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Thread: Big storm and no power in SA

  1. #1371
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    Quote Originally Posted by RANDLOVER View Post
    For "average Joe consumer" power factor can be thought of as two horses pulling a cart, they are most efficient when pulling in the same direction (unity/PF of 1.0) not at an angle to each other.

    The article refers to "synchronous condensers" for old petrol car owners this should remind them of points and condensers, a condenser is a capacitor, power factor correction can be achieved with capacitors. I think the reason they have opted for the synchronous motors, is they can alter phase angle (and even frequency which is pro'ly what they'll be used for in this case) , as they do in America because they don't have a national grid, so states buy in power from other states that are not synchronised and use a synchro to align with their local power.
    Ah no, not quite. The condenser in a car ignition is used to quench the small spark across the points as they open in an attempt to prevent pitting and excessive wear.

    The lagging phase angle is nothing to do with efficiency in the context of power being produced. The problem is the waste of "wattless" power that has to be produced using fuel, plus the windings in the generator and all of the distubution network has to be sized a lot bigger than it would be if the generator could be run just at unity PF.

    Yes, PF and be corrected, or more correctly improved, with a fixed condenser, as used to be used in fluorescent lights for example.
    With a rotary condenser the excitation is continuously varied by monitoring the PF as the load varies in an attempt to improve it.
    A synchronous motor is a different piece of equipment altogether.

    No, the frequency of an AC generator is a function of the number of magnetic poles and the speed of rotation. The whole grid is locked to whatever frequency is desired. Usually one power station is nominated as "master" and the rest slaves to it. It has nothing to do with the PF.

    The power grids in the USA (3 major ones) use high voltage DC at the interconnect. It is then converted back to AC with a variety of DC to AC equipment, which may or may not be rotatory, but not a synchronous condenser.

  2. #1372
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    Quote Originally Posted by Old Farang View Post
    Ah no, not quite. The condenser in a car ignition is used to quench the small spark across the points as they open in an attempt to prevent pitting and excessive wear.

    The lagging phase angle is nothing to do with efficiency in the context of power being produced. The problem is the waste of "wattless" power that has to be produced using fuel, plus the windings in the generator and all of the distubution network has to be sized a lot bigger than it would be if the generator could be run just at unity PF.

    Yes, PF and be corrected, or more correctly improved, with a fixed condenser, as used to be used in fluorescent lights for example.
    With a rotary condenser the excitation is continuously varied by monitoring the PF as the load varies in an attempt to improve it.
    A synchronous motor is a different piece of equipment altogether.

    No, the frequency of an AC generator is a function of the number of magnetic poles and the speed of rotation. The whole grid is locked to whatever frequency is desired. Usually one power station is nominated as "master" and the rest slaves to it. It has nothing to do with the PF.

    The power grids in the USA (3 major ones) use high voltage DC at the interconnect. It is then converted back to AC with a variety of DC to AC equipment, which may or may not be rotatory, but not a synchronous condenser.

    In the interest of full disclosure, I should say that I used to construct, service, install and repair (to circuit board or even component level if you count replacing printed cct board caps that normally are the 1st to go due to drying out, not tantalum obviously) power factor correction equipment and have a Diploma in Elec Eng. A.K.A (also known as) an Assoc Dip in Aus?

    So not to put too fine a point on it but, condenser is an old term for capacitor.
    "Condenser is a term used for a capacitor in the past. In time the term ceased to be used, with capacitor turning into the most commonly used term from 1926. Condenser and capacitor are one and the same viewed from electrical perspective. However in other fields of study, condenser may likewise allude to various different things.


    Read more: Difference Between Capacitor and Condenser | Difference Between Difference Between Capacitor and Condenser | Difference Between "

    A synchronous condenser would give better PF control as capacitor banks operate in switched steps, usually with a half step to give finer control, the cost benefit analysis normally proves it is not worth going beyond 0.98 PF.

    The lagging phase angle is what causes the inefficiency i.e my previous analogy of two horses pulling at different angles.

    "In electrical engineering, the power factor of an AC electrical power system is defined as the ratio of the real power absorbed by the load to the apparent power flowing in the circuit, and is a Dimensionless number in the closed interval of −1 to 1. A power factor of less than one indicates the voltage and current are not in phase, reducing the average product of the two." https://en.wikipedia.org/wiki/Power_factor

    I'm sure I've seen the synchronous motor/generator used in the USA to stabilise the power from different grids this was on TV so they might've glossed over it's proper function. "Long distance and highly concentrated grids.

    For electric suppliers whose grids span great distances, synchronous condensers come in particularly handy. The synchronous condensers move reactive power and change the voltage of the grid to balance the distribution across greater distances or to a greater number of consumers. " https://www.powermag.com/aes-uses-sy...rid-balancing/

    In broad brush strokes, a motor is a generator depending on how the EMF (Electro Motive Force) is applied which is how Electric cars work, they use the same rotating component as both motor and generator. "In electrical engineering, a synchronous condenser (sometimes called a synchronous capacitor or synchronous compensator) is a DC-excited synchronous motor, whose shaft is not connected to anything but spins freely.[1]Its purpose is not to convert electric power to mechanical power or vice versa, but to adjust conditions on the electric power transmission grid

    . Its field is controlled by a voltage regulator to either generate or absorb reactive power as needed to adjust the grid's voltage , or to improve power factor. The condenser’s installation and operation are identical to large electric motors and generators." https://en.wikipedia.org/wiki/Synchronous_condenser

    Just different names for the same thing depending on how they are used, I've even heard Motor/Generators (with huge flywheels) also called "Rotary UPS's" (Uninterruptible Power Supplies). A joke in the electrical industry is that really stands for Unreliable Power Supply, particularly for battery powered ones, as the batteries are the weakest link.

    Thanks for the trip down memory lane.

    Cheers,
    Randy


    2005 D3 TDV6 Present
    1999 D2 TD5 Gone

  3. #1373
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    Quote Originally Posted by Old Farang View Post

    Not sure just who sees them as an "interim measure". For grid power generating stations their sole purpose is the "bottom line". They are not put there to make a grid more reliable, or to provide customers with cheaper power.

    The simple fact is, the more that the power factor can be kept towards unity, the more the return is to the operator because the fuel input, regardless of what form it is, is not being wasted generating "wattless power".

    The argument being touted concerning "renewables" is only valid because the wind and the sun are "free". The infrastructure still has to have the capacity to tolerate a poor power factor, but it is a one off cost only built into the design of the system.

    This conversation is pointless if we take the latest news from China as it reads. [ or perhaps this is the reason they are being touted as interim]

    China will need to replace its 1,300GW fleet of coal generators and around 85GW of gas generation with zero emissions sources.

    China changes the game on climate action, for renewables and for coal | RenewEconomy
    I’m pretty sure the dinosaurs died out when they stopped gathering food and started having meetings to discuss gathering food

    A bookshop is one of the only pieces of evidence we have that people are still thinking

  4. #1374
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    Quote Originally Posted by bob10 View Post
    This conversation is pointless if we take the latest news from China as it reads. [ or perhaps this is the reason they are being touted as interim]

    China will need to replace its 1,300GW fleet of coal generators and around 85GW of gas generation with zero emissions sources.

    China changes the game on climate action, for renewables and for coal | RenewEconomy

    Just making a wild guess but I doubt many here will not be too worried about that in 2060.

  5. #1375
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    Quote Originally Posted by 4bee View Post
    Just making a wild guess but I doubt many here will not be too worried about that in 2060.
    Probably upgrade from the D3 to a D4 or even a 5 around then!
    'sit bonum tempora volvunt'


  6. #1376
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    Quote Originally Posted by Saitch View Post
    Probably upgrade from the D3 to a D4 or even a 5 around then!

    I hope you are still kicking whilst waiting for the new D14 or D15 but the Law of Averages for me is telling me otherwise.

    No really.


    BTW Encycla. Brittanica more or less says bollocks about Lemmings jumping off cliffs.

    Do Lemmings Really Commit Mass Suicide? | Britannica

  7. #1377
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    Quote Originally Posted by 4bee View Post
    Just making a wild guess but I doubt many here will not be too worried about that in 2060.
    It's not just all about us. That's the problem really. Most boomers can't think past their next doctors appointment. Let alone thinking about leaving the world better than when we had it. Like lemmings off a cliff. must be happy hour soon, surely.
    I’m pretty sure the dinosaurs died out when they stopped gathering food and started having meetings to discuss gathering food

    A bookshop is one of the only pieces of evidence we have that people are still thinking

  8. #1378
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    South Australia leading the way.

    The Tesla big battery in South Australia – officially known as the Hornsdale Power Reserve – delivered a windfall profit to its Paris-based owner Neoen in the first half of 2020, largely due to the key role it and other big batteries played when a massive storm blew down the state’s main link to Victoria.
    The Hornsdale battery, along with another Tesla battery at Lake Bonney and the Dalrymple North battery, were asked to play a key role stabilising the South Australia grid during the 17 days that the state was “isolated” from the rest of the main grid, and it reaped a huge bonus in revenue and profits in return.


    Tesla big battery in South Australia delivers stunning windfall profits | RenewEconomy
    I’m pretty sure the dinosaurs died out when they stopped gathering food and started having meetings to discuss gathering food

    A bookshop is one of the only pieces of evidence we have that people are still thinking

  9. #1379
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    I’m pretty sure the dinosaurs died out when they stopped gathering food and started having meetings to discuss gathering food

    A bookshop is one of the only pieces of evidence we have that people are still thinking

  10. #1380
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    Quote Originally Posted by bob10 View Post
    It's not just all about us. That's the problem really. Most boomers can't think past their next doctors appointment. Let alone thinking about leaving the world better than when we had it. Like lemmings off a cliff. must be happy hour soon, surely.
    I can't agree there, Bob. I think most boomers, because of their upbringing, have a more balanced grip on reality, compared to today's media fed, information observers/absorbers.

    By the way, Lemmings only jump off cliffs in Disneyland!
    'sit bonum tempora volvunt'


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