Grid Connected Wind Energy System Research Articles

A Novel Method for Fast Configuration of Energy Storage Capacity in Stand-Alone and Grid-Connected Wind Energy Systems

In this paper, a novel method is proposed and applied to quickly calculate the capacity of energy storage for stand-alone and grid-connected wind energy systems, according to the discrete Fourier transform theory. Based on practical wind resource data and power data, which are derived from the American Wind Energy Technology Center and HOMER software separately, the energy storage capacity of a stand-alone wind energy system is investigated and calculated. Moreover, by applying the practical wind power data from a wind farm in Fujian Province, the energy storage capacity for a grid-connected wind system is discussed in this paper. This method can also be applied to determine the storage capacity of a stand-alone solar energy system with practical photovoltaic power data.

Optimization of the inverter size for grid-connected residential wind energy systems with peak shaving

This paper addresses the problems of output power distribution and variability of small wind turbines. The aim of the study was to increase the share of locally consumed renewable energy and decrease power fluctuation in residential houses that meet their energy demand using wind energy. A system with shiftable water heating and decreased inverter power, which avoids unnecessary conversion steps for shifting of power peaks is proposed. Autocorrelation functions were used to analyse the energy consumption and production patterns for optimization of the inverter and hot water storage tank size for load shifting. The optimal sizing of these components for applying the method was found for different wind conditions. The results of simulations with high temporal resolution data and experiments showed that the proposed system is able to shave stochastic power peaks and shift electrical loads. The analysis of net energy flow revealed that the renewable energy cover factors can be enhanced by 14.4–36.0% and the wind turbine's nominal inverter power can be decreased down to 29.2–52.3% without increasing the system's energy losses or changing the hot water consumption pattern.

Performance Analysis of Bang-Bang and d - q Reference Frame Control Schemes for Power Quality Improvement of Grid Connected Wind Energy System

Performance Analysis of Bang-Bang and d - q Reference Frame Control Schemes for Power Quality Improvement of Grid Connected Wind Energy System

Power Quality Improvement on Wind Energy System by Using STATCOM

Wind energy known as a cheap, clean and uncontrolled resource and becomes an important green electricity source. However, installation of wind system into an electric grid introduces the Power Quality (PQ) phenomenon. These poses great challenges leads to various control schemes and new techniques to mitigate the PQ events. This paper described the improvement of PQ events in a grid connected wind energy system by using Static Compensator (STATCOM) with a Battery Energy Storage System (BESS) at the Point of Common Coupling (PCC). The performance of the proposed wind energy system is simulated via MATLAB/SIMULINK in power system block set.

An Improved Synchronous Reference Frame Controller based Dynamic Voltage Restorer for Grid Connected Wind Energy System

The production of wind generation has expanded considerably today. The main problem with wind generation system is to regulate the voltage at wind turbine terminals even under abnormal grid conditions.This is mainly as a result of consumption of non active power from the grid during grid disturbances. This paper investigates an improved Synchronous Reference Frame control; Dual Decouple Synchronous Reference Frame (DDSRF) based control for Dynamic Voltage Restorer (DVR) to upgrade the dynamic response of wind energy system. The proposed method uses DDSRF PLL for extracting clean grid voltage and phase angle even under adverse grid conditions. The proposed control scheme provides the ability for fixed speed wind generator to ride through under voltage interruptions in the grid to meet the latest grid codes. The proposed control is competent of stabilising the voltage at the wind turbine terminals under symmetrical sag/swell and asymmetrical fault conditions. simulation studies have been peformed in MATLAB/SIMULINK to manifest the effectiveness of proposed control strategy

A STATCOM-Control Scheme for Grid Connected Wind Energy System for Power Quality Improvement using PI Controller

The grid-connecting wind energy generation system for power quality improvement by using STATCOM-control scheme is simulated with the help of MATLAB When the wind power is connected to an electric grid affects the power quality. The effects of connecting wind turbine into the grid system covers power quality areas are the active power, reactive power, harmonics and variation of voltage, and electrical performance of switching operations. The installation of wind system with the grid creates the power quality problems which can be determined by studying this paper. By using the Static Compensator (STATCOM) with using. battery energy storage system (BESS) at the point of common coupling to improving the power quality of the grid The battery energy storage used to keep real power from varying wind power. At lower power demand hours the generated power can be stowed in the batteries. The combination of battery storage with wind energy generation system will even out the grid system by absorbing or injecting reactive power and enable the real power flow essential to the load. This recreates the main supply source from the reactive power demand of the load and induction generator in this proposed scheme.

Probabilistic power quality indices for electric grids with increased penetration level of wind power generation

Abstract In future electric grids it is expected that the share of power produced by renewable energy systems will increase to supply large deficits in power demand. Wind energy is one of the most important sources of renewable energy generation systems. With increased penetration level of wind energy conversion systems in modern electric grid, the quality of power will inevitably be affected. Power quality (PQ) indices are used to quantify the quality of the power. They serve as the basis for comparing negative impacts of different disturbances on power networks. Previous research of PQ indices with electric grids including wind energy sources was mainly based on fixed wind speed. Therefore, the PQ indices were calculated as instantaneous values that do not reflect the overall power quality impact of the grid connected wind energy systems. The main objective of this paper is to propose new probabilistic PQ indices for electric grids including wind energy systems. The proposed PQ indices combine both the probabilistic nature of wind speed using discrete Markov analysis and the electric grid behavior. The main PQ indices proposed are those concerning harmonics, flicker, and voltage sag. The developed indices are suitable for electric grids that include high penetration level of wind based power sources. The method used is general and can be applied to other power quality indices or power system performance indices.

A Novel Hybrid Control Strategy of a STATCOM for Power Quality Improvement in a Grid Connected Wind Energy System

A Novel Hybrid Control Strategy of a STATCOM for Power Quality Improvement in a Grid Connected Wind Energy System

Enhancement of Power Quality through Shunt Compensators and Main Grid Interfaced with DGs

Injection of power generated by the wind turbine system into an electric grid mainly effects the power quality. The performance of this wind turbine and its power quality is determined on the basis of its measurement of power ratings as per Institute of Electrical and Electronics Engineers (IEEE) standards. The influence of the wind turbine in the grid system concerning the power quality measurements are the active power, reactive power, variation of voltage, flicker, harmonics, and electrical behavior of switching operation. To mitigate the power quality problems this paper proposes the shunt compensator techniques. Here, the proposed system is verified experimentally using both Static Synchronous Compensator (STATCOM) and Thyristor Switched Capacitor (TSC) compensators. This control schemes for grid connected wind energy system is simulated using Matlab/Simulink.

Power Control in Grid-Connected Wind Energy System Using Diode-Clamped Multilevel Inverter

ABSTRACTThis paper presents dynamic modelling and control of real and reactive power in grid-connected variable speed wind energy conversion system using diode-clamped multilevel inverter (DCMLI). A modified five-level DCMLI is used for power control, which eliminates the requirement of transformer and improves the quality of controlled output voltage. It is shown that the system is dynamically stable and is able to control the real and reactive power independently, and provides harmonic compensation within standard limits. The voltage balancing across the capacitors of the five-level diode-clamped inverter is obtained using external balancing circuits. The performance of the proposed control method is tested under variable wind speed, sudden load changes, and under single-phase and three-phase faults. Simulation studies PSCAD/EMTDC verifies the proposed control method.

Harmonic Reduction in Grid Connected Wind Energy System with Dynamic Voltage Restorer Using Fuzzy Logic Technique

Grid connected Wind energy conversion system uses power Electronic converters hardly in fixed speed systems except for reactive power compensation. This Power Electronic converter causes major electrical losses and affects power quality of the system. The quality of the voltage and current is also affected by sensitive loads which are used widely in most of Automated Industries and Research laboratories. Disturbances in waveforms occurs which results in harmonics. To improve such power quality problem of the system DVR which is based on fuzzy logic technique is introduced. The system is tested for conventional technique and also with fuzzy logic. The performance is investigated through MATLAB/SIMULINK software. The simulation results confirm the superior performance of the proposed DVR based fuzzy logic technique than conventional technique. The proposed system reduces harmonics as well as mitigates voltage sag/swell.

Simulation and Performance Study of Grid-connected Wind and Photovoltaic Hybrid Energy System

Hybrid energy system (HES) includes several (two or more) energy sources with appropriate energy conversion technologies connected together to feed power to local load/grid. HES allows a wide variety of primary energy sources, frequently generated from renewable sources as the stand alone system for rural electrification and also for grid extension. The objective of this work is to model photovoltaic (PV) & wind grid connected HES using Matlab/Simulink. The model is useful for simulation of PV & wind grid connected HES. Blocks like wind model, PV model, energy conversion system and loads are implemented and the results of simulation model are also presented.

Active and reactive power regulation in grid connected wind energy systems with permanent magnet synchronous generator and matrix converter

This study presents a simple voltage oriented vector control scheme to regulate active and reactive power in a grid connected variable speed wind electrical system that consists of permanent magnet synchronous generator and matrix converter, which enables the maximum power tracking in wind electrical systems. The maximum extractable power from wind is derived from power curves and set as reference active power. Reactive power reference is chosen as zero. The deviations in powers are processed by proportional and integral (PI) controllers which vary the voltage gain of MC through which the desired regulation of powers is carried out. Since the relationship between wind speed and reference active power is nonlinear, single PI controller is insufficient, hence gain scheduling is required to adjust the controller parameters in response to changes in wind speeds. The controller parameter change is abrupt in conventional gain scheduling which leads to unstable performance. To avoid this, neural network-based PI (NN-PI) is designed which is more robust. In the presented work, both conventional gain scheduled PI and NN-PI are applied to validate the suggested voltage oriented control for power regulation. Simulation and experimental studies are presented to confirm the effective functionality of the system.

Mitigation of Voltage sag and Harmonics in Grid connected Wind Energy System using STATCOM

Power quality gains its importance with the introduction of sophisticated electrical gadgets. The performances of these devices are sensitive to the quality of input power supply. Various power quality problems results in failure or mal-operation of end user equipment. Some of the major power quality issues are voltage sag, voltage swell and harmonics. To solve these problems, capacitors, voltage regulators and filters, are conventionally used. These techniques involve inherent drawbacks. So it is proposed to use Flexible AC Transmission System (FACTS) devices for the mitigation of power quality problems. With the usage of these devices, drawbacks associated with conventional methods can be overcome easily. The application of FACTS devices provides faster control and enhances the way of using the transmission system at their rated thermal capability. In this work, it is proposed to use Static Var Compensator (STATCOM) for mitigating voltage sag and harmonics by providing proper reactive power support. The device is modelled and simulated using MATLAB-SIMULINK. In order to validate the proposed approach, it is tested with three phase fault simulated in the designed model. The graphical, numerical results with and without STATCOM are compared to measure the effectiveness of control.

Design and Modeling of Wind Fed Resonant DC-DC Converter through Synchronous Generator using MATLAB/Simulink

This study presents the design, modelling and simulation of variable speed wind turbine through the LCL type DC-DC resonant converter for grid connected wind energy system using MATLAB/Simulink. Owing to enhancing the power demand and environmental issues, power generation from renewable energy is getting more consideration. The designed converter has main merits like reduced switching loss using soft switching methods, reduced transformer size, and filter size. In addition, this paper investigates the resonant converter application to obtain a constant D.C voltage at the output of the designed converter, reduced stress, EMI, and high power density. In this paper, fuzzy logic controller (FLC) is used to regulate the output voltage of resonant converter in comparison with PI controller. The simulation has been done in MATLAB/Simulink frame work. It is shown that a resonant converter enhances voltage profile of power grid containing synchronous generator based wind system.

Power Quality Improvement In Grid Connected Windenergy System Using Statcom

Power Quality Improvement In Grid Connected Windenergy System Using Statcom

A Svc Light Based Technique for Power Quality Improvement for Grid Connected Wind Energy System

The power produced from wind energy source is always fluctuating due to variation in the wind. Connecting this wind sources to grids leads the system to issues , and shows the impact on the functionality of the grid to be impaired. Thus wind power injection in to an electric grid affects the quality of power.. This project deals the existence of the power quality problems due to the installation of wind turbine with grid. In order to eliminate these power quality problems, this project proposes a scheme based on FACTS device called SVC light which is connected at a Point of Common Coupling. The proposed model is compared with the model that do not use any compensating device .Performance of the system with BESS under load variations and Fault ride through capability of the svc light is also analysed. This control scheme for the grid connected wind energy generation system is to improve the power quality and this system is simulated using MATLAB /SIMULINK in power system block set. Keywords: Power Quality, Wind Generating System (WGS), Svc lig ht, Statcom, and Fault r i d e thro ugh capability, Battery energy storage system (BESS).

A STATCOM-Control Scheme for Grid Connected Wind Energy System for Power Quality Improvement

Injection of the wind power into an electric grid affects the power quality. The performance of the wind turbine and thereby power quality are determined on the basis of measurements and the norms followed according to the guideline specified in International Electro-technical Commission standard, IEC-61400. The influence of the wind turbine in the grid system concerning the power quality measurements are-the active power, reactive power, variation of voltage, flicker, harmonics, and electrical behavior of switching operation and these are measured according to national/international guidelines. The paper study demonstrates the power quality problem due to installation of wind turbine with the grid. In this proposed scheme STATic COMpensator (STATCOM) is connected at a point of common coupling with a battery energy storage system (BESS) to mitigate the power quality issues. The battery energy storage is integrated to sustain the real power source under fluctuating wind power. The STATCOM control scheme for the grid connected wind energy generation system for power quality improvement is simulated using MATLAB/SIMULINK in power system block set. The effectiveness of the proposed scheme relives the main supply source from the reactive power demand of the load and the induction generator. The development of the grid co-ordination rule and the scheme for improvement in power quality norms as per IEC-standard on the grid has been presented.

Power limits of grid-connected modern wind energy systems

Wind energy is a prominent area of application of variable speed generators operating on the constant grid frequency. A modern wind energy system of this type consists of a surface mounted permanent-magnet generator with a frequency converter, which allows variable speed operation. The maximum power capability of the wind energy system is limited by the grid inverter. The theoretical formulation for active and reactive power limits is given. This formulation is used to set power reference limits to the inverter. Two different regions are distinguished depending on the tolerable Ac current harmonic distortion. Experimental results in a variable frequency wind energy generation system are shown.

Grid-Connected Bulk Wind Energy System Installing Neural- Controlled Switched Reluctance Generators

Grid-Connected Bulk Wind Energy System Installing Neural- Controlled Switched Reluctance Generators