Shaik, Abdul Gafoor

This paper presents the experimental investigation of power quality (PQ) disturbances associated with the grid integrated wind energy generator. PQ disturbances associated with the grid synchronization and outage of doubly fed induction generator (DFIG) based wind energy generation system have been investigated in the presence of various types of loads. The voltage signal has been captured at point of common coupling (PCC) using the data acquisition system consisting of power quality analyser, laptop, and WT viewer software. The voltage signal has been analysed using MATLAB software to find the PQ disturbances. It has been observed that the PQ disturbances such as voltage fluctuations, flicker, voltage sag, voltage swell and harmonics are associated with the grid synchronization and outage of DFIG based wind energy conversion system.

Renewable energy (RE) sources when integrated to utility network to form hybrid power system pose challenges in terms of stability and power quality. A method based on Stockwell's transform (S-transform) is presented in this paper for power quality (PQ) assessment and detection of islanding, outage and grid synchronization of renewable energy sources. Voltage signals are decomposed using multi-resolution analysis (MRA) of S-transform and features extracted are realized to assess the power quality disturbances associated with various events. Operational events are detected with the help of features extracted from the S-transform based decomposition of negative sequence component of voltage. A power quality index is proposed to rank the various operational events based on power quality. Proposed algorithm has been tested successfully on IEEE-13 bus test system with necessary modifications to integrate wind and solar PV generators to form the hybrid power system. Simulation results are validated in real time environment with the help of real time digital simulation (RTDS) system.

A method based on Stockwell's transform and Fuzzy C-means (FCM) clustering initialized by decision tree has been proposed in this paper for detection and classification of power quality (PQ) disturbances. Performance of this method is compared with S-transform based ruled decision tree. PQ disturbances are simulated in conformity with standard IEEE-1159 using MATLAB software. Different statistical features of PQ disturbance signals are obtained using Stockwell's transform based multi-resolution analysis of signals. These features are given as input to the proposed techniques such as rule-based decision tree and FCM clustering initialized by ruled decision tree for classification of various PQ disturbances. The PQ disturbances investigated in this study include voltage swell, voltage sag, interruption, notch, harmonics, spike, flicker, impulsive transient and oscillatory transient. It has been observed that the efficiency of classification based on ruled decision tree deteriorates in the presence of noise. However, the classification based on Fuzzy C-means clustering initialized by decision tree gives results with high accuracy even in the noisy environment. Validity of simulation results has been verified through comparisons with results in real time obtained using the Real Time Digital Simulator (RTDS) in hardware synchronization mode. The proposed algorithm is established effectively by results of high accuracy to detect and classify various electrical power quality disturbances.

This paper presents a technique to recognize the power quality (PQ) disturbances associated with solar energy penetration in distribution network. The voltage signal is analysed with the help of Stockwell's transform (S-transform) then its features are utilized to recognize power quality events with the help of Fuzzy C-means clustering (FCM). The operations considered for PQ assessment include grid synchronization and outage of solar photovoltaic (PV) system. The PQ events associated with sudden change in solar insolation have also been investigated. The proposed study is carried out using a standard IEEE-13 bus test system modified by incorporating the solar PV system. The effect of increase in solar energy penetration in terms of power quality assessment has also been investigated with solar PV systems of capacities 100kW, 500kW and 1MW using the proposed power quality index, maximum deviations in frequency and total harmonics distortions of voltage and current. The study has been carried out using MATLAB/Simulink and simulation results are compared with the real time results obtained using real time digital simulator (RTDS) for validating the effectiveness of proposed study.

Grid-connected solar photovoltaic (PV) systems are increasingly attracting the attention of industry and academia mainly motivated by potential to provide an alternative to the conventional fossil fuel generation. This helps to meet out the increasing energy demands and to limit the pollution of environment caused by fossil emissions. This paper presents a comprehensive overview of the grid-connected solar PV systems. The intention of this review is to provide a wide spectrum on architecture of grid-connected solar PV system and its constituent components such as solar cell, PV array, maximum power point tracking, filters, DC-DC converters, single-phase inverters, and three-phase inverters to the researchers, designers, and engineers working on solar energy and its integration into the utility grid. Brief overview of control techniques for the single and three-phase inverters has also been presented. More than 100 research publications on the topologies, configurations, and control techniques of grid-connected solar PV systems and their major constituent components have been thoroughly reviewed and classified for quick reference.

Requirement of green supply with higher quality has been consumers' demand around the globe. The electrical power system is expected to deliver undistorted sinusoidal rated voltage and current continuously at rated frequency to the consumers. This paper presents a comprehensive review of signal processing and intelligent techniques for automatic classification of the power quality (PQ) events and an effect of noise on detection and classification of disturbances. It is intended to provide a wide spectrum on the status of detection and classification of PQ disturbances as well as an effect of noise on detection and classification of PQ events to the researchers, designers and engineers working on power quality. More than 150 research publications on detection and classification techniques of PQ disturbances have been critically examined, classified and listed for quick reference.

Wind energy is becoming more important in recent years due to its contribution to the independence of power generation industry from traditional fossil energy resources and availability of continuous harvest-able potential on earth approximately around 106MW. This paper presents a comprehensive overview of grid interfaced wind power generation systems. This is intended to provide a wide spectrum on the status of wind profile, wind potential estimation, configuration/design of wind energy conversion systems, wind generators, power converter topologies used for grid integration of wind power, energy storage systems for wind power applications, power smoothing methods, HVDC links used for wind integration, international grid codes and maximum power point tracking methods to the researchers, designers, manufacturers, and engineers working on the grid interfaced wind power generation. More than 200 research publications on the topic of grid interfaced wind power generation systems have been critically examined, classified and listed for quick reference. This review is ready-reckoner of essential topics for grid integration of wind energy and available technologies in this field.

This paper presents a method for detection and classification of power quality (PQ) disturbances using Stock-well's transform. PQ disturbances are generated using MATLAB as per IEEE-1159 standard. Various features of signals are extracted from the multi-resolution analysis based on Stockwell's transform. These features are used to classify PQ disturbances using the decision tree initialized Fuzzy C-means clustering. It is observed that the Fuzzy C-means clustering based classification yields satisfactory accuracy even under noisy conditions. The investigated PQ disturbances include voltage sag, swell, interruption, harmonics, notch, flicker, oscillatory transient, impulsive transient and spike. Effectiveness of proposed algorithm has been established by satisfactory results of various case studies.

This paper presents a comprehensive review of the distribution static compensator employed for harmonic filtering, power factor correction, neutral current compensation, and load balancing in the distribution network. The intention of this review is to provide a wide spectrum on architecture, topologies, and control techniques to the researchers, designers, and engineers working on power quality improvement. More than 100 research publications on the topologies, configuration, control techniques, and applications of distribution static compensator have been thoroughly reviewed and classified for quick reference.

This paper presents a technique for the detection and localization of the power quality events associated with outage and grid synchronization of solar photovoltaic plant in distribution network. A standard IEEE 13 bus distribution network has been modified by adding 100kW solar photovoltaic plant. The proposed test system is simulated in MATLAB/simulink environment. Voltage signals captured at nodes of the test system are used for power quality analysis. The harmonic detection has been carried out using fast Fourier transform and the voltage sag, swell has been detected by voltage index calculated based on wavelet analysis. The unbalance in the voltage has been detected by sequence components of voltages. The power quality events associated with sudden change in the solar insolation have also been investigated. Detection and discrimination of synchronization, outage and sudden changes in solar insolation has been proposed using sequence components of voltages measured.