3 phase waveform simulator/generator/calculator

[ArchieMedes]

Hi,

Do you know any website which has a 3 phase waveform generator/simulator/calculator? I want to see the values or effect if, example, one phase is lost or only half cycling. Particularly, the instantaneous power or waveform, the total voltage or power and the phase to phase voltage reading of the faulty phase w.r.t normal phase.
Thanks for the help!

 

[SAC]

This is pretty easy to use and visualize the different effects.

http://ee.mxpark.com/mwbc/mwbc.html

There are links to the author's page at the bottom. ctrl-click on the empty black area to bring up the editing menu. ctrl-click on an element to change the value. For the link given, try changing one of the 10 ohm "loads" of the mwbc and see the effect on the neutral current.

 

[ArchieMedes]

Thanks for the link!

 

[ArchieMedes]

I saw the link and tried to simulate. I would recommend it for single phase ac or dc simulation but for three phase, it seems not accurate. I tried to use three single phase ac supply and connected them in wye, changed the phase sequence to that of a three phase with 120 degrees apart. The phase voltage of the load, which is also in wye, is the same as the line voltage, unlike in a real three phase which should be divided by square root of 3. For waveform monitoring, it seems OK but don't take the values seriously.

 

[SAC]

I saw the link and tried to simulate. I would recommend it for single phase ac or dc simulation but for three phase, it seems not accurate. I tried to use three single phase ac supply and connected them in wye, changed the phase sequence to that of a three phase with 120 degrees apart. The phase voltage of the load, which is also in wye, is the same as the line voltage, unlike in a real three phase which should be divided by square root of 3. For waveform monitoring, it seems OK but don't take the values seriously.

Hmm. That is strange, I didn't seem to get that result. For example, I attached a picture of a 3-phase 208/120 wye setup (I think). Each phase is RMS 120v (peak 170/sqrt(2)), 120? out of phase. Phase to phase are RMS 208v (peak 294/sqrt(2)), 120? out of phase. 208v = 120v * sqrt(3).


Here is the code for it. You should be able to ctrl-click, select "file" -> "import", and paste it in:

$ 1 5.0E-6 2.008553692318767 33 5.0 50
r 96 176 304 288 0 1.0
w 304 144 304 176 0
w 304 176 304 208 0
g 368 192 368 208 0
w 304 176 368 176 0
w 368 176 368 192 0
r 416 48 416 288 0 1.0
w 416 48 304 48 0
w 416 288 304 288 0
v 304 144 304 48 0 1 60.0 170.0 0.0 0.0 0.5
v 304 208 304 288 0 1 60.0 170.0 0.0 2.0943951023931953 0.5
v 304 176 96 176 0 1 60.0 170.0 0.0 4.1887902047863905 0.5
r 304 48 96 176 0 1.0
o 9 128 0 35 299.3155353253689 766.2477704329444 0 -1
o 10 128 0 35 299.3155353253689 766.2477704329444 1 -1
o 11 128 0 35 299.3155353253689 766.2477704329444 2 -1
o 6 128 0 35 320.0 409.6 3 -1
o 0 128 0 35 320.0 409.6 4 -1
o 12 128 0 35 320.0 409.6 5 -1

 

[ArchieMedes]

Hi SAC,

I imported the code and it looks fine. All values seem accurate. Maybe I made some bad connections.
I have some question for you. Below is the code. I tried to create an unbalanced scenario by removing a resistor for the thyristor trigger so the output was only have cycle causing different voltage values on the 3 resistor loads. From what I know, the imbalance should be corrected by the neutral or star point in the load. I monitored the voltage and current on the neutral wire or star point ground but it looks the same, zero flat. Am I missing something here? Thanks for the replies.

$ 5 5.0E-6 13.097415321081861 50 5.0 43
v 672 256 704 64 0 1 60.0 331.0 0.0 0.0 0.5
v 672 256 720 432 0 1 60.0 331.0 0.0 2.0943951023931953 0.5
v 672 256 592 256 0 1 60.0 331.0 0.0 4.1887902047863905 0.5
r 288 256 208 256 0 1.0
r 208 256 96 64 0 1.0
r 208 256 80 432 0 1.0
w 448 64 704 64 0
w 448 64 448 96 0
d 432 32 368 32 1 99.0
w 496 32 704 64 0
w 352 64 304 64 0
w 352 96 304 96 0
w 304 96 304 64 0
w 304 64 96 64 0
177 448 64 352 32 0 -2.809188206326752 -2.8091882063267803 0.0010 0.0010 0.0010
d 352 128 432 128 1 99.0
177 352 96 448 112 0 2.809188206326752 2.645477820821924 0.0010 0.0010 0.0010
w 96 64 272 128 0
w 288 256 288 320 0
177 368 288 464 304 0 2.785676504705208 2.6239838529555186 0.0010 0.0010 0.0010
d 368 320 448 320 1 99.0
177 464 256 368 224 0 -2.785676504705208 -2.7856765047052363 0.0010 0.0010 0.0010
w 320 256 288 256 0
w 320 288 320 256 0
w 368 288 320 288 0
w 368 256 320 256 0
w 512 224 512 256 0
d 448 224 384 224 1 99.0
w 464 256 464 288 0
w 464 256 512 256 0
w 512 256 592 256 0
w 512 432 592 432 0
w 464 432 512 432 0
w 464 432 464 464 0
d 448 400 384 400 1 99.0
w 512 400 512 432 0
w 368 432 320 432 0
w 368 464 320 464 0
w 320 464 320 432 0
w 320 432 288 432 0
177 464 432 368 400 0 4.696106050972219 4.369804255057602 0.0010 0.0010 0.0010
d 368 496 448 496 1 99.0
177 368 464 464 480 0 -4.696106050972219 -4.696106050972162 0.0010 0.0010 0.0010
w 592 432 720 432 0
w 288 432 80 432 0
w 288 432 288 496 0
p 592 256 592 432 0
p 704 64 592 256 0
p 704 64 592 432 0
p 96 64 288 256 0
p 288 256 80 432 0
p 96 64 80 432 0
g 208 256 208 352 0
r 432 32 496 32 0 100.0
r 272 128 352 128 0 100.0
r 448 224 512 224 0 100.0
r 288 320 368 320 0 100.0
r 448 400 512 400 0 100.0
r 288 496 368 496 0 100.0
g 672 256 656 320 0
o 6 64 0 297 320.0 409.6 0 -1
o 30 64 0 297 320.0 409.6 0 -1
o 43 64 0 297 320.0 819.2 0 -1
o 47 64 0 34 640.0 9.765625E-5 1 -1
o 46 64 0 34 640.0 9.765625E-5 1 -1
o 48 64 0 34 640.0 9.765625E-5 1 -1
o 49 64 0 298 640.0 9.765625E-5 2 -1
o 50 64 0 298 640.0 9.765625E-5 2 -1
o 51 64 0 298 640.0 9.765625E-5 2 -1
o 52 64 0 291 7.62939453125E-5 102.4 3 -1

 

[hurk27]

for a Y supply and a Y load the Xo from the supply has to be connected to the centerpoint of the load star to have the neutral balanced, but the program locks up when I try it.

 

[hurk27]

Just figured out that using the ground symbols does create a bond for the two neutrals:roll:

 

[SAC]

Hi SAC,

I imported the code and it looks fine. All values seem accurate. Maybe I made some bad connections.
I have some question for you. Below is the code. I tried to create an unbalanced scenario by removing a resistor for the thyristor trigger so the output was only have cycle causing different voltage values on the 3 resistor loads. From what I know, the imbalance should be corrected by the neutral or star point in the load. I monitored the voltage and current on the neutral wire or star point ground but it looks the same, zero flat. Am I missing something here? Thanks for the replies.

First, circuit simulators have trouble with floating nodes, so the floating diode terminal may be causing problems. I think you can effectively disable the thyristor by removing the resistor and then connecting the diode back on the source side of the thyristor. Secondly, I don't see any way the circuit can compensate with the thyristor disabled - there is no current path back to the source during that half cycle. I think if it was delta connected instead of wye connected, then there would be source redundancy. Isn't that the main advantage of delta over wye?