Performance evaluation of a binary control technique for brushless dc motor drives

With the availability of effective, yet low cost speed/torque regulators, brushless dc (BLDC) motor drives have now become very popular in electric drives. One promising controller [1] uses the binary (two-state) control scheme of current conduction angle. However, the scheme was limited to one load torque and a narrow speed range. Because the scheme was implemented on PSIM software, it was easy to verify/compare the results. In this paper, the simulation studies are further extended to the broad range of speed-torque combinations. In addition to percentage speed ripple, a performance index (percentage steady state error in speed) based on average and desired speed is defined. Both of these indices are calculated for a number of speed ranges keeping the load torque constant. The performance indices are repeatedly calculated for the same number of speed ranges by keeping the load torque constant at different values. Variations of the performance indices with speed and torque provide definite patterns which can be used to meet the system design for specific applications.