Sensorless Control of Induction Motor Using MRAS Observer and Five-Level NPC Inverter
Abstract
This paper evaluates the use of active disturbance rejection control (ADRC) and a five-level neutral-point-clamped (NPC) inverter for a sensorless induction motor (IM) drive. The approach is based on a model reference adaptive system (MRAS) observer and a hybrid control technique, combining the advantages of vector control (VC) and direct torque control (DTC). ADRC is specifically engineered to handle disturbances common in system control and lessen their effects, while the MRAS observer provides precise speed estimation for sensorless operation. The system capitalizes on their collective advantages, tackling issues like stator current harmonic distortion and torque ripples, critical in dynamic systems. Also, the five-level NPC inverter helps reduce these problems, allowing the system to run with a nearly sinusoidal voltage, a plus for the electrical motors. The simulation results using MATLAB assess the effectiveness of the ADRC and MRAS observer for the sensorless speed control of the IM system through a hybrid VC-DTC technique and five-level NPC inverter. The results of the approach are compared with the obtained values and reference signals. Different operation modes of the induction motor have been discussed, such as speed variations, speed reversal, and brake application. This study suggests the experimental implementation and use of multilevel NPC inverters for high power quality, and ADRC control associated with MRAS and a hybrid VC-DTC approach for reference tracking and disturbance handling.