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Magnetic materials have become more and more user friendly in recent days particularly in an electronic based infrastructure. The study proposes a direct drive permanent magnet based Synchronous Generator as Tidal turbine in a hybrid tidal wave energy conversion system (TWECS) and discusses its performance for better stability. The objective of the study is to analyse the role of permanent magnet based generator in TWECS for overall improvement of stability through reactive power management. The isolated TWECS becomes unstable either by random load variations or by non uniform wind and tidal power inputs. Consequently the overall stability of the TWECS is brought to stable and normal stage by the control of reactive power with the inclusion of the custom power based devices. In addition to the effects of permanent magnet in case of DDPMSG for improving the overall system stability, optimisation tools like PSO, GSA and PSOGSA are added for further improvement in system performance. • Small signal modelling of DDPMSG based Micro grid has been implemented. • UPFC controller addresses the Reactive power compensation and stability issues of the Micro grid. • Comparison between DDPMSG and DFIG based systems are carried out with variable load and wind power inputs. • Stability analysis with nyquist, popov, Nichols are carried out. • Overall stability of the system is studied with Eigen values, participation factors. [ABSTRACT FROM AUTHOR]

Abstract This work discusses the implementation of JAYA-DE algorithm with Static Var Compensator for optimum voltage control through Reactive Power compensation inside solar based hybrid power system.The stability aspect of isolated solar based hybrid power system is enhanced through compensation of the reactive power by optimized SVC and are further analyzed with different stability criterion. The dynamic performance of the new hybrid technique under intermittent wind power input and variable load show superiority over the conventional control methods. [ABSTRACT FROM AUTHOR]

Abstract This paper presents wavelet transform, independent component based detection of the power quality disturbances in a microgrid. Wavelet transform (WT) is well known for its better time-frequency multi-resolution analysis because of selection of adaptive window size depending inversely with the frequency. This makes it suitable for identification of both stationary and non-stationary characteristics of the power quality disturbances. But, it is analyzed in the study that the detection capability of wavelet is degraded when the input voltage signal contains noise and completely fails when the noise level is increased to 25 dB. Of course, a wavelet-denoising technique is tested to improve the ability of wavelet transform under noisy conditions, but observed to increase the detection time. Hence, independent component analysis (ICA) is proposed for detection based on its property of finding the significant components which are statistically independent and non-Gaussian. In addition, the statistical features are extracted to formulate the input dataset for support vector machine (SVM) to classify different power quality disturbances like sag, swell, interruptions, harmonics, transients, and flickering. A comparative analysis is presented and it is observed from the study that ICA-SVM hybrid combination provides better classification accuracy as comparison to WT-SVM under different operating scenarios. [ABSTRACT FROM AUTHOR]

Solar photo voltaic cells are increasingly finding application in either grid connected power system or Standalone solar power system. PV cells are being used in combination with other renewable energy sources to form a distributed generation based hybrid power system. Though solar cell ideally contributes lot in hybrid power generation, uncertainty in solar insolation creates disturbances and power quality problem. Variable solar insolation, uncertain weather condition affects the Photo voltaic cell causing voltage disturbance, harmonics and other quality problems. Because of this Efficiency of solar cell is highly affected though harmonics remains low in comparison to conventional AC power supply in both load and source side. This paper analyses a practical set up of solar system in lab VIEW platform and investigates the effect of variable solar radiation on it. [ABSTRACT FROM AUTHOR]

Modified wavelet called wavelet packet transform (WPT) based approach is proposed in this paper for the detection of different disturbances occurring due to faults in grid-connected solar photovoltaic (SPV) power system. The detection performance of WPT is compared with that of wavelet transform under different operating scenarios. Further, performance indices such as energy and standard deviation (SD) are calculated to identify the faults from normal operating conditions. The qualitative and quantitative study suggests better detection performance of WPT over WT under different operating scenarios. [ABSTRACT FROM AUTHOR]

In industrial and utility power system it has been observed that harmonics build a major role in reducing the quality of power. These harmonics are caused because of increasingly utilize of nonlinear loads connected to the power system. In this context, active power filters play a very significant role for improvement in power quality. Moreover, at transmission ground, there is a high requirement to control reactive power and voltage stability. Conventionally, passive and active filters (shunt and series filters) were used for the development of power quality. But, they suffered from the issues like resonance, fixed compensation, and other PQ problems. Therefore, to minimize these issues, a hybrid combination of filters using passive and active filters is designed. In this paper, a comparative study of two hybrid model of HAPF is done based on current control techniques like d-q and p-q theory under different operating conditions. These results are again compared with a new estimation technique proposed in this paper well known called as recursive least square (RLS) harmonic estimation technique. The amplitude and phase angle of both the fundamental and harmonic currents are estimated with the proposed RLS technique. At the point of common coupling (PCC) the signal which is composed with harmonics is estimated with and without HAPF. Finally, it is analysed from the observation that the load current and supply current is improved significantly with a decrease of total harmonic distortion (THD) under different operating scenarios. [ABSTRACT FROM AUTHOR]

This paper presents a dynamic stability study in a solar energy based power system connected to infinite bus based on optimal design of a Static Var Compensator (SVC). In the proposed study, SVC is incorporated in order to improve the rotor angle and voltage oscillations because of different disturbances created in the power system. A new computational hybrid optimization approach using Particle Swarm Optimization (PSO) and Gravitational Search (GS) technique is considered for designing an optimal SVC damping controller for an improved dynamic performance. The optimization technique is used for tuning the gains of proportional integral derivative (PID) controller. Transient oscillation results for conventional PID, PSO optimized PID and PSO-GS based PID are compared analytically as well as quantitatively. It is observed that the proposed PSO-GS based PID controller is robust and effective in minimizing the oscillations in the system as compared to the other two and thus improves the stability. [ABSTRACT FROM AUTHOR]

This paper discusses the power management of standalone PV based Microgrid.PV based Microgrids can be of great importance in rural areas which are devoid of power through centralized Grid. Even a mesh microgrid can be devised with Solar PV systems located on different houses interconnected together. But there are certain challenges like voltage instability and other power quality problems which are to be addressed time to time to protect the Microgrid from collapsing. Addition of diesel generator help in resoration of voltage stability of the system through reactive power management. Further inclusion of FACTS devices improve the system stability as well as the damping of the system. System's behavior during different loading conditions has been monitored and contribution of solar power with different irradiations has been watched. [ABSTRACT FROM AUTHOR]

This paper proposes a robust H-infinity STATCOM controller for compensating reactive power in stand-alone micro grid consisting of a PV–Wind–Diesel hybrid system. In order to carry out MATLAB based simulation, a small signal linear model of the stand-alone hybrid power system is considered, comprising of a photo voltaic cell, a DFIG based wind turbine and a diesel generator. Synchronous generator based DG acts as a backup for the hybrid system. Generally these standalone systems experience frequent variation of loads, wind power input and solar radiation, which affect the vital system parameters like reactive power, terminal voltage and frequency to a great extent. These variations of system parameters with variation of load inputs are studied and its impact on overall system stability and reactive power compensation is properly monitored. Furthermore the system performance is improved and the robustness of the controller is enhanced with the incorporation of GA and PSO. [ABSTRACT FROM AUTHOR]

This paper proposes the application of fractional order PID controller (FOPID) for reactive power compensation and stability analysis in a stand-alone micro grid. For enhancement of voltage stability and reactive compensation of the isolated system, a SVC based controller has been incorporated. This paper emphasizes the role of fractional PID based SVC controller for reactive power management and improved stability in the stand alone micro grid, as it provides a special advantage of having two more degree of freedom for accurate tuning in comparison with the conventional controller The system performance, particularly the variations in different parameters values are studied properly with different input parameters and loading conditions. Further improvement of stability margin and optimisation of the system parameters have been achieved by the controller, based on Imperialist competitive algorithm. [ABSTRACT FROM AUTHOR]

This paper gives a novel idea of application of fuzzy based UPFC controller for Reactive Power compensation in an isolated hybrid system and also discusses the improvement of stability in the hybrid system. For detailed analysis a small signal linear model of the hybrid wind- Diesel- tidal model is considered with different loading conditions. The reactive power compensation and stability analysis have been thoroughly analysed by a UPFC Controller. A fuzzy logic controller is designed to tune the parameters of UPFC controller. Simulation result shows that the system parameters attend steady state value with lesser time and complexities. [ABSTRACT FROM AUTHOR]

This paper gives a novel idea of application of ANN based SVC controller for voltage stability improvement in an isolated wind-diesel-micro hydro hybrid system. For detailed analysis a small signal linear model of the hybrid wind- Diesel-micro hydro model is considered with different loading conditions. The voltage stability analysis has been thoroughly analysed by a SVC Controller and is further improved by a feed forward neural network with back propagation technique which is designed to tune the parameters of SVC controller. Detailed stability analysis has been done with different criterias like bode, nyquist and eigen value synthesis. Simulation result justifies the working of the isolated systems performance which shows that the system parameters attend steady state value with lesser time and complexities. [ABSTRACT FROM AUTHOR]

This paper gives a novel idea of application of ANN based UPFC controller for Reactive Power compensation in a standalone hybrid power system and thereby enhances the stability of the system .For the Isolated WECS a linear small signal transfer function model of the hybrid wind Diesel model is considered with different loading conditions. The reactive power compensation and stability analysis have been carried out with UPFC Controller with an IEEE exciter I. A feed forward neural network with back propagation technique is designed to tune the parameters of UPFC controller. From the matlab Simulation it is clear that the system parameters attend steady state value with lesser time and complexities. [ABSTRACT FROM AUTHOR]

This paper suggests the application of PSO based SVC controller for Reactive Power compensation and optimisation of an isolated hybrid system consisting of wind diesel and micro hydro system. The small signal linear model of the hybrid wind Diesel micro hydro model is considered with different loading conditions. The reactive power compensation and stability analysis have been carried out with SVC Controller with an IEEE exciter I. The PSO algorithm is used to optimise the SVC controller and a comparison is made with the GA based controller. The system undergoes through variable wind power inputs and uncertain load change. The stability of the system is verified from the eigen value analysis. [ABSTRACT FROM AUTHOR]

This paper focuses on application of intelligent methods behind TCSC controller for Reactive Power compensation in an isolated hybrid system and enhancement of the stability of the system. A small signal linear model of the hybrid PV based microgrid model is considered and simulated for different solar insolations, Wind inputs and with uncertain loading conditions. The reactive power control as well as the stability analysis have been carried out with TCSC Controller .A feed forward neural network with back propagation technique has been designed for tuning the parameters of TCSC controller. Simulation result verify the fact that the system parameters improve by the application of ANN and attend steady state value with lesser time and complexities. [ABSTRACT FROM AUTHOR]

This paper presents a novel methodology for compensating reactive power in a microgrid, having a DFIG based wind-diesel system, to enhance the voltage stability of the hybrid system. UPFC as a FACTS device is proposed in order to improve the control of reactive power mismatch and the stability of the system. A small signal model of the wind-diesel system, DFIG based wind turbine system, UPFC and the controllers are designed for the stability analysis. Further, the voltage variation and reactive power compensation is analysed with the incorporation of proposed ANFIS based UPFC controller. Simulations are performed in MATLAB environment for transient stability analysis in a wind-diesel based microgrid with different wind power input and 2% step increase in load demand. Simulation results illustrate the efficiency and effectiveness of the proposed approach and its impact upon transient behaviour of the microgrid. [ABSTRACT FROM AUTHOR]

Abstract This work describes a number of soft-computing based solar forecasting techniques that facilitate the modelling of newly installed solar cell. The solar cell model is developed and validated against measured data. Prediction of solar radiation of a particular location depends upon number of inputs. So selection of most relevant input parameters is an important task for getting good predictions. The input parameters of the model used in this paper are sunshine duration, temperature, humidity where as the clearness index is considered as an output parameter. The magnitude of active current associated with PV inverter has been finalised by the solar based irradiation. The reactive current associated with the PV based inverter is controlled through the optimised solar radiation. [ABSTRACT FROM AUTHOR]

In this paper, the simulation results of static var compensator (SVC) for improvement of transient stability in a photo voltaic (PV) system integrated power system are presented. A Proportional Integral Derivative (PID) controller was also incorporated with SVC for contributing necessary damping in case of various disturbance conditions. Here, the dynamic stability of the PV based power system was studied in single machine infinite bus (SMIB) and power system. SVC is integrated with the above PV based power system for damping low frequency oscillations produced due to disturbances in the power system. Further a novel soft computing based approach called quasi-oppositional differential search algorithm (QODSA) was for designing an optimal SVC-PID based damping controller. Initially DSA was applied for optimizing the gains of the controller and finally quasi oppositional learning was incorporated to DSA for obtaining the optimal parameters of SVC-PID controller and also for enhancing the convergence speed. The effectiveness of the proposed technique was also tested with particle swarm optimization (PSO) technique. Transient stability analysis for conventional PID controller, PSO based PID controller, DSA based PID controller and QDSA based PID controller was done analytically as well as quantitatively. It can be observed from the simulation results that the proposed QDSA based PID controller outperforms over other techniques in improving power system stability and also damping low frequency oscillations. [ABSTRACT FROM AUTHOR]

Solar energy is going to play a measure role in the future global energy supply. Its acceptance has already been on rise in developing countries like India, where there is acute shortage of energy due to economic and other climatic reasons. Forecasting or predicting the future output of solar energy is a much needed step to integrate high insolation of solar energy to the nation's power grid. Due to the fluctuating nature of solar energy, an efficient use is possible depending on reliable forecast information and its availability in various time and spatial scales. The current status of forecasting of solar irradiance for energy generation proposes a review of solar radiation prediction and its application in a rapidly increasing economy like India. Various models are developed for analysis which can be developed either by empirical, soft computing or by simulation approach. [ABSTRACT FROM AUTHOR]

• A Cyber-resilience based frequency regulation study is proposed in this paper. • To make the test system more realistic, different uncertainties such as solar insolation, wind. • Speed pattern, and random load changes are considered. • An adaptive type-2 fuzzy logic control method is applied, whose performance is being Compared with type-1 fuzzy logic. • IT Achieves robust frequency regulation under load change, uncertainties and cyber-attacks. • The proposed model is also validated through real-time digital simulator opal-rt. Cyber-physical attacks and parameter uncertainties are becoming a compelling issue on load frequency control, directly affecting the resilience (i.e., reliability plus security) of the microgrid and multi-microgrid systems enabled by internet of things and the fifth generation communication system. A resilient system aims to endure and quickly restore a system's transients during extreme events. Therefore, it is critically important to have a resilient system to evade the total system failure or blackout in order to make them attack-resilient. With this objective, this paper presents a resilience-based frequency regulation scheme in a microgrid under different operating conditions, such as, step and random change in load and different wind speed patterns. Furthermore, a cyber-attack model is considered in the problem formulation to make the system robust against external attacks. To protect against the cyber-attack and parameter uncertainties in the system, different control schemes are employed, and their robustness characteristics are compared through various performance indices. Besides, the proposed control schemes are validated through a real-time software synchronisation environment, i.e., OPAL-RT. As noted, the proposed type-2 fuzzy proportional-integral-derivative based controller provides the most significant improvement in the dynamic performance for frequency regulation compared to that of the others under the cyber-attack and uncertainties. [ABSTRACT FROM AUTHOR]

• First, we summarize the concept of SST with design principles, including converters, switches, and other components. • In addition, the applications of SST for power distribution systems, traction locomotives, and electric vehicles are discussed. • The various topologies of SST are also discussed and reported in tabular forms. • Further, SST outcrop suchlike reliability, resiliency, and stability using SST are presented. The modern power systems have now prompted the practice of power electronics-based converters for power conversion purposes, which has emerged a solid-state device named as solid-state transformer (SST). It provides the isolation between low/medium-voltage ports with a high-frequency transformer (HFT), and in addition, it facilitates controlling the active and reactive power automatically through power converters. With this objective, the SST is projected as an essential device for smart/microgrids, particularly in multi-microgrid systems, to enhance modern distribution systems' resiliency. This study explores how it is beneficial to the distribution systems in regards to the reduction of size, controllability, reliability, resiliency, and end-use applications. Moreover, the different component types and broad applications have also been discussed pertaining to their characteristics. Lastly, the conclusion gives a brief summary, and the possible direction of future research is presented, which will be useful for researchers and engineers working in future microgrids and smart grids. This review will guide to select appropriate components to develop an SST for a particular application. [ABSTRACT FROM AUTHOR]