I always had this question that I never really found written anywhere and I have the good or bad habit of not believing my teachers when answering this kind of odd questions.
Whenever I read about the induction motor equivalent circuit R1 is always the resistance of the stator winding. Great! I have a stator, how do I get R1?
My first guess is to measure the resistance value between one phase and neutral in Y (star) connection. That or take the resistance value between phases in Delta connection and divide it by 1.5 to get the resistance of only the winding that connects them directly.
Second question: To extract the parameters of the equivalent circuit, I tested the motor in Delta connection, with the rotor blocked and in free running mode. Is V1 the phase to phase voltage? What about Is? Should I test it in Y instead? I have V(t) (phase to phase) and I(t) that I got using an oscilloscope and a current probe.
Equivalent circuit with variable names: eq circuit http://myelectrical.com/Portals/0/SunBlogNuke/2/WindowsLiveWriter/InductionMotorEquivalentCircuit_D7EF/Induction%20Motor%20Equivalent%20Circuit%20-%20Simplified_2.png