I have a permanent magnet synchronous machine (PMSM) that I intend to run as a generator. I'd like to test its load characteristics under resistive load. The PMSM is Y-connected. Assuming Y-connected load, the circuit will look like this.
My objective is to plot the load characteristics of the generator (load voltage vs. load current), for 10-12 different values of load resistance, starting from a maximum resistance to a minimum resistance. I want to be able change the load resistance while keeping the load balanced. However, I only have access to potentiometers and simple resistors. If I manually change the POT resistances by hand at each step, there is bound to be imprecision and thus, load will become unbalanced.
My questions: (1) Is there any way I can achieve this using potentiometers? (2) Is there an alternative way to do it, keeping the load balanced? Thanks a lot!