Prakash K. Ray

FogGIS: Fog Computing for geospatial big data analytics

Cloud Geographic Information Systems (GIS) has emerged as a tool for analysis, processing and transmission of geospatial data. The Fog computing is a paradigm where Fog devices help to increase throughput and reduce latency at the edge of the client. This paper developed a Fog Computing based framework named FogGIS for mining analytics from geospatial data. It has been built a prototype using Intel Edison, an embedded microprocessor. FogGIS has validated by doing preliminary analysis including compression and overlay analysis. Results showed that Fog Computing hold a great promise for analysis of geospatial data. Several open source compression techniques have been used for reducing the transmission to the cloud.

Self tuned Fuzzy-PI based reactive power compensation in wind-diesel hybrid system

Self tuned Fuzzy logic based PI controller is developed in this paper to regulate the reactive power of a decentralized wind-diesel hybrid power system under different disturbance conditions. The study incorporating small signal analysis has been taken. The linearized model of wind, diesel is used where IEEE Excitation system (type-1) with synchronous generator is taken into account. Due to the abrupt load changes and sporadic nature of wind, reactive power and voltage stability problem occur. For the above problem, a Auto tuned Fuzzy Logic PI (STFLPI) controller is designed, which automatically tunes the coefficients of PI controller (KP and Ki). From Simulation it shows that the proposed controller attains the steady state value with less settling time and overshoot for a wide and unpredicted load changes and thereby proves its superiority.

Reactive power compensation using PSO controlled UPFC in a microgrid with a DFIG based WECS

This article represents the reactive power compensation issue with the help of FACTS controller and transient stability analysis in a Wind-Diesel hybrid power system. DFIG is widely used due to its simplicity and high efficiency in wind energy generation system. Back to back converters are employed in DFIG based Wind Energy Conversion System (WECS) with proper active and reactive power control strategy. Mathematical model of the proposed hybrid system with Unified Power Flow (UPFC) controller is developed to compensate the reactive power in the proposed system. The mathematical model of UPFC is employed for transient stability analysis of hybrid system with incorporation IEEE type 1 excitation system. The analysis of the proposed system is performed with varying loading conditions. A comparison based on simulation is then performed between PI controlled UPFC and PSO controlled UPFC.

Swarm and bacterial foraging based optimal power system stabilizer for stability improvement

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.

Fuzzy Sliding Mode Based Series Hybrid Active Power Filter for Power Quality Enhancement

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.

Detection and location of fault in a micro grid using wavelet transform

The main objective of utility companies is continuous power supply which motivates them for the quick detection and location of faults occurring in a power system. Fault analysis of different fault condition is a difficult task in a Hybrid power system. The wavelet transform is used for the detection and location of fault taking place in a hybrid power system. For proper fault analysis, exact location of the fault distance from the source and type of fault information is very much essential. The proposed model used in this paper is a hybrid combination of wind energy and photovoltaic generation system. For detecting the fault voltage signals are extracted and passed through wavelet transform. Detailed information about the faulted signal is received. The wavelet transform has the special property of time-frequency resolution, from which we can detect the fault. In this paper wavelet transform (WT) is used for determining the location and detection of fault. For clearing the fault in less time detection and location of fault are two important tasks for a power engineer. All the signals are analyzed using the wavelet transform toolbox after selecting the suitable wavelet level. From the analyzed signal the pre fault and post fault coefficients are derived. The fault detection and location study are simulated in MATLAB/Simulink for a typical power system.

Islanding detection in a hybrid power system using continuous wavelet transform

Now a days, Distributed Generation is taking an important part in power systems. In the present scenario distributed generation has given lot of importance in energy systems. With the contribution of the distribution of energy to power generation, the impact on the power system becomes more apart. Now the island has become a major problem in the use of distributed generators (DGs)in the power systems. The increase in the Distributed Generator(DG) in the power system causing major issue of islanding. This condition is referred to as an isolated condition when a portion of the distributed system is electrically separated from the rest of the systems and the DG in the isolated portion continues to power the local load. When DG(s) continues to supply power to a separated power network and another part of it becomes electrically isolated from the power network, this frequent phenomenon is called as Islanding condition. In this paper, in order to detect the islanding effect in distributed generation, we use the wavelet transform components of current and voltage. In this work, we used continuous wavelet transforms which are caused by negative sequence components of voltage and current for the indication of islanding in distributed generation. When the detailed coefficients at level 1(d1) clearly isolate the event, further detection of the island condition.

Enhancement of power quality disturbances using hybrid power filters

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.

MATLAB/Simulink based FA for optimizing TCSC controller in a power system

An interconnected power system, the real transfer of power form one area to another might take inadvertent routes depending on impedances of transmission lines connecting the regions. Thyristor controlled series capacitor (TCSC) provides capable of increasing power transfer level and controlling a system. In particular TCSC have been widely used considered as a dynamical device and is also being used to reduce SSR (Sub synchronous resonance). In the present work, a systematic procedure of a MATLAB/Simulink-based modelling, simulation and optimal tuning of the parameters of a TCSC controller, it is possible to operate at stable power levels well exceeds those for which the system was formerly designed without risk in system stability. In dynamic application by using TCSCs, different control techniques and designs have been proposed in an optimization problem. A comparative study of remote input signal corresponding to speed deviation is employed by using Firefly Algorithm (FA) and Differential evolution (DE) optimization. In this study the performance of TCSC controller is analyzed with proper selection of objective function and optimum value of controller parameter and simulation results are shown. The proposed model of the system is used to represent under various loading and perturbations are studied and compared.

Bacterial foraging optimized STATCOM for stability assessment in power system

This paper presents a study of improvement in stability in a single machine connected to infinite bus (SMIB) power system by using static compensator (STATCOM). The gains of Proportional-Integral-Derivative (PID) controller in STATCOM are being optimized by heuristic technique based on Particle swarm optimization (PSO). Further, Bacterial Foraging Optimization (BFO) as an alternative heuristic method is also applied to select optimal gains of PID controller. The performance of STATCOM with the above soft-computing techniques are studied and compared with the conventional PID controller under various scenarios. The simulation results are accompanied with performance indices based quantitative analysis. The analysis clearly signifies the robustness of the new scheme in terms of stability and voltage regulation when compared with conventional PID.