is not the same as the physical angle occupied by the same pair of north and south poles which will depend upon the number of poles of the stator as an example of stator design there may be 12 stator coils in each stator winding for a pair of north and south poles the electrical angle between adjacent stator coils is called the difference angle which in this example is equal to 360 12 30 electrical degrees in order that such a stator i e having stator windings as shown in fig7 operates correctly the voltages and current in the thyristor power converter 22 should be offset by the same difference angle as the voltage and currents in the thyristor power converter 24 the use of this difference angle can provide additional benefit by helping to cancel torque harmonics in the stator windings the alternative drive circuit shown in fig2 i e where the thyristor power converters 22 and 24 are replaced by the pulse width modulated pwm power converters 200 and 202 suffers from significant pwm frequency current harmonics due to the proximity of the stator coils within the first and second stator windings 208 and 210 for example it may be the case that the stator coil in pole 1 slot 1 of the first stator winding 208 is in physical proximity to the stator coil in pole 1 slot 2 of the second stator winding 210 this would mean that there is a high degree of mutual coupling between these two stator coils and a transformer action may.