Thanks, it makes sense. So basically a cylindrical rotor would be preferred in all cases due to uniform airgap, and hence reduce distortion in the airgap flux? However due to the slow operating speed of i.e. hydro plants we need to use salient rotors, because we would require a lot of poles to...
Hi all,
I tried to post in this post https://www.physicsforums.com/threads/salient-and-non-salient-pole-synchronous-generator.878198/ but I now realize that creating a new thread might have been better.So...
Salient rotors are not used in high rotational speed applications, and we must use...
Hi,
imagine we have the following circuit shown in the figure below. There are installed a passive filter to filter the 5th harmonic. Now, after installation this creates a parallel path with a generator connected, let's say that this parallel circuit has a resonance frequency at the 7th...
Hi, I think that full cancellation is theoretical possible if the loads are equal, here's why:
In the delta-delta the currents are the same at primary and secondary.
a1 = x1 = sin(5 \omega t)\\b1 = y1 = sin(5 \omega t - 120^{\circ})\\c1 = z1 = sin(5 \omega t + 120^{\circ})
for the delta-wye we...
Thanks, for your time. No extra elaboration is needed @cabraham.
By the way I found some Spice simulations for the pretty much the same problem, can't believe I have not seen that page before.
http://www.allaboutcircuits.com/textbook/alternating-current/chpt-10/harmonics-polyphase-power-systems/
Hi, I have also been struggling with this topic, I have some questions.
If we think of a 3 phase load producing tripling harmonics (current sources in parallel with load, injecting harmonic currents into the system).
(I've read that harmonics generated due to non-linear loads can be thought of...
Hi, sorry for interrupting your thread @OliskaP.
@jim hardy, How exactly do a zig zag transformer manage to shift 60 degrees? I neither fully understand the zig zag transformer, and can not really seem to understand how this 60 degree phase shift is created.
best regards.
Hi,
how do power operators change the droop setting in modern power plants? Back in the days it was with help of a flyball governor(?). In todays power plants do operators adjust some sort of gain electronically via a scada system or something?
1. Problem Statement:
A 4-pole, star-connected, 50 Hz, 11kV, 40 MVA turbogenerator, with a synchronous reactance of 0.8 p.i., is connected to a power network. This power network can be represented by 11-kV infinite bus with a series reactance of j 0.5 Ω. A voltage regulator adjusts the field...
When I calculated and got the wrong sign I did the following:
(V_2-V_{Ground}) \times Y_c
When I do it like this I am assuming the current leaves the bus, which should not be the case, therefore I should do it like this:
(V_{Ground}-V_2) \times Y_c
Doing it this way assumes that current flows...
j0.25 is the admittance not impedance, so if I solve the value for C, I get a positive value.
Y = \frac{1}{Z} \rightarrow Z = \frac{1}{Y} = \frac{1}{j0.25} = -j4
\\
Z = \frac{1}{j\omega C} = -j4 \rightarrow C = \frac{1}{4 \times \omega}
I did not write that it was the admittance, I just...