Electrotechnical Systems

387Electric Power Production and Transmission Simulation

windings of two transformers in delta; thus, the primary transformer voltages have

the phase shifts as 7.5°, −22.5°, −7.5°, −37.5°. The transformer’s primary windings

are connected in series, and the modulating signals are shifted, respectively, by 0°,

−30°, −15°, −45°, so that all the fundamental harmonics are in-phase, and the most of

the high harmonics cancel out. We note that the shift of 30° between the transform-

ers having star and delta connection leads to cancelling-out of the harmonics of the

orders 5 + 12n and 7 + 12n, and the shift by 15° between the rst and the second

groups ...