Measuring the torque characteristics of synchronous machines by using open-loop control of an hybrid stepper motor

Osnovna cilja diplomskega dela sta bila izdelava eksperimentalnega sistema in izvedba avtomatiziranega postopka izvajanja meritev statičnih navornih karakteristik sinhronskih strojev (SS) s pomočjo izdelanega sistema. Eksperimentalni sistem smo zasnovali na osnovi hibridnega koračnega motorja (HKM) in senzorja navora. HKM smo uporabili kot aktuator, s katerim smo na osnovi odprto-zančnega vodenja spreminjali položaj rotorja glede na statorsko magnetno polje. Navor SS je odvisen od tega položaja, zato smo lahko pri različnih kotih zasuka s pomočjo senzorja izmerili pripadajoče navore. Meritve smo izvajali statično, torej v ustaljenih stanjih kota zasuka. Z uporabo HKM smo lahko izmerili karakteristiko tako v stabilnem kot tudi nestabilnem območju navorne karakteristike. Meritve smo avtomatizirali s pomočjo razvojnega orodja Texas Instruments LaunchPad, ki smo ga uporabili za izvedbo odprto-zančnega vodenja HKM kot tudi za zajemanje meritev v vseh merilnih točkah. V okviru diplomske naloge smo izmerili navorne karakteristike dveh različnih tipov SS: prvi tip predstavlja sinhronski stroj s cilindričnim rotorjem (SSCR), drugi tip pa sinhronski stroj z izraženim rotorjem (SSIR). S sistematičnim napajanjem statorskih in rotorskih navitij smo eksperimentalno določili vse komponente navornih karakteristik, ki vsebujejo reluktančni navor zaradi magnetne izraženosti posameznih delov stroja, elektromagnetni navor zaradi interakcije statorskih in rotorskih navitij ter mehanski navor zaradi mehanskih napetosti v mehanskem podsistemu merilnega sistema.The two main objectives of this thesis were the production of an experimental system and the implementation of an automated procedure for measuring the static torque characteristics of synchronous machines using the developed experimental system. The experimental system was designed based on a hybrid stepper motor and a torque sensor. The hybrid stepper motor was used as an actuator, with which we changed the position of the rotor with respect to the stator magnetic field based on open-loop control. The torque of synchronous machines depends on this position, so we were able to measure the corresponding torques at different angles of rotation with the help of a sensor. Measurements were performed statically in steady states of the rotation angle. Using a hybrid stepper motor, we were able to measure the characteristic in both the stable and unstable torque region. Measurements were automated using the Texas Instruments LaunchPad development tool, which was used to perform open-loop control of a hybrid stepper motor as well as to capture measurements at all measurement points. As part of the diploma thesis, we measured the torque characteristics of two different types of synchronous machines: the first type represents a synchronous machine with a cylindrical rotor, the second type represents a synchronous machine with salient pole rotor. All components of torque characteristics were experimentally determined by systematic powering of stator and rotor windings. By systematically supplying stator and rotor windings, we experimentally determined all components of torque characteristics that contain reluctance torque due to magnetic saliency of individual machine parts, electromagnetic torque due to interaction of stator and rotor windings and mechanical torque due to mechanical stresses in the mechanical subsystem of the measuring system