Modeling and Real-Time Scheduling of DC Platform Supply Vessel for Fuel Efficient Operation

DC marine architecture integrated with variable speed diesel generators (DGs) has garnered the attention of the researchers primarily because of its ability to deliver fuel efficient operation. This paper aims in modeling and to autonomously perform real-time load scheduling of dc platform supply vessel (PSV) with an objective to minimize specific fuel oil consumption (SFOC) for better fuel efficiency. Focus has been on the modeling of various components and control routines, which are envisaged to be an integral part of dc PSVs. Integration with photovoltaic-based energy storage system (ESS) has been considered as an option to cater for the short time load transients. In this context, this paper proposes a real-time transient simulation scheme, which comprises of optimized generation scheduling of generators and ESS using dc optimal power flow algorithm. This framework considers real dynamics of dc PSV during various marine operations with possible contingency scenarios, such as outage of generation systems, abrupt load changes, and unavailability of ESS. The proposed modeling and control routines with real-time transient simulation scheme have been validated utilizing the real-time marine simulation platform. The results indicate that the coordinated treatment of renewable based ESS with DGs operating with optimized speed yields better fuel savings. This has been observed in improved SFOC operating trajectory for critical marine missions. Furthermore, SFOC minimization at multiple suboptimal points with its treatment in the real-time marine system is also highlighted

Effect of Phytate Phosphorus on the Utilisation of Rice Bran in Broiler Chickens)

Rice bran (RB) is a by-product of rice milling industry and is produced in many parts of the world including Malaysia. It is a high energy source for both ruminant and nonruminant animals with a crude protein content of 12-13%. Its fibre content is about 7-16%. Rice bran is also rich in phytate phosphorus (pP) which is not easily available to poultry. This study examines the utilisation of pP by broiler chickens fed RB based diets at the finishing stage. The role of phytase enzyme and vitamin D3 in improving the utilisation of pP was also examined. Two growth trials were carried out with 21 day-old broiler chickens to determine the effects of replacing com with RB on their performance. It was found that the performance of birds were adversely affected when RB was included at 45% level. The results obtained from these two studies suggest that RB can be included up to 35% in the diet of broiler chicken without any adverse effects on their performance