Sharif Digital Repository

Two main sources for power dissipation in parallel buses are data transitions on each wire and coupling between adjacent wires. So far, many techniques have been proposed for reducing the self and coupling powers. Most of these methods utilize one (or more) control bit(s) to manage the behavior of data transitions on the parallel bus. In this paper, we propose a new coding scheme, referred to as GPH, to reduce power dissipation of these control bits. GPH coding scheme employs partitioned Bus Invert and Odd Even Bus-Invert coding techniques. This method benefits from Particle Swarm Optimization (PSO) algorithm to efficiently partition the bus. In order to reduce self and coupling powers of... 

This paper proposes a new method to detect and classify all kinds of faults, capacitor switching, and load switching in a power system network based on wavelet transform and support vector machines (SVMs). In this regard, a sample of a power system is simulated via MATLAB/Simulink, and by reading the voltage of the point of common coupling and using the wavelet transform, the differences of the outputs of the wavelet transform are investigated. The SVM approach is employed to distinguish the type of the transient (capacitor switching, fault, and/or load switching) in use for the high level outputs of the wavelet transform. Similar to neural networks, this method, which is based on learning,... 

The Class-E power amplifier has been widely studied and formulated in the literature. Although the majority of reported inductive coupling wireless power transfer (WPT) systems use a class-E power amplifier for driving the primary coil, still there is a lack of a comprehensive study on class-E circuit dedicated to WPT, providing a set of closed form design equations for proper class-E operation. This paper presents the required design equations needed to design a 'true' class-E circuit for WPT applications. Equations for the series-tuned secondary coil WPT system are presented, as well as two different design procedures for the parallel-tuned secondary coil. The derived equations have been... 

Brushless doubly fed induction machines show promising results for wind power applications. Due to their poor rotor magnetic coupling and relatively high value of slip, core loss is an important factor which affects the steady state and dynamic performance. The core loss in brushless doubly fed induction machines has not been extensively studied in the literature. In this paper, a steady state equivalent circuit taking core loss into account is introduced. Simple relationships are derived which show that the brushless doubly-fed induction machine is similar to the cascaded doubly-fed induction machine in terms of core loss. The proposed equivalent circuit is simulated to derive the steady... 

We propose an energy-efficient procedure for transponder configuration in few-mode fiber-based elastic optical networks in which bit error rate and physical constraints are guaranteed and joint optimization of temporal, spectral, and spatial resources are addressed. We use geometric convexification techniques to provide convex formulations for the signal-to-interference plus noise ratio, transponder power consumption, and transponder configuration problem. Simulation results demonstrate that the proposed convex formulation for the transponder configuration problem is considerably faster than its mixed-integer nonlinear counterpart. We consider transmit optical power as a configurable... 

This paper discusses the application of unified power quality conditioner (UPQC) for improving power quality of a system supplying an electric arc furnace (EAF). The UPQC includes combined series and shunt active filters sharing a common DC link. It is used to mitigate voltage disturbances and compensate for reactive power, harmonics and interharmonics. A novel control strategy for the UPQC is presented. As voltages at the point of common coupling contain low-frequency interharmonics, conventional methods cannot be used for extracting voltage reference signals. In the proposed method, voltage references are extracted using a phase-locked loop to generate sinusoidal waveforms. Current...