Voltage with constant amplitude and phase when 'vType' is 'parameter',
with variable amplitude and phase when 'vType' is 'signal'.
Optional input:
omega angular frequency (choose fType == "sig") vPhasor {norm(v), phase(v)}, amplitude(v_abc)=sqrt(2/3)*vPhasor[1] vPhasor[1] in SI or pu, depending on choice of 'units' vPhasor[2] in rad