutions for simple models of interference for the general case of any number of turbines in line with the wind. For the simplest case of no wake recovery, analytical solutions for co-operative and selfish optimization are derived. They show that co-operative optimization nearly always yields more power and never yields less. Adding a simple form of wake recovery for equally spaced turbines precludes analytical solutions, but numerical solutions are developed to find the power to any required level of accuracy. Again, co-operative optimization is superior in nearly all cases. These simple solutions should be useful for demonstrating the importance of interference and for testing methods for optimizing wind farm layout and operation. It is shown that the maximum benefit from co-operative operation occurs at turbine spacing comparable to that commonly used in wind farms. The analysis is then extended to include topographical effects modeled as changes in wind speed along the line. Explicit solutions are obtained for two turbines in line. Co-operative optimization remains the best strategy. In particular, when the wind speed increases, it quickly becomes optimal to shut down the first turbine.