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Wind Turbines with Permanent Magnet Synchronous Generator and Full-Power Converters: Modelling, Control and Simulation

Research about dynamic models for grid-connected wind energy conversion systems is one of the challenges to achieve knowledge for the ongoing change due to the intensification of using wind energy in nowadays. This book chapter is an involvement on those models, but dealing with wind energy conversion systems consisting of wind turbines with permanent magnet synchronous generators (PMSG) and full-power converters. Particularly, the focus is on models integrating the dynamic of the system as much as potentially necessary in order to assert consequences on the operation of system. In modelling the energy captured from the wind by the blades, disturbance imposed by the asymmetry in the turbine, the vortex tower interaction, and the mechanical eigenswings in the blades are introduced in order to assert a more accurate behaviour of wind energy conversion systems. The conversion system dynamic comes up from modelling the dynamic behaviour due to the main subsystems of this system: the variable speed wind turbine, the mechanical drive train, and the PMSG and power electronic converters. The mechanical drive train dynamic is considered by three different model approaches, respectively, onemass, two-mass or three-mass model approaches in order to discuss which of the approaches are more appropriated in detaining the behaviour of the system. The power electronic converters are modelled for three different topologies, respectively, two-level, multilevel or matrix converters. The consideration of these topologies is in order to expose its particular behaviour and advantages in what regards the total harmonic distortion of the current injected in the electric network. The electric network is modelled by a circuit consisting in a series of a resistance and inductance with a voltage source, respectively, considering two hypotheses: without harmonic distortion or with distortion due to the third harmonic, in order to show the influence of this third harmonic in the converter output electric current. Two types of control strategies are considered in the dynamic models of this book chapter, respectively, through the use of classical control or fractional-order control. Case studies were written down in order to emphasize the ability of the models to simulate new contributions for studies on grid-connected wind energy conversion systems.

Two-level and multilevel converters for wind energy systems: A comparative study

This paper is concerned with modeling and simulation of a wind energy system with different topologies for the power converters, namely a two-level converter and a multilevel converter. Pulse modulation by space vector modulation associated with sliding mode is used for controlling the converters, and power factor control is introduced at the output of the converters. Finally, a case study is presented, showing the electric behavior of the power and the current at the output of the converters and the direct voltage at the multilevel converter.

ZigBee standard in the creation of wireless networks for advanced metering infrastructures

The current grid must be updated and controlled with automated systems that offer the intelligence of the smart grid. In this task the wireless networks for sensors and actuators are very important component of the future grid infrastructure, being the “nerve cells” of the entire system. The most important player in the smart grid is probably the consumer, that can use the electricity and at the same time can have its own generation to be feed into the grid. Hence, metering devices are essential components in the smart grid, monitoring the consumers behavior and offering valuable information to the utilities and electric entities that will adapt the generation to match the consumption in a seamless way. The ZigBee standard is getting an increased adoption for the creation of cheap wireless networks that will connect the smart grid devices with each other. Still, there are little or no works that study the actual installation approaches, minimizing possible obstacles and decreasing costs. This paper present new field tests that study the integration and installation of ZigBee capable meters, offering at the same time several installation approaches.

A Pitch Control Malfunction Analysis for Wind Turbines with Permanent Magnet Synchronous Generator and Full-power Converters: Proportional Integral Versus Fractional-order Controllers

Abstract A transient analysis for two full-power converter wind turbines equipped with a permanent magnet synchronous generator is studied in this article, taking into consideration, as a new contribution to earlier studies, a pitch control malfunction. The two full-power converters considered are, respectively, a two-level and a multi-level converter. Moreover, a novel control strategy based on fractional-order controllers for wind turbines is studied. Simulation results are presented; conclusions are in favor of the novel control strategy, improving the quality of the energy injected into the electric grid.

Modeling and Simulation of Wind Energy Systems with Matrix and Multilevel Power Converters

This paper is concerned with modeling and simulation in Matlab/Simulink of wind energy systems with different topologies for the power converters: matrix converter and multilevel converter. We use pulse modulation by space vector modulation associated with sliding mode for controlling the converters, and we introduce power factor control at the output of the converters. Finally, we present the electric behavior for the power and the current at the input and at the output of the converters.

Electrical grid integration and power quality studies of a variable-speed wind energy conversion system

This paper is concerned with the behavior of a variable-speed wind energy conversion system, in order to assess the power quality injected in the electrical grid. Different topologies for the power-electronic converters are considered, namely two-level and multilevel converters. We use pulse width modulation by space vector modulation associated with sliding mode for controlling the converters, and we introduce power factor control at the output of the converters. We present the total harmonic distortion and the fast Fourier transform of the current injected in the electrical grid, considering each power-electronic converter. Finally, conclusions are duly drawn.

GA-ANN Short-Term Electricity Load Forecasting

This paper presents a methodology for short-term load forecasting based on genetic algorithm feature selection and artificial neural network modeling. A feedforward artificial neural network is used to model the 24-h ahead load based on past consumption, weather and stock index data. A genetic algorithm is used in order to find the best subset of variables for modeling. Three datasets of different geographical locations, encompassing areas of different dimensions with distinct load profiles are used in order to evaluate the methodology. The developed approach was found to generate models achieving a minimum mean average percentage error under 2 %. The feature selection algorithm was able to significantly reduce the number of used features and increase the accuracy of the models.

PV system modeling by five parameters and in situ test

This paper focuses on a novel formalization for assessing the five parameter modeling of a photovoltaic cell. An optimization procedure is used as a feasibility problem to find the parameters tuned at the open circuit, maximum power, and short circuit points in order to assess the data needed for plotting the I-V curve. A comparison with experimental results is presented for two monocrystalline PV modules.

Fractional-order control and simulation of wind turbines with full-power converters

This paper is on wind energy conversion systems with full-power converter and permanent magnet synchronous generator. Different topologies for the power-electronic converters are considered, namely matrix and multilevel converters. Also, a new fractional-order control strategy is proposed for the variable-speed operation of the wind turbines. Simulation studies are carried out in order to adequately assess the quality of the energy injected into the electric grid. Conclusions are duly drawn.

Modeling and simulation of a wind energy system: Matrix versus multilevel converters

This paper is concerned with modeling and simulation of a wind energy system with different topologies for the power converters, namely a matrix converter and a multilevel converter. We use pulse modulation by space vector modulation associated with sliding mode for controlling the converters, and we introduce power factor control at the output of the converters. Finally, we present the electric behavior for the power and the current at the output of the converters.