Hybrid power control and contention window adaptation for channel congestion problem in internet of vehicles network

Technology such as vehicular ad hoc networks can be used to enhance the convenience and safety of passenger and drivers. The vehicular ad hoc networks safety applications suffer from performance degradation due to channel congestion in high-density situations. In order to improve vehicular ad hoc networks reliability, performance, and safety, wireless channel congestion should be examined. Features of vehicular networks such as high transmission frequency, fast topology change, high mobility, high disconnection make the congestion control is a challenging task. In this paper, a new congestion control approach is proposed based on the concept of hybrid power control and contention window to ensure a reliable and safe communications architecture within the internet of vehicles network. The proposed approach performance is investigated using an urban scenario. Simulation results show that the network performance has been enhanced by using the hybrid developed strategy in terms of received messages, delay time, messages loss, data collision and congestion ratio.

Modelling of Solar-Diesel Hybrid Power Plant

The article highlights the problems of distributed energy generation and focuses on solar-diesel hybrid power plant modelling and optimization. Designing power systems based on renewable energy sources includes a very relevant task of building mathematical models of such systems and their elements. The article presents an approach and definition of mathematical models describing photovoltaic-diesel (PV-D) hybrid power system elements used in decision making processes as a part of PV-D operation control. An overview of PV module output power, performance and temperature models is given. Along with the analysis of the specific fuel consumption dependencies on the operating power of the diesel generator, an example of diesel power plant unit commitment is shown.

Improving Hybrid Power Supply System for Telecommunication Service Providers in Nigeria

The aim of this research is to use a combination of renewable energy sources and conventional diesel generator to model a cost effective, alternative energy source for telecommunication base stations in Nigeria. Actually, this study uses various theoretical and mathematical modelling tools, such as, Mat lab Simulink and HOMER software. In the same way, the study references several Base Transceiver Stations (BTS) from gsm providers at select geographical locations in Rivers State. The study references BTS infrastructure in locations such as Ogoni, Port Harcourt and Emohua. These locations were selected to reflect different climatic conditions in Rivers state. Against this background, various hybrid combinations comprising at least two sources of renewable energy e.g Wind Turbine generator(WTG) and Solar Photovoltaic (SPV) were modelled. Also, Fuzzy logic optimization algorithm was used in tracking the maximum power in the SPV. A sample Diesel Generator(DG) was studied to analyze which possible combination gives optimum performance and is most cost effective. The total cost for installation and maintenance of the hybrid system was also considered. Consequently, one of the common negative effects of conventional power generation and usage, which is environmental pollution, was also highlighted during the study. In the course of this research, Homer was used to model a hybrid system in which the initial capital Cost (ICC) was N101,517,040 for 96 nos battery, 1 no 10kw WTG, 1 no hydro-turbine, 48 nos converters, labour etc. The replacement cost for component has a depreciation of 30%; while maintenance for diesel is 30% of the ICC. Eventually, the results obtained from the simulations showed that with an increase in supply from renewable energy sources the overall cost spent when compared to using a diesel generator only is cut by 50%, while the pollution effects also dropped. In fact, the cost also reduces if the renewable energy system is designed efficiently to track and harness maximum power. Furthermore, it is also evident that the location of the base station site and the availability of Renewable energy source affects the efficiency and cost of the entire system. Hence, it is recommended that any telecommunication company which intends installing a hybrid power system for its base stations must carry out detailed feasibility studies using input parameters described here; especially, as it relates to siting of base stations in rural off-grid areas. Keywords: Hybrid Power Supply System