scholarly journals Development and Evaluation of a Degree of Hybridisation Identification Strategy for a Fuel Cell Supercapacitor Hybrid Bus

Energies ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 142 ◽  
Author(s):  
Wei Wu ◽  
Julius Partridge ◽  
Richard Bucknall

Fuel cells (FC) are a clean energy source that are capable of powering a vehicle’s electrical energy requirements whilst providing zero operating emissions. In this study, a full-scaled computer model FC/supercapacitor (SC) hybrid has been developed to investigate the performance of the hybrid propulsion system under real-world performance conditions. A control strategy focused on maintaining a constant FC output at a user-defined value has been developed and applied to the FC/SC hybrid model. Driving cycles collected from a practical double-decker bus have been utilised to evaluate the developed model. It has been demonstrated that the proposed control strategy is capable of maintaining a constant and stable FC output while meeting a real world dynamic load. Based on the obtained results, a general strategy to identify the degree of hybridisation between the FC and the SC in a FC hybrid system has been developed and demonstrated.

Author(s):  
Seyed Amid Tahami ◽  
Mohammadreza Gholikhani ◽  
Samer Dessouky

Asphalt pavement is continuously exposed to solar radiation, which can heat the asphalt up to 60 to 70°C because of the high absorptivity of its black materials. This potential source of energy has gone unused but has recently attracted attention for its potential to be collected as a renewable and clean energy source. In this paper, a novel thermoelectric roadway energy harvester is introduced that can be inserted into pavement to scavenge electrical energy from thermal energy. The energy harvester system consists of different components, including a thermoelectric generator (TEG), an L-shaped heat conductor plate, a heat sink filled with phase change material, and an insulation box. Finite element analysis and experimental testing in the laboratory were conducted to evaluate the performance of this harvesting system. Different parameters that could affect the power output were investigated, such as asphalt slab temperature (e.g., 45°C, 55°C, 65°C), type of TEG module, number of TEG modules, and TEG configurations. The results indicate that the system is capable of producing sufficient energy to run low-powered electrical equipment used in transportation infrastructure.


Vehicles ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Partridge ◽  
Wu ◽  
Bucknall

This paper presents the development of a control strategy for a fuel cell and supercapacitor hybrid power system for application in a city driving bus. This aims to utilise a stable fuel cell power output during normal operation whilst allowing variations to the power output based on the supercapacitor state-of-charge. This provides flexibility to the operation of the system, protection against over-charge and under-charge of the supercapacitor and gives flexibility to the sizing of the system components. The proposed control strategy has been evaluated using validated Simulink models against real-world operating data collected from a double-decker bus operating in London. It was demonstrated that the control strategy was capable of meeting the operating power demands of the bus and that a wide range of degrees of hybridisation are viable for achieving this. Comparison between the degree of hybridisation proposed in this study and those in operational fuel cell (FC) hybrid buses was carried out. It was found that the FC size requirement and FC variation can be significantly reduced through the use of the degree of hybridisation identified in this study.


MRS Bulletin ◽  
1999 ◽  
Vol 24 (11) ◽  
pp. 40-44 ◽  
Author(s):  
R.B. Schwarz

Magnesium can reversibly store about 7.7 wt% hydrogen, equivalent to more than twice the density of liquid hydrogen. This high storage capacity, coupled with a low price, suggests that magnesium and magnesium alloys could be advantageous for use in battery electrodes and gaseous-hydrogen storage systems. The use of a hydrogen-storage medium based on magnesium, combined with a fuel cell to convert the hydrogen into electrical energy, is an attractive proposition for a clean transportation system. However, the advent of such a system will require further research into magnesium-based alloys that form less stable hydrides and proton-conducting membranes that can raise the operating temperature of the current fuel cells.Following the U.S. oil crisis of 1974, research into alternative energy-storage and distribution systems was vigorously pursued. The controlled oxidation of hydrogen to form water was proposed as a clean energy system, creating a need for light and safe hydrogen-storage media. Extensive research was done on inter-metallic alloys, which can store hydrogen at densities of about 1500 cm3-H2 gas/ cm3-hydride, higher than the storage density achieved in liquid hydrogen (784 cm3/cm3 at –273°C) or in pressure tanks (˜200 cm3/cm3 at 200 atm). The interest in metal hydrides accelerated following the development of portable electronic devices (video cameras, cellular phones, laptop computers, tools, etc.), which created a consumer market for compact, rechargeable batteries. Initially, nickel-cadmium batteries fulfilled this need, but their relatively low energy density and the toxicity of cadmium helped to drive the development of higher-energy-density, less toxic, rechargeable batteries.


2017 ◽  
Vol 29 (7) ◽  
pp. 1481-1499 ◽  
Author(s):  
Yu Jia ◽  
Jize Yan ◽  
Sijun Du ◽  
Tao Feng ◽  
Paul Fidler ◽  
...  

The convention within the field of vibration energy harvesting has revolved around designing resonators with natural frequencies that match single fixed frequency sinusoidal input. However, real world vibrations can be random, multi-frequency, broadband and time-varying in nature. Building upon previous work on auto-parametric resonance, this fundamentally different resonant approach can harness vibration from multiple axes and has the potential to achieve higher power density as well as wider frequency bandwidth. This article presents the power response of a packaged auto-parametric VEH prototype (practical operational volume of ∼126 cm−3) towards various real world vibration sources including vibration of a bridge, a compressor motor as well as an automobile. At auto-parametric resonance (driven at 23.5 Hz and 1 g rms), the prototype can output a peak of 78.9 mW and 4.5 Hz of −3dB bandwidth. Furthermore, up to ∼1 mW of average power output was observed from the harvester on the Forth Road Bridge. The harvested electrical energy from various real world sources were used to power up a power conditioning circuit, a wireless sensor mote, a micro-electromechanical system accelerometer and other low-power sensors. This demonstrates the concept of self-sustaining vibration powered wireless sensor systems in real world scenarios, to potentially realise maintenance-free autonomous structural health and condition monitoring.


Author(s):  
Archana Sudhakar Talhar ◽  
Sanjay B. Bodkhe

This paper gives a review of energy scenario in India and other countries. Today’s demand of the world is to minimize greenhouse gas emissions, during the production of electricity. Henceforth over the world, the production of electrical power is changing by introducing abundantly available renewable energy sources like sun and wind. But, because of the intermittent nature of sustainable power sources, the electrical power network faces many problems, during the transmission and distribution of electricity. For resolving these issues, Electrical Energy Storage (EES) is acknowledged as supporting technology. This paper discusses about the world electrical energy scenario with top renowned developed countries in power generation and consumption. Contribution of traditional power sources changed after the introduction of renewable energy sources like sun and wind. Worldwide Agencies are formed like International Energy Agency (IEA), The Central Intelligence Agency, (CIS) etc. The main aim of these agencies is to provide reliable, affordable and clean energy. This paper will discuss about the regulatory authority and government policies/incentives taken by different countries.  At the end of this paper, author focuses on obstacles in implementation, development and benefits of renewable energy.


2021 ◽  
Vol 1047 ◽  
pp. 120-127
Author(s):  
Reylina Garcia Tayactac ◽  
Edward B.O. Ang

Geothermal is known as renewable energy and a clean energy source but inherent properties make this energy clean. Minerals and deposits in geothermal reservoirs create a scale that is persistent in its corrosive nature. In addition, heat extremes and pressure variations present challenges to the integrity of the wellhead components and the downhole casing. Such challenges need to be mitigated to achieve maximum output from these aging or even newly commissioned wells. The geothermal power industry has reported a wide range of corrosion problems. Given the highly corrosive conditions to be treated in the geothermal sector and the benefits of reduced unplanned downtime, operating cost savings would be expected if more CRAs clad products were used. In many cases, only the material's surface requires corrosion resistance and carbon or alloy steel can be clad with a more corrosion-resistant alloy. Up to 80% of the cost of using solid alloy can be saved by cladding. Carbon or low-alloy steel cladding can be carried out by overlay welding. This paper reviews available literature on corrosion in the geothermal environment and presents the successful use of clad products in other industries to support the rising demand for Philippine geothermal applications.


Author(s):  
Vulisi Narendra Kumar ◽  
Gayadhar Panda ◽  
Bonu Ramesh Naidu

The growing demand for electrical energy calls for the assimilation of renewable energy sources to the main utility grid. Multiple renewable energy sources (RESs) like solar PV array, wind turbine, micro-hydro plant, etc. can be combined and controlled to form a microgrid. In spite of the availability of different microgrid topologies, DC microgrid largely facilitates the injection of DC power from various renewable energy sources into the stabilised DC power pool. The requirement for a minimal number of conversion stages, simple structure, economic operation, and numerous localised applications are driving factors for the DC microgrid technology. The mettle of the DC microgrid technology lies in choosing the appropriate microgrid participants for energy interchange and the suitable supervisory control to tap power from the microgrid partakers even after respecting their operating constraints. The use of high gain DC-DC converters is inevitable in DC microgrid due to the low terminal voltage levels of different RESs.


Author(s):  
Kelly S. Moreira ◽  
Diana Lermen ◽  
Leandra P. dos Santos ◽  
Fernando Galembeck ◽  
Thiago A. L. Burgo

Converting humidity into useful electrical energy was only recently demonstrated and the improvements presented in this work are not only highly energy efficient, but also contributes to the development of scalable, real-world applications.


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