Closed loop sensorless control of permanent magnet synchronous motors

摘要

Method of controlling a PMSM, comprising measuring phase current i(t) of at least one phase of the PMSM, calculating a phase angle ϕ between the measured phase current i(t) and a phase voltage u(t) of said at least one phase, and estimating external load torque z as a function of the cosine of the phase angle ϕ.