jackorocko
- Apr 4, 2010
- 1,284
- Joined
- Apr 4, 2010
- Messages
- 1,284
I been messing around with LTSPICE lately in an attempt to play around with some 3 phase wiring ideas I had been trying to understand. All was working out well till I tried to simulate a step down isolation transformer according to this pdf file here page 44 http://www.ieca-inc.com/images/Spice-Simulation_Using_LTspice_Part_1.pdf
In the above link he uses a 50Hz 3 phase sine wave. I noticed that he used a time delay to setup properly the 3 phase. I was using prior to this the PHI[deg] to set 120 and 240 degrees per phases 2 and 3. But when trying to do a transient analysis over even a microsecond takes forever once you add in the isolation transformers. The key is using a time delay to setup the 3 phase, but what exactly is the time difference between 3 phase on 60Hz like in the states and why so long for spice to simulate with the phase shift set in PHI?
I came to some numbers, but I know I am wrong with my mathematical understanding.
I used for phases
1 - 0 ms/delay
2 - 5.66666ms
3 - 11.33333ms
Now, how I came up with those answers, 60Hz cycle means the wave changes 120 cycles per second. so 1000ms/120 = ~8.3ms * 66% = ~5.6ms * 2 = ~11.3ms. Which I know is utter crap, but how are those values really derived?
A final summary of the above - Best way to do transient analysis with mutual inductance using 3 phase that won't slow the simulation down to a crawl?
In the above link he uses a 50Hz 3 phase sine wave. I noticed that he used a time delay to setup properly the 3 phase. I was using prior to this the PHI[deg] to set 120 and 240 degrees per phases 2 and 3. But when trying to do a transient analysis over even a microsecond takes forever once you add in the isolation transformers. The key is using a time delay to setup the 3 phase, but what exactly is the time difference between 3 phase on 60Hz like in the states and why so long for spice to simulate with the phase shift set in PHI?
I came to some numbers, but I know I am wrong with my mathematical understanding.
I used for phases
1 - 0 ms/delay
2 - 5.66666ms
3 - 11.33333ms
Now, how I came up with those answers, 60Hz cycle means the wave changes 120 cycles per second. so 1000ms/120 = ~8.3ms * 66% = ~5.6ms * 2 = ~11.3ms. Which I know is utter crap, but how are those values really derived?
A final summary of the above - Best way to do transient analysis with mutual inductance using 3 phase that won't slow the simulation down to a crawl?