Optimisation and Management of Energy Generated by a Multifunctional MFC-Integrated Composite Chassis for Rail Vehicles

With the advancing trend towards lighter and faster rail transport, there is an increasing interest in integrating composite and advanced multifunctional materials in order to infuse smart sensing and monitoring, energy harvesting and wireless capabilities within the otherwise purely mechanical rail structures and the infrastructure. This paper presents a holistic multiphysics numerical study, across both mechanical and electrical domains, that describes an innovative technique of harvesting energy from a piezoelectric micro fiber composites (MFC) built-in composite rail chassis structure. Representative environmental vibration data measured from a rail cabin have been critically leveraged here to help predict the actual vibratory and power output behaviour under service. Time domain mean stress distribution data from the Finite Element simulation were used to predict the raw AC voltage output of the MFCs. Conditioned power output was then calculated using circuit simulation of several state-of-the-art power conditioning circuits. A peak instantaneous rectified power of 181.9 mW was obtained when eight-stage Synchronised Switch Harvesting Capacitors (SSHC) from eight embedded MFCs were located. The results showed that the harvested energy could be sufficient to sustain a self-powered structural health monitoring system with wireless communication capabilities. This study serves as a theoretical foundation of scavenging for vibrational power from the ambient state in a rail environment as well as to pointing to design principles to develop regenerative and power neutral smart vehicles

System-level modelling and validation of a strain energy harvesting system by directly coupling finite element and electrical circuits

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.— There is a lack of system-level finite element (FE) model which can directly predict the performance of a piezoelectric energy harvester connected with interface circuits and electric load. This work developed a system-level model of piezoelectric strain energy harvesting system by directly coupling the finite element and electrical circuits. The strain energy harvester (SEH) is a macro fibber composite adhesively bonded to a composite beam. Simulations were performed with the SEH connected with three circuits individually (i) a load resistor, (ii) a rectifier terminated with a load resistor and (iii) a rectifier terminated with a smoothing capacitor and a load resistor. Experimental tests were carried out to validate the simulation results. Good agreements were observed between the simulated and measured results. The developed model is able to predict the performance of the energy harvesting system when different circuit was connected. The validated system-level model can be used for the design and optimization of piezoelectric energy harvesting system by investigating the interactions between energy harvester and electrical circuits

Energy harvesting technologies for structural health monitoring of airplane components - a review

With the aim of increasing the efficiency of maintenance and fuel usage in airplanes, structural health monitoring (SHM) of critical composite structures is increasingly expected and required. The optimized usage of this concept is subject of intensive work in the framework of the EU COST Action CA18203 "Optimising Design for Inspection" (ODIN). In this context, a thorough review of a broad range of energy harvesting (EH) technologies to be potentially used as power sources for the acoustic emission and guided wave propagation sensors of the considered SHM systems, as well as for the respective data elaboration and wireless communication modules, is provided in this work. EH devices based on the usage of kinetic energy, thermal gradients, solar radiation, airflow, and other viable energy sources, proposed so far in the literature, are thus described with a critical review of the respective specific power levels, of their potential placement on airplanes, as well as the consequently necessary power management architectures. The guidelines provided for the selection of the most appropriate EH and power management technologies create the preconditions to develop a new class of autonomous sensor nodes for the in-process, non-destructive SHM of airplane components.The work of S. Zelenika, P. Gljušcic, E. Kamenar and Ž. Vrcan is partly enabled by using the equipment funded via the EU European Regional Development Fund (ERDF) project no. RC.2.2.06-0001: “Research Infrastructure for Campus-based Laboratories at the University of Rijeka (RISK)” and partly supported by the University of Rijeka, Croatia, project uniri-tehnic-18-32 „Advanced mechatronics devices for smart technological solutions“. Z. Hadas, P. Tofel and O. Ševecek acknowledge the support provided via the Czech Science Foundation project GA19-17457S „Manufacturing and analysis of flexible piezoelectric layers for smart engineering”. J. Hlinka, F. Ksica and O. Rubes gratefully acknowledge the financial support provided by the ESIF, EU Operational Programme Research, Development and Education within the research project Center of Advanced Aerospace Technology (Reg. No.: CZ.02.1.01/0.0/0.0/16_019/0000826) at the Faculty of Mechanical Engineering, Brno University of Technology. V. Pakrashi would like to acknowledge UCD Energy Institute, Marine and Renewable Energy Ireland (MaREI) centre Ireland, Strengthening Infrastructure Risk Assessment in the Atlantic Area (SIRMA) Grant No. EAPA\826/2018, EU INTERREG Atlantic Area and Aquaculture Operations with Reliable Flexible Shielding Technologies for Prevention of Infestation in Offshore and Coastal Areas (FLEXAQUA), MarTera Era-Net cofund PBA/BIO/18/02 projects. The work of J.P.B. Silva is partially supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/FIS/04650/2020. M. Mrlik gratefully acknowledges the support of the Ministry of Education, Youth and Sports of the Czech Republic-DKRVO (RP/CPS/2020/003

Piezoelectric energy harvesting solutions

This paper reviews the state of the art in piezoelectric energy harvesting. It presents the basics of piezoelectricity and discusses materials choice. The work places emphasis on material operating modes and device configurations, from resonant to non-resonant devices and also to rotational solutions. The reviewed literature is compared based on power density and bandwidth. Lastly, the question of power conversion is addressed by reviewing various circuit solutions

Low power adaptive power management with energy aware interface for wireless sensor nodes powered using piezoelectric energy harvesting

A batteryless power management circuit incorporating an energy aware interface (EAI) for wireless sensor nodes (WSNs) powered by piezoelectric energy harvester (PEH) has been proposed and implemented. Traditional power management usually requires two DC-DC converters, each for maximum power point tracking (MPPT) and voltage regulation functionalities. The proposed circuit requires only one DC-DC converter for both the MPPT and voltage regulation. The EAI also provides a means to voltage regulation. This allows the circuit to have higher efficiency as the energy transfer does not have to go through two stages to reach the load. A PEH connected to the proposed circuit was tested under various vibration conditions. The circuit was found to have end-to-end efficiency of about 66% under most of the test conditions.Innovate UKEngineering and Physical Sciences Research Counci

Energy efficient processor operation and vibration based energy harvesting schemes for wireless sensor nodes

A wireless Sensor Network (WSN) is a network of spatially distributed autonomous sensors deployed in the environment in order to cooperatively monitor physical or environmental conditions such as temperature, sound, pressure, motion or pollutants at different locations. Each node in a sensor network is equipped with a radio transceiver, a microprocessor and an energy source such as a battery which should be replaced periodically. To increase the lifetime of the network keeping the small size in mind, methods should be put in place to reduce the power consumption of the sensor node or increase the node life and/or to supply power to the battery from external sources. In this thesis, the first paper presents an energy-efficient frequency adaptation based approach to minimize the power consumption of the microprocessor in an attempt to increase the lifetime of the sensor node...The second paper, on the other hand, presents an energy harvesting circuitry to charge the battery of the sensor node so that the time to replacement can be extended --Abstract, page iv

Energy Harvesting for Tire Pressure Monitoring Systems

Tire pressure monitoring systems (TPMSs) predict over- and underinflated tires, and warn the driver in critical situations. Today, battery powered TPMSs suffer from limited energy. New sensor features such as friction determination or aquaplaning detection require even more energy and would significantly decrease the TPMS lifetime. Harvesting electrical energy inside the tire of a vehicle has been considered as a promising alternative to overcome the limited lifetime of a battery. However, it is a real challenge to design a system, that generates electrical energy at low velocities while being robust at 200 km/h where radial accelerations up to 20000 m/s2 occur. This work focusses on developing different electromechanical energy transducers that meet the high requirements of the automotive sector. Different approaches are addressed on how the change of acceleration and strain within the tire can be used to provide mechanical energy to the energy harvester. The energy harvester converts the mechanical energy into electrical energy. In this thesis, piezoelectric and electromagnetic transducers are discussed in depth, modelled as electromechanical networks. Since the transducers provide energy in the form of an AC voltage, but sensors require a DC voltage, various common interface circuits are compared, using LTspice and applying method of the stochastic signal analysis. Furthermore, a buck-boost converter concept for the electromagnetic energy harvester is optimized and improved. Experiments on a tire test rig validate the theoretically determined output and confirm that well designed energy harvesters in the tire can generate much more energy than required by an TPMS not only at high velocities but also at velocities as low as 20 km/h

DESIGN OF RECTIFIED PIEZOELECTRIC POWER GENERATORS BY FINITE ELEMENT METHODS

ABSTRACT The article proposes designing rectified piezoelectric power generators based on the direct finite element method. It accounts for the consideration of common interface circuits such as the standard and parallel-/series-SSHI (synchronized switch harvesting on inductor) circuits, and complicated structural configurations such as arrays of piezoelectric oscillators. The proposed model suggests replacing the energy harvesting circuit by an equivalent load impedance in series with negative piezoelectric capacitance. As the expression of the equivalent load impedance can be explicitly derived, the proposed finite element approach is capable of handling common interface circuits without resorting to circuit solvers. Finally, the model is extended to the consideration of SECE (synchronized electric charge extraction) circuit which offers an advantage of independence of harvested power on external loads. INTRODUCTION Tremendous efforts have been made for developing vibration-based piezoelectric energy harvesting due to the ubiquitous presence of ambient vibrations as well as high electromechanical coupling in piezoelectric material

Smart Materials and Devices for Energy Harvesting

This book is devoted to energy harvesting from smart materials and devices. It focusses on the latest available techniques recently published by researchers all over the world. Energy Harvesting allows otherwise wasted environmental energy to be converted into electric energy, such as vibrations, wind and solar energy. It is a common experience that the limiting factor for wearable electronics, such as smartphones or wearable bands, or for wireless sensors in harsh environments, is the finite energy stored in onboard batteries. Therefore, the answer to the battery “charge or change” issue is energy harvesting because it converts the energy in the precise location where it is needed. In order to achieve this, suitable smart materials are needed, such as piezoelectrics or magnetostrictives. Moreover, energy harvesting may also be exploited for other crucial applications, such as for the powering of implantable medical/sensing devices for humans and animals. Therefore, energy harvesting from smart materials will become increasingly important in the future. This book provides a broad perspective on this topic for researchers and readers with both physics and engineering backgrounds