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flywheel to keep the Hz up to prevent blackouts

jcm
I suppose it had to happen these ugly blights on the tops of mountains can now cause blackouts ,  yesterday as I look around mountains (not much breeze) one or two turbines try to turn a little then fall back exausted. Not sure how this flywheel works ? , although it must take a lot of power to get it rotating. Glad to hear that they are now keeping Kilroot power station open (it was running  coal / oil and owned by the AES Corporation). In 2019 it was sold to a subsidiary of Energetický a průmyslový holding. They are going to converting it to gas.    


www.theguardian.com/.../giant-flywheel-project-in-scotland-could-prevent-uk-blackouts-energy



EXCLUSIVE. £1MILLION was paid out to wind farm owners to turn off their turbines and stop generating electricity for Northern Ireland's power grid for 20 months.7 hours ago


And in january:-

Wind farms paid up to £3 million per day to switch off turbineswww.telegraph.co.uk › News › Politics

19 Jan 2020 - Wind farms were paid up to £3 million per day to switch off their turbines and not produce electricity last week, The Telegraph can disclose. ... the additional expense of a £1 billion interconnector that is itself proving unreliable.

No further comment needed. Regards

jcm
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  • 0
    There are actually at least 3 sorts of systems, the induction machine

    (IM),  permanent magnet machine (PM), and variable reluctant machine (VRM).

    Permanent magnet machines are physically smaller, but lose energy all the time to magnetic hysteresis,  where the others can be spun up and left with the magnetic field reduced  until needed.

    Induction machines, especially squirrel cage  are simpler, but of course are not quite synchronous - the analogy of motor slip applies in reverse while generating, and the low frequency difference frequency flows in the core. More complex designs can force a specific frequency in the core ,so that the output is synchronous, and some earlier wiind turbines did this too.

    The variable recluctance motors are more interesting, being more of notched cog between coils, so that the inductance of the coils is modulated while current is flowing giving a varying voltage. This can generate or motor depending on the phase of the applied voltage to the coils to force the phase of the current or vice versa,  these are the best sort of genset where speeds are very high - like an un-geared gas turbine or small diameter wheel.

    Nearly all serious (megawatt-minute) systems are indeed AC/DC/AC and have large banks of thyristors or IGBTs depending on the era it was designed in.


    A Diesel Rotary UPS wikki article DRUPS is something else as the prime mover is the diesel engine, but also worth understanding to get a scale of what is being asked for on big systems

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  • 0
    There are actually at least 3 sorts of systems, the induction machine

    (IM),  permanent magnet machine (PM), and variable reluctant machine (VRM).

    Permanent magnet machines are physically smaller, but lose energy all the time to magnetic hysteresis,  where the others can be spun up and left with the magnetic field reduced  until needed.

    Induction machines, especially squirrel cage  are simpler, but of course are not quite synchronous - the analogy of motor slip applies in reverse while generating, and the low frequency difference frequency flows in the core. More complex designs can force a specific frequency in the core ,so that the output is synchronous, and some earlier wiind turbines did this too.

    The variable recluctance motors are more interesting, being more of notched cog between coils, so that the inductance of the coils is modulated while current is flowing giving a varying voltage. This can generate or motor depending on the phase of the applied voltage to the coils to force the phase of the current or vice versa,  these are the best sort of genset where speeds are very high - like an un-geared gas turbine or small diameter wheel.

    Nearly all serious (megawatt-minute) systems are indeed AC/DC/AC and have large banks of thyristors or IGBTs depending on the era it was designed in.


    A Diesel Rotary UPS wikki article DRUPS is something else as the prime mover is the diesel engine, but also worth understanding to get a scale of what is being asked for on big systems

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