In this paper, an analytical model with a new space-vector modulation strategy for a four-switch (B4), inverter feeding an induction motor drive is derived. The proposed modulation strategy for the B4 operation has the same symmetry as in a classical B6 inverter. The analysis is based on a novel space-vector decomposition technique. The analytical results of the machine are accomplished in an alpha beta complex plane by space vector decomposition and by using a mixed p-z approach. As shown; good agreement exists-between the analytically calculated waveforms and the experimentally determined ones. Therefore, the proposed analytical model becomes a very useful method for motor investigation under unbalanced as well as balanced supply conditions.