The electrical characteristics of an isolated induction-generator-based system are improved through the association with a voltage-source pulsewidth modulation (PWM) inverter. electronic converter allows achievement better behavior in many aspects: voltage regulation, frequency stabilization, and reactive power compensation. operation strategy consists maintaining constant synchronous at induction generator via PWM balance regulation may be accomplished by two different means: rotor speed or...

This paper concerns an application of a three-phase cage induction machine (IM) as self-excited generator connected to the AC side voltage-source PWM bidirectional inverter. The is supposed be driven by low-head unregulated shaft hydraulic turbine. proposed system intended applied in rural plants low-cost source high-quality sinusoidal regulated voltage with constant frequency. Simulation results are obtained based on /spl alpha//spl beta//spl gamma/ stationary reference frame model IM....

The forecasting of solar irradiance in photovoltaic power generation is an important tool for the integration intermittent renewable energy sources (RES) electrical utility grids. This study evaluates two machine learning (ML) algorithms intraday forecasting: multigene genetic programming (MGGP) and multilayer perceptron (MLP) artificial neural network (ANN). MGGP evolutionary algorithm white-box method a novel approach field. Persistence, MLP were compared to forecast at six locations,...

This paper is concerned with an application of a three-phase cage induction machine as self-excited hydroturbine driven generator connected to the AC side voltage source PWM (VS-PWM) bi-directional converter. The supposed be by low-head unregulated shaft hydraulic turbine. Under this condition, range turbine speed variation narrower than for wind generators. Frequency and at load are regulated action proposed system intended applied in rural plants low-cost high quality sinusoidal frequency...

This paper is concerned with the application of a three-phase cage induction machine as self-excited hydraulic-turbine driven generator connected to AC side voltage source PWM bi-directional power converter. Frequency and at load are regulated by action structure also provides energy utility grid via buck converter current inverter single-phase line. The controlled factor corrector IC so that sinusoidal sent unity factor. proposed system intended be applied in rural plants frequency...

The operating cost reduction of photovoltaic (PV) systems is an important way to increase its economic viability for stakeholders. In this study, inverter sizing ratio (ISR) analysis carried out in order quantify potential benefit the context building‐integrated PV and distributed generation central region Brazil. An algorithm was created analyse ISR considering 12 years measured climate data provided by manufacturers system components. Among three analytical methodologies discussed power...

Renewable energy sources (RES) like solar and wind, naturally present high daily seasonal variability of power generation. This paper presents a real case study photovoltaic (PV) forecasting building-integrated PV plant as tool for systems operation. A new methodology composed data processing strategy, Artificial Neural Networks (ANN) modelling, error metrics definitions are proposed validated the intra-day forecasting. Data were modelled in time steps 15-minute averages forecasts obtained...

Abstract This paper presents a methodology to calculate the value of Carter's factor for airgaps with polygonal slots. A numerical evaluation Schwarz–Christoffel transformation is performed using Genetic Algorithms. The presented here extends method more complicated geometry. Some case studies compare results developed results. Copyright © 2010 John Wiley & Sons, Ltd.

A PWM voltage-source inverter is used in order to improve the electrical characteristics of an isolated induction generator. The electronic converter allows achievement a better system behavior many aspects: voltage regulation, frequeney stabilization and reactive power compensation. DC control variable generator speed governor, therefore balance regulation accomplished by control, which exerted governor. Both simulation experimental results demonstrated that stable, robust effective source...

The use of cage-rotor three-phase induction generator (IG) presents considerable advantages mainly due to its robustness and low cost. However, the performance in terms voltage frequency stabilization is an important drawback when trying guarantee power quality load. This paper contributes presenting IG-basic structure which employs power-electronic converters associated with order improve both operation characteristics system. Moreover, proposed does not require a speed governor generator,...

This study focused on developing a sustainability project carried out in 11 Federal Institute of Education, Science, and Technology Goiás (IFG) campuses wherein energy efficiency distributed generation actions were developed. Energy consumption was optimized by retrofitting the lighting system, installing photovoltaic (PV) quantifying building efficiency, monitoring, training, qualification, focusing efficient use electric energy. We first present Brazilian legislation that regulates...

This work proposes a design method for robust state feedback grid current controller applied to single‐phase grid‐connected photovoltaic (PV) systems. The proposed achieved high system reliability even dealing with distorted voltages and other power quality issues. robustness of the was verified in face parametric uncertainties at first‐order output filter, also satisfactory disturbance rejection performance achieved. is based on linear matrix inequalities associated constraints involving...

This work deals with the feedback operation strategy of a low-voltage distributed generation system composed by three-phase four-leg inverter connected to typical four-wire grid-utility in PCC (Point Common Coupling). The desired modulation and switching pattern for is determined Model Predictive Control (MPC) method. Some reasons choosing control method topology are presented discussed. rules MPC defined so that load supplied full generator power factor maximized. A total four cases local...

Penetration of Distributed Energy Resources (DERs) stands the problem taking into account uncertainty and volatility power output. Such becomes crucial for choosing capacities DERs storages, estimating reliability indexes selecting energy management strategies. This paper presents research based on data from 34-kWp grid-connected PV system, located in campus Federal University Goias (Brazil). The were used modeling stochastic generation output photovoltaic panels during year period kernel...

This paper proposes a half-bridge doubler boost converter associated with an active commutation cell in order to minimize losses. The operates unity power factor and is able provide high output voltages. voltages across the semiconductor devices are low approximately equal voltage, as doubled reduced frequency ripple can be achieved. A detailed mathematical analysis concerning its operation presented, since simulation experimental results describe performance.

This study addresses a proposal of bench to test single-phase induction motors and switched reluctance with rated power up 1 hp. The was set so that motor tests meet requirements IEEE Std. 114-2001 the Brazilian related Standard (ABNT NBR 5383-2/2008). In addition, procedures for comprise sequential steps in order determine performance under different switching angles constant speed. measurement system is completely computer automated using virtual instrumentation based on LabVIEWtrade...

This paper aims to present some applications of Wavelet Transform (WT) in grid-connected photovoltaic (PV) systems, main differences among transform and Fourier transforms also aspects related power quality (PQ) islanding detection methods a PV system. An example Discrete (DWT) applied detect disturbs on electrical signals is presented. analysis an important addition time-frequency with practical systems. The wavelet has more advantages than techniques such as Short-Time Transform....

This paper presents a small-signal model of the single-phase asymmetrical cascaded h-bridge multilevel inverter (ACHMI), mainly related to several applications like voltage/current controllers design, power factor control and active filter, or not photovoltaic (PV) systems. The considered in this work has configuration, its individual dc-link voltages are scaled by (1:2:6:…), which guarantee low Total Harmonic Distortion (THD) output voltage. proposed is presented step-by-step considering...

The electrocoagulation of aqueous matrices has been gaining considerable attention because the versatility and good results obtained. treatability rainwater was evaluated by means electrocoagulation/flotation in cylindrical reactor with aluminium electrodes. experimental procedure conducted pilot-scale reactor, operated continuous flow hydraulic detention time 100 seconds 12.3 current density mA/cm2. built acrylic tube on dimensions 8 cm diameter 60 height, being electrodes made aluminum 15...

This study addresses a proposal of bench to test single-phase induction motors and switched reluctance with rated power up 1 hp. The was set so that motor tests meet requirements IEEE Std. 114–2001 the Brazilian related Standard (ABNT NBR 5383-2/2008). In addition, procedures for comprise sequential steps in order determine performance under different switching angles constant speed. measurement system is completely computer automated using virtual instrumentation based on LabVIEW™ platform...

This study demonstrates the application of layer model theory to analysis synchronous machines. The derivation from Maxwell's equations is briefly described. With use steady‐state and terminal operation information, a methodology established, machine modelled. Two case examples are then analysed. It shown that can be applied machines with promising results.