HF noise from wind farms - ZL6QH

Discussion in 'Investigations New Technology' started by Brian Miller, Jan 13, 2015.

  1. Brian Miller

    Brian Miller New Member

    I was interested to read the article on wind farm QRM in the EMC column for the August 2014 issue of Radcom. The article encouraged readers to report any issues experienced in relation to interference from wind farms.

    I'm writing this post to inform you about the impact of wind farm noise on the ZL6QH HF station that was operational from Quartz Hill (near Wellington, New Zealand) until 2007. I was the Chair of the committee responsible for the station. A report on our investigation into the noise from the wind farm is available at http://www.zl6qh.com/rf-noise-measurements-quartz-hill-2009-v3.pdf .

    Our investigation concluded that it would not be possible to continue operating an amateur radio HF station in the vicinity of Quartz Hill due to the high level of radiated noise interference from the wind turbine infrastructure. At 3.73 MHz, the measured level of radiated noise was approximately 50 dB greater than that sought for weak signal HF amateur radio communications. Our analysis of the measurement data suggested that an amateur radio station would need to be separated from the nearest turbines by a distance of at least several kilometres in order to reduce the interference to a workable level.

    We found that the observed noise appeared to be directly radiated by the infrastructure within the immediate vicinity of each turbine. The turbines were a Siemens 2.3 MW variable speed design. It is likely that most of the noise was created by the water cooled electronic power converter that translated the variable voltage and frequency output from the generator to the fixed voltage and frequency of the national grid.

    73

    Brian Miller VK3MI ZL1AZE
  2. M0JAV

    M0JAV Moderator

    Many thanks Brian very useful information. We will incorporate that into documentation we are preparing to try to get some standards for emc of these structures drawn up. I have copied David Lauder so he may follow up.
    If you made any spectrum recordings SDR or spectrum analyser it would be useful to have them to see if the noise characteristics are similar to what we see.
    The paper is an excellent piece of work. Great Job
    John Rogers M0JAV
    Chairman RSGB EMCC


    I was interested to read the article on wind farm QRM in the EMC column for the August 2014 issue of Radcom. The article encouraged readers to report any issues experienced in relation to interference from wind farms.

    I'm writing this post to inform you about the impact of wind farm noise on the ZL6QH HF station that was operational from Quartz Hill (near Wellington, New Zealand) until 2007. I was the Chair of the committee responsible for the station. A report on our investigation into the noise from the wind farm is available at http://www.zl6qh.com/rf-noise-measurements-quartz-hill-2009-v3.pdf .

    Our investigation concluded that it would not be possible to continue operating an amateur radio HF station in the vicinity of Quartz Hill due to the high level of radiated noise interference from the wind turbine infrastructure. At 3.73 MHz, the measured level of radiated noise was approximately 50 dB greater than that sought for weak signal HF amateur radio communications. Our analysis of the measurement data suggested that an amateur radio station would need to be separated from the nearest turbines by a distance of at least several kilometres in order to reduce the interference to a workable level.

    We found that the observed noise appeared to be directly radiated by the infrastructure within the immediate vicinity of each turbine. The turbines were a Siemens 2.3 MW variable speed design. It is likely that most of the noise was created by the water cooled electronic power converter that translated the variable voltage and frequency output from the generator to the fixed voltage and frequency of the national grid.

    73

    Brian Miller VK3MI ZL1AZE
    [/quote]
  3. Brian Miller

    Brian Miller New Member

    Thanks for the feedback John.

    We do not have any spectrum recordings of the wind farm noise at Quartz Hill but it certainly sounded like broadband electrical hash - it did not exhibit any significant peaks or nulls when tuning across the 80M band.

    At one of the measurement locations we could also hear and observe the amplitude of the noise varying in time with the rotation of the turbine blades, So it appears that at least some of the noise was being radiated by the lightning protection conductor that is fitted along the blades.

    73

    Brian Miller VK3MI ZL1AZE
  4. Brian Miller

    Brian Miller New Member

    I also wish to point out that we conducted some HF radio frequency noise measurements at the Meridian Energy Te Apiti wind farm (near Palmerston North in New Zealand) in October 2005 but could find no evidence of significant noise being radiated by the turbines, even at locations within 100 metres of the nearest turbines. Unlike the Quartz Hill turbines, the Te Apiti turbines are a fixed speed design and do not use a separate electronic power converter.

    73

    Brian Miller VK3MI ZL1AZE

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