Search results for "Circuits"
showing 10 items of 358 documents
Noise and gain performance of PSA transistor series for personal communication systems vs. emitter number and operating conditions
1995
The booming market of communication system applications in the low microwave range put greater demands on the component performance at lower supply voltages and limited current consumption, as well as on production cost and integration level. In this work, we present the results of an extensive characterization activity carried out on several advanced polysilicon bipolar transistors as requested by the manufacturer. The devices were grouped according to their emitter finger number and were characterized over the 2-6 GHz frequency range in terms of noise, gain and scatterino parameters at different bias conditions. A comparative analysis has been performed to explore how the transistor perfo…
Development of 3D Anti-Swing Control for Hydraulic Knuckle Boom Crane
2021
In this paper, 3D anti-swing control for a hydraulic loader crane is presented. The difference between hydraulic and electric cranes are discussed to show the challenges associated with hydraulic actuation. The hanging load dynamics and relevant kinematics of the crane are derived to model the system and create the 3D anti-swing controller. The anti-swing controller generates a set of tool point velocities which are added to the electro-hydraulic motion controller via feedforward. A dynamic simulation model of the crane is made, and the control system is evaluated in simulations with a path controller in actuator space. Simulation results show significant reduction in the load swing angles …
DC link voltage swinging and load current unbalance in fault tolerant VSI. overview and compensation strategies
2015
The topic of this paper is the discussion on the performance of a three-phase fault tolerant inverter with particular attention to the underrated aspect of current unbalances occurring due to the DC link voltage fluctuates after the inverter reconfiguration. Capacitor voltage unbalance affects not only the average output voltage of the inverter, but also its performance. In fact, the inverter performance depends on the fluctuating DC-link voltage components rather than on the average DC-link voltage. After a brief analysis of the voltage fluctuation phenomena resulting from fault tolerant configuration and their effect on load current unbalance, the Authors consider different compensating p…
Magnetic Tunnel Junction (MTJ) Sensors for Integrated Circuits (IC) Electric Current Measurement
2013
We report on MgO Magnetic Tunnel Junction (MTJ) devices focusing on their potential application in the measurement of electrical current at the integrated circuit level. Single devices and full bridges have been specifically developed for this purpose. A sort of different designs regarding their geometry arrangement as well as the number of constitutive elements have been tested. Experimental characterization has been performed and results including impedance and sensitivity measurements are given.
A new backward/forward method for solving radial distribution networks with PV nodes
2008
Abstract In this paper, a new backward/forward (b/f) methodology for the analysis of distribution systems with constant power loads is presented. In the proposed method, at each iteration, the loads are considered as constant impedances; in the backward sweep all the network variables (bus voltages and branch currents) are evaluated considering a scaling factor which is determined at the end of the backward phase. Indeed the forward sweep is eliminated and the node voltages calculation does not demand the sequentiality needed in the b/f methodology. The developed method, although deriving conceptually from the b/f methodology, presents only the backward phase in which all the network variab…
Low-Power Design of Delay Interpolating VCO
2008
In this paper, a design methodology for low-power MCML based delay interpolating VCOs is presented. The methodology allows a fast and accurate graphical evaluation of the optimum design. It utilizes two closed form expressions for the upper and lower oscillation frequencies of the VCO. An expression of the tuning range is also derived. The effectiveness of the proposed design methodology has been tested by simulating several VCOs in an IBM 0.13 mum CMOS technology.
Phasor total unbalance power: Formulation and some properties
2007
Unbalance power has been used to quantify unbalance phenomenon effects in the electric power systems for a long time. Expressions of this power developed by some different theories only give the value of its module. Therefore, total unbalance power values in electric power systems cannot be obtained by the unbalance power values of each of their loads. For that, it is necessary to express the unbalance power as a complex number. In this paper the unbalance power is expressed in phasor notation and some of their properties are described, applied to electric systems with balanced voltages. Results are verified by simulation and also practical comparative experiences are realized in actual ins…
Higher PV Module Efficiency by a Novel CBS Bypass
2011
There is an increasing focus on reducing costs and improving efficiency for photovoltaic (PV) cells and modules as well as finding a more efficient approach to the product manufacturing. This letter introduces an innovative solution to bypass shaded PV cells instead of a traditional Schottky diode, in order to avoid overheating of cells in the case of partial shading. The goal is to reduce the power dissipation and improve the general efficiency of a PV generator. A novel device called cool bypass switch is then presented. It is made up of a Power MOS driven by a controller with the task to charge a storage capacitor. Tests and comparisons with standard Schottky diodes are then performed an…
A suitable control technique for fault-tolerant converters in Distributed Generation
2011
The penetration of Distributed Generation (DG) in power systems is deeply changing the existing distribution networks which is becoming a very sophisticated and complex systems incorporating both active (generators) and passive systems (distribution systems, converters and loads). The necessary simplification can be obtained dealing with small networks, namely Micro-Grids, reproducing, in a smaller scale, the structure and the problems of large networks including production, transmission and distribution of the electrical energy. In order to achieve an adequate level of reliability, fault-tolerant operations of micro-grids become very important. This result can be achieved only using power …
COMPARATIVE ANALYSIS OF RIGID AND FLEXIBLE STRUCTURES OF THE ECCENTRIC PRESSES
2007
Abstract The aim of this paper is to make a comparative study of the static behaviour of the eccentric presses, using the finite elements method, on the rigid structure and on the flexible structure, respectively. The finite elements modelling of the component elements of the presses are done in two ways: node by node link type (rigid structure) or using a linking element spring damper type (flexible structure). On these two structures there is successively applied a number of static analyses, in order to determine the strain of working area and the design of the stiffness graph.