Unfolded resonant converter with current doubler structure module for welding applications

A new multiphase resonant converter arrangement with series dual phase in the primary side and parallel dual current doubler in the secondary side, operating as a phase shift controlled current source is presented. Sharing the voltage and current stress among the active and passive components with a high DC input voltage and arc current motivates this structure, which also uses WBG devices to increase the efficiency at high switching frequency. The resulting module is intended to operate in continuous and pulsating mode and can be parallelized to extend the output arc current rate.This work was funded by the Spanish Ministry of Science and the EU through the project TEC2014-52316-R: ‘Estimation and Optimal Control for Energy Conversion with Digital Devices’ ECOTRENDD

Envelope-based modeling for single-phase grid-following and forming converters

The study of the interaction with the grid, including synchronization, controller design and stability assessment for 1o grid-following (GFL) and grid-forming (GFM) power converters requires an efficient modeling tool to design universal grid-connected converters considering the different grid scenarios. From the initial time-periodic system, approximated linear time-invariant (LTI) models are obtained through dynamic phasors, linearization of variables represented in a virtual synchronous rotating reference frame (RRF) or linearization in the frequency domain, i.e. harmonic linearization. The accuracy and complexity of the obtained model depend on the method used. This work proposes to use the well-known envelope modeling approach used for resonant converters but requiring the time periodic input to generate its related phase synchronization for the model. The result is a simple and accurate LTI model of 1º GFL/GFM power converter for such stability studies. The proposed 1o modeling approach is valid for any application with phase locked loop (PLL) synchronization. Simulation results validating de proposal are provided.This work has been supported by the Ministry of Science and Innovation through the project RTI2018-095138-B-C31:"Electrónica de potencia aplicada a la red eléctrica y a procesos industriales": PEGI

Frequency estimation in DSOGI cells by means of the teager energy operator

Second Order Generalized Integrator (SOGI) cells are used for notch filtering due to their simplicity and their harmonic rejection capability. SOGI and Dual SOGI (DSOGI) filter cells, combined with Frequency Locked Loops (FLL) to adjust the notch frequency, are commonly used in both 1f and 3f grid following (GFL) power converters for synchronization, i.e. SOGI-FLL and DSOGI-FLL, respectively. The FLL relies on a gradient descent method to minimize a cost function built up around one inner SOGI cell variable, e.g., the in-quadrature voltage estimation, and one outer variable, i.e. the error signal due to the SOGI filter cell. As a result, the FLL manages relatively large DC offsets and harmonic distortion passing through the outer SOGI cell variable, which deteriorates the frequency estimation and then, the SOGI-FLL performance. To attenuate such issues, the method proposed in this digest only uses inner SOGI cell variables. It minimizes the deviation between the estimated grid frequency and the frequency of the signal across the SOGI cell, which is detected through the Teager Energy Operator (TEO). The proposal is validated in simulation and experimentally.This work has been supported by the Ministry of Science and Innovation through the project RTI2018-095138-B-C31:"Electrónica de potencia aplicada a la red eléctrica y a procesos industriales": PEGIA

Emulator of a boost converter for educational purposes

Project-based learning (PBL) is proposed for the development of a Hardware-in-the-Loop (HIL) platform and the design of its digital controller for an undergraduate course on Digital Electronic Systems. The objective for students is the design of a digitally controlled HIL Boost converter, a digital pulse-width modulator (DPWM) and a current mode controller, implemented in field-programmable gate array (FPGA) devices. To this end, the di erent parts of the project are developed and evaluated, maximizing the use of FPGA resources in the design of the HIL and DPWM blocks, and applying design techniques that minimize the use of the digital resources used in the design of the controller. Students are equipped with a new individualized educational experience, allowing them to test their technical competence and knowledge in an environment close to the reality of the industry

Two-phase resonant converter to drive high-power LED lamps

This paper presents the design and modeling of a two-phase resonant converter that drives a LED lamp with a high-frequency pulsed current free of instabilities and flicker efect, fulfilling the recommendations of the IEEE PAR 1789-2015, so that it enables visible light-based communication at a 10 kB/s bit rate. The dynamic study of the converter takes into consideration the efect of the reflected impedance of the output filter on the AC side. In order to evaluate the dynamic response of the converter, a Spice model is defined. A 120 W prototype intended for street lighting applications has been built to validate the analysis and modeling.This work has been sponsored by the Spanish Ministry of Science and Innovation and the EU through the projects CICYT-FEDER-TEC2014-52316-R: “Estimation and Optimal Control for Energy Conversion with Digital Devices, ECOTRENDD” and RTI2018-095138-B-C31: “Power Electronics for the Grid and Industry Applications”

Power source electronic ballast for electrodeless fluorescent lamps

This paper presents the design, control strategy and experimental results of a two-step, power factor correction stage (PFC) and resonant inverter (RI), electronic ballast proposal to supply 150 W electrodeless fluorescent lamps (EFL). The PFC acts as a controlled power source and provides mid and long-term stability to the system, while the stability of the current through the lamp is achieved with the RI. In addition, the power-mode control requires limitation of the output voltage. The dual operation mode of the PFC (voltage source mode and power source mode) enables an e cient soft resonant ignition and the implementation of simple dimming regulation.This work has been supported by the Spanish Ministry of Science and Innovation and the EU through the projects CICYT-FEDER-TEC2014-52316-R: “Estimation and Optimal Control for Energy Conversion with Digital Devices, ECOTRENDD” and RTI2018-095138-B-C31 PEGIA: “Power Electronics for the Grid and Industry Applications”

Pulsed current source with active control of the on-time current for LED lamp driver applications

This paper presents a simplified envelope model to study the dynamics of a phase-controlled resonant converter suitable to drive light emitting diode (LED) lamps. The approximate closed form of the transfer function is obtained from the proposed reduced-order model. The fast dynamics of the resonant converter allows us implementing a pulsed current source with active control of the on-time-current free of instabilities and flicker effect with a type II or integral-single-lead controller. A 120W prototype intended for street lighting applications has been built to validate the study.This work is sponsored by the Spanish Ministry of Science and the EU through the project CICYT-FEDER- TEC2011- 23612: “Power conversion with new digital control techniques and soft-saturation magnetic cores”

Energy efficiency considerations for LED based lighting of multipurpose outdoor environments

Nowadays, street lighting accounts for 53% of outdoor lighting use, and the market is continuously increasing. In the context of rising energy prices and growing environmental awareness, energy efficiency is becoming one of the most important criteria for street lighting systems design. LED-based lights have become the primary option for replacing conventional light bulbs, being digitally controllable, small, highly efficient, and cheap to manufacture. Advanced control strategies adapted to ambient conditions are needed to combine low energy consumption and high-quality light ambience according to changing specifications. This paper describes an outdoor lighting solution aimed at energy-efficient performance in the context of multipurpose outdoor environments, where control is crucial in achieving efficiency improvements. This paper addresses efficiency at the component level, by optimizing the performance of LED drivers, and at the system level, by defining the control strategy and associated hardware infrastructure. The approach designed was tested in a real environment. The performance of the lighting installation was assessed using the Web-based monitoring application, providing real-time consumption information and aggregated historical data.This work was supported in part by the Spanish Government through the National Project “Estimation and Optimal Control for Energy Conversion with Digital Devices”, ECOTRENDD, under Grant TEC2014-52316-R, in part by ARTEMIS Joint Undertaking and the Finnish Funding Agency for Technology and Innovation through the ARTEMIS12 Project under Grant 332987

Impact of the noise on the emulated grid voltage signal in hardware-in-the-loop used in power converters

This work evaluates the impact of the input voltage noise on a Hardware-In-the-Loop (HIL) system used in the emulation of power converters. A poor signal-to-noise ratio (SNR) can compromise the accuracy and precision of the model, and even make certain techniques for building mathematical models unfeasible. The case study presents the noise effects on a digitally controlled totem-pole converter emulated with a low-cost HIL system using an FPGA. The effects on the model outputs, and the cost and influence of different hardware implementations, are evaluated. The noise of the input signals may limit the benefits of increasing the resolution of the model.This research was funded by the Spanish Ministry of Science and Innovation under Project PID2021-128941OB-I00 TRENTI–Efficient Energy Transformation in Industrial Environment

Sistema electrónico de arranque suave y de optimización de la transferencia de energía para lámparas de descarga

La presente invención consiste en un sistema electrónico de conversión de potencia para conseguir el encendido y control de las lámparas de descarga. Cuenta con los siguientes elementos: Un convertidor electrónico de potencia que transforma corriente alterna de la red en continua. Un convertidor electrónico de potencia de corriente continua a alterna de alta frecuencia (cc/ca). Un circuito resonante de autoinductancias y condensadores. Los elementos constituyen el inversor resonante. La lámpara; de baja presión de mercurio o bien de alta presión de: sodio, mercurio o halogenuros metálicos. El circuito de control del elemento que genera una señal con un valor de frecuencia y ancho de pulso ajustable. Un temporizador u otro sistema de decisión de jerarquía superior. Se enciende la lámpara mediante una aproximación suave al punto de operación. En régimen de encendido se establece automáticamente la frecuencia de operación y el ancho de pulso de control según criterios de optimización de trasferencia de potencia a la lámpara para diferentes niveles de luminosidad. El sistema presenta las ventajas de eliminar efectos estroboscopios y reducir los niveles de tensión e intensidad que soportan los componentes.Solicitud: 009900367 (17.02.1999)Nº Pub. de Solicitud: ES2153314A1 (16.02.2001)Nº de Patente: ES2153314B1 (01.09.2001