Performance and Tracking Control of Three-Phase Induction-Motor Drive Fed from a DC-Modified Nano-grid

摘要

Nowadays, induction motor (IM) can be used in tracking systems to follow a predefined path like in robotics and servos. The modified nanogrid is a small scalable-renewable energy intermittent source that powers loads via a single-stage inverter (SSI). Higher utilization of the inverter dc-link voltage improves its output voltage and dependently, the performance of the motor tracking speed. So, this paper proposed a switched boost inverter (SBI) to feed IM from PV-source to boost its dc-link output voltage. The usage SBI utilizes minimum passive components, more active elements, introduces shot-through mode as z-source inverter and produces both ac and dc voltages simultaneously. The performance of the motor-tracking speed depends directly on the motorstator voltage. So, the proposed method depends mainly on two parameters to verify the pre-defined trajectory speed. The first proposed intention is a simple algorithm for a closed-loop dc-link boosting control based-on the reference model to compute the optimum duty ratio (D). The second one depends mainly on the modulation index (M) to produce the reference signals needed to adjust the speed of the motor through a (voltage/frequency) control of a predefined value. The modelling and validation of the proposed system was implicit with the help of Matlab/ Simulink package. The robustness of the system has been tested by selecting several speed trajectories and was able to track them. Furthermore, SBI-based system was compared with other VSI-inverter techniques such as the space-vector PWM single- and two-stage VSI inverters. Test results explored that the SBI-based system is a strong competitor to other inverter techniques especially at low-voltage intermittent supply.