Dynamical changes from harmonic vibrations of a limited power supply driving a Duffing oscillator

The harmonic oscillations of a Duffing oscillator driven by a limited power supply are investigated as a function of the alternative strength of the rotor. The semi-trivial and non-trivial solutions are derived. We examine the stability of these solutions and then explore the complex behaviors associated with the bifurcations sequences. Interestingly, a 3D diagram provides a global view of the effects of alternate strength on the appearance of chaos and hyperchaos on the system.

Tap-Off Power From the Overhead Shield Wires of an HV Transmission Line

In recent years, there was an increase of ancillary service loads, such as signaling systems, inspection robots, surveillance cameras, and other monitoring devices distributed along high-voltage transmission lines which require low-power dc voltage supplies. This paper investigates the use of the induced voltage in the shield wires of an overhead 525 kV transmission line as a primary power source. Since phase current variations throughout the day affect the induced voltage in the overhead ground wire, a step-down dc-dc converter is used after rectification of the ac voltage to provide a regulated dc output voltage. The initial encouraging results obtained indicate that this form of power supply can be a feasible and cost-effective alternative for feeding small ancillary service loads. The simulation results are validated by field measurements as well as the installation of a 200 W voltage stabilization system prototype.

Remarks on Parametric Surface Waves in a Nonlinear and Non-Ideally Excited Tank

We studied free surface oscillations of a fluid in a cylinder tank excited by an electric motor with limited power supply. We investigated the possibility of parametric resonance in this system, showing that the excitation mechanism can generate chaotic response. Numerical experiments are carried out to present the existence of several types of regular and chaotic attractors. For the first time powers (power of the motor, power consumed by the damping force under fluid free surface oscillations, and a total power) are calculated, investigated, and shown for different regimes, regular and chaotic ones for parametric resonance interactions. [DOI: 10.1115/1.4005844]

A complete CMOS UWB timed-array transmitter with a 3D Vivaldi antenna array for electronic high-resolution beam spatial scanning

We present a new Ultra Wide Band (UWB) Timed- Array Transmitter System with Beamforming capability for high-resolution remote acquisition of vital signals. The system consists of four identical channels, where each is formed of a serial topology with three modules: programmable delay circuit (PDC or τ), a novel UWB 5th Gaussian Derivative order pulse generator circuit (PG), and a planar Vivaldi antenna. The circuit was designed using 0.18μm CMOS standard process and the planar antenna array was designed with filmconductor on Rogers RO3206 substrate. Spice simulations results showed the pulse generation with 104 mVpp amplitude and 500 ps width. The power consumption is 543 μW, and energy consumption 0.27 pJ per pulse using a 2V power supply at a pulse repetition rate (PRR) of 100 MHz. Electromagnetic simulations results, using CST Microwave (MW) Studio 2011, showed the main lobe radiation with a gain maximum of 13.2 dB, 35.5º x 36.7º angular width, and a beam steering between 17º and -11º for azimuthal (θ) angles and 17º and -18º for elevation (φ) angles at the center frequency of 6 GHz

A novel method for power quality multiple disturbance decomposition based on Independent Component Analysis

In this paper, a novel method for power quality signal decomposition is proposed based on Independent Component Analysis (ICA). This method aims to decompose the power system signal (voltage or current) into components that can provide more specific information about the different disturbances which are occurring simultaneously during a multiple disturbance situation. The ICA is originally a multichannel technique. However, the method proposes its use to blindly separate out disturbances existing in a single measured signal (single channel). Therefore, a preprocessing step for the ICA is proposed using a filter bank. The proposed method was applied to synthetic data, simulated data, as well as actual power system signals, showing a very good performance. A comparison with the decomposition provided by the Discrete Wavelet Transform shows that the proposed method presented better decoupling for the analyzed data. (C) 2012 Elsevier Ltd. All rights reserved.