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In this paper, the benefits that can be derived from the installation of an energy storage system in an industrial facility are analyzed, and an optimal control strategy of the storage system is proposed. The proposed control strategy is based on a two-step procedure and aims at (i) reducing the electricity costs sustained by an industrial customer that provides demand response and (ii) satisfying...
This article presents experimental tests made on a DC to DC Boost Converter of 24 V–48 V. The boost converter was first realized on a laboratory version, regarding it's utility as a voltage source for the E.I.A (Equipments and Installations for Aviation) laboratory of the University of Craiova, and also to be used in teaching activities and for research. During tests it was point out the performances...
Early surge detection in rotating gas compressors is an important part of any compressor control strategy. To minimize potential equipment damage the surge detection needs to be as quick as possible. Traditionally it is done by looking at process signals, such as pressures and temperatures. Powering compressors by variable speed drives gives opportunity to use additional drive signals for surge detection...
CNC (Computer Numerical Control) machine tools are devices of high precision milling largely employed due to their high precision and to allow simultaneous positioning and velocity control of each machine's axis. The main objective of this paper is to develop a virtual environment to realize a comparative study between two types of actuation systems (stepper motor and DC motor) focusing on implementation...
The Control Methods of the drive system in a wind energy converter has a significant influence on the operational behavior of the system. In this paper, a number of speed and torque control methods introduced and compared with special interest to active damping of vibrations in the drive system. The design of two control concepts (speed and torque) for an active vibration damping — based on the principle...
This study presents a parameter tuning approach for Extended Kalman Filter (EKF) based observers for the sensorless control of Induction Motor (IM) drives. After an analysis performed on the effect of covariance matrix elements of EKF, the study demonstrates the improved performance of the EKF based estimation (performed for stator currents, rotor flux, rotor speed, stator resistance and load torque),...
Many electrical machines are nowadays controlled using digital controllers resulting in variable-speed drives. To enhance control engineers want to deal with the switching behaviour of the power converters or pulse-width modulation in more detail. To help them, in this paper, a previously proposed enhanced discrete-time model in the z-domain is applied to machine drives. Additionally, the application...
This paper presents a free piston compressor with a new type of linear reciprocating drive which is designed to increase efficiency and performance. The integrated mechatronic system comprises a free piston compressor that is directly powered by a linear permanent magnet synchronous motor. Two major challenges of linear free piston compressors are to reach a high power density which can be expressed...
Signature analysis methods have been proven to deliver good results in the laboratory environment and successfully applied to isolated motors. The influence of fault signal on a non-faulty motor may be interpreted as faulty condition of the healthy motor. Therefore, it is difficult to identify a motor fault within a network and precisely identify the type of fault. This paper presents a supervised...
To achieve high performance operation of micro-grids that contain stochastic sources and loads is a challenge that will impact cost and complexity. Developing alternative methods for controlling and analyzing these systems will provide insight into tradeoffs that can be made during the design phase. This paper presents a design methodology, based on Hamiltonian Surface Shaping and Power Flow Control...
The provisions of UE directives adopted by countries of the European Union oblige EU member states to improve energy efficiency and reduce the level of harmful substances released into the atmosphere. The provisions are defined as energy packets, especially the directive Energy Performance of Buildings require of new buildings after 2020 nearly zero-energy consumption from the viewpoint of the distribution...
The electricity has a predominant importance in everyone's life: no one can do (live) without it. However, this involves the use of raw materials, which except for a few cases, come from nonrenewable fossil fuels. It becomes need therefore be able to take full advantage of the energy contained in the fuel, creating cycles that allow to use the energy released from oxidation and maintaining contained...
We present the use of [m, m]-Padé approximants in the implementation of repetitive learning controls for the asymptotic link position tracking in robotic manipulators with uncertain dynamics and periodic position reference signals (with known period). The resulting linear learning controllers are described by transfer functions exhibiting all their poles with negative real part. Analyses from both...
This paper focuses its attention on the wave energy converters (WEC), particularly the ones that use a moving body (wave activated bodies) coupled directly to a power take-off (PTO). It describes the analysis and the design of a small reciprocating linear permanent magnet generator. A comprehensive design methodology, which embraces both the electromagnetic and mechanical design, is described. Nonlinear...
Fast Field Cycling (FFC) Nuclear Magnetic Resonance (NMR) relaxometers require controlled current sources in order to get accurate flux density with respect to its magnet. The main elements of the proposed solution are a power semiconductor, a DC voltage source and the magnet. The power semiconductor is commanded in order to get a linear control of the flux density. To implement the flux density control,...
It has been shown that repetitive compensators can be a useful strategy for tracking periodic references or rejecting periodic disturbance signals with a known period. A class of modified repetitive compensators reproduces exactly an infinite set of resonant filters tuned at the appropriate frequencies; however, they add an infinite set of notch filters between the resonant filters. A sufficient stability...
A stochastic modelling of electrochemical battery for their lifetime assessment is proposed and numerically evaluated in smart grids context. The method uses a proper battery model, characterized by stochastic current demand, for deducing the battery lifetime. In particular, a stochastic process for describing the current load is adopted, which is namely described by a proper Poisson stochastic process,...
Estimating the useful life of power system components is of considerable importance both in planning, to properly assess the costs, and in the management of such systems, to effectively schedule maintenance programs. The paper discusses the reliability of the insulation of power system components on the basis of well-known life models of such devices, with the aim of parametric statistical estimation...
Li-ion batteries are a very attractive energy storage technology due to their high energy density and their capability for high charge and discharge rates. This makes them very suitable for power applications such as Electric Vehicles (EV), Hybrid Electric Vehicles (HEV) or electric grid oriented applications. However, in order to take advantage of Li-ion batteries' good properties, an accurate battery...
The paper is devoted to the estimation of technical and economic efficiency of using the supercapacitors in the frequency-controlled electric drives, which are used in hoisting applications. In the article the frequency-controlled electric drive of passenger elevator is described in detail. The simulation results, energy consumption, calculation of economic efficiency and payback period of using electric...
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