Research On Accurate Measurement Of Wind Speed And Direction In Icing Environment

Wind has a significant impact on the surface of power equipment such as transmission lines and is an important meteorological parameter for studying the mechanism of equipment icing and ice-melting technology under icing weather.However,severe weather conditions such as rain,snow,and freezing pose challenges to wind speed and direction measurement.Anemometers are easily frozen and damaged in high-cold weather,resulting in data distortion or a significant decrease in monitoring accuracy.At present,there are few researches on the accurate measurement of anemometers in ice-coated environments,and there is a lack of mature accurate measurement products.Therefore,designing a set of mature wind speed and direction measurement and anti-icing technical solutions has important academic significance and engineering practical value for studying the accurate measurement of wind speed and direction in icing environments.This paper proposes a method that can measure wind speed and direction by using a differential pressure sensor in icing environment,which can accurately measure wind pressure and convert it into wind speed and direction data.A wind pressure anemometer with a cylindrical porous structure was developed according to the measurement method,and the feasibility of the anemometer was verified through wind tunnel tests and the wind pressure distribution curve was obtained.The measurement performance of the anemometer was verified in the natural environment of Xuefeng Mountain,and the results showed that the sampling rate of the wind pressure anemometer was high,accurate and stable.The heating anemometer in icing environment has the function of anti-icing and deicing,and can measure the wind speed and direction normally.The main work and results of the thesis are as follows:(1)A measurement method of cylindrical porous structure based on the principle of differential pressure measurement is proposed.The use of 6 wind speed tubes with adjacent angles of 60 degrees makes the air pressure anemometer more accurate in terms of measurement principle.On the circumference of the designed anemometer,six evenly distributed small holes are respectively connected to a pressure sensor through wind speed tubes.When the wind direction changes,the numerical changes of the three adjacent pressure sensors on the windward side satisfy a certain functional relationship.Through experiments,the wind pressure around the actual cylinder can be determined,and a high-precision wind pressure distribution curve can be obtained by fitting.The wind direction and the maximum dynamic pressure are derived from the pressure distribution relationship on the cylindrical surface,and the wind speed is obtained from the dynamic pressure.(2)Analyze the factors affecting the measurement accuracy of the anemometer,propose a design plan to improve the accuracy of the wind speed and direction from the pressure sensor chip,circuit system design and wind speed and direction processing algorithm,and make a wind pressure anemometer.The anemometer detection and control system includes modules such as differential pressure,liquid crystal,temperature measurement,etc.,and uses related sensor chips that can work normally under 0°C and are stable and sensitive to realize the measurement of the anemometer in an ice-coated environment.The single-chip microcomputer is used to realize the conversion of wind pressure and wind speed and direction to improve measurement accuracy.(3)Based on the analysis of the effect of icing on the anemometer and the establishment of a heat exchange model,a heating anti-icing/deicing scheme is designed that integrates the anemometer cylinder and the wind speed tubes.In an icing environment,adjusting the heating power and the upper and lower limits of the temperature are important factors to determine the adaptability of the anemometer to different degrees of icing,and at the same time,it can prevent the sensor components from being burned or the ice and snow cannot be melted.In order to ensure that the anemometer cylinder and the wind speed tubes with smaller diameter can effectively remove ice,a soft carbon fiber heating element is used to tightly wrap the cylinder and the wind speed tubes,and the heating device is automatically started based on the temperature.The deicing test shows that the deicing effect is good,and the deicing scheme is feasible.The ice coating test proves that the anemometer will not be iced during heating,so as to ensure the normal operation of the anemometer and continuous measurement of wind speed and direction.(4)A natural environment test was conducted to verify the performance of the wind pressure anemometer under normal temperature and ice-coated environment.In a comparative analysis under normal temperature environment,the deviation of the average wind speed of the wind pressure type compared with the three-cup type at the same time period is 9.572%;the overall trend of the wind speed and direction measured by the wind pressure type and the ultrasonic measurement is the same,and the wind speed within 1 minute is relatively stable.The test proves that the anemometer has reliable performance in the range of 0～30 m/s and wind direction in the range of 0～360degrees,and has a high sampling rate of 2 Hz that can measure instantaneous wind speed and direction.Analyze the causes of wind speed and wind direction errors in the icing environment,and use software compensation algorithms to process and correct the problems of density changes and sudden changes in wind direction in the icing environment.In addition,the zero point calibration is performed to reduce the thermal zero drift error of the anemometer caused by the ambient temperature and improve the accuracy of wind speed and direction.