EBM 510 Tutorial Questions Two: Worked Solutions

Worked answers to the second tutorial. Torque is taken from the series motor relations, torque proportional to the square of armature current and back electromotive force to current times speed, so that supply voltage equals current times the sum of the speed term and armature resistance; the speed of 1000 rpm is converted to 104.67 radians per second and the half converter's average voltage evaluated from the firing angle at 210 volts, giving 62.87 amperes and 118.59 newton-metres. The same machine is then run on a full converter, whose average voltage of 195 volts gives 58.38 amperes, and the two arrangements are compared.