Asit Mohanty

Small-Signal Analysis of Hybrid Distributed Generation System with HVDC-Link and Energy Storage Elements

A small-signal analysis of isolated autonomous hybrid system with high voltage direct current link (HVDC) or high voltage alternating current (HVAC) line for different energy storage combinations is proposed in this paper. The hybrid systems supplying power to isolated loads comprise of different renewable energy resources such as wind, photovoltaic (PV), fuel cell (FC) and diesel engine generator (DEG) along with the energy storage devices such as flywheel energy storage system (FESS), battery energy storage system (BESS).Ultracapacitor (UC) is incorporated as an energy storing element in order to improve the hybrid system performance. A comparative assessment for deviation in frequency profile for different hybrid systems in the presence of different storage system combinations is carried out which reflects the improvements of the deviation in frequency profile in the presence of the ultracapacitors (UC) as compared to other storage elements.

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.

Power quality improvement in 3-Φ grid connected photovoltaic system with battery storage

The paper presents a study of power quality (PQ) improvement in a 3-Φ grid connected photovoltaic (PV) system. The variable step perturb & observe (VS-PO) maximum power point tracking (MPPT) scheme has been used to force the PV generation reach the maximum power operation. A battery energy storage system (BESS) via a bi-directional DC/DC converter is introduced in the DC bus to maintain the DC bus voltage level at a constant value. A 3-Φ hybrid filter is connected into the utility grid to compensate the reactive power and the load current harmonics, generated by the non linear load. Control strategy of hybrid filter is based on the vectorial theory dual formulation of instantaneous reactive power. The performance study is simulated under variations of solar insolation and loads.

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.

Impact of Fuzzy Logic Based UPFC Controller on Voltage Stability of a Stand-Alone Hybrid System

The main focus of the paper is to compensate the Reactive Power generated in the isolated wind–diesel hybrid system and enhancement of the Voltage stability by the use of Fuzzy PI based UPFC Controller. Linearised small signal model of the wind-Diesel System with different loading conditions is taken with IEEE Excitation system. In this paper the compensation has been carried out with UPFC Controller for different loading conditions. A self tunned Fuzzy PI controller is designed to tune the parameters of PI Controller Kp and Ki. Simulation result shows that the parameters of the system attend steady state value with less time due to the proposed controller.

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.

Fault Detection in IEEE 14-Bus Power System with DG Penetration Using Wavelet Transform.

Wavelet transform is proposed in this paper for detection of islanding and fault disturbances distributed generation (DG) based power system. An IEEE 14-bus system with DG penetration is considered for the detection of disturbances under different operating conditions. The power system is a hybrid combination of photovoltaic, and wind energy system connected to different buses with different level of penetration. The voltage signal is retrieved at the point of common coupling (PCC) and processed through wavelet transform to detect the disturbances. Further, energy and standard deviation (STD) as performance indices are evaluated and compared with a suitable threshold in order to analyze a disturbance condition. Again, a comparative analysis between the existing and proposed detection is studied to prove the better performance of wavelet transform.

Detection of Faults in Power System Using Wavelet Transform and Independent Component Analysis.

Uninterruptible power supply is the main motive of power utility companies that motivate them for identifying and locating the different types of faults as quickly as possible to protect the power system prevent complete power black outs using intelligent techniques. Thus, the present research work presents a novel method for detection of fault disturbances based on Wavelet Transform (WT) and Independent Component Analysis (ICA). The voltage signal is taken offline under fault conditions and is being processed through wavelet and ICA for detection. The time-frequency resolution from WT transform detects the fault initiation instant in the signal. Again, a performance index is calculated from independent component analysis under fault condition which is used to detect the fault disturbance in the voltage signal. The proposed approach is tested to be robust enough under various operating scenarios like without noise, with 20-dB noise and variation in frequency. Further, the detection study is carried out using a performance index, energy content, by applying the existing Fourier transform (FT), short time Fourier transform (STFT) and the proposed wavelet transform. Fault disturbances are detected if the energy calculated in each scenario is greater than the corresponding threshold value. The fault detection study is simulated in MATLAB/Simulink for a typical power system.

Interval system analysis and PID-PSO control of boost converter for uncertain load parameter

This paper deals with the characteristics of a Boost Converter in the presence of uncertain load parameters. An Interval System analysis is adopted to evaluate the interval extension of load parameters and then a PID controller is designed using Particle Swarm Optimization(PSO). The PID-PSO controller meets the requirement of robust design and the design specification is satisfied over the entire parameter set. The particle swarm optimization (PSO) method is used to determine near optimum PID controller parameters assuring improved response for uncertain load parameters. Here, all the analyses have been done for continuous conduction mode (CCM) mode of operation and simulation results are plotted in MATLAB.

Integrating Concentrating Solar Plant-Based System in Multi-area AGC Using LabVIEW

An attempt has been made to analyze the model of automatic generation control (AGC) of a two unequal interconnected deregulated power systems using LabVIEW. In this study, teaching–learning process-inspired algorithm, i.e., TLBO is employed for tuning the gains of PID controller. This study portrays the investigation of an AGC for two-area power system with PID, DE-based PID, and TLBO-enhanced PID. The execution of TLBO-PID is discovered and enhanced in contrast with PID, DE-PID controller as far as stability, overshoot, and damping. The inclusion of generation rate constraint (GRC) leads to difficult task for the design of successful controller. The difficulty is improved by step and random load variation. Examination demonstrates that TLBO improves and optimizes the control parameters at different loading conditions and wide change in sustainable power source, area capacity ratio. Consequently, incorporation of thermal power–concentrating solar power (CSP) for AGC has improved the interconnected power system.