Reliability evaluation of power network: A case study of Fiji Islands

The reliability of electrical power network is the driving force for the development of a country Nowadays most electrical power industries and companies are working for the better satisfaction of the customers while considering the associate cost. Utility companies must have precise information concerning system performance to achieve these goals, consequently guarantee the assets maintenance. The reliability standard of electric power delivered to the customer in Fiji is still in developing stage. Hence it is obvious to have a thorough understanding on the present situation of Fiji islands. In this paper, the performance of electricity delivered being evaluated using commonly used reliability indexes. So that modification and improvement can be done to enhance reliability of Fiji Islands' power network

Vehicle to grid system to design a centre node virtual unified power flow controller

Centre node unified power flow controller can fulfil various power flow control objectives, such as the needs of reactive shunt and series compensation, phase shifting and ensure higher degree of control freedom. However, as they are expensive, they are not widely used. The potential of a low-cost solution that utilises the capabilities of plug in electric vehicle (PEV) in vehicle-to-grid mode of operation for the design of a centre node virtual unified power flow controller (CVUPFC) using PEV charging stations is explained. Simulations are performed to establish that the proposed CVUPFC improves the power quality utilising PEV charging stations as DC bus for the converters with higher degree of freedom to control

A review of human error in marine engine maintenance

Maritime safety involves minimizing error in all aspects of the marine system. Human error hasreceived much importance, being responsible for about 80% of the maritime accident worldwide. Currently,more attention has been focused to reduce human error in marine engine maintenance. On-board marineengine maintenance activities are often complex, where seafarers conduct maintenance activities in variousmarine environmental (i.e. extreme weather, ship motions, noise, and vibration) and operational (i.e. workoverload and stress) conditions. These environmental and operational conditions, in combination with generichuman error tendencies, results in innumerable forms of error. There are numerous accidents that happeneddue to the human error during the maintenance activities of a marine engine. The most severe human errorresults in accidents due to is a loss of life. Moreover, there are other consequences too such as delaying theproductivity of marine operations which results in the financial loss. This study reviews methods that arecurrently available for identifying, reporting and managing human error in marine engine maintenance. As abasis for this discussion, authors provide an overview of approaches for investigating human error, and adescription of marine engine maintenance activities and environmental and operational characteristics

Design of LMS algorithm for noise canceller based on FPGA

This paper presents the design of an adapting filtering method to remove the noise in the biomedical signal records. The major concern about analyze the presence of various artifacts in ECG records and modular artifacts in EEG records caused due to various noise factors. Here, we have proposed a design based on LMS (Least Mean Square) algorithm to remove the artifacts from biomedical signal using Verilog HDL based on been mapped on  commercially available FPGAs (Field Programmable Gate Arrays). In this design the LMS algorithm used as a noise canceller and the reference signal was adaptively filtered and subtracted from primary signal to obtain the estimated biomedical signal. The original biomedical signal can be reconstructed by passing the digital bit stream through a low pass filter. This design is suitable for its low power biomedical instrument design and it reduces the whole system cost. Keywords: LMS algorithm, noise canceller, Verilog HDL, artifacts, biomedical signal, Low power application

Aromatic network for power distribution system

Electricity is an essential part of our existence in present days but inconsistent supply of electricity during tropical cyclones and natural disasters or fault in grid can create a dilemma over our life style, especially for remote area or island and even for the entire nation. These problems can be addressed at the distribution level by using smart, self-controlled and resilient micro electric grid that can operate on its own as microgrid or with grid connected mode as distribution network and energized by Renewable Energy Sources (RES). Three different designs of distribution network are commonly used and modified as microgrid structure which are: radial network, ring/loop network and mesh network architecture. Each of them has serious drawbacks to work during the disaster situations especially during the tropical cyclone or even snowstorm. To overcome these situation; a novel distribution network with better control and management techniques is designed here which is intrinsically potential for the future power systems to achieve reliability, efficiency and quality power supply even during the disaster. This design is essentially inspired by natural structure of an aromatic molecule which could be applied in the grid structure that would be strong enough to withstand any unexpected situations or faults. The novel network structure is represented as an aromatic molecule, like dichlorodiphenyltrichloroethane (DDT) where hexagonal benzene is the basic element for the network. This aromatic structure and the properties of the compound are used as the concept of the proposed design for the distribution network to ensure better stability and resiliency. Moreover, self-healing mechanism is embedded in the distribution system to minimize system interruptions during common faults. Finally, to maximize energy efficiency and reduce human effort, smart wireless communication system, effective control technology and switching of distributed generations (DG’s) with respect to demand and consumption have been included in this network design

Impact of Stray Voltage on Renewable Energy-based Farm in Pacific Island Country

Recent advancements in solar technology offer an enormous opportunity for the people of Pacific Islands to use electricity from the off-grid solar system for both their energy needs and farming activities. However, a farm’s productivity and animal health might be seriously threatened if it experiences stray voltages caused by the improper grounding of its installed electrical systems. As a shift in the neutral point of an electrical system creates a current flow to the ground through conducting elements, the impacts of stray voltages need to be addressed from both technical and economic viewpoints. In this research, the effects of stray voltages passing through animals are explored using circuit designs for solar sources considering variable grounding resistances due to the different body resistances of various types of animals, and environmental and grounding design issues. A comparison of the stray voltages of two different sources (off-grid solar and traditional grid) with various configurations are conducted to determine their effects on a farm. Finally, their economic impacts together with possible techniques for mitigating them are explained

Evaluation of concrete corrosion using EMI sensor

Reinforced Concrete (RC) is globally used to make the building structure strong and more durable. Civil and structural engineers face major challenges as concrete structures deteriorate and get weaker. Recent development in field of assessing and monitoring the health condition of the building structure have shown that corrosion in concrete reinforcement is the cause of failure. Thus, there lies a better research opportunity in the field of monitoring and assessing health condition of the building structure. This paper presents an innovative technique of initial monitoring of corrosion in concrete structures using Non-Destruction Evaluation (NDE). An early monitoring sensor was developed using Faradays law of electromagnetic induction (EMI) principle, multiple loop coil (MLC) acts a sensor which has a receiver and transmitter coil. The placement of the two coils on concrete structures measures the potential difference which later is used to analyse the level of corrosion

Design of an optimum MPPT controller for solar energy system

Solar energy is compared to be the best potential source of renewable energy in Pacific region. For this reason a photovoltaic cell is needed to harvest this kind of energy, gathering the most of it and the PV having a good efficiency. The maximum efficiency is achieved when the PV works at its Maximum Power Point which entirely depends on the irradiation and temperature. This paper proposes a new design of hybrid Maximum Power Point Tracking and a comparative study is made with various existing MPPT techniques which include Perturb and Observe method, Incremental Conductance and Fuzzy Logic. From the comprehensive comparison study between existing MPPT technique and the proposed MPPT technique/theory, a hardware setup was demonstrated to verify the proposed design by charge controller in photovoltaic systems to which maximize the output power under various lighting conditions. The design is based on the computed results using the buck-boost DC-DC conveter. From the simulation, the proposed method tends to show better performance with almost no oscillations around the MPP

Impact of Wind Generators in Power System Stability

Wind electricity is one of the quickest developing renewable resources of power. This rapid development is expected considering the environmental factors, but in terms of power system stability, it comes with a number of concerns. Generators play a vital role on stability for a particular capacity and design of a network. This paper investigated the overall performance of 3 foremost types of wind turbines via small signal stability analysis on IEEE 9 bus system. Simulations have been done and established that the generators dynamic model have significant impact on power system stability at different capacity of the generators

Distributed energy resources and the application of AI, IoT, and blockchain in smart grids

Smart grid (SG), an evolving concept in the modern power infrastructure, enables the two-way flow of electricity and data between the peers within the electricity system networks (ESN) and its clusters. The self-healing capabilities of SG allow the peers to become active partakers in ESN. In general, the SG is intended to replace the fossil fuel-rich conventional grid with the distributed energy resources (DER) and pools numerous existing and emerging know-hows like information and digital communications technologies together to manage countless operations. With this, the SG will able to “detect, react, and pro-act” to changes in usage and address multiple issues, thereby ensuring timely grid operations. However, the “detect, react, and pro-act” features in DER-based SG can only be accomplished at the fullest level with the use of technologies like Artificial Intelligence (AI), the Internet of Things (IoT), and the Blockchain (BC). The techniques associated with AI include fuzzy logic, knowledge-based systems, and neural networks. They have brought advances in controlling DER-based SG. The IoT and BC have also enabled various services like data sensing, data storage, secured, transparent, and traceable digital transactions among ESN peers and its clusters. These promising technologies have gone through fast technological evolution in the past decade, and their applications have increased rapidly in ESN. Hence, this study discusses the SG and applications of AI, IoT, and BC. First, a comprehensive survey of the DER, power electronics components and their control, electric vehicles (EVs) as load components, and communication and cybersecurity issues are carried out. Second, the role played by AI-based analytics, IoT components along with energy internet architecture, and the BC assistance in improving SG services are thoroughly discussed. This study revealed that AI, IoT, and BC provide automated services to peers by monitoring real-time information about the ESN, thereby enhancing reliability, availability, resilience, stability, security, and sustainability