Search results for "switch"

Innovative Computational Approach to Harmonic Mitigation for Seven-level Cascaded H-Bridge Inverters

2020

Low frequency modulation strategies are a good solution to increase the energy conversion efficiency in high power applications. The paper is devoted to presents an innovative way to low order harmonics mitigation for seven-level Cascaded H-Bridge Inverters. In particular, this approach is based on the mitigation of selected harmonics without solve non-linear equations for an extended range of the fundamental amplitude. In fact, in real-Time operation to evaluate the control angles the polynomial equations have been identified. Through circuit simulation analysis in MatLab/PLECS environment, the effectiveness of the harmonic mitigation method has been tested and compared with theoretical re…

A Novel Computational Approach for Harmonic Mitigation in PV Systems with Single-Phase Five-Level CHBMI

2018

In this paper, a novel approach to low order harmonic mitigation in fundamental switching frequency modulation is proposed for high power photovoltaic (PV) applications, without trying to solve the cumbersome non-linear transcendental equations. The proposed method allows for mitigation of the first-five harmonics (third, fifth, seventh, ninth, and eleventh harmonics), to reduce the complexity of the required procedure and to allocate few computational resource in the Field Programmable Gate Array (FPGA) based control board. Therefore, the voltage waveform taken into account is different respect traditional voltage waveform. The same concept, known as “voltage cancelation”, used for single-…

Post extractive implant: evaluation of the critical aspects

2017

Purpose Nowadays, implant supported prosthetic rehabilitation is a reliable procedure to replace compromised or untreatable teeth. The purpose of this review is to explore the concept of post extractive implant and the indications for clinical practice through an analysis of recent studies in the literature. All the main factors that could influence the outcome of this treatment will also be considered. Materials and methods Focusing on the extraction-socket healing time, three different implant insertion protocols have been defined: Immediate implant placement (IIP), Early implant placement (EIP), Delayed implant placement (DIP). The entity of bone remodeling can be associated with differe…

Characterization of inductors in partial saturation for SMPS applications

2017

The exploitation of partially saturated inductors in Switching Mode Power Supply (SMPS) is a key strategy for reducing the size of SMPS and increasing their power density [1]. However an accurate characterization and modellization of each inductor is needed for a correct design and control of the SMPS [2]. Most of inductors' datasheets only indicate the nominal inductance at low current. Anyway, when the inductor is subjected to a higher current, the value of the inductance is lessened. Moreover, inductance meters often actuate their measurements at no or moderate DC bias. In this work we describe the realization of an automated test bench (Fig. 1) for characterizing an inductor under varia…

Fuel cells for household appliances: Experimental test of power management algorithms

2013

In this paper, fuel cell - based hybrid power supplies for household appliances are addressed. The profile of residential power consumption is evaluated during working, non-working days in both summer and winter periods. The worst-case load power demand is therefore highlighted. A 5kW Nuvera PowerFlow proton exchange membrane fuel cell for household appliances is tested. On the basis of the characterization of the fuel cell stack under test, stand-alone and fuel cell - battery active hybrid power supply architectures are both considered. Experimental validation of three power management algorithms is proposed in terms of hydrogen consumption, cost and energy saving. Power management algorit…

Power system consumption model using SPICE

2014

Space missions have very stringent mass, volume and also power budgets. This requires very precise knowledge of the power consumption of the whole satellite, not only peak power but also static and long term dynamic power. This calculation becomes very complex if all the operational modes (long term dynamic changes) are taken into account, including the different environmental situations. The power budget of any Power Converter Module (PCM), which includes not only the DC/DC converter but also the distribution unit, depends on the power it delivers and on external factors like temperature and input voltage. We propose to use a linear SPICE model using electronic models of discrete component…

Design of a solar-battery-thermoelectric power converter prototype

2015

In this paper a multisource renewable energy system for high-current applications is proposed. The power architecture is based on a multi-input power converter including control and reconfiguration subsystems. Independently of the type of connected renewable sources, a proper control of the output DC voltage bus is provided as well as a proper control on the operating point of each renewable source to achieve the maximum power transfer. A 48V thermoelectric-photovoltaic-battery system in a three input configuration is designed. Three interacting feedback networks are implemented: the outer loop which controls the output voltage and as many inner loops as connected renewable sources to achie…

Performance evaluation of a multisource renewable power converter prototype

2014

Pantilliset on tour : Code-switching in Finnish magazine advertisements

2010

 Mainonnan määrä lisääntyy eri medioissa ja sen myötä mainonta vaikuttaa käyttäytymiseemme yhä enemmän. Maailman globalisoituessa englannin kielen rooli muuttuu myös mainonnassa. Englanti on usein monikielisen mainonnan suosituin vieras kieli maailmanlaajuisesti ja sitä hyödynnetään suomalaisessa lehtimainonnassa yhä enenevässä määrin. Englannin kieltä sekä englannin ja suomen kielen välistä koodinvaihtoa suomalaisessa mainonnassa on tutkittu aiemminkin, mutta huomioimatta on jäänyt englannin kielen määrä suomen kieleen verrattuna. Tämän kandidaatintutkielman tarkoituksena oli selvittää missä suhteessa suomen kieli on korvattu englannin kielellä kahden suomalaisen yleisaikakauslehtien, Imag…

Asset Return Dynamics under Alternative Learning Schemes

2009

In this paper we design an artificial financial market where endogenous volatility is created assigning to the agents diverse prior beliefs about the joint distribution of returns, and, over time, making agents rationally update their beliefs using common public information. We analyze the asset price dynamics generated under two learning environments: one where agents assume that the joint distribution of returns is IID, and another where agents believe in the existence of regimes in the joint distribution of asset returns. We show that the regime switching learning structure can generate all the most common stylized facts of financial markets: fat tails and long-range dependence in volati…