Hi

If we consider the induction motor's equivalent circuit,we find that the rotor's resistance is affected by the slip and when the torque rises,the slip rate approaches one,In other words the amount of impedance in the equivalent circuit changes.

a motor is not a pure resistance... you must review the relationship between speed, current, magnetic field, active power, reactive ..... good luck

Hello, plese read more about theory of asynchronous motor, equivalent circuit and dependence of material's electric resistance generally.

Few comments:

• Resistance is not constant and it has dependence on temperature.
• Temperature inside motor has relationship on power losses
• Power losses are mainly made by current (neglecting mechanical friction and ventilation)
• Power losses can be subdivided into winding PL and magnetic circuit PL
• Winding power losses are in square dependence of current (dP=R×I×I)
• By loading of motor shaft the leakage inductance (magnetic flux) is also changing
• Power output of motor is clearly mechanical (torque and rpm), but input power is electrical (voltage, current, PF), so there are a lot of electro-machanical dependences in flow of energy
• Source voltage(input voltage on terminals) is also not constant. Each source has internal resistance(impedance) and dependence on current in circuit

Have a nice day,

Petr

You are mixing voltage and power. Your voltage is fixed, but that does not fix the power...

As load increase, current also increase. Since the Power P = VI, to maintain power constant, voltage has to be decreased. In Power system, current is inversely proportional with voltage.