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This PULSE software determines the official sound power of a wind turbine by guiding the user through the necessary steps to meet the measurement standards IEC61400–11 and FGW Technischen Richtlinie für Windenergie. It works together with a microphone placed at the downwind reference position of the turbine, and interfaces to the turbine’s data to incorporate the turbine’s power output, and the wind direction and speed. The software guides the user through the measurement procedure required to fulfil the relevant standard.

USE SCENARIOS

• Manufacturers determining sound power and tonality
• Checking the expected specified noise levels of new or refurbished units or components such as rotors or blades
• Calibrating and validating environmental noise maps for single wind turbines or extensive wind farms

STANDARDS

The software calculates the wind turbine’s tonality and impulsivity, and can calculate sound directivity, infrasound and low-frequency noise. It produces reports for IEC 61400-11 Edition 2.1 and IEC 61400-11 Edition 3.0. With Brüel & Kjær’s service including accredited calibration, you can trace the validity of your measurements to the appropriate national standards body.

CAPABILITIES

• Measures operational and background noise with simultaneous CPB and FFT analysis
• Plots all measured data pairs containing measured total noise and background noise
• Plots all measured total noise versus electrical power data
• Plots sound power spectrum in 1/3-octaves for each bin centre wind speed
• Produces spectra for sound power and sound pressure for each wind bin
• Calculates the apparent sound power level (i.e., equivalent continuous A-weighted sound pressure level)

WIND SPEEDS

Because wind speed and direction are critical to the measurements, the system allows users to determine acoustic emission information at various wind speeds. It permanently monitors these parameters to determine whether enough data has been acquired in the necessary wind classes, known as ‘bins’, to fulfil the standard. It can obtain wind speed from the turbine’s power curve, or from the anemometer on the turbine’s tower or nacelle.

COMPLETE SYSTEM

A typical system incorporates a portable LAN-XI data acquisition unit, one Type 4189 microphone and preamplifier, a DC signal converter box to interface the turbine parameters and the weather parameters to the auxiliary channels in the PULSE software, and a laptop PC.