Showing papers by "Navid Reza Abjadi published in 2012"

Space-vector pulse-width modulation of a Z-source six-phase inverter with neural network classification

Abstract: In this study, a space-vector pulse-width modulation (SVPWM) method is presented for a Z-source six-phase inverter using the neural network (NN) classification. The Z-source inverter is a new generation of inverters with buck and boost features. Using an L–C network placed between the power supply and the switches, this modulation method can result in unique features which are not achieved through traditional inverters. NN classification can help in reducing the complexity of calculations for the SVPWM method in a six-phase inverter. NN classification reduces the required computational efforts and makes it possible to increase switching frequency. In addition, the method results in a smaller system in terms of hardware and software, and generates more precise pulses. The modulation method presented in this study uses the minimum number of switching vectors. Here, 14 switching vectors are employed instead of 64. In fact, only large vectors in a plane are selected. Moreover, an additional vector, called ‘shoot through’, is considered for creating buck and boost features in the six-phase Z-source inverters. Therefore using 15 switching vectors, it is possible to achieve minimum switching in the six-phase Z-source inverters with buck and boost capabilities. Practical and simulation results for this type of inverter connected to a six-phase induction motor are also presented.

Direct torque control of a single phase induction motor using Feedback Linearization Control

Abstract: Single phase motors are widely used in indoor and low power industrial equipments. One of the essential problems of single phase induction motors (SPIMs) is their high torque pulsation which causes acoustic noise and mechanical damage. Torque pulsation also restricts the application of such motors when high precision application is needed. In this paper Input-Output Feedback Linearization Control (IOFLC) technique is used to control the torque (speed) and stator flux of a SPIM separately. Simulation results show the effectiveness of the proposed method.