Power system angular stability

[viniciuschrist]

I really liked your video, straightforward explanation and nice analogy with the horse-spring-weight example.

[arch]

Thanks. I have started a career in electrical transmission (utility control). This video is a great resource in addition to my textbooks. I am definitely going to watch some more of your content.

[donberg]

Love your explanations w/great graphic representations! Clear to the point tutorials! TX

[ali]

Excellent work THANK YOU... I paid for degree and I STILL looking for information to understand!!!

[yxmati]

Hello Mr. Schett! Thank you very much for uploading the series on power systems engineering. However, as far as I can see, you've overlooked something here. The mistake you make is based on the assumtion that power line angle stability is equivalent to rotor angle stability, which it is not from my point of view.

For an ideal power line & synchronous machine you'll have following formula:
P = U1*U2/X*sin(theta)

In case of a generator, U2 will be the more or less constant grid voltage & U1 the rotor voltage (assumed to be constant as well). Therefore, your calculations are correct. However, in case an electric line where U1 might be the voltage deep inside the grid (constant), there is no reason to assume that U2 is a constant in theta. Increasing theta will decrease U2, and at some tipping point U2 will decrease faster than sin(theta) increases -> power is at its maximum. The angle at which this happens is !not! 90° but a function of the load angle (solely). In order to calculate it, you'll have to find an equation U2=f(P, load angle). Therefore, it is convenient to use the equation of an ideal power line: U2 = on which coordinate system you use, you'll get a different sign. Substitute I1 with some expression of P & load angle, this will yield a quadratic equation in U2. Solve it and you'll end up with a term U2=f(P, load angle) which can be plugged into the first equation P = U1*U2/X*sin(theta). This will yield a curve P(theta) similar to yours, but with the essential difference that theta(P_max) is around 50-60°, depending on the load angle.


Best regards,
Matthias Maier

[ismailbinmail]

great explanation, but sir im still confuse, please answer. in 11:37 you say that "and you can see the phase angle between the line ends are still well below 90 degrees"
pleasee tell me which one is the phase angle, helpp

[ahmedimamovic]

Great explanation, please keep making this kind of videos.

[MagneManet]

Hello Schett, great video. Just wonder if there is an intuitive way to understand why active power depends on a certain phase angle between source and load?

[vaibhavpatil-mjzj]

Thank you sir. What is the direction of torque. Same with rotation of rotor or opposite it

[felipe_dlt]

Excellent work! Regards from Argentina.

[ismailbinmail]

sir, i want to ask one more question please. so what is exactly the rotor angle stability? i mean what angle exactly? angle between what and what? because i read and see another video and i am confused now. please help

[dubol]

I appreciate your video. However, regarding the formula @7:00, is V^2 the difference between the source and terminal voltage squared, or is it one of those voltages squared? If it is one of them, which one?

[SoherNasr-uv]

Please, I think there is a mistake in the last two minutes, or may be the mistake in my understanding.

[chinniahshanmugam]

Excellent I required a little more explanation and exposure could you help me...Electrical Safety Inspector