Elisenda Bou-Balust

Scalability Analysis of SIMO Non-Radiative Resonant Wireless Power Transfer Systems Based on Circuit Models

Resonant inductive coupling wireless power transfer (RIC-WPT) is a leading field of research due to the growing number of applications that can benefit from this technology: from biomedical implants to consumer electronics, fractionated spacecraft, and electric vehicles, amongst others. However, applications are currently limited to point-to-point-links and do not target single input-multiple output (SIMO) scenarios. New challenges and applications of resonant non-radiative wireless power transfer emphasize the necessity to explore, predict, and assess the behavior of RIC-WPT in SIMO links. Moreover, new system-level metrics have to be derived to study the scalability of multi-point wireless power transfer applications and to provide design guidelines for these systems. In this article a single input-multiple output RIC-WPT system is modeled analytically from a circuit-centric point of view and validated using a finite element field solver. The analytical model and associated closed formulation is finally used to derive system-level metrics to predict the behavior and scalability of RIC SIMO systems, showcasing the results for an asymmetric SIMO scenario.

3Cat-1 project: a multi-payload CubeSat for scientific experiments and technology demonstrators

ABSTRACT This article introduces 3Cat-1, the first project of the Technical University of Catalonia to build and launch a nano-satellite. Its main scope is to develop, construct, assemble, test and launch into a low Earth orbit a CubeSat with seven different payloads (mono-atomic oxygen detector, graphene field-effect transistor, self-powered beacon, Geiger radiation counter, wireless power transfer (WPT), new topology solar cells and WPT experiment), all fitted in a single-unit CubeSat. On one hand, this is mainly an educational project in which the development of some of the subsystems is carried out by undergraduate and postgraduate students. The satellite demonstrates its capabilities as a cost-effective platform to perform small scientific experiments and to demonstrate some of the new technologies that it incorporates.

On tunable switch-mode reactive networks: A gyrator-based resonator emulation

This paper introduces the concept of switch-mode tunable emulated reactive networks. The idea of implementing reactive networks based on the theory of gyrators is proposed and characterized in an application-driven design-oriented context. By means of using switch-mode power processing converters to synthesize gyrators, small capacitors or inductors are effectively multiplied to emulate larger ideally lossless reactive elements. The proposed idea enables to electronically tune the values of reactive elements by means of timing control variables. The proposed tunable reactive networks target many potential applications such as tunable-front-ends for energy harvesting, electronic compensating active power filters, and tunable-front-ends for wireless power transfer links.

On autonomous software architectures for distributed spacecraft: A Local-Global Policy

New trends such as satellite swarms or fractionated spacecraft have experienced a very significant growth in the last decade. Migration from monolithic satellite architectures to new mission architectures involving large constellations of collaborative spacecraft is enabled by several hardware technologies and the application of modularity-driven designs, and presents numerous benefits such as low development costs and times and high flexibility. This has forced the exploration of new techniques and designs which have been often tackled from the hardware perspective but scarcely approached from the software architecture standpoint. This paper presents an autonomous software architecture and a management policy targeted for the broad range of distributed architecture missions. The paper presents the Local-Global approach, an adaptive management policy based on the collaboration between two levels of control which is aimed at enabling distributed mission control in dynamic and changing environments with limited computational capabilities. The Local- Global policy establishes the behaviouralmodel of a systemcomposed of a master scheduler and an arbitrary number of local schedulers, and describes the parameters that can be adjusted to reduce the amount of information processed by the master node which makes it suitable for different distributed spacecraft architectures.

Advances in non-radiative resonant inductive coupling wireless Power Transfer: A comparison of alternative circuit and system models driven by emergent applications

Recent research in wireless power transfer (WPT) using resonant inductive coupling has demonstrated very high efficiencies at large distances compared to the transmitting element dimensions, thereby increasing the number of potential applications of WPT. Since resonant inductive coupling is a very multidisciplinary field of research, different approaches have been proposed to predict the behaviour of these systems from the physical theory of resonators (coupled-mode theory) and circuit theory. Although the equivalence of these models for a point-to-point link has already been studied together with the performance metrics Power Transferred to the Load (PTL) and Power Transfer Efficiency (PTE), the new challenges and applications of this technology emphasize the necessity of analytical models to predict and assess the behavior of Multiple Input - Multiple Output (MIMO) links. In this article we revisit the current analytical models from the MIMO perspective, derive the analytical equations for the equivalent performance metrics PTE and PTL and demonstrate how to maximize them in a non-radiative resonant wireless power transfer link from a circuit-centric point of view, providing design guidelines in terms of optimal source and load impedances. This work concludes with a prospective discussion on open challenges of WPT.

Switch-mode gyrator-based emulated inductor enabling self-tunability in WPT receivers

Magnetic resonance wireless power transfer (WPT) is a very promising technology for a wide range of applications. The transmission range and efficiency of wireless power transfer have been reasonably enhanced by resonating transmitter and receiver coil at a common frequency. The transmitter and receiver sides have to be perfectly tuned, otherwise power transfer capability is greatly reduced. This paper discusses the detuning effect of parallel compensated receivers, and thereof a novel self-tuning method and related circuit topology and control is proposed and characterized in the system application. The proposed method is based on the concept of switch-mode gyrator emulating variable lossless inductors oriented to enable self-tunability in WPT receivers.

Unveiling nonlinear dynamics in resonant inductively coupled wireless power transfer

Coupled magnetic resonance is considered to be a key enabling technology for mid-range wireless power transfer. Models and systems have hitherto considered linear resonators as underlying dynamics, thereby limiting practical deployability due to the extreme sensitivity in front of parameter mismatch and resonance detuning. In this work, structural nonlinear modeling of constituent elements of the resonant link-resonant coils- is considered to unveil the existence of nonlinear dynamic regimes. The methodology considered to explore the nonlinear behavior is based on a behavioral model consisting of state equations, Floquet theory and Filippov method to study the stability of the periodic regime through the associated monodromy matrix. The ultimate aim of the investigation is a design-oriented parameter space exploration which characterizes the border of occurrence of the different dynamic modes in wireless power transfer links.