A sweeping ultrasonic wind speed measurement method

Abstract

The invention discloses a frequency sweeping type ultrasonic measuring method for a wind speed, and belongs to the technical field of wind power generation. According to the method, a sinusoidal signal source of which the frequency is continuously changed is utilized from a signal source; a corresponding wind speed vector is calculated through a collected frequency difference; the influences of temperature, noise and the like on measurement precision are effectively avoided. According to the method, the sinusoidal signal source of which the frequency is continuously changed is utilized from the signal source; the corresponding wind speed is calculated through the collected frequency difference; by using the method, the difficulty and the cost of a wind speed measuring system are effectively decreased; the measurement precision of the wind speed is improved. The picosecond-grade time collection in a wind speed measuring circuit in a time-difference method is avoided; more importantly, the influences of an error introduced by the nonnegligible time delay of an ultrasonic driving circuit in the time-difference method, the temperature, the noise and the like on the measurement precision are avoided. The frequency sweeping type ultrasonic measuring method is shorter in measuring period and quicker in response speed; moreover, the influence of a sound velocity on the measurement precision is eliminated.

Description

technical field [0001] The invention relates to a frequency-sweeping ultrasonic wind speed measurement method, which belongs to the technical field of wind power generation. Background technique [0002] With the rapid development of the wind power industry, the introduction of variable pitch wind turbines. The wind speed signal is used as the input variable of the control system to control the speed and power. When the wind speed is lower than the rated wind speed, the unit can track the best power curve, so that the unit has the highest wind energy conversion efficiency; when the wind speed is higher than the rated wind speed, it should Increase the flexibility of the transmission system to make the power output of the unit more stable. Due to the high uncertainty of wind energy, it is necessary to accurately and timely measure the wind speed and control the wind turbine accordingly in order to control the power generation of the wind turbine well so that it can obtain th...

AI Technical Summary

Problems solved by technology

At present, the method used in domestic ultrasonic anemometers is the time difference method. The time difference method uses the speed difference of ultrasonic waves propagating on the downwind and upwind paths to determine the wind speed. The speed difference cannot be directly measured. The time difference propagated on the path, but because this time difference is at the level of picoseconds, it will be affected by the accuracy of the existing time module when measuring time, and the circuit delay of the ultrasonic drive circuit in the time difference method cannot be ignored, and accurate measurement and calculation are required , otherwise the introduced error will cause greater interference to the measurement results. In addition, since the measured value is a small signal, temperature, noise, etc. will have a certain impact on the measurement accuracy.

Generally speaking, the time difference method is costly and technically difficult

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