Study of Disturbing Factors in Current Sensorless Control Applied to NPC MLC

Implementation of current sensorless control make it possible to eliminate instantaneous sensing of current and consequently feedback from current sensor in the control loop. However, the performance of mentioned type of current control strongly depends on precision of mathematical model and stability of crucial circuit parameters under different disturbing factors, like manufacturer tolerances, ambient temperature change, aging etc. This paper demonstrates vulnerability of the current sensorless control from the defined disturbing factors. The simulation analysis is performed by means of PSIM software.