EEET2099 Varriable Speed Drives

QUESTION 1: A separately excited DC motor is rated at Prated, and has a rated speed of Nrated. The motor armature has to be fed with VNL to run it under no-load at its rated speed. The armature resistance is Ra and the  eld winding resistance is Rf . The voltage supply feeding the armature circuit has an upper voltage limit of Va;max. The rotational losses are negligible. The  eld winding is supplied at its rated voltage of Vf;rated in (a), (b), (c), (d) and (e). The values for Prated;Nrated; VNL;Ra;Rf ; Va;max and Vf;rated are to be obtained from the Q1 part of the Excel spreadsheet. (a) Determine the armature terminal voltage required to run the motor under no-load at a speed of 700 rpm (b) Determine the armature current when the motor is operating at a speed of 700 rpm delivering 1000 W to a load. (c) Determine the armature terminal voltage required to run the motor at a speed of 700 rpm delivering 1000 W to a load.