Search results for "Power converter"
showing 10 items of 43 documents
Hammerstein Model-Based Robust Control of DC/DC Converters
2007
This paper deals with model-based robust control of DC/DC power electronic converters. The converter is modelled by means of its static characteristic and a few continuous-time linear and time-invariant (LTI) models corresponding to contiguous ranges of duty-cycle. The model appears as a Hammerstein model in which the values of the parameters of the LTI part depend on the actual duty-cycle operating range. This suggests to describe the converter as an uncertain system to be controlled using robust control techniques. Frequency domain approach is used for describing the nominal model and the uncertainty. In view of applying robust control, identification of the LTI models is performed by mea…
Flexible power converters for the fault tolerant operation of Micro-Grids
2010
The progressive penetration level of Distributed Generation (DG) is destined to cause deep changes in the existing distribution networks no longer considered as passive terminations of the whole electrical system. A possible solution is the realization of small networks, namely the Micro-Grids, reproducing in themselves the structure of the main production and distribution of the electrical energy system. In order to gain an adequate reliability level of the microgrids the individuation and the management of the faults with the goal of maintaining the micro-grid operation (fault tolerant operation) is quite important. In the present paper flexible power converters and a companion control al…
Design and simulation of a fast DC recharging station for EV
2017
In this paper a detailed description of the design and simulation of a DC ultra-fast recharging station for Electric Vehicles is carried out. The system consist of a single AC/DC grid connected inverter, a DC-Bus and two DC/DC converter to recharge the batteries of the EVs. The system also has the vehicleto- grid (V2G) capability. The design of the components of the system and the control schemes are explained and a simulation of the system, performed in Matlab/Simulink environment is presented.
Effects of post-filtering in grid-synchronization algorithms under grid faults
2018
Abstract The spread of distributed generation systems has reinforced concerns and requirements on grid-tied power converters. The synchronization with the utility voltage vector is a major concern. In the literature, algorithms based on Phase Locked Loops are extensively presented. In spite of adequate performances under ideal and balanced grid conditions, under grid faults great inaccuracies arise. Shortcomings are overcome by advanced algorithms at the expenses of the complexity and computational cost. In this paper, grid synchronization algorithms are addressed. A solution is proposed by introducing a new post-filter stage in a Decoupled Double Synchronous Reference Frame not affecting, …
Power losses comparison between Silicon Carbide and Silicon devices for an isolated DC-DC converter
2021
In recent years, new efficient power devices have been implemented. Silicon Carbide has replaced silicon as regards the production and the utilization of many devices, such as MOSFETs, diodes, IGBTs and many others. SiC devices are characterized by a low reverse recovery charge, high carrier saturation velocity, by which it is possible to work at high frequency, and high breakdown voltage. Thanks to the great thermal conductivity and the wide bandgap, these devices can operate at high temperature and reach high voltages and currents. What is important to stress is the fact that power losses in SiC devices are lower than the silicon ones. These are the reasons why these devices are utilized …
NON-LINEAR INDUCTOR CONTRIBUTION TO HARMONIC SPECTRUM IN POWER CONVERTERS
The paper investigates the harmonic content in DC/DC power converters where the inductor is operated in the non-linear region. This operation is often exploited to use lighter and cheaper inductors; as a drawback, an increasing number of harmonics is noticeable. A theoretical analysis is proposed. It is based on a polynomial model of the inductor used in a boost converter. Results are given by the spectra of the output voltage performed on a circuit prototype.
Automatic EMI filter design for power electronic converters oriented to high power density
2018
In this paper, a complete computer aided procedure based on the power density concept and aimed at the automatic design of EMI filters for power electronic converters is presented. It is rule-based, and it uses suitable databases built-up by considering information on passive components available from commercial datasheets. The power density constraint is taken into consideration by imposing the minimization of the filter volume and/or weight; nevertheless, the system in which the automatically designed filter is included satisfies the electromagnetic compatibility standards limits. Experimental validations of the proposed procedure are presented for two real case studies, for which the per…
Computer Aided Optimal Design of High Power Density EMI Filters
2016
Power density of power converter systems is becoming an increasingly stringent design constraint for a wide range of applications. Size reduction of EMI filter in power converters is an important aspect due to its significant impact on the overall converter volume and weight. In order to take on this issue, a computer aided procedure for a fast selection of optimal discrete EMI filter components and configuration is described in this paper. The proposed technique is a rule-based automatic procedure based on suitable databases that consider datasheets information of commercially available passive components (e.g. magnetic cores, capacitors). It allows the minimization of the filter's volume …
Overview and performance comparison of grid synchronization algorithms
2014
Distributed power generation units are experiencing an impressive growth. Consequently, the amount of energy injected by non-linear loads as power converters is expected to increase. Stability and quality of the overall grid are heavily affected by performances of grid-side converters. In this paper, an overview of grid-synchronization technique is proposed. The grid-side inverter is implemented in MATLAB/Simulink® environment including current control and grid-synchronization section. Both Synchronous Reference Frame (SRF) and Decoupled Double Synchronous Reference Frame (DDSRF) PLL algorithms are implemented. A performance comparison is carried out under ideal and unbalanced utility condi…
Simulation and experimental validation of multicarrier PWM techniques for three-phase five-level cascaded H-bridge with FPGA controller
2017
The FPGA represents a valid solution for the design and implementation of control systems for inverters adopted in many fields of power electronics because of its high flexibility of use. This paper presents an overview and an experimental validation of the MC SPWM techniques for a three-phase, five-level, cascaded H-Bridge inverter with FPGA controller-based. Several control algorithms are here implemented by means of the VHDL programming language and the output voltage waveforms obtained from the main PWM techniques are compared in terms of THD%. Simulation and experimental results are analyzed, compared and discussed.