Development of a low cost rotor position sensor

This paper is concerned with the development of a low cost rotor position sensor for mechanical position dependent applications. An hall-effect sensor is used for the development of a low cost rotor position of the electrical machine. An Arduino Due micro-controller was used for programming and serial synchronous with the hall effect sensor. The developed rotor position sensor is compared with the high cost conventional rotor position sensor. The two sensors were mounted on the shaft of a Synchronous Reluctance Machine for comparison. The rotor position sensor had a resolution of 0.088 degrees. The maximum error was 7° (mechanical) for a range between 50 rpm and 1500 rpm. The low cost position sensor registered a maximum THD of 1.8%, while the conventional high cost encoder had a lower THD at all speeds tested. The developed low cost encoder is estimated to cost approximately 30% of the cost of the conventional position sensor. The proposed low cost position sensor suffers from mechanical mis-alignment between magnet and the hall effect sensor. However, the developed low-cost position sensor is a promising candidate for future position information dependent applications.