High Performance Sensorless Control Of Double Three-phase Permenant Magnet Synchronous Motor

Compared with the traditional electric excitation asynchronous motor,the double three-phase permanent magnet synchronous motor(DTP-PMSM)has many obvious advantages such as high efficiency,high reliability,high design flexibility,high torque and small volume.Meanwhile,if the sensorless control system is used for DTP-PMSM,the rotor position and speed measurement hardware(such as encoder)can be omitted.The trouble caused by various hardwares during position sensor measurement can be eliminated.And it can help to improve system reliability and reduce system complexity and cost.Aimed at the problems existing in several traditional rotor position estimation algorithms of DTP-PMSM,a new rotor position estimation algorithm for low and even zero speed is proposed.The algorithm is based on the saturation saliency effect of the DTP-PMSM.The novel algorithm exploits the transient response of line currents and voltages to gain information of rotor position in α-βsubspace or x-y subspace,which are integrated within a fundamental PWM cycle.Meanwhile,aimed at the obvious dead time effect under low speed and light load,a dead time compensation algorithm based on quasi proportion resonanace is used to construct the x-y subspace current closed loop.Since the current slope sampling requires the lower limit of the voltage vector action time,a negative vector compensation algorithm is proposed to solve the problem that the motor runs unstablely without compensation.The simulation model of a dual three-phase PMSM drive system is set up in the Matlab /Simulink environment.The simulation results show that proposed algorithm can track rotor position effectively.Proposed algorithm is also realized by a dual three-phase PMSM experimental platform controlled by DSP.The validity of proposed algorithm is verified under different conditions.