Micropower system optimization for the telecommunication towers based on various renewable energy sources

This study investigates the technical and cost-effective performance of options renewable energy sources to develop a green off-grid telecommunication tower to replace diesel generators in Malaysia. For this purpose, the solar, wind, pico-hydro energy, along with diesel generators, were examined to compare. In addition, the modeling of hybrid powering systems was conducted using hybrid optimization model for energy (HOMER) simulation based on techno-economic analysis to determine the optimal economically feasible system. The optimization findings showed that the hybrid high-efficiency fixed photovoltaic (PV) system with battery followed by 2 kW pico-hydropower and battery are the optimal configurations for powering off-grid telecommunication towers in Malaysia with the lowest net present cost (NPC) and cost of energy (COE). These costs of NPC and COE are more down than diesel generator costs with battery by 17.45%, 16.45%, 15.9%, and 15.5%, respectively. Furthermore, the economic evaluation of the high-efficiency solar fixed PV panels system annual cash flow compared to the diesel generator with the battery system indicated a ten-year payback period.

Variable Speed Diesel Generators: Performance and Characteristic Comparison

Diesel generators (DGs) are set to work as a backup during power outages or support the load in remote areas not connected to the national grid. These DGs are working at a constant speed to produce reliable AC power, while electrical energy demand fluctuates according to instantaneous needs. High electric loads occur only for a few hours a day in remote areas, resulting in oversizing DGs. During a low load operation, DGs face poor fuel efficiency and condensation of fuel residues on the walls of engine cylinders that increase friction and premature wear. One solution to increase combustion efficiency at low electric loads is to reduce diesel engine (DE) speed to its ideal regime according to the mechanical torque required by the electrical generator. Therefore, Variable Speed Diesel Generators (VSDGs) allow the operation of the diesel engine at an optimal speed according to the electrical load but require additional electrical equipment and control to maintain the power output to electrical standards. Variable speed technology has shown a significant reduction of up to 40% fuel consumption, resulting in low GHG emissions and operating costs compared to a conventional diesel generator. This technology also eliminates engine idle time during a low load regime to have a longer engine lifetime. The main objective of this survey paper is to present the state of the art of the VSDG technologies and compare their performance in terms of fuel savings, increased engine lifetime, and reduced greenhouse gases (GHG) emissions. Various concepts and the latest VSDG technologies have been evaluated in this paper based on their performance appraisal and degree of innovation.

Research of current distribution by phases in asynchronous electric motor with a combined winding

THE PURPOSE. Consider the use of propeller electric installations as part of ship electrical complexes with a single electric power system. Highlight the rudder drives as a special type of electric propulsion of ships in northern latitudes. Investigate unified electric power systems with a propeller electric installation for the existence of power exchange oscillations in them. Propose methods and means for eliminating power oscillations in such systems.METHODS. To carry out the research, a single electric power system with electric rudder propellers of the world's only asymmetric icebreaker Baltika was considered. All the main elements of such system have been analyzed in detail. Experimental studies were carried out aimed at studying the operating modes of a unified electric power system.RESULTS. Experimental oscillograms of currents of parallel operating diesel-generator sets in different modes have been obtained. The existence of exchange and in-phase power oscillations during the operation of the unified electric power system of the icebreaker "Baltika" is noted. The data on the negative influence of power oscillations on the operation of the electrical complex of the icebreaker are presented.CONCLUSION. The use of ice-class sea vessels is an extremely important task for the Russian Federation. The installation of blocks that eliminate exchange and in-phase power oscillations will improve the reliability and efficiency of the use of marine vessels with electric rudder propellers when servicing hydrocarbon production on the Arctic shelf.

Energy Management Strategy for an Autonomous Hybrid Power Plant Destined to Supply Controllable Loads

This paper proposes an energy management strategy (EMS) for a hybrid stand-alone plant destined to supply controllable loads. The plant is composed of photovoltaic panels (PV), a wind turbine, a diesel generator, and a battery bank. The set of the power sources supplies controllable electrical loads. The proposed EMS aims to ensure the power supply of the loads by providing the required electrical power. Moreover, the EMS ensures the maximum use of the power generated by the renewable sources and therefore minimizes the use of the genset, and it ensures that the batteries bank operates into the prefixed values of state of charge to ensure their safe operation. The EMS provides the switching control of the switches that link the plant components and decides on the loads’ operation. The simulation of the system using measured climatic data of Mostoles (Madrid, Spain) shows that the proposed EMS fulfills the designed objectives.

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

A new torsional vibration coupling model for transmission system in diesel generator

The coupling between the crankshaft and the camshaft is neglected before in fault diagnosis which may lead to incomplete fault information. In this paper, a new torsional coupling model of a diesel generator transmission system is proposed for fault diagnosis. The natural frequency and forced torsional vibration response of the model are obtained by the system matrix method and Newmark-β method. For the system without considering the lumped mass of camshafts, some key natural frequencies are lost. The vibration dynamics are compared for the transmission system with and without the new coupling model. And important frequency responses are missed in the spectrums of the forced torsional vibration without the new coupling model. Finally, the new coupling model is implemented in fault diagnosis and the cause of an unusual vibration fault is deduced in the simulation, which confirms the feasibility of the proposed model in fault diagnosis.

INCREASING MICROGRID ENERGY EFFICIENCY WITH DIESEL GENERATORS

It is shown that increasing the energy efficiency of Microgrid with diesel generators requires solving the problem of optimizing the modes of operation of Microgrid using as an optimization criterion for reducing the consumption of primary fuel diesel generators. To study the energy efficiency of such types of Microgrid as a criterion that has a direct impact on the amount of electricity generated, selected adequate accounting of primary fuel consumption when generating a given amount of electricity in the system. The article determines that one of the important indicators of diesel generator sets is their efficiency, which is determined by the ratio of energy produced to fuel consumption per hour of operation at rated load. It is shown that the reduction of fuel consumption allows to increase the efficiency of diesel generators, and different types of steady and transient modes of diesel generators significantly affect the efficiency of Microgrid in terms of technical and financial efficiency. To improve the technical and economic indicators in Microgrid with diesel generators, the article proposes to use the electric cost model of the power generation system, which allows to calculate both the dynamic change of generated power and the dynamic change of its cost and the cost of primary fuel. This model allows flexible nonlinear tracking of fuel consumption, which, taking into account the cost of diesel fuel, can serve as an economic criterion for determining the energy efficiency of the generating system. The article presents an algorithm for evaluating the financial and technical performance of Microgrid in dynamic modes over a period of technology, which not only evaluates the economic and energy efficiency of Microgrid with diesel generators, but can also be used to modify Smart meters, which can significantly expand their functionality.