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Three phase shunt active power filter (SAPF) using multilevel inverter (MLI) is implemented in this paper for a grid integrated solar photovoltaic (PV) system for eliminating the harmonics. The obj...

A novel switching pulse generation methodology based on adaptive fuzzy hysteresis current controlled hybrid shunt active power filter (A-F-HCC-HSAPF) is presented in this paper for compensating reactive power and harmonics in distribution network. The harmonic problems are mainly evolved because of extensive use of nonlinear loads in industry and domestic sectors. There are some adverse effects of harmonics such as: malfunctioning of sensitive equipment, resonance issues, conductors heating, power losses and reduced efficiency in distribution system. To mitigate harmonics issues passive, filters are used but when the harmonic component increases the design of passive filters is complex and becomes bulky. With the advancement in power electronic, the active power filter has been designed. Generally, the rating of the active filter is very high for some applications; hence hybrid shunt active power filter (HSAPF) is proposed by low-rated shunt active power filter (SAPF) and low-cost shunt passive filter. Proportional-integral or fuzzy logic controller is used to estimate the reference current and to regulate the dc capacitor voltage. To generate the switching pulse for the voltage source inverter of the SAPF, a novel adaptive fuzzy hysteresis current controller (A-F-HCC) is adopted. The performance of the proposed A-F-HCC-HSAPF is investigated during steady-state and transient conditions using MATLAB/Simulink and real-time environments.

This paper presents a Hybrid Shunt Active Power Filter (HSAPF) optimized by hybrid Particle Swarm Optimization-Grey Wolf Optimization (PSO-GWO) and Fractional Order Proportional-Integral-Derivative Controller (FOPIDC) for reactive power and harmonic compensation under balance and unbalance loading conditions. Here, the parameters of FOPID controller are tuned by PSO-GWO technique to mitigate the harmonics. Comparing Passive with Active Filters, the former is tested to be bulky and design is complex and the later is not cost effective for high rating. Hence, a hybrid structure of shunt active and passive filter is designed using MATLAB/Simulink and in real time experimental set up. The compensation process for shunt active filter is different from predictable methods such as (p-q) or (id-iq) theory, in which only the source current is to be sensed. The performance of the proposed controller is tested under different operating conditions such as steady and transient states and indices like Total Harmonic Distortion (THD), Input Power Factor (IPF), Real Power (P) and Reactive Power (Q) are estimated and compared with that of other controllers. The parameters of FOPIDC and Conventional PID Controller (CPIDC) are optimized by the techniques such as PSO, GWO and hybrid PSO-GWO. The comparative simulation/experiment results reflect the better performance of PSO-GWO optimized FOPIDC based HSAPF with respect to PSO/GWO optimized FOPIDC/CPIDC based HSAPF under different operating conditions.

This article focuses on the implementation of a hybrid firefly algorithm-particle swarm optimization (FAPSO) scheme for optimizing the parameters of an interval type-2 fractional order fuzzy proportional integral derivative (IT2FOFPID)-based power system stabilizer (PSS) to minimize the low-frequency oscillations in a power system. Here, the IT2FOFPID-based PSS is designed by considering speed deviation and acceleration as input signals. In this article, a single machine infinite bus system and the New England 10 machine 39-bus power system are used for testing and comparing the approaches. Stability studies are also performed using OPAL-RT's OP5600, a real-time digital simulator. The comparative studies demonstrate that the hybrid FAPSO optimized IT2FOFPID-PSS provides better damping and stability performance when compared with the PSSs based on the FA/PSO/ hybrid genetic algorithm and bacterial foraging optimization and hybrid differential evolution and pattern search optimized IT2FOFPID approaches under various operating scenarios.

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.

In this paper, a multilevel inverter based shunt hybrid active filter is used, which is composed of passive filter and shunt active filter, used for enhancing the quality of power, by reducing the total harmonic distortions below 5% as per IEEE-519 standard and managing the reactive power as well as correcting the power factor. The objective of this paper is to advance the power quality by reducing the harmonic distortions in the distribution line, which are affected because of utilising non-linear loads across the load end. For reference current generation and for controlling the switching signal, conventionally PI controller was used with different reference signal detection techniques. But with the evolution of different intelligence approaches, made more advantageous than the PI controller. In this paper, two artificial intelligence methods, i.e, artificial neural network and adaptive neuro-fuzzy interference system (ANFIS) are applied. Comparison of the results of the proposed methods is analysed using MATLAB/ SIMULINK tool. For reference current generation, synchronous reference frame theory is used and hysteresis current control technique is employed for generating the gating signal.

In this paper, a three-phase series hybrid active filter (SEHAF) interconnected with photovoltaic (PV) system and dc–dc boost converter is proposed to minimize sag, swell, and harmonics caused due to nonlinear power electronic loads. The SEHAF consists of a voltage source inverter (VSI) with a capacitor connected across it to provide consistency in managing and compensating the reactive power. This minimizes the sag, swell, and harmonics present in the source and load voltages. With the integration of PV, the voltage across the dc-link capacitor of VSI is controlled effectively, which helps in better compensation. Reference current generation is done using the proposed robust extended complex Kalman filter (RECKF) technique. The performance of the PV-integrated-HAF is analyzed using a synchronous reference frame with proportional-integral (PI) as well as fuzzy logic controller (FLC) and is compared with the proposed RECKF technique. The PV-integrated hybrid power system is developed using MATLAB/SIMULINK. Further, real-time digital simulation using OPAL-RT OP5142 is also carried out to support the simulation results. It is observed that the proposed control scheme provides better harmonic compensation compared to conventional PI and FLC.

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.

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.

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.

A comprehensive review on stability analysis in multimachine power system is presented in this study. The increasing demand of power has led to the expansion of power system and complexity in design as well as operation. This threatens to deteriorate the stability and reliability in the power network. However, with the advances in semiconductor and power electronic control technology, various flexible AC transmission systems (FACTS) are designed to enhance the power system stability. Different power system configurations with the incorporation of conventional and distributed generations (DGs) are proposed whose stability is being tested in the presence of the FACTS controllers. The optimal damping of power system oscillations under transient operating conditions are studied in presence of HVAC and HVDC links with conventional as well as DG systems and energy storage options like battery, supercapacitors and so on. Different control approaches such as classical control, robust control, wide-area control along with soft computing approaches like neural networks, fuzzy logic control, adaptive neuro-fuzzy inference system, genetic algorithm, particle swarm optimisation and so on are broadly discussed. A comparative analysis of different methodologies is presented to establish a quick survey of the proposed solutions for stability enhancement.

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.

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.

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.

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.

It is necessary to detect the fault disturbances as quick as possible to improve performance of microgrid. Keeping an eye to the above issue this paper introduces a novel technique for the detectio...

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.

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.

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.

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.

This study attempts to measure the relative debt burden of 18 major states of India by grouping them into high-, middle- and low-income states for the post– Fiscal Responsibility and Budget Management (FRBM) Act, 2003 period (from 2005–2006 to 2018–2019) through developing a new debt burden index (DBI) using the relative-distance method. Data are sourced from ‘Handbook of Statistics on Indian States’ published by the Reserve Bank of India (RBI). Using DBI, the study shows the interstate variations in debt burden and thereby compares debt management across the states. The analysis reveals that the debt burden has been consistently declining in the case of low-income states, whereas it has been increasing for both middle- and high-income states. DBI may be used as an important input for the credit rating for State Development Loans (SDLs).

This paper projects an isolated hybrid model of Offshore wind-diesel-tidal turbine and discusses the stability and reactive power management issue of the whole system. The hybrid system often loses its stability as it becomes prone to uncertain load and input parameters and therefore the necessity of Reactive power management becomes necessary. The overall stability of the hybrid offshore wind-diesel-tidal turbine is made possible by the management of reactive power in the hybrid system through the application of FACTS devices. And therefore the dynamic hybrid model of the DFIG and DDPMSG based offshore wind-diesel-tidal turbine is analysed for stability with different input parameters like wind and tidal energies. For detailed modelling and simulation, a small signal model of the whole hybrid system is designed and reactive power management of the system is achieved by the incorporation of a STATCOM controller. For improvement of stability and reactive power compensation of the hybrid system, GA and PSO optimised STATCOM controller is used.

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.

This study presents a comparative study of transient stability and reactive power compensation issues in an autonomous wind–diesel-photovoltaic based hybrid system (HS) using robust fuzzy-sliding mode based unified power flow controller (UPFC). A linearised small-signal model of the different elements of the HS is considered for the transient stability analysis in the HS under varying loading conditions. An IEEE type 1 excitation system is considered for the synchronous generator in the HS, with negligible saturation characteristic, for detailed voltage stability analysis. It is noted from the simulation results that the performance of UPFC is superior to static VAR compensator and static synchronous compensator in improving the voltage profile of the HS. Further, fuzzy and fuzzy-sliding mode based UPFC controller is designed in order to improve the transient performance. Simulation results reflect the robustness of the proposed fuzzy-sliding mode controller for better reactive power management to improve the voltage stability in comparison with the conventional PI and fuzzy-PI controllers. In addition to this, system stability analysis is performed based on eigenvalue, bode and popov for supporting the robustness of the proposed controller.

This paper focuses on reactive power management as well as stability enhancement in a standalone hybrid power system (SHPS) with a proposed back stepping sliding mode controller based STATCOM. A comprehensive dynamic model of the standalone hybrid power system(SHPS) having a combination of wind turbine generator, diesel engine backup and storage device is represented with its control scheme. Detailed model of the DFIG based wind energy conversion system (WECS) has been proposed for the SHPS and is experimentally analyzed through dSPACE DS1104 for transient stability improvement with variable load dynamics. At the beginning a sliding mode controlling approach has been implemented for the non linear standalone power system and later a back stepping sliding mode controller (BSSMC) approach is initiated for both rotor and grid side converters. Further studies regarding voltage stability have been implemented with Eigen value, bode and nyquist analysis.

In the present scenario of power system network, active filter are being designed using advanced technology for compensating harmonics and reactive power for better quality of power supply. The present paper implements a Shunt Hybrid Active Filter (SHAF), necessary for reactive power compensation in the nonlinear load and suppresses harmonics for improving the power quality (PQ) in the distribution network. In this work, an adaptive linear neuron (Adaline) based variable step size leaky least mean square (VSSLLMS) control approach is applied for extracting harmonics. This competent approach is needed for generating the gating pulses essential for IGBT inverter and increasing the performance compared to the conventional Adaline-LMS controller. The proposed controller provides faster convergence and also provides better performance compared to conventional one. Simulation results show the significant improvement in Adaline-VSSLLMS approach compared to Adaline-LMS approach. The simulations of the proposed controller and system is done using MATLAB/ SIMULINK under different load conditions.

Interconnected power systems require more intelligent and flexible ways to balance and monitor a generation load. Power generated from single source is becoming less reliable and therefore, movement from single energy source to hybrid system has been preferred in recent time. Inclusion of renewable energy sources in automatic generation control (AGC) is a major concern on account of intermittent nature of renewable energy sources. In this work, we intend to study an AGC with diversified renewable energy sources (RES) integrated such as solar and wind in association with thermal reheat system. In the present work an AGC with hybrid thermal-solar and thermal-wind power generation system is simulated. The AGC is studied with traditional Proportional Integral Derivative (PID) controller and Fractional order PID (FOPID) controller. The gains of the FOPID controller are optimized by firefly algorithm (FA) algorithm. Further, the performances of all the controllers have been investigated and compared based on which it is suggested that FA optimized FOPID controller is showing much better performance amongst all other controllers. In addition to that, sensitivity analysis is performed using various loading and parameter variation to access the robustness of the proposed controllers. The study reveals that, the system performance is better using FA optimized FOPID controller with different solar radiation and different wind speed. Finally, to validate the proposed hybrid system the real time hardware in-the loop (HIL) emulation is carried out using Typhoon HIL 402.

This paper presents an improvement in stability in a single machine connected to infinite bus power system by designing an optimal fractional order fuzzy PID based power system stabilizer (FOFPID-PSS). The low frequency oscillations resulting from load switching are damped out by the designed PSS under different operating conditions. In this paper, a bio-inspired algorithm called firefly algorithm (FA) has been employed for tuning the parameters of the proposed FOFPID-PSS controller. The robustness of the proposed controller is tested for enhancing the transient stability under different operating conditions like step and random variations in load demand. In addition to the graphical results, a comparative analysis of the proposed FOFPID-PSS controller with that of conventional PID-PSS and fuzzy PID-PSS (FPID-PSS) is also presented in terms of the performance indices (PIs) like maximum overshoot, settling time and integral squared error (ISE). The results suggest that the proposed FOFPID-PSS outperforms the FPID-PSS and PID-PSS controllers.

This paper presents a Hybrid Active Filter (HAF) used in the distribution network and is required for compensating reactive power in the load end and mitigate harmonics for the improvement of power quality. The compensation process used in this paper reduces number of sensors and also reduces the complication and depends on source current extraction. Initially for extraction of reference currents from harmonics surrounded line current, the Proportional-Integral (PI) or Fuzzy Logic Controller (FLC) is used, which controls the dc-link voltage of the inverter. The HAPF is designed with the use of Voltage Source Inverter (VSI). In this paper, an innovative approach called robust extended Kalman filter (RECKF) is implemented for reference current estimation/calculation using model predictive current (MPC). This RECKF-MPC essentially requires less number of voltage sensors and also overcome the problems associated with PI controllers like gain tuning. The new RECKF with MPC is compared with conventional PI and FLC and observed to be providing better performance to improve the power quality.

This paper presents frequency control in a hybrid two-area power system which is a combination of conventional and renewable energy resources (RES). Area-I consists of thermal with solar, while area-II contains thermal integrated with wind energy. As RES are intermittent in nature, load frequency control (LFC) is a challenging issue in hybrid power system where thermal power stabilizes the power management to maintain the system frequency. This paper proposes differential evolution (DE) optimized proportional-integral-derivative (PID) controller to achieve frequency control in the hybrid power system. The frequency control study is performed in different configurations of power system simulated using LabVIEW software. The efficacy of the proposed controller is also investigated using the performance indices such as deviation in frequency, integral time absolute error (ITAE), peak over/under shoots and settling time. Based on the on the simulation study, it is observed that DE optimized PID controller perform better in comparison to that of the conventional PI, PID controllers.

The present paper examines the causal nexus between public debt and economic growth for 15 NSC states of India for the period 1991-2015 using Dumitrescu Hurlin causality test. The panel causality test identified the endogeneity issue as it revealed the bidirectional causality between these two variables. Further, we revisited the effect of public debt on economic growth for NSC states for the same period by incorporating other controlled variables in the model. Understanding the potential endogeneity issue, we employed FMOLS which solves the endogeneity as well as serial autocorrelation problem in the model. The results of the present study revealed that public debt, total revenue receipts and total credit have favorable effect on economic growth. As regards policy implications, the government should adopt proper tax reform strategies to minimize tax leakages. Further, it should implement effective credit and risk management practices to improve the asset quality. Lastly, suitable debt management strategy should be adopted to utilize debt in the most effective and proficient way to expand productivity capacity of the economy. This, in turn, will sustain high economic growth in India.

Nowadays, power quality is one of the sensitive issues considered in power system. In order to develop this superiority of power, the disturbances present in the signal have to be eliminated. This disturbance is nothing but the harmonics which was traditionally filtered out by the use of passive filter, and later on it claims superiority by use of active power filter due to certain problems raised in passive filters like resonance and fixed compensation. Particularly, the hybrid active power filter is used to eliminate the harmonics present in the fundamental signal and also compensates reactive power. In this paper, methods like instantaneous power theory (p-q) and synchronous reference frame theory (id-iq) are used to calculate the compensating current. Both the above methods are simulated with help of PI and fuzzy controller for different voltage conditions. The obtained results show the active behavior of fuzzy logic controllers over PI controllers.

Ergonomic design of a product considers design, cognitive and behavioral information during the design stage with a view to improve the comfort level of the user and aesthetic look of the product. However, a large number of products are available in the market place possessing a wide range of features to address the ergonomic considerations. Many times, the features may be redundant and hardly enhance interaction between the user and the product leading to user dissatisfaction. But few important features focusing its functionality and physical comfort can possibly address the usability of product and improve satisfaction level of the user. This paper proposes a fuzzy multi-attribute decision making (MADM) approach integrating both subjective and objective weights for each criterion so that superior ergonomically designed product can be evaluated. The methodology is explained with the help of an example of selection of an office chair. Three popular approaches have been considered to compare the ranking of alternatives. Keywords: Multi-attribute decision making (MADM), TOPSIS (Techniques for Order Preference by Similarity to Identical Solution), VIKOR (VIseKriterijumska Optimizacija I Kompromisno Resenjea), PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluations)

This paper presents design of power system stabilizer (PSS) based on conventional fuzzy-PID and type-1 fuzzy controller for stability improvements in single as well as multimachine power system connected to infinite bus under different loading conditions. Again, fuzzy and integral sliding mode controllers (FSMC and I-SMC) are being incorporated with PSS into the power system to improve the stability performance. But, the presence of chattering in this controller may lead to low frequency oscillations of smaller magnitudes that can sustain to disturb the power transfer capability and the stability of the system. Therefore, to enhance the performance and efficiency of the power system, a novel adaptive fuzzy sliding mode controller with a robust sliding surface is designed to overcome the possible chattering due to system uncertainties and dynamics. In the proposed adaptive fuzzy sliding mode controller (AFSMC), the stability is ensured through Lyapunov analysis and synthesis test. In addition to the graphical simulation analysis, a quantitative stability approach and real-time test using OPAL-RT OP5600 is also carried out in order to augment the stability study. Further, stability test using eigen modes, root locus and Bode plots are presented to assess the stability performance of the proposed controller. Both the qualitative and quantitative analysis ensures better and robust performance of proposed controllers in comparison to the conventional fuzzy-PID and type-1 fuzzy controller.

Fast detection of islanding is very important for effective operation and control in distributed generation (DG) penetrated distribution networks. The islanding detection techniques such as passive, active, communication, and hybrid have their own merits and demerits. This paper proposed wavelet transform (WT) and wavelet packet transform (WPT) based techniques for detection of islanding and fault disturbances in a microgrid consisting of resources like wind turbine generator, fuel cell (FC), and microturbine. Voltage signal is extracted at the point of common coupling (PCC) and is passed through these detection techniques to obtain the time-frequency multi-resolution analysis. Further, to validate the graphical study, performance indices (PIs) like standard deviation and entropy are calculated for the disturbance detection using suitable selection of threshold. A comparative analysis using WT and WPT is presented in the form of graphical simulation as well as in terms of PIs to analyse their effectiveness and robustness under different operating conditions. It is observed that WPT shows better detection capability in comparison to WT even under 20-dB noisy scenarios. National Research Foundation (NRF) Accepted version Authors acknowledge the support for research from the National Research Foundation, Prime Minister’s Office, Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) programme.

This paper contributes an innovative gating signal generation technique based on fuzzy sliding mode pulse width modulation (FSMPWM) with a Series Hybrid Active Power Filter (SEHAPF) for reducing the total harmonic distortion (THD). Hybrid filters are used for compensating reactive power on the load side and mitigate harmonics for the growth of power quality under variable source and load conditions in the utility system. The objective of the paper is to eradicate the various power quality (PQ) problems with development in power factor and reducing distortion in transmission and distribution line due to harmonics. With the implementation of FSMPWM of the proposed filter, the gating pulses are generated by implementing a Mamdani fuzzy rule with sliding surfaces. For producing a fixed pulse the presented method reduces the chattering reaction by controlling the narrow boundary coating on the sliding surface. The results of the projected technique are analyzed and compared with the traditional hysteresis band current controller (HCC). The overall proficiency and results are examined with the help of MATLAB/SIMULINK environment.

Improvement of power quality (PQ) has became an essential aspect in current situation of power system. Conventionally power quality improvement was done through passive filters, shunt filter and series filter but they suffer from problems like resonance, fixed compensation and other PQ problems. Therefore in order to eradicate these issues some hybrid combination of filters including passive and active power filter (APF) are used. This paper proposes an analysis and comparative study of two different schemes of hybrid active power filter (HAPF). HAPF is configured with the arrangement of series, passive and shunt filter. One arrangement is modeled with shunt passive filter linked in series with shunt active filter and the other is designed with series active filter and shunt passive filter. For both the schemes of hybrid filter, different control strategy and power circuit design are considered. Finally for individual configuration the control and compensation design is proved by simulation.

This paper presents frequency regulation in a microgrid consisting of wind, photovoltaic (PV), fuel cell (FC) and diesel engine generator (DEG) along with the energy storage system such as flywheel energy storage (FES) and battery energy storage (BES). In this study, firefly and particle swarm (FF–PSO) based hybrid optimization technique is proposed to tune parameters the proportional–integral–derivative (PID) controller to minimize the frequency deviation in microgrid system under different operating conditions such as variation in wind speed, and load demand. Further, a comparative analysis for tuning of the PID controller is performed using particle swarm optimization (PSO), and firefly algorithms (FFA) to minimize the deviation in frequency. The power management as well as frequency control in microgrid is studied with the help of the performance indices; integral absolute errors (IAE), peak overshoots, settling times and standard deviation (SD). In addition, the effect of communication delay with higher non-linearity is tested to assess the performance of the controllers. Further, the frequency control is validated in real-time digital simulation environment using OPAL-RT. The qualitative, quantitative and real-time analysis reflects the improvements in frequency deviation in microgrid using the proposed hybrid FF–PSO optimized PID as comparison to the PSO/FF optimized PID controllers.

This paper suggests a non linear fuzzy sliding mode UPFC controller to enhance reactive power and transient stability of isolated wind-diesel-fuel cell hybrid power system (HPS). Fuzzy sliding mode controller (FSMC) gives an improvised response to the controller by interchanging the sliding surface adjacent to the error trajectory and in this way avoids the state errors for hitting the sliding surface. The modified controller improves the system performance enhances the system working performance despite variations of different parameters like wind, fuel power inputs and load variations. To validate the worthiness of the said controller the system has been simulated just after the transient disturbances and at different operating points. Results with conventional controller have been compared with Fuzzy sliding mode controller and results relating to voltage stabilization, damping of power oscillation and transient stability are collected.

This paper presents a robust power system stabilizer (PSS) based PID controller for study of stability in a single-machine-infinite-bus (SMIB) power system. The PID controller gains are optimized by bacterial foraging optimization (BFO) and particle swarm optimization (PSO) for improvement of system stability in SMIB system. The robustness of the controller was tested under different operating conditions and their performances are being compared with the conventional PSS-PID controller. In addition, their effectiveness are also investigated through the performance indices like Integral Squared Error (ISE), peak overshoot and settling time. Further, stability of the power system is evaluated by bode plot and mean squared error curve of the proposed optimization techniques. It is observed from the simulated results that PSO based PSS-PID controller provide better performance and stability as compared to BFO optimized PSS-PID and conventional PSS-PID controllers under different operating scenarios.

Energy being a major factor of production plays a pivotal role in inducing a sustained and high economic growth of an economy. This paper attempts to examine the Vector Autoregression (VAR) based Granger causality between billing efficiency and growth rate of per capita Gross Domestic Product (GDP) of India using annual time series data for the period 1970-71 to 2014-15. The conventional Augmented Dicky-Fuller and Phillips-Perron tests reveal that both the series are non-stationary and individually integrated of order one. Johansen-Juselius cointegration approach finds no evidence on the long-run equilibrium association between these variables. However, the VAR - based Granger causality approach reveals unidirectional causality running from billing efficiency to economic growth without any feedback effect. As regards policy implication, implementation of both the short term and long term measures in improving billing efficiency, through the enhancement of commercial and operational efficiency in electricity distribution sector will undoubtedly aid in achieving sustained and high economic growth in India.