A hybrid sensorless position system has been developed that offers the possibility of achieving improved performance over existing schemes. Through the use of a brushless DC motor model (BLDCM) a range of possible machine parameters are established. These are used with a PSpice model of the BLDCM's electrical sub-system to obtain simulated phase voltage and current data with which the sensorless system may be tested for robustness to variation in motor parameters. Having established the performance under simulation, performance is then analysed with experimental data and results are presented. The sensorless system is shown to be extremely robust to parameter variation
