1,720,991 research outputs found
METODO DI PILOTAGGIO DI UN MEZZO PONTE ATTIVO COMPRENDENTE ALMENO DUE TRANSISTORI, CIRCUITO DI PILOTAGGIO DI CIASCUN TRANSISTORE DEL MEZZO PONTE E RELATIVO SCHEMA DI MODULAZIONE PERIODICO DI SEGNALI DI COMANDO
No full textBidirectional Bootstrapped Gate Driver for High-density SiC-based Automotive DC/DC Converters
No full textDesign and Control of a High-density High-voltage Smart Converter for Food Ohmic Heating
No full textThe design of an innovative converter for ohmic heating of fluid foods is presented. Application-specific requirements are addressed with new solutions and verified on a commercial-size 60 kW prototype. A multi-output high-voltage (0.8 to 4 kV) transformer with automatic tap change enriches a basic H-bridge topology, enabling processing of a wide set of foods and allowing grounding one of the outputs. High power density is achieved by power switches Pareto optimization in the reliability-efficiency objectives and by pushing the switching frequency up to 30 kHz, solving the electrode corrosion problem, too. Reproducible and reliable operation is assured by three different control strategies: load variability is dealt with a high-dynamics power control, repeatable output is guaranteed by input voltage compensation, optimal working point is ensured by control of the transformer primary current DC component. This last control allows also removing the output capacitors, improving density metrics with respect to the state-of-the-art. Analytical models for all control strategies are given to support dynamic performance tuning while guaranteeing stability
Stability and performance analysis of a voltage controlled resistor circuit for wide band-gap device gate drivers
No full textWide band-gap devices are making inroads in the power converters scenario, and specific circuits to drive these components are actively under development. The purpose of this paper is to analyze, from the stability and dynamic performance point of view, a Voltage Controlled Power Resistor (VCPR), that can be used to control the gate resistance of the device driver with values over a continuous range. Parametric analysis, SPICE simulations and experimental outcomes are presented, in order to determine circuit characteristics. Results show that the proposed topology is stable under a wide range of electric parameters, and suggest that the circuit bandwidth can be tuned in order to benefit from the VCPR in a wide band-gap device gate driver
Design, Control and Prototyping of a Bidirectional Dual Active Bridge Converter for integrating a Sodium Metal Halide Battery into a Telecom Station
No full textThe paper presents the design, control and prototyping of a Dual Active Bridge converter (DAB) devoted to interface a Sodium Metal Halide Battery (SMHB) to the DC grid of a telecom station. The design process is accomplished starting from telecom DC supply and SMHB specifications, especially power and voltage ratings and their corresponding variation ranges. Furthermore, DAB components are selected carefully based on an extensive performance analysis to maximise the energy efficiency, by enabling Zero-Voltage Switching (ZVS) over wide power and voltage operating ranges. The effectiveness of the proposed configuration is guaranteed also by a nested PI-based control system, which avoids unsuitable DC-bias current components by a proper management of phase-shift variations. Both simulations and experiments are presented and discussed, which corroborate the validity of all the design solutions
Assessing the Economic Feasibility of PV-BESS Systems in Connection with Pandemic-induced Loads
No full textCOVID-19 has impacted on energy (uses, load pro-files) and mobility (patterns, means of transport). The change can create a fertile environment for local renewable generation, energy storage, and electrical mobility. In this context, the scope of this work is to assess the economic feasibility of a residential system of PV generation, electrochemical storage, and charging point, following pandemic-induced loads. First, the prospected impact is estimated via a simplified model. Then, a dynamic model is used to simulate the system operation subjected to a rule-based control. Different scenarios are considered, to assess the impact of the pandemic. The results show that the pandemic loads increase the savings from the PV-BESS system, +36% in the presence of a home-charged EV and +40% in its absence. Further savings can be theoretically achieved by tailoring the system design to the specific load demand
Comparing control topologies for wide-bandgap power-device drivers: A simulation study
No full textWide-bandgap power switches, based on SiC and GaN, are emerging on the semiconductor market. Standard resistor drivers are insufficient to exploit all the advantages of these new devices. Fine control over current and voltage waveforms during switching, equivalent on-state resistance and immunity to noisy environments, demand the development of dedicated drivers. This study aims at determining a suitable control topology for the gate (or base) terminal of the power device, in order to enact regulation of the switching waveforms and performances. Four different topologies, both open- and closed-loop are simulated, examined, and compared with the standard resistor driver
Design of a control unit for advanced gate drivers featuring adaptive dead-time and diagnostics
No full textThe growing demand for high-performance power converters calls for the adoption of new strategies, not only in architectures, but also in electronic technologies. To take full advantage of wide-bandgap semiconductor (SiC, GaN) power devices, and to exploit their amazing capabilities, dedicated drivers need to be developed. This paper presents a control unit for advanced gate drivers, based on a finite-state machine (FSM), and discusses design criteria; the proposed design is verified by simulation in Matlab-Simulink. The presented automaton not only «follows» the power switch during its state transitions, but features also automatic dead-time insertion when the switch is operated in bridge configurations, and is able to provide important diagnostic and self-test information
Wavelet-based prognostic-oriented temperature sensing with sigma-delta ADCs in power applications
No full textThermal stress is one of many possible failure causes of power electronics systems; thermal cycles are known to produce mechanical fatigue on power electronic devices, thus leading to their failure in time. Temperature swing can be somehow controlled, if some decrease in efficiency can be tolerated by the power system, changing gate driver parameters to heat up the device in low load conditions. This is known as Active Thermal Control (ATC). To implement ATC, the temperature information of devices is needed. Since this sensing is carried out near power conductors, switched at high frequency, strong disturbances will affect the reading. This paper proposes a new signal-conditioning scheme based on discrete wavelet transform (DWT) and compares it to some established filtering techniques to assess which is most suitable for the application. Hints about insulation of measuring equipment will be given, too. Moreover, the possibility offered by the algorithms to store long-Time temperature information (through compression of incoming data) will be described, as large-span observation can help prognostic algorithms in forecasting the remaining useful life of the power apparatus
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