A low-cost, high reliability drive without mechanical sensor is described. The application concerns awash machine system that, in spite of the simple, but effective solution, implemented in a fixed pointDSP, presents a good dynamic performance and good steady-state speed accuracy in a very wideoperating speed range.Motor phase current reconstruction is performed suitably sampling the voltage across three shuntresistances put in series to the IGBT emitters while, as far as phases voltage measurement isconcerned, bus voltage is sampled and then motor phase voltages are reconstructed inside the DSPusing PWM duty cycle and dead-time correction strategy.Drive performances, as far as torque production is concerned, have been tested using a dynamometerin a speed range up to 12000 rpm and compared with the torque produced with the usual constant Voltper Hertz (V/f) method. The proposed sensorless control in spite of hardware simplicity that,obviously, translates in low cost, comparable with the open loop solution, presents superior dynamicalperformances, higher torque per ampere, and then efficiency.
Design of a high speed induction motor sensorless drive based on admcf341 dsp controller / Franceschini, G.; Lorenzani, Emilio; Tassoni, C.; De Mari, Y.. - ELETTRONICO. - (2003), pp. 1-7. (Intervento presentato al convegno EPE 2003 tenutosi a Touole, France nel September 2-4 2003).