Showing 3 results for Yousefi
R. Yousefi, M. K. Moravvej-Farshi, K. Saghafi,
Volume 6, Issue 2 (June 2010)
Abstract
In this paper, using the neural space mapping (NSM) concept, we present a
SPICE-compatible modeling technique to modify the conventional MOSFET equations, to
be suitable for ballistic carbon nanotube transistors (CNTTs). We used the NSM concept in
order to correct conventional MOSFET equations so that they could be used for carbon
nanotube transistors. To demonstrate the accuracy of our model, we have compared our
results with those obtained by using open-source software known as FETToy. This
comparison shows that the RMS errors in our calculated IDS, under various conditions, are
smaller than the RMS errors in IDS values calculated by the existing analytical models
published by others.
Sh. Yousefi, M. Parsa Moghaddam, V. Johari Majd,
Volume 7, Issue 3 (September 2011)
Abstract
In this paper, an agent-based structure of the electricity retail market is presented based on which day-ahead (DA) energy procurement for customers is modeled. Here, we focus on operation of only one Retail Energy Provider (REP) agent who purchases energy from DA pool-based wholesale market and offers DA real time tariffs to a group of its customers. As a model of customer response to the offered real time prices, an hourly acceptance function is proposed in order to represent the hourly changes in the customer’s effective demand according to the prices. Here, Q-learning (QL) approach is applied in day-ahead real time pricing for the customers enabling the REP agent to discover which price yields the most benefit through a trial-and-error search. Numerical studies are presented based on New England day-ahead market data which include comparing the results of RTP based on QL approach with that of genetic-based pricing.
A. Darabi, M. Yousefisefat, M. Nikkhoo,
Volume 10, Issue 1 (March 2014)
Abstract
Quadrature-axis reactance for various reasons comes into account as one of the most important parameters of salient pole synchronous machine. There are several common standard methods for measuring this parameter that also have been explained with some details in the standards, scientific papers and text books. One of these methods is the maximum lagging current test that is done simply at no-load, having a three phase voltage source and applying very low power even for a high power machine. How this experiment is done is described at some references such as the books related to electrical machinery. This paper presents a detail analysis and description of the test and some simulation results regarding the performance of the machine during pole-slipping. It is shown when the reversal field current is increased very slowly, the transient of the pole-slipping commences at load angle equal to 45 degrees or by a better language at 225 instead of zero which is the common opinion of almost all the previously published literatures. In this paper, a realistically developed analysis of the test is presented applying appropriate assumptions. The maximum lagging current test is then simulated applying a small salient pole machine with the rated 31.5 kVA using Matlab/Simulink. Some simulation results are illustrated that prove correctness and validity of the new analysis and the proof described by the present paper.
