Novel Sensorless Vector Control System of Induction Machine Based on Flux Observer in Field Weakening

A speed-sensorless vector control system for induction machines （IMs）is presented, According to the vector control theory of IMs, the rotor flux is estimated based on a flux observer,and the speed is estimated through the method of q-axis rotor flux converging on zero with proportional integral regulator, A 0.75 kW,50 Hz,two-pole induction machine was used in the simulation and experimental verification, The simulation model was constructed in Matlab. A series of tests were performed in the field weakening region, for both no-load and loaded operation. The estimated speed tracks the actual speed well in the based speed region and field weakening region （ 1 per unit value to 4 per unit value）. The small estimation error of residual speed is due to the existence of slip.

Novel Sensorless Vector Control System of Induction Machine Based on Flux Observer in Field Weakening

A speed-sensorless vector control system for induction machines( IMs)is presented. According to the vector control theory of IMs. the rotor flux is estimated based on a flux observer, and the speed is estimated through the method of q-axis rotor flux converging on zero with proportional integral regulator. A 0. 75 kW.50 Hz,two-pole induction machine was used in the simulation and experimental verification. The simulation model was constructed in Matlab. A series of tests were performed in the field weakening region,for both no-load and loaded operation. The estimated speed tracks the actual speed well in the based speed region and field weakening region ( I per unit value to 4 per unit value). The small estimation error of residual speed is due to the existence of slip.