This simulation shows how to implement a back-EMF observer by comparing the measured phase current with the estimated phase current and using the error signal to recreate the missing back-EMF signal.
TRANSIENTS: At t=0, the estimator is initiated and starts converging on the actual back-EMF signal. Notice the speed by which it locks on to the actual back-EMF voltage.
PLOTS: Actual Back-EMF and Estimated Back-EMF
REQUIREMENTS: Spice Executable, Support Pack
Unzip the files for this simulation into the same folder as the files extracted from the Support Pack. Then run "45 PMSM Digital BEMF Observer.asc".