A New Fixed Switching Frequency Direct Torque Controlled PMSM Drives with Low Ripple in Flux and Torque

Direct Torque Control (DTC) has gained popularity for development of advanced motor control due to its simplicity and offers fast instantaneous torque and flux controls. However, the conventional DTC which is based on hysteresis controller has major drawbacks, namely high torque ripple and variable inverter switching frequency. This paper presents an improved switching strategy for reducing flux and torque ripples in DTC of PMSM drives; wherein the torque hysteresis controller and the look-up table used in the conventional DTC are replaced with a constant frequency torque controller (CFTC) and an optimized look-up table, respectively. It can be shown that a constant switching frequency is established due to the use of the CFTC while the reduction of torque and flux ripples is achieved mainly because of the selection of optimized voltage vector (i.e. with an optimized look-up table). This paper also will explain the construction of DTC schemes implemented using MATLAB-Simulink blocks. Simulation results were shown that a significant reduction of flux and torque ripples which is about 90% can be achieved through the proposed DTC scheme

How Can We Identify Hijacked Journals?

By developing research and academic centers, the number of performed research articles has also increased. On the other hand, publishing the results of these articles in scientific journals shall also grow. In the meantime, researchers are trying to publish the findings of their research in journals which have been approved by one or more International indices so that such findings can be seen. In order to enhance the academic standards of Universities, proper journal choice will be of interest to researchers, especially those that are indexed in websites such as Thomson Reuters. However, certain forgery frauds researchers by launching fake Web sites that have been named by academic journal titles. In this paper, we introduce an approach to identify this type of journals that will be applicable by researchers in various academic disciplines