Publications related to Frequency changer

Dc-Link Ripple Suppression of Cascaded H-Bridge Based MV Grid Emulator Apparatus for Analysis and Testing of Grid-Tied Converters in Distribution System

Drazen Dujic, Chengmin Li, Jing Sheng, Xin Xiang

The medium-voltage grid emulator is gaining popularity for testing grid-code compliance of large-capacity converters for renewable energy resources. The cascaded H-bridge converter based on active-front-ends is a promising candidate for high-power grid emu ...

2023

Methods for Calibrating the Electrochemical Quartz Crystal Microbalance: Frequency to Mass and Compensation for Viscous Load

Stefano Mischler, Anna Neus Igual Muñoz

The main output from an Electrochemical Quartz Crystal Microbalance is a frequency shift. This note describes how to separate the mass- and viscous load contributions to this shift by a calibration procedure. The mass calibration is made by electroplating ...

MDPI2023

SOFTGATE – An IGCT Gate Unit for Soft Switching

Drazen Dujic, Jakub Kucka

This paper presents an IGCT unit that has been tailored for emerging soft-switching high-power applications. Redefining the state-of-the-art design and driving concepts, the size and consumption of the proposed unit can be reduced significantly. The paper ...

2022

High frequency IGCT operation for DC transformer

Gabriele Ulissi

In spite of the dominance of ac technology for the vast majority of power transmission and distribution since the late 19th century, the past decades have seen an increase in use of dc electrical power. In particular, this has been the case both in high vo ...

EPFL2022

On the Maximum Power Density of Implanted Antennas within Simplified Body Phantoms

Anja Skrivervik, Mingxiang Gao, Zvonimir Sipus

With the application requirements of wireless technology in implantable bioelectronics, knowledge of the fundamental limits for implanted antennas becomes critical. In this work, we investigated the variation of maximum power density within simplified body ...

IEEE2022

A dc/dc converter and a method for operating a dc/dc converter

Drazen Dujic, Jakub Kucka

The present invention relates to a DC/DC converter (1) for transferring an active power between two DC subsystems (5, 6) comprising: - a first converter stage (3) and a second converter stage (4) both configured to be selectively operated as an active inve ...

2022

Physical Bounds on Implant Powering Efficiency Using Body-Conformal WPT Systems

Anja Skrivervik, Denys Nikolayev, Zvonimir Sipus, Mingxiang Gao

The efficiency of an on-body wireless power transfer system for implant powering is defined by how the electromagnetic energy interacts with the lossy, heterogeneous, and dispersive body tissues. The objective of this study is to discuss the methodology an ...

IEEE2021

High Frequency Operation of Series-Connected IGCTs for Resonant Converters

Drazen Dujic, Gabriele Ulissi

Series connected IGCTs find application in hard-switched commercial power converters at the MW power levels. Expanding the application of these devices to medium voltage dc-dc resonant converters is of great interest due to the IGCTs low conduction losses. ...

2021

ANTIGONE: A Programmable Energy-Efficient Current Digitizer for an ISFET Wearable Sweat Sensing System

Maher Kayal, Evgenia Voulgari, François Krummenacher

This article describes the design and the characterization of the ANTIGONE (ANalog To dIGital cONvErter) ASIC (Application Specific Integrated Circuit) built in AMS 0.35 m technology for low dc-current sensing. This energy-efficient ASIC was specifically d ...

2021

Real-time Control of Battery Energy Storage Systems to Provide Ancillary Services Considering Voltage-Dependent Capability of DC-AC Converters

Mario Paolone, Sidi-Rachid Cherkaoui, Antonio Zecchino, Zhao Yuan

Frequency response and voltage support are vital ancillary services for power grids. In this paper, we design and experimentally validate a real-time control framework for battery energy storage systems (BESSs) to provide ancillary services to power grids. ...

2021

Optimized kW-Range Boost Converter Based on Impulse Rectification with 52 kW/l and 98.6% Efficiency

Elison de Nazareth Matioli, Remco Franciscus Peter van Erp, Armin Jafari

Maximizing the efficiency and power density of dc-dc converters demands parallel optimizations in design and control, especially for variable-frequency converters operating over wide frequency ranges. This work presents the full-scale optimization of a kil ...

2021

Fully Soft-Switched High Step-Up Nonisolated Three-Port DC-DC Converter Using GaN HEMTs

Marco Mattavelli, Elison de Nazareth Matioli, Georgios Kampitsis, Rasoul Faraji

In this article, a soft-switched nonisolated high step-up multi-input dc-dc converter is proposed. The proposed converter has overcome the hard switching problem of the conventional boost three port converter (boost-TPC) by providing zero-voltage-switching ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2020

Highly tunable second-harmonic generation in all-optically poled silicon nitride waveguides

Camille Sophie Brès, Anton Stroganov, Ozan Yakar, Edgars Nitiss

The availability of nonlinear parametric processes, such as frequency conversion in photonic integrated circuits is essential. In this contribution, we demonstrate a highly tunable second-harmonic generation in a fully complementary metal–oxide–semiconduct ...

2020

IGCT Based Solid State Resonant Conversion

Dragan Stamenkovic

Driven by the environmental changes, penetration of renewables and the need for more flexible power grid, DC is reemerging as a basis for future power networks. Already established in the area of HVDC for very long distance transmission, more and more atte ...

EPFL2020

Design of an Energy-Efficient Current-to-Frequency Converter for a Wearable Sensor Platform

Maher Kayal, Evgenia Voulgari, François Krummenacher

This paper presents the design of the ANTIGONE ASIC in AMS 0.35 mu m technology that interfaces with ion-sensitive field effect transistors (ISFETs) to detect biomarkers like pH, Na+ and K+ in human sweat. The ISFET sensors generate a low current dc signal ...

IEEE2019

Impact of Fundamental Frequency Definition in IpDFT-based PMU Estimates in Fault Conditions

Mario Paolone, Asja Derviskadic, Guglielmo Frigo

In modern power systems, frequency measurements are employed in many monitoring and control applications. In this context, Phasor Measurement Units (PMUs) may represent a promising solution in view of a distributed and synchronized measurement infrastructu ...

IEEE2019

Tuning high-Q nonlinear dynamics in a disordered quantum magnet

Gabriel Aeppli

Quantum states cohere and interfere. Atoms arranged imperfectly in a solid rarely display these properties. Here we demonstrate an exception in a disordered quantum magnet that divides itself into nearly isolated subsystems. We probe these coherent spin cl ...

Nature Research2019

Analysis of photosensor frontends for biomedical applications: a focus on noise

Paul Stanislas Gosselin

Photosensing has proven to be highly useful in biomedical research and medical care. Being able to detect and quantify the light emitted by fluorescent or bioluminescent reporters has significantly participated in the development of new cancer treatments a ...

EPFL2019

A programmable low-power ADC interface for an ISFET sweat sensor used in a wearable multi-sensing system

Maher Kayal, Evgenia Voulgari, François Krummenacher

An application specific integrated circuit (ASIC) named ANTIGONE (ANalog To dIGital cONvErter) was designed in AMS 0.35 mu m technology to interface with four Ion-sensitive field-effect transistor (ISFET) sensors and perform real-time monitoring of some bi ...

IEEE2019

Multimode microwave circuit optomechanics as a platform to study coupled quantum harmonic oscillators

Nathan Rafaël Bernier

Harmonic oscillators might be one of the most fundamental entities described by physics. Yet they stay relevant in recent research. The topological properties associated with exceptional points that can occur when two modes interact have generated much int ...

EPFL2019