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Abstract: This paper is part B of a two-part paper regarding the development of a novel meteorological sensor designed to detect conditions leading to atmospheric icing and act upon it. This paper focuses on the integration of the meteorological probe, presented in part A of this paper, into the design of an ice-free anemometer prototype. Several heating strategies used on commercially available heating instruments as well as strategies developed during this project are first presented. The design of the integrated constant temperature control probe is then presented including a theoretical analysis. The concept was then integrated into the design of the 3rd generation prototype and then into the 4th generation prototype. The improvements between the 3rd and 4th generation are included into this paper as well as the results gathered for both prototypes under laboratory conditions. It is shown that it is possible to detect conditions leading to icing and when icing is occurring through an intelligent algorithm based on a projected heat transfer rate. [Copyright &y& Elsevier]

Abstract: Heating control of an ice-free anemometer can be challenging especially when the objective of the control is to minimize the power consumption. The novel meteorological probe presented in this paper is a first step towards a fully integrated probe for anemometer heating control purposes. This proof of concept is a heating cylinder that, when used in conjunction with a wind sensor, an outside temperature probe and a computing unit, can provide accurate information on the presence of conditions prone to icing. This information can then be used to turn on the heating power required by the anemometer to stay ice free and/or to monitor the risk of icing at a given site. [Copyright &y& Elsevier]

Abstract: Under rapidly fluctuating wind speed, high inertia cup anemometers have a tendency to overspeed. The main objective of this article is to develop an inverse time domain model that could be used in real-time during cup anemometer operation to minimize the so-called “u-error”. A model proposed by Kristensen and an artificial neural network (ANN) direct model were first investigated to simulate the dynamic behavior of a heated cup anemometer with relatively high rotor inertia. Once the anemometer behavior was known, several virtual inputs were generated and the direct model was used to predict the instrument behavior. These models were built to emphasis the non-linear relationship between the free stream fluctuating wind and the wind speed measured by the anemometer. A semi-empirical inverse model derived from Kristensen's model was then studied and an ANN inverse model was suggested in order to minimize the so-called u-error. A methodology is proposed to gather the appropriate data to create both the direct and inverse model using an artificial neural network. The output of each model was compared with experimental data for validation and good agreement was found between the ANN models and the experimental data used for validation. [Copyright &y& Elsevier]

Abstract: The main objective of this article is to present the results gathered during the commissioning of a new ice-free cup anemometer developed at Université Laval. These tests took place at the Wind Energy Institute of Canada (WEICan) between January 2011 and April 2011, whereby icing events occurred and through the observations in this paper will show the need for ice-free anemometers in the wind industry in cold climates. Unbiased wind measurements cannot be obtained without ice-free anemometers. At such sites, the use of unheated wind speed sensors during the resource assessment phase leads to higher uncertainty of the wind speed. The use of properly heated anemometers can reduce wind speed measurement uncertainty, thus reducing financial uncertainty. A crude estimation of the financial losses based on the number of icing hours and the number of installed MW is also proposed. Caution should be exerted when choosing and installing ice-free instruments. Under specific conditions, improperly heated anemometers can lead to less accurate wind measurements than unheated anemometers. Wind turbines safe operation could be jeopardized with the use of improperly heated anemometers. [Copyright &y& Elsevier]

Abstract: The main objective of this article is to analyze the angular (off-axis) response of heated cup anemometers designed specifically for wind power generation in cold climate. Three commercial heated cup anemometers are tested together with two ice-free prototypes developed as part of a broader research program focusing on ice-free sensors. Three indexes are proposed to allow better data analysis of angular response measurements. It is shown that careful attention to the anemometer geometry can lead to a nearly perfect cosine shape response while improper rotor geometry can lead to very bad angular response. A patented rotor geometry design is tested on different anemometers to see if one could expect the desired angular response for cup anemometers used in the wind energy industry to be obtained with such rotor geometry. [Copyright &y& Elsevier]

Abstract: The wind industry has grown over the years along with the collective desire to produce clean energy. High wind potential sites are often located in northern regions where harsh climatic conditions arise. The performance of anemometers, which provide essential measurements to wind turbine operation and wind resource assessment, is then jeopardized by ice build-up and snow accumulation. These conditions result in the need for heated instruments able to remain ice-free regardless of weather conditions while minimizing energy consumption. The main objective of this work was to develop an intelligent heating control for a new generation of ice-free anemometers. The controller is based on vision recognition of ice build-up on the cups of the anemometer using a neural network. Heating power is applied according to the icing state and the icing history of the instrument. Primary results have shown that, for a completely ice-free performance, the developed controller uses an average of less than two thirds of the energy consumed by common control systems similar to those used by other ice-free anemometers available on the market. [Copyright &y& Elsevier]