Sensorless control of interior permanent magnet synchronous machine using a Kalman filter

The application of vector control techniques in AC motor drives demands accurate position and speed feedback information for the current control and servo-control loops. The paper describes a full mechanical sensorless speed digital control system for interior permanent magnet synchronous machines (IPMSM). A Kalman filter is used for the mechanical state estimation of the motor. The observer was developed based on the nonlinear model of the synchronous motor that employs a rotating reference frame attached to the rotor. The control system includes a rotor frame vector current controller with feedforward decoupling circuit and an integral+proportional integral (I+PI) speed controller.