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We developed and field-tested an electric vehicle quick charger (EVQC) with storage battery to suppress the lengthening of charging time while preventing a rise in a building's peak power usage caused by EV charging. This EVQC features a demand control technique that determines the amount of power to be used by the charger according to the amount of power used by the building. In addition, charging...
This paper presents an experimental study with a pilot hybrid microgrid system that is proposed and implemented in Tagajo campus of Tohoku Gakuin University, Japan. The developed microgrid system is designed to be able to supply power to both DC and AC loads simultaneously by renewable power sources such as PV and wind power generations, etc. Meanwhile, in case that the renewable power is insufficient...
This paper looks at multiple energy sources now available at the cell site, as well as design and management complexities that have risen as a result. The goal of this paper is to outline design considerations for each alternative energy source, such as technologies, logistics, setup and operation. By showing these considerations, decision-makers can refine objectives for deployment and operation,...
Site infrastructure sharing is the trend of future base station construction. Telecom infrastructure operators require for smooth upgrading and low TCO when sharing sites power supply, spaces and operation management. This paper introduces a new integrated hybrid power supply system suitable for the site sharing requirements. It perfectly combines many functions together, such as energy generation,...
The output voltage characteristics of a thermoelectric generator were analyzed to suppress heat leakage for low-temperature waste-heat thermoelectric generation. The experimental results show that the pre-cooled thermoelectric device output a higher voltage than the reference device. The experimental results also show that the influence of heat leakage took a longer time to appear using the pre-cooled...
A single-stage ac-dc converter consisting of full-bridge converter is proposed for EV charger applications. The proposed approach is superior to conventional two-stage ac-dc converter widely used for EV charger applications. The two stage ac-dc converter is apt to be costly and large. However a single-stage ac-dc converter is suitable to a low cost, small volume due to a reduced number of components...
This paper studies the dynamics of the proposed vibration energy harvester to develop the method of designs and controls for the system. The harvester converts vibrational energy into electrical energy through rotational motion of a mechanical pendulum or a so-called parametric pendulum. The rotation is maintained for periodic vibration with appropriate amplitude and frequency. However, such appropriate...
BTS sites are subject to constant cost pressure. Operational cost and especially Diesel consumption form ever increasing cost components. Here, photovoltaics (PV) is an effective measure to cut down operational cost and emissions for hybrid BTS sites. Often PV is integrated in a non-optimal way opening up room for improvements to the operational management. Three different advanced PV-hybrid operational...
The increasing market of mobile phones, has increased the need for electricity to power mobile phones, as well. This paper investigates the possibilities to charge a mobile phone by harvesting energy from the surroundings. Some technologies are better suited for this purpose than others. Through previous analyses solar cells and electromagnetic generator were found to be the most suitable solution...
This paper presents an Energy Optimization Model (EOM) for Mobile Service Providers (MSP) that enables the optimization of power efficiency and the integration of optimum renewable and clean energy sources into the mobile network. The model approach drives both Operational Expenditure (OPEX) and Capital Expenditure (CAPEX) reduction via re-engineering power provisioning and site solutions. The features...
This paper presents a distributed control for dc microgrids that minimize the total generation cost and regulate the average voltage at the desired value. The proposed controller includes two modules; lower cost regulator and voltage regulator. In addition, a sparse communication network with a balanced laplacian matrix is used for data exchange between converters as each converter communicates only...
Supply of power is an increasing cost factor in the operation of base transceiver stations (BTS). Selecting the optimized power system for a set of site requirements is key to minimize total cost of ownership (TCO). In this paper we show how dimensioning of a power system through combined technical and commercial simulation helps to optimize the system configuration. The savings on fuel and diesel...
Increasing use of intelligent devices in smart grids inevitably brings along the possibility of a cyber-attack These attacks can be targeted at not only control equipment but also measurement and communication instruments. Impediment of intelligent electrical devices (IEDs) due to attacks in cyber systems is a highly probable event which reveals the delicate operation required in Cyber-Physical Systems...
Conventional power management schemes for standalone wind systems typically use maximum power point tracking (MPPT) methods to extract maximum power from the wind even when the energy storage has reached its capacity. By doing so, the dummy load suffers from unnecessary stress when the load and energy storage element cannot absorb the excess power. This paper proposes an intelligent sensor-less fuzzy-logic...
Microgrid is a single controllable unit constituting distributed generation (DG) and load in the power system. The micro source includes photovoltaic (PV) cells, wind turbine, micro turbine, fuel cell, electric accumulator and flywheel etc. Usually, the micro source operates in parallel with the normal distributed network that uses the power electronic devices. There are two typical operation modes...
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