SPICE-Simulation using LTspice IV

7. Project 3: Three Phase AC System
7.1. Schematic and Simulation
We need 3 voltage sources, 3
transformers and 3 load resistors
to review this technique.
For the transformers we will use
our well-known file
„xformer_01.lib“,
but in this case choose
identical main
inductances on the
primary and secondary
side to get a turns ratio of
1:1.
Fetch all these parts from the
library and draw the circuit
diagram.
Then move the cursor over the symbol of
every voltage source and right click. All
entries for the 3 sources are identical
(except one....):
DC offset = 0 Volt
Amplitude = 325 V (peak value for
RMS = 230V)
Frequency = 50 Hz
Phi = 0 degrees (start phase of the sine
curve)
Important:
The 3 voltages have the same amplitude
and the same frequency, but differ in the
phase shifts. We cannot enter the
necessary phase difference of 120
degrees in the property menu -- so
simply enter different start delays:
for V1 the delay time is 0ms
for V2 the delay time is 6,66666 ms
(see figure)
for V3 the delay time is 13,33333ms
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