A sliding model speed/position observer integrated with a PI controller for PM synchronous motors

The sliding model speed observer proposed in this paper can work out the rotor angular speed reliably and perform well both at high speed and low speed with less steady state error by using a distinct sliding hyper plane which actually contains a PI controller. Through broadening the condition of the Lyapunov´s stability theory reasonably and skillfully, the proposed observer gets rid of the low pass filter which is necessary in other proposed sliding model observers. The sensorless Field Oriented Control (FOC) scheme for PMSM drive based on the sliding model speed observer is constructed to eliminate the usual shaft encoder. Then the proposed observer has been fully analyzed by simulations to test the performance both in the steady state and transient operations. At last the experimental results based on DSP TMS320F2812 controller are offered, showing the performance of the sensorless control strategy proposed in this paper over a wide range of operating conditions.