Sensorless IPMSM driving control method and device based on extended nonlinear observer

The invention relates to a sensorless IPMSM driving control method and device based on an extended nonlinear observer. The method comprises the steps of obtaining a state equation under a polar coordinate system through linearization based on a voltage equation and a mechanical equation; constructing a nonlinear state observer based on the synthetic back electromotive force according to the state equation; constructing an estimated load torque adjustment rule based on the quadrature-axis current estimation error, and merging the estimated load torque adjustment rule into a nonlinear state observer to obtain an extended nonlinear observer based on synthetic back electromotive force; under a stable condition, calculating a rotor position and a rotating speed estimation error, substituting the rotor position and the rotating speed estimation error into the extended nonlinear observer, and combining a steady state condition to obtain an estimation value of an equivalent flux linkage error; and the estimated value