Automatic Wind Gauge MSE Wind2

I. Choice of sensor

Sensor for wind speed MS&E PISPV-3 of automatic wind gauge MS&E-Wind 2 is rotoanemometar of three cups type.It is developed and produced by Consortium "MS&E". With this type of sensors, the rotor (suspended precision bearings on vertical axis) is rotated by the airflow due to differences in Стоксовото (aerodynamic) resistance of the front and the back of the cups. It is experimentally shown that the moment of the aerodynamic forces,which are acting on the three cups rotor, is amended least during the turnover, compared to other number of cups. This leads to uniform movement of the rotor and, consequently, reduce the role of friction, which is essential when measuring low flows.

The suspension system of the sensor MS&E PISPV-3 provides a minimum friction force for a range of speeds from 0.5 to 50 m/s.The lack of mechanical contact of the converter also contributes to this. These technical solutions provide the sensor high sensitivity (about 0.5 m/s) and linear transfer characteristic. At the top of the sensor is mounted electric heater, which is automatically switched on by an electronic thermostat at 0°C and switched off at 5°C. This, besides protecting the sensor from icing in winter, helps to maintain the coefficient of friction of the rotating mechanical part in a wide temperature range.

Sensor for wind direction is the type wind vine,with precise suspension which together with the lack of friction parts of the converter provides a threshold sensitivity of the sensor below 0.2 m/s. Also thermostated.

The project was started in 2001 and was completed in 2003. The need for development is caused by two reasons:

- Initiating research in Bulgaria on the characteristics of wind for generating electricity;

- Need to replace outdated "wind gauges of Wilde" in weather stations from the national meteorological network of NIMH with modern automatic wind gauges.

II. Developing Data Logger

Microprocessor unit (Data Logger) of the automatic wind gauge MS&E-Wind2 must perform the following functions:

- Work with sensor MS&E PISPV-3;

- To perform averaging of wind speed and direction;

- Modes of operation and calibration curve of the sensor can be introduced through RS232;

- Indicate on a two line LCD the wind speed and direction at the current time;

- Have an indication of the value of maximum wind speed and direction for the current date and the time of its recording;

- To record average wind speed and direction in nonvolatile memory in a random, predetermined, time interval and with start of an arbitrary starting point;

- To record top speed of wind and its direction for the day and time of its registration.

At night and in low visibility, when you press the button for the light, it will be switched on and after 30 seconds automatically switched off.

Regression Analysis - Linear model: Y = a + b*X

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Dependent variable: V_A3_01

Independent variable: F_A3_01

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Standard T

Parameter Estimate Error Statistic P-Value

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Intercept 0.236543 0.0619412 3.81884 0.0028

Slope 0.0941703 0.000307131 306.613 0.0000

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Analysis of Variance

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Source Sum of Squares Df Mean Square F-Ratio P-Value

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Model 1920.14 1 1920.14 94011.56 0.0000

Residual 0.22467 11 0.0204245

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Total (Corr.) 1920.37 12

Correlation Coefficient = 0.999942

R-squared = 99.9883 percent

R-squared (adjusted for d.f.) = 99.9872 percent

Standard Error of Est. = 0.142914

Mean absolute error = 0.115708

Linear model:

V_A3_01 = 0.236543 + 0.0941703*F_A3_01