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Most of the large scale photovoltaic power plants (LS-PVPP) count on power converters with a central configuration. Advantages such as robustness, low maintenance and installation cost makes this configuration the preferred specially suitable in large scale systems. However, important drawbacks like the low efficiency level make necessary to develop new solutions for future power plants. In this paper...
This paper presents a new configuration of an off-grid single-phase generator using a three-phase induction machine. The use of this kind of machine, cheap and robust, is in line with the “jugaad” philosophy, better known as frugal innovation. In such an application, three-phase induction machines are usually operated as stand-alone single-phase generator which are either self-excited using terminal...
In an Organic Rankine Cycle (ORC) systems, the Permanent Magnet (PM) generator is directly coupled to high-speed turbine shaft, in order to increase system efficiency avoiding introduction of gear-box. On the other hand, current time harmonics induce high frequency currents in rotor parts, which cause a temperature increase. PMs are strongly affected by the operating temperature, since both remanence...
The value of sub-transient reactance depends on the design of damper winding or amortissuer. All synchronous generators have sub-transient reactants even though it does not have damper winding physically. The damper winding can contribute to reduce the sub-transient current when generator in fault condition. The generator quantitative parameters are used to perform the simulation using MATLAB/Simulink...
Synchronous machines exhibit, under normal operating conditions, torque oscillation problems. This work presents a study that proposes a methodology for the reduction of these oscillations. It was tested in a synchronous generator powered environment with DC voltage supplying power to a common bus in permanent regime, this bus has the presence of a nonlinear load. There are oscillating components...
This papers deals with the control of active and reactive powers in wind energy conversion systems (WECS) powered by dual-stator-winding squirrel-cage induction generators (BDFIG). In these systems, the MPPT technics based on a torque control present coupling with reactive power objectives. A High Order Sliding Mode MIMO control is proposed for satisfying the power objectives in a decoupled way. The...
Integrated power systems (IPSs) with medium voltage direct current (MVDC) distribution are gaining importance in civil and defense marine vessels as they promise to provide cleaner, more reliable operation of vessels along with reduced fuel consumption. The integration of battery energy storage systems (BESSs) in the MVDC distribution system enables peak shaving of generators, optimal scheduling of...
The concentrated winding is the common winding method used in the conventional permanent magnet flux reversal machines (FRPM). In this paper a distributed winding for FRPM as a generator is proposed. To investigate the advantages of the proposed machine a comparative analysis of both the distributed and the concentrated winding for FRPM is performed. The output voltage waveforms of both machines are...
This paper discusses high-voltage, high-speed permanent magnet generators and their possible applications: space and aviation aircrafts, ships, mobile installations, etc. The main qualitative criteria for the electrical machinery power supply systems for spacecraft are determined. Different design topologies of the high-voltage, high-speed permanent magnet generators are reviewed and the optimal option...
In this paper, the excitation control with rotary exciter of generator A2 in Thermal Power Plant “Kostolac A” is presented. Excitation system under consideration consists of a main exciter, an auxiliary exciter and power semiconductor rectifiers. The main exciter is a synchronous-reluctance generator with windingless toothed rotor. That excitation system is specific due to the fact that the main exciter...
This paper presents a practical way of identifying the defective diodes of an alternator. For this purpose are presented a series of experimental tests of some car alternators. There are detailed the automatic voltage control by modifying the excitation current of the generator and different waveforms of the voltage obtained when one or more rectifier diodes are damaged. The paper ends with conclusions...
This paper deals with fault tolerant control of a sinusoidal EMF five-phase permanent-magnet synchronous generator (PMSG) connected to an AC-DC converter without neutral connection. Under one open phase condition, the proposed global method is based on an original approach optimization problem minimizing copper losses and cancelling torque ripples. The used optimization algorithm is based to a Particle...
Modular design of wind turbine generators is a promising means to increase the generator availability by reducing downtimes, especially for offshore turbines. With such physically modular designs, the structural support for the generator is an important consideration as it needs to overcome the loss of rigidity in the generator yoke. This makes the structural support design of the generator an important...
This contribution presents the control of the variable speed wind energy conversion systems. It is based on a six-phase symmetrical induction generator combined to a matrix converter. Rotor flux vector control algorithm and a scalar strategy modulated matrix converter are used to control the wind energy conversion system. Characteristics of the matrix converter are used for maximizing the power tracking...
This paper presents the design and the measurement of two identical PM-generators driven by an axial counter-rotating micro-turbine, called DuoTurbo-microturbine. This prototype for drinking water networks has been jointly developed by the HES-SO Valais//Wallis, the EPFL-Laboratory for Hydraulic Machines and industrial partners. The modular in-line “plug & play” technology requires low investment,...
The paper deals with the analysis of electromagnetic phenomena in a two-winding permanent magnet synchronous generator (PMSG) driven by wind turbines. The machine's winding is designed to facilitate application of a low cost and reliable AC/DC power electronic converter. The finite element method has been employed to develop numerical models for the case study problem of the machines. Special attention...
This paper reviews relevant published IEC standards on converter-fed motor insulation and discusses some technical issues on offline PD tests methods with repetitive impulse voltage of IEC60034-27-5. In order to qualify PD-free insulation system for IEC 60034-18-41, the detail of PD testing method should be fixed as possible in IEC 60034-27-5, while there are still arbitrary factors in PD measurements:...
Direct drive propulsion motors have the advantage of simplicity and reliability over conventional geared offerings, but often cannot compete due to size & weight penalties. A new in-slot cooling approach is optimized for torque and efficiency and yields a motor small enough to make direct drive propulsion attractive. This innovative approach to liquid-cooled motor delivers higher torque density...
The integrated starter generator (ISG) is one of the key components of hybrid electric vehicles. However, with the significant difference in power range between the two operation modes of the starter and generator, it is difficult for the generator to exhibit excellent behaviors in both modes. To solve this problem, a dual air-gap permanent magnet ISG is investigated in this paper. Torque characteristics...
In order to improve the power quality of wind power generation system, a direct power control (DPC) strategy of open-winding brushless doubly-fed generator (BDFG) system based on dual converters is presented in this paper. The control method is divided into two parts: the grid side converter control and the machine side converter control. In terms of the grid side converter, a model predictive-based...
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