Yes.
The role and purpose of reactive energy are to maintain the em fields within the electrical network. Although reactive energy only flows within such networks it requires reactive current which together with the active component of current dissipates heat in the conductors and as such it too experiences or creates an active power loss within the transmission and distribution system. Note that the power losses are due to the MAGNITUDE of the current and not just the active component.
So
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Yes, and it happens all the time. However the frequency deviations are very small and within the range of normal operations. One bus may be at 60.01 Hz and the other at 59.96 Hz and the system is still stable. Larger frequency deviations would be unstable however as the synchronous generators lose synchronization and their protection systems take them offline.
However is the frequency difference is much larger, then the two AC sections cannot be directly connected. In this scenario, an asynchronous connection using either a DC tie or variable frequency transformer is needed to connect the two grid sections.
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The largest losses in long distance electrical power transmission come from energy lost in the resistance of the power line.
If P is the power transmitted, and R is the resistance of the line:
If P is fixed by community demand, then you can reduce lost power dramatically by increasing the transmission voltage. As a result, all long-distance power transmission, AC or DC, is done at high voltage.
The advantage of AC has always been that it is easy to change the voltage up and down with a transformer; DC requires more equipment and some losses to convert.
That being said, transferring AC power between separate grids requires making sure the phase of the power transmitted matches from the two grids (so that the power from the two grids doesn't cancel or ring), which is difficult and expensive. This is not a problem for DC, so DC lines are used in cases such as where power is transferred from another grid to increase the capacity of an existing grid, or between countries that use different frequency power.
Capacitance between the AC phases (usually 3 phases are transmitted at once over a line) or between the line and the surrounding soil or water causes losses that are not a problem with DC. Therefore, undersea high voltage lines tend to be DC.
Overall line loss is also lower per 1,000 km, so very long distance transmission lines sometimes use DC.
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I think you're talking about these vines. I'll explain what is their use and why they are made in this specific manner in layman terms to make sure it's not a boring electrical engineering lecture to you. Let's get into it.
Short answer : These are Insulators
Long answer (with explanation) : Electrical power lines have some voltage associated to it, usually in the order of kilovolts. The potential for the ground is zero.
Why we need an Insulator?
Why this specific shape with discs?
An electric spark (even the lighting) happens due to the potential difference between two points which can ionize air.
So, we need to manage this potential difference, and that is done by fragmenting it using multiple discs which create kind of zones with somewhat same potential drop.
The material we use is ceramic.
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Batteries that big are BIG
This is the world's biggest battery, near Jamestown north of Adelaide, South Australia.
It's 139 megawatt hours storage and can deliver power at 100 megawatts. So at full delivery, it could supply power for about an hour and 20 minutes. For a size comparison, you can see a car parked to the right.
South Australia (pop about 1.4 million) requires about 3000 megawatts in the middle of summer, so even the world's biggest battery would need to be 30 times larger to supply the whole state (for just an hour and 20 minutes!). It performs a very important function though - because it can be switched on in seconds, it provides a very stable back up for the grid if there is a big power failure elsewhere, and it has brought down the cost of providing peaking power to the interstate grid by a BIG margin. Powering up a steam generating plant can take several hours from cold. And even peaking turbine or diesel generators can take some minutes to start and bring on line.
And it's not just the battery that's big - you have to charge it from something. You can see the associated wind farm in the distance, and that's BIG too. The battery can also buy charging power off the grid at off-peak times too.
The cost - $90 million Aussie Dollars - about $US 65 million. It is expected to pay for itself in 3–4 years.
It's been so successful that another smaller 30 megawatt hour battery has been built near Whyalla to the west, and a third battery is planned for the south east of the state.
This huge battery has been so successful at stabilizing South Australia's power grid and reducing the cost of peak power previously bought from interstate suppliers at "rip-off" prices, they are expanding it from 139 MwH to 170 MwH.
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If they are both standard 12v batteries but one is showing a higher voltage than the other the higher one will drop and the lower one will rise. In other words the voltage of both will change until they reach equilibrium.
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A 3 phase AC circuit is a circuit or installation connected to a 3 phase supply. A 3 phase supply uses 3 active lines that may or may not need a neutral wire. A balanced 3 phase load like a 3 phase motor does not need a neutral. Each phase voltage is displaced by 120 degrees. This is due to the cool arrangement in the generator. 3 phases being the most economical arrangement of windings to produce a reasonable smooth load and a a reasonably smooth power source for a motor. On the left side is the 3 phase generators.
Below is a pictorial representation of the 3 phase voltages and winding inside a large generator.
Each phase is also referenced to neutral. So in a 400 volt 3 phase system the voltage between each phase is 400 volts and 230 volts between each phase to neutral. typical application is for a 3 phase motor or a machine that has a high load or several 3phase motors in the machine.
Most factories have a 3 phase supply because they have a high maximum demand ( or a high anticipated load) or have 3 phase motors.
Below is a typical 3 phase motor and circuit.
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