A separately-excited dc motor is delivering rated torque at rated speed. Find the efficiency of the motor at this operat
Posted: Fri Apr 29, 2022 8:46 am
A separately-excited dc motor is delivering rated torque at
rated speed. Find the efficiency of the motor at this operating
point. The field current is constant and the armature voltage is
variable. Assume the motor also includes brush voltage
losses.
Machine details:
2000 kW, 450V, rated current = 2000A, 700 rpm, Brush voltage drop =
4 V, Field power input = 75 kW, Ra = 0.003645 fl, La = 0.1 mH,
Machine frictional torque coefficient = 15 N-m/(rad/sec).
Calculate the input power to the armature circuit if the field
current is constant and the armature voltage is variable:
rated speed. Find the efficiency of the motor at this operating
point. The field current is constant and the armature voltage is
variable. Assume the motor also includes brush voltage
losses.
Machine details:
2000 kW, 450V, rated current = 2000A, 700 rpm, Brush voltage drop =
4 V, Field power input = 75 kW, Ra = 0.003645 fl, La = 0.1 mH,
Machine frictional torque coefficient = 15 N-m/(rad/sec).
Calculate the input power to the armature circuit if the field
current is constant and the armature voltage is variable: