Alexis Cabello

Induction Motor Direct Torque Control Using Matrix Converters

This work presents an approach to the selection of the voltage space vector produced by a matrix converter (MC) used in the implementation of an induction motor direct torque control (DTC) in order to improve the machines dynamic response and limit the start-up currents. The selection strategy chooses the space vectors that reduce generated electromagnetic torque ripple and improve the MC input power factor. Final space vector selection is performed taking into account the optimised DTC selection table, the MC current vector required to minimise the converter input displacement factor, and the torque ripple minimisation function. The simulation results, obtained using a system model, show the method efficiency

Matrix converter induction motor drive with DTC-based fuzzy control

This work presents a new fuzzy control scheme based on DTC for a matrix converter induction motor drive. The control scheme decouples the stator flux and the motor torque determining a stator voltage vector with a fuzzy inference system. Simulation results obtained using a model of a 5 kW prototype matrix converter show improvements in the system dynamic response and reduction in the steady-state motor torque ripple.

Active energy recovering snubber for the asymmetric inverter

This paper presents a single capacitor active snubber circuit for the asymmetric inverters used to drive switched reluctance motors. The proposed configuration uses the motor coil inductance as an integral component in the snubber process, acting in sequence to ensure the low-loss commutation of each inverter main power device. The two auxiliary snubber switches naturally commutate in ZCS mode. Only one minor change in the inverter firing sequence is required to include the snubber. Initial simulations in AIMSPICE show that the snubber produces significant reduction in commutation losses without affecting the asymmetric inverter operation. A laboratory prototype is undergoing tests to study the complete operating envelope of the modified inverter driving a switched reluctance motor under DTC control.

Direct Torque Control of the Switched Reluctance Motor using A Variable Structure Fuzzy Controller

This work presents a control scheme for the switched reluctance machine (SRM). The proposed control scheme combines the principles of direct torque control (DTC), space vector modulation (SVM) and variable structure fuzzy control to provide a high performance, robust and simple driver. Simulations of the proposed controller show that the current, flux and torque ripple are considerable reduced during steady state operation, the performance and robustness characteristics hold while maintaining a constant switching frequency