The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper highlights the role of power electronics and digital control in the performance improvements of RFX (Reverse Field eXperiment), a toroidal device for plasma physics studies related to nuclear fusion research. Designed and built in the `80s, it started operation in early `90s, with the mission to explore the physics of Reverse Field Pinch (RFP) configuration at high plasma current, up to...
The aim of this article is to describe how closely PV grid-connected inverters operate at the actual maximum power point. To carry this study out six 50 Hz single-phase inverters were selected from European market. Each one of them was put into an outdoor grid-connected system installed in Leganes (Madrid) Spain (by using flat and concentrating PV modules). Different electrical signals with respect...
Harmonic current control with converters is widely practiced, e.g. compensation of harmonics generated by a load. Control of harmonic grid voltage components is much more difficult due to the fact that the grid impedance for harmonic frequencies changes in a wide range, which changes the behavior of the control loop significantly. This paper shows how a STATCOM is used to reduce voltage harmonics...
This paper proposes two fault tolerant power converter permanent magnet synchronous motor (PMSM) drive topologies. A reconfigured conventional DC link/two-level VSI converter and a reconfigured conventional matrix converter are presented to improve the reliability of the drive system under open phase fault operating condition. Additional phase redundancy and its control technique are included. Simulation...
This paper deals with the multiobjective optimization (MO) design of high frequency (HF) transformers using genetic algorithms (GAs). In its most general form, the design problem requires minimizing the mass or overall dimensions of the core and windings as well as the loss of the transformer while ensuring the satisfaction of a number of constraints. In this contribution, the area product (i.e. the...
The electric power generation using hydro potential is increasing around the globe due to many reasons like increasing power demand, deregulated markets, and environmental concerns etc. At the same time, extended transmission networks, higher degrees of interconnection between different networks, and fast connection and disconnection of the heavy loads demand flexible, fast power generation and consumption...
Although the term "Power Electronics" covers a very wide spectrum of power ratings and applications (from Watts to Gigawatts), Power Electronics applications for the transmission and distribution (T&D) market tend to be amongst the very highest in terms of voltage and power rating. Moreover, these applications are part of a very rapidly growing market and one that is closely linked with...
→ UNIFLEX-PM project: Flexible, modular, multi-level, multi-cell architecture with MF transformer isolation. → Comprehensive analysis of system operation and limitations undertaken → Control solutions for balancing of power flows within converter derived and implemented → Simulation studies to test control proposals under all expected operation conditions → A 3.3kV, 300/500 kVA experimental prototype...
The current characteristics of two types of parallel three-phase voltage source inverter configurations are analyzed, and the suitability of different pulse width modulation methods in the control of parallel inverters is discussed. The analysis and discussion are based on state-space models derived in this paper and presented for the parallel connection of n units. For the sake of repeatability,...
This paper presents a fuzzy adaptive control scheme for automatic control of excitation angles in switched-reluctance motor (SRM) drives. A turn-on and turn-off angles play important roles in developing electromagnetic torque in SRM. The value of excitation angles are usually variable and depend upon the motor speed and other parameters of the inverter that excites the SRM. As the motor speed increases...
Reactive power injection has been the common practice to stabilize and support the voltage in electric power systems and its provision was traditionally considered to be part of the duties of the units dispatching active power. This article proposes the provision of reactive power by electric loads which are interfaced to the grid by active rectifiers that enable them to inject reactive current to...
This work deals with a parametric identification using the least square method based on the output error. An appropriate particle swarm optimization algorithm is applied as a technique to minimize the objective function in order to obtain simultaneously the electrical and the mechanical parameters. The validation and comparison of the two algorithms used are obtained from experiments carried out on...
The optimal operation of a rail vehicle with on-board energy storage device minimizing energy consumption in catenary free mode is discussed in this paper. The electric double layer capacitor (EDLC) is assumed as an energy storage device because of its high power density, long lifetime and quick charge/discharge. The proposed method can determine the optimal acceleration/deceleration at each sampling...
In this paper, a 600 KW electrical balance of plant (EBOP) for a molten carbonate fuel cell (MCFC) power plant is introduced. The requirements for EBOP are categorized into as follows : demands on grid interconnection and operational interface with a fuel cell. EBOP has three modes of operation, i.e. grid-connected (GC) mode, grid-independent (GI) mode, and grid-synchronization (GS) mode, to control...
This paper presents a maximum power point tracking (MPPT) method which is applied on a wind turbine with permanent magnet synchronous generator (PMSG). A three-phase switched mode rectifier (SMR) is connected with the three phase output of the PMSG. The SMR employs a modulation strategy which is based on the space vector modulation (SVM) technique. Thus, the three phase input voltage is divided in...
The paper analyzes the theory of generating short circuit current during three-phase fault to research the low voltage ride through (LVRT) control of doubly fed induction generator (DFIG). The approximate analytical expressions of short circuit current are given in the condition of no load and synchronous speed to simplify the analysis. Based on this, the influences of different pre-fault conditions,...
With its new SineFormertrade EPCOS is introducing a fully new output filter technology for frequency converters. In contrast to conventional filter topologies the new SineFormertrade simultaneously converts the phase-to-phase voltage into a sinusoidal signal, damps the common mode currents and also forms the conductor-to-ground voltage to sine shaped voltage. This offers users a number of key benefits...
An estimation method for sensorless control employing a test signal based reference model is presented. The method estimates the slip frequency by a comparison of the measured impedance curve while the machine is in operation with the reference model curves. The reference model is measured during DC magnetisation of a cold machine at steady state and constant rotor flux linkage. During normal machine...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.