Fast Flexible Direct Power Flow for Unbalanced and Balanced Distribution Systems

The study proposes a fast flexible direct power flow solution for radial distribution systems and a fast flexible direct weakly meshed power flow solution for weakly meshed distribution systems. The algorithm is based on the direct forward sweep power flow solution, which is an updated version of the backward/forward sweep solution. The fast flexible direct power flow uses a unique conversion matrix (CM) to rapidly determine the power flow solution. The inverted conversion matrix and its slide-modified matrix are used to solve the power flow problem in a single forward sweep step, which is a novel feature of this work. To ensure the invertibility of the conversion matrix, it is constructed to have a small condition number and a determinant of minus one, and all of its eigenvalues must be equal to that of minus one. Additionally, by modifying the conversion matrix to accommodate the loop branch using the break-point idea, a new weakly meshed conversion matrix (WMCM) is generated with the same following modification as for the radial network and employed in the fast flexible direct weakly meshed power flow (FFDWMPF) solution for the weakly meshed distribution network. The usage of a single matrix in the power flow solution and advanced direct techniques decreases the number of iterations and CPU execution time when MATLAB programming is executed. Furthermore, the proposed method is flexible enough to incorporate any changes in the radial or weakly meshed distribution system just by incorporating the changes in the CM and WMCM for any radial or weakly meshed system. Moreover, the robustness of FFDPF and FFDWMPF is evaluated under various loading scenarios on balanced radial and weakly meshed distribution networks. Finally, to validate the proposed algorithm, the proposed strategy is applied to numerous balanced and unbalanced distribution systems

Generator Rescheduling under Congested Power System with Wind Integrated Competitive Power Market

Integration of renewable energy like wind or solar energy creates a huge pressure to the system operator (SO) to ensure the congestion free transmission network under deregulated power market. Congestion Management (CM) with integration of wind farm in double auction electricity market are described in this work to minimize fuel cost, system losses and locational marginal price (LMP) of the system. Location of Wind Farm (WF) is identified based by using Bus sensitivity factor (BSF), which is also used for selection of load bus for double auction bidding (DAB). The impacts of wind farm in congested power system under deregulated environment have been investigated in this work. Modified 39-bus New England test system is used for demonstrate the effectiveness of the presented approach by using Sequential Quadratic Programming (SQP)

Stochastic dilation of a quantum dynamical semigroup on a separable unital C<SUP>&#8727;</SUP> algebra

Given a uniformly continuous quantum dynamical semigroup on a separable unital C<SUP>&#8727;</SUP> algebra, we construct a canonical Evans-Hudson (E-H) dilation. Such a result was already proved by Goswami and Sinha ([GS]) in the von-Neumann algebra set-up, which has been extended to the C<SUP>&#8727;</SUP> algebraic framework in the present article. The authors make use of the coordinate-free calculus and results of [GS], but the proof of the existence of structute maps differs form that of [GS]

Impact of COVID-19 vaccination on menstruation pattern among female nursing and paramedical students in a peripheral medical college in Eastern India

Background: Many females worldwide have reported abnormalities in their menstrual patterns post-COVID-19 vaccination. The present study was conducted to determine the impact of the COVID-19 vaccination on menstrual patterns among female nursing and paramedical students at a peripheral medical college in eastern India. Materials and Methods: The cross-sectional, online self-administered survey was conducted using Microsoft Forms after taking institutional ethical clearance and informed consent from the participants. Two hundred BSc nursing and paramedical students who had received two doses of COVID vaccination (Covaxin or Covishield) and were not suffering from any endocrinopathies, bleeding disorders, structural gynecological abnormalities, or taking any medication known to affect the hypothalamic–pituitary–gonadal axis were included in the study. The questionnaire included menstrual length cycle length and amount of bleeding and there were no direct identifiers. Results: The participants reported a significant increase in the amount of bleeding on the heaviest day (mean ± standard deviation [SD] of the number of pads used was 3.52 ± 1.15 during prevaccination months vs. 4.64 ± 1.36 during postvaccination months; P < 0.001) following vaccination. A similar result of increased bleeding on the heaviest day of the period was obtained in both the Covaxin group (mean ± SD: 3.08 ± 1.16 vs. 4.88 ± 1.53; P: 0.001) and the Covishield group (mean ± SD: 3.59 ± 1.13 vs. 4.6 ± 1.34; P < 0.001). No difference in change in the menstrual pattern was observed between the two groups who had received two different types of vaccine (P: 0.527). Conclusion: The study showed a possible connection between the COVID-19 vaccination and the change in menstrual patterns

Wind power: Existing status, achievements and government's initiative towards renewable power dominating India

Wind power has shown enormous potential in capacity addition and substantial use throughout the world during the last few decades. From the very last era of the 1990s, wind energy has re-emerged and framed as a major source of renewable power generation. The worldwide wind power installed capacity has been doubled in every three years over the last decades of the 20th century. This paper demonstrates the important aspects along with the promotion policies which are adopted by the Indian government for enlarging the country's own energy security by proper utilization of available renewable energy sources. In India's perspective, wind power is not only used for power generation but also to provide the energy in a cost-effective manner. The details of India's entire power generation, demand, and contributions of various renewable sources are also comprised in this study. The present scenario of wind power potential in India has been also compared with the other leading countries in the world. Keywords: Indian wind power scenario, Grid associated renewable power generation, Levelized tariff, Accelerated depreciation, Electricity ac

Gravity Search Algorithm hybridized Recursive Least Square method for power system harmonic estimation

This paper presents a new hybrid method based on Gravity Search Algorithm (GSA) and Recursive Least Square (RLS), known as GSA-RLS, to solve the harmonic estimation problems in the case of time varying power signals in presence of different noises. GSA is based on the Newton’s law of gravity and mass interactions. In the proposed method, the searcher agents are a collection of masses that interact with each other using Newton’s laws of gravity and motion. The basic GSA algorithm strategy is combined with RLS algorithm sequentially in an adaptive way to update the unknown parameters (weights) of the harmonic signal. Simulation and practical validation are made with the experimentation of the proposed algorithm with real time data obtained from a heavy paper industry. A comparative performance of the proposed algorithm is evaluated with other recently reported algorithms like, Differential Evolution (DE), Particle Swarm Optimization (PSO), Bacteria Foraging Optimization (BFO), Fuzzy-BFO (F-BFO) hybridized with Least Square (LS) and BFO hybridized with RLS algorithm, which reveals that the proposed GSA-RLS algorithm is the best in terms of accuracy, convergence and computational time

Impact of plug-in electric vehicles and distributed generation on reliability of distribution systems

The use of Plug-in electric vehicles (PEV) are increasing in recent years because of its environmental friendly nature over the conventional vehicles. In the upcoming years, the use of PEVs will increase significantly. The connection of PEVs to the distribution system will lead to the new challenges. This paper evaluates the impact of PEV connection on system reliability. Studies are carried out for different PEV penetration levels to analyze the impact. Some PEVs are operated in vehicle to grid (V2G) mode to support the system peak loads. Distributed generation (DG) units are integrated with charging stations to reduce the PEVs charging impact on the system. In the present study, charging stations are integrated with solar PV units which magnifies the intention of PEV usage. Along with the system reliability evaluation, Expected Energy Not Charged (EENC) is proposed to measure the reliability of the PEVs in the system. The combined effects of PEV charging and DGs are also studied. The impact assessment is done for two practical systems