Sensorless control of a permanent magnet synchronous motor for PV-powered water pump systems using the extended Kalman filter

The system studied in this paper is a sensorless control of a permanent magnet synchronous motor (PMSM). Its structure is based on the extended Kalman filter theory using only the measurement of the motor current for the online estimation of speed and rotor position. The PMSM, driving a water pump, is supplied by a PV array. The implemented PV array is designed for a peak power of 1.2 kW. To search the maximum power point (MPP) of the PV array, the inverter is operated with variable frequency adapting the power input of the motor. The PWM generation is done by space vector modulation. The motor voltages necessary for the Kalman algorithm are calculated considering the nonlinearity of the inverter. The main control is done by a TMS320C31 DSP. The I/O subsystem and the PWM generation are based on a TMS320P14 working as a slave-DSP. Finally, an evaluation of the experimental results is presented