Hardware implementation of sensorless SMPMSM drive for wide speeds using modified MRAS and DC link quantities based on dsPIC33E DSC

This paper proposes a hardware implementation of new method for speed sensorless control of surface mounted (SM) permanent magnet synchronous motor (PMSM) drive. It adopts combination of the DC link measurement and the modified model reference adaptive scheme (MRAS) to estimate rotor speed and position. A 16-bit dsPIC33EP256MC506 DSC is used to implement the proposed estimation algorithm and the control loops which makes the hardware very simple and compatible. The stator currents and voltages required for the speed and position estimation are not measured directly but reconstructed using the DC link voltage and current. For this purpose, voltage and current sensors which are already available in the DC link for protection purpose are used. Thus no additional sensor is needed making the proposed scheme almost a sensorless drive. Unlike existing MRAS based speed estimators which make use of both d and q-axes currents, the proposed scheme has a simplified adaptive mechanism based on quadrature axis current only. This results in a significant cost diminution. The Lyapunov´s criterion is employed to develop the stable adaptive mechanism. The effectiveness of proposed scheme is verified under several operating conditions using Matlab Simulink software. The simulation results confirm how quickly the estimated speed can follow the real speed in all modes of operation. To validate the simulation results an experimental setup is implemented in the laboratory using a 1HP SMPMSM and dsPICDEM MCHV-2 Development Board. The practical results are in close agreement with simulation results and prove the effectiveness of proposed scheme.