Subhransu Ranjan Samantaray

This paper presents a new approach based on the application of a bit-shift operator based multi-objective seeker-optimization-algorithm (BS-MOSOA) for designing of combined primary and secondary power distribution system (CPDS) considering both system cost and reliability. In number of researches works the planning of secondary power distribution system (PDS) has not been considered for planning strategy. However, it is observed that the total investment and operational cost components of secondary PDS plays an important role in the overall system cost. Thus, in this proposed research a CPDS has been considered for comprehensive planning of complex PDS. Furthermore, a reliability index called Contingency-load-loss-index is used for the reliability assessment of the network. The algorithm uses a modified version of seeker-optimization-algorithm (SOA), which is based on the status of changing switches and shift operator to generate a group of non-dominated solutions. Also, fuzzy theory approach is used for selection of most suitable solution among the non-dominated solutions from the obtained Pareto-front. The proposed method is illustrated on a real test case consist of a residential primary and secondary network of 75 electrical nodes. Furthermore, a qualitative comparison is made with existing traditional and classical methodologies, to show the efficacy of the proposed planning approach.

This paper proposes a synchrophasors-assisted intelligent relaying scheme for transmission lines compensated by Unified Power Flow Controller (UPFC). The algorithm uses a new relaying signal termed as imaginary part of integrated impedance (IPII). The synchronized phasor measurements at both ends of the transmission line are used to extract voltage and current phasors from instantaneous voltage and current signals. The voltage and current phasors are utilized to derive IPII of each phase. Further, IPII of each phase is used as input to a data-mining model termed as decision tree (DT) which provides the final relaying decision. The proposed algorithm is validated on real-time digital simulator (RTDS) platform, and the results obtained indicate that the proposed scheme is both dependable and secure in protecting transmission system compensated by UPFC.

Micro‐grid (MG) monitoring and information sharing between them through a central monitoring unit is required in the present day operational environment. The proposed research focuses on developing wide‐area monitoring platform for multiple MGs running in parallel. This is achieved by using C37.118.1 complied phasor measurements units (PMUs) which provides accurate and reliable information monitoring at remote ends of the MGs and are further connected to the Phasor Data Concentrator which acts as the central monitoring unit. This process not only retrieves information at different nodes of the MGs equipped with PMUs, but the information can be exchanged between MGs for further action if required during contingencies. The PMUs are used to monitor phasors (amplitude and phases) and frequency of fundamentals which are further used to compute wide‐area functions at different operating nodes of the MGs at grid connected and islanded modes of operation including different operating conditions. The proposed PMU and MG models are developed on MATLAB/SIMULINK platform. Extensive test results indicate that the proposed monitoring process is highly essential to retrieve the operational status of the multiple MGs observed at the central monitoring unit.

To improve the performance of the conventional distance protection scheme for compensated lines with high resistance faults, an adaptive distance protection scheme is proposed. This study presents an analytical approach for finding the possible impacts of shunt connected flexible AC transmission systems (FACTS) devices such as static synchronous compensator/static volt‐ampere reactive (VAR) compensator (SVC) integrated with off‐shore wind farm (WF) on distance relay characteristics. Analytical results are presented and verified on simulation platform compares under reach phenomena in presence of both FACTS devices and it is found that under reach is more severe for SVC connected system. Moreover, presence of SVC changes the line characteristic presented to relay even for bolted faults. It is also seen that type of coupling transformer has a considerable effect on apparent impedance. Furthermore, the reach setting of the relay is significantly affected as the relay end voltage and power fluctuates continuously (due to non‐linear relationship with speed) when off‐shore WFs are connected to power transmission systems. Thus, adaptive tripping characteristics for high resistance line‐to‐ground fault with shunt‐FACTS devices considering appropriate operating conditions is a demanding concern and the same has been addressed in the proposed research work.

This article presents an extreme learning machine based fast and accurate adaptive distance relaying scheme for transmission lines in the presence of a static synchronous series compensator. The ideal trip characteristics of the distance relay is greatly affected by pre-fault system conditions, ground fault resistance, and zero-sequence voltage. The proposed research develops an extreme learning machine based adaptive distance relaying scheme for two-terminal transmission networks with static synchronous series compensators when a single-line-to-ground fault situation is most likely to occur. The study includes an analytical approach, including a steady-state model of static synchronous series compensator with detailed simulation on MATLAB/Simulink (The MathWorks, Natick, Massachusetts, USA) and open real-time simulation software with MATLAB (OPAL-RT) platform (OPAL-RT Technologies, Montreal, Quebec, Canada). The proposed extreme learning machine based adaptive distance relaying scheme is extensively validated on the two terminal transmission lines with static synchronous series compensators, and the performance is compared with the existing radial basis feed-forward neural network based adaptive distance relaying scheme. The results on simulation and real-time platform show significant improvements in the performance indices, such as speed, selectivity, and reliability of the digital relay.

This study proposes a method for designing advanced power distribution system (PDS) including distributed generations, using a combination of fundamental loop generator and multi‐objective seeker‐optimisation algorithm (MOSOA). The proposed approach reduces the searching space using fundamental loop generator technique to obtain initial feasible solutions which is further improved by SOA to generate new set of solutions with improved aptitude. The proposed methodology uses a contingency‐load‐loss‐index for reliability evaluation, which is independent of the estimation of failure rate and fault repair duration of feeder branches. This planning strategy includes distribution automation devices such as automatic reclosers (RAs) to enhance the reliability of PDS. The proposed algorithm generates a set of non‐dominated solution by simultaneous optimisation of two conflicting objectives (economic cost and system reliability) using Pareto‐optimality‐based trade‐off analysis including a fuzzy‐operation to automatically select the most suitable solution over the Pareto‐front. The performance of the proposed approach is assessed and illustrated on 54‐bus and 100‐bus PDS, considering realtime design practices. Extensive comparisons are made against some well‐known and efficient MO algorithms such as fast non‐dominated sorting genetic algorithm‐II, MO particle‐swarm‐optimisation and MO immunised‐particleswarm‐optimisation. Simulation results show that the proposed approach is accurate and efficient, and a potential candidate for large‐scale PDS planning.

This study introduces a novel unified framework for simultaneous denoising and compression of electric power system disturbance signals using sparse signal decomposition and reconstruction on overcomplete hybrid dictionary (OHD) matrix. In the proposed method, the power quality signal is first decomposed into deterministic sinusoidal components and non‐deterministic components using the OHD matrix, including discrete impulse dictionary ( I ), cosine dictionary ( C ), sine dictionary ( S ) and the ℓ ₁ ‐norm optimisation algorithm. Then, the hard‐thresholding, uniform threshold dead‐zone quantisation, modified index coding and Huffman coding techniques are used for compression of significant detail signal samples and approximation coefficients. To justify the selection of OHD matrix, four compression methods are implemented using the decomposition techniques based on the dictionaries Ψ = [ I C S ] and Ψ = [ I C ], the wavelet transform (WT) and the discrete cosine transform (DCT). The performance of each method is tested and validated using a wide variety of typical power quality disturbance (PQD) signals taken from the IEEE‐1159‐PQE and GIM–PQE databases and generated using the Microgrid model. The results show that the method with dictionary Ψ = [ I C S ] is capable of effectively compressing the PQD signals as well as suppressing the noise components in the signals.

This study presents an analytical approach for finding the possible impacts of flexible AC transmission system (FACTS) devices such as unified power flow controller (UPFC) and off‐shore wind penetration on distance relay characteristics. Generating relay tripping characteristics is one of the challenging issues for transmission line distance relays as the present day transmission systems is subjected to a more stressed environment with respect to power system operation. Moreover, inclusion of FACTS devices such as UPFC in the transmission system seriously impacts the performance of the distance relays as the apparent impedance changes. Furthermore, the reach setting of the relay is significantly affected as the relay end voltage fluctuates continuously when off‐shore wind‐farms are connected to power transmission systems. Thus, generating tripping characteristics for appropriate operating conditions is a demanding concern and the same has been addressed in the proposed research work. Extensive testing is carried out in generating relay tripping characteristics with possible variations under the operating conditions of UPFC and wind‐farm and it is observed that the characteristics are significantly affected for different operating conditions. Furthermore, the performance of the derived relay characteristics is validated on possible transmission line fault events and is found to work effectively.

This article presents an adaptive distance relay setting for a power transmission network connecting more than one wind farm. The ideal trip characteristics of the distance relay is greatly affected in the presence of complex mutual coupling of transmission lines, as the apparent impedance is significantly affected. Similarly, the reach setting of the relay for the lines connecting wind farms is significantly affected, as the relaying voltage fluctuates continuously. Thus, the proposed study focuses on developing an adaptive relay setting for a transmission network including more than one wind farm and considering variations in operating conditions of wind farms and mutual coupling of transmission lines together. The proposed relay algorithm is extensively tested on two-terminal as well as multi-terminal power networks with wide variations in operating parameters. The performance testing of the proposed adaptive relay characteristics for faults and faults during power swing indicates the potential ability of the approach in handling distance relaying in a transmission system.