especially in the already running industrial plants. Concerning the large power
demand of these motors and the high level of low order harmonics injected by
the conventional converter used, many solutions are tested and implemented. In
this paper an upgrading scheme for driving the separately DC-motor in the four
quadrants is suggested. The power circuit used is based on PWM voltage source
converter (VSC) capable of bidirectional power flow with controllable power
factor and pure sinusoidal supply currents. The drive details are presented and
its performance is investigated via simulation work. A comparison of
performance of the suggested scheme and the conventional scheme shows that
the suggested one can economically replace others with valuable contribution to
power factor improvement and harmonics reduction in power system.