Abstract: In a variable reluctance electric drive system motor the fractions of a cycle during which the winding inductance of a phase increases with movement in either direction are such that the motor is self starting in either direction. The timing of the power converter in relation to the cycle of inductance is such that the current increases from its minimum value to substantially its maximum value while the winding inductance is substantially at its minimum value and thereafter substantially decreases before the power converter disconnects the winding from the supply. This can be achieved by making the switch-on and commutation of current occur at predetermined positions so related to the variation of inductance that the peak current ip at maximum power and maximum speed, is greater than I, where I=E/(R+dL/dt), E is the supply voltage, R the winding resistance and dL/dt is the maximum rate of increase of inductance before the commutation point.