A 25kw,60Hz induction motor is required to move mechanical load at different speeds:200,550,1200 and 2000rpm
at rated voltage 380v such that the rotor speed at full load 1640rpm.
1- what should be the supply frequency and voltage in each case with no slip compensation?
2- If the motor operates at 75% of rated torque what should be the supply frequency and voltage in each case with slip compensation? Can the motor operate at all speeds without exceeding the motor rated current? Explain.