Impact of increased distributed generation on fault levels and the network equipment

Attention towards the development of Distributed Generation (DG) is globally high. UK's concentration is to use sustainable and renewable sources to generate electricity thereby protecting the environment from getting polluted. In this paper, Distributed Generation concept is explored regarding the types, sizes, ratings, locations and benefits. It is very important to connect the developed distributed generator to the distribution network to satisfy the demand but without developing any faults and causing damage to the existing switchgear. Legal contracts that are required to be signed in order to connect the DG to the network and proper Protection Review to be followed in suppressing the faults are also mentioned. To study the impact of increased DG on fault levels, simulation approach is adopted. ETAP 7.1.0 is used to build a case study network and the results obtained are analyzed based on which critical comparison is made. The network comprises of three wind farms, each consisting of six wind turbines and a small hydroelectric plant. Various scenarios are considered and the results obtained are clearly analyzed. Protection is provided for the circuit and Star Device coordination study is performed. © JES 2014

A novel policy making proposition for EV charging infrastructure management at HEI's

This paper is based on real time EV charging infrastructure development that took place at Brunel University, which is located in west of London, UK. The aim of this paper is to establish the policy making process that has stages of an initial student-staff interest survey, records of the consultation process with EV owners, results of competitive benchmarking with other HEI's and the discussion on Type 2 Mode 3 charging stations which are 240V, 32A, 7kW, 50Hz compliant with IEC 62196 and ISO 14443 Mifare standards. The first time ever PAYG concept of POD Point Ltd is explained. Benefits of using PAYG concept for charging EV are mentioned. Various other factors that played major role were also considered as follows: deciding the tariff of the electricity used by the EV owners, charging cable compatibility with charging station, hours of operation, creation of new enforcement rules and recommendations to provide incentives that recognise and motivate EV community

Can Centralized Sanctioning Promote Trust in Social Dilemmas? A Two-level Trust Game with Incomplete Information

The problem of trust is a paradigmatic social dilemma. Previous literature has paid much academic attention on effects of peer punishment and altruistic third-party punishment on trust and human cooperation in dyadic interactions. However, the effects of centralized sanctioning institutions on decentralized reciprocity in hierarchical interactions remain to be further explored. This paper presents a formal two-level trust game with incomplete information which adds an authority as a strategic purposive actor into the traditional trust game. This model allows scholars to examine the problem of trust in more complex game theoretic configurations. The analysis demonstrates how the centralized institutions might change the dynamics of reciprocity between the trustor and the trustee. Findings suggest that the sequential equilibria of the newly proposed two-level model simultaneously include the risk of placing trust for the trustor and the temptation of short-term defection for the trustee. Moreover, they have shown that even a slight uncertainty about the type of the newly introduced authority might facilitate the establishment of trust and reciprocity in social dilemmas.published_or_final_versio

Variations and correlations in the composition of bovine, ovine and caprine milk

Variations in the milk composition of cattle, sheep and goats as well as residual phenotypic correlations between the milk constituents were investigated. The study utilised Bunaji, Yankasa and Red Sokoto breeds of cattle, sheep and goats, respectively. Results indicated that sheep and goats differed significantly (P0.05). Residual phenotypic correlations between the milk constituents revealed highly significant (P<0.01) and positive relationships between total solids and solids-not-fat (0.97 and 0.98 in cattle and sheep, respectively). All other correlations were positive (ranging from 0.12 to 0.77), except between protein and total solids (-0.44) and protein and solids-not-fat (-0.64) in cattle. Multiple linear regression equations were fitted to predict the percentages of protein and fat. It was demonstrated that protein percentage could be predicted from total solids and solids-not-fat with the highest accuracy of 94, 86 and 82 % in cattle, sheep and goats, respectively. On the other hand, the accuracy of prediction of fat percentage was very low in all the species (R2=0.01, 0.03 and 0.37 in cattle, sheep and goats, respectively)

Low-operating-voltage polymer thin-film transistors based on poly(3-hexylthiophene) with hafnium oxide as the gate dielectric

The effects of hafnium oxide $(hbox{HfO}-{2})$ gate dielectric annealing treatment in oxygen $(hbox{O}-{2})$ and ammonia $(hbox{NH}-{3})$ ambient on the electrical performance of polymer thin-film transistors (PTFTs) based on poly(3-hexylthiophene) are investigated. The PTFTs with $hbox{HfO}-{2}$ gate dielectric and also octadecyltrichlorosilane surface modification, prepared by spin-coating process, exhibit good performance, such as a small threshold voltage of $-$0.5 V and an operating voltage as low as $-$4 V. Results indicate that the PTFT with $hbox{NH}-{3}$-annealed $hbox{HfO}-{2}$ shows higher carrier mobility, larger on/off current ratio, smaller subthreshold swing, and lower threshold voltage than the PTFT with $hbox{O}-{2}$-annealed $hbox{HfO}-{2}$. Capacitancevoltage analysis for metal-polymer-oxide-silicon structures indicates that the better electrical performance of the PTFT with $hbox{NH}-{3}$ -annealed $hbox{HfO}-{2}$ is attributed to improved dielectric/polymer interface and reduced series resistance in the transistor. © 2006 IEEE.published_or_final_versio

Design of CMOS PSCD circuits and checkers for stuck-at and stuck-on faults

[[abstract]]We present in this paper an approach to designing partially strongly code-disjoint (PSCD) CMOS circuits and checkers, considering transistor stuck-on faults in addition to gate-level stuck-at faults. Our design-for-testability (DFT) technique requires only a small number of extra transistors for monitoring abnormal static currents, coupled with a simple clocking scheme, to detect the stuck-on faults concurrently. The DFT circuitry not only can detect the faults in the functional circuit but also can detect or tolerate faults in itself, making it a good candidate for checker design. Switch and circuit level simulations were performed on a sample circuit, and a sample 4-out-of-8 code checker chip using the proposed technique has been designed, fabricated, and tested, showing the correctness of the method. Performance penalty is reduced by a novel BiCMOS checker circuit.[[fileno]]2030108010057[[department]]電機工程學

Gridless optical networking field trial: flexible spectrum switching, defragmentation and transport of 10G/40G/100G/555G over 620-km field fiber

We present results from the first gridless networking field trial with flexible spectrum switching nodes and 620 km of installed fibre links. Signals at 10G, 12.25G, 42.7G, DP-QPSK 40G, DP-QPSK 100G and 555G are generated, successfully transported and switched using flexible, custom spectrum allocation per channel. Spectrum defragmentation is demonstrated using integrated SOA-MZI wavelength converters. Results show error-free end-to-end performance (BER<1e-9) for the OOK channels and good pre-FEC BER performance with sufficient margin to FEC limit for the 40G and 100G coherent channels as well as for the 555G super-channel. © 2011 Optical Society of America