# Example induction motor

I have three phase induction motor:

• $$U=6\text{ kV}$$
• $$P=630\text{ kW}$$
• $$f_1=50\text{ Hz}$$
• speed of rotor $$n=1410\text{ rpm}$$

Maximum moment is reached when $$n=1120\text{ rpm}$$. Now voltage and frequency change to $$U=2\text{ kV}$$, $$f_2=42\text{ Hz}$$. I need to calculate the power of the motor for this voltage if the rotational speed is $$n=1200\text{ rpm}$$.

Stator parameters, impedance of the parallel branch and losses caused by friction are all 0.

Can you please help me with this problem? I tried to solve it but my values of rotor resistance and reactance are $$R=2\ \Omega$$ and $$X=12\ \Omega$$. I stopped here because I think these values are too high and maybe I've done something wrong.