The current climatic scenario requires the use of innovative solutions to increase the production of electricity from renewable energy sources. Multilevel Power Inverters are a promising solution to improve the penetration of renewable energy sources into the electrical grid. Moreover, the performance of MPIs is a function of the modulation strategy employed and of its features (modulation index and switching frequency). This paper presents an extended and experimental analysis of three-phase five-level Cascaded H-Bridges Multilevel Inverter performance in terms of efficiency and harmonic content considering several MC PWM modulation strategies. In detail, the CHBMI performance is analyzed by varying the modulation index and the switching frequency. For control purposes, the NI System On Module sbRIO-9651 control board, a dedicated FPGA-based control board for power electronics and drive applications programmable in the LabVIEW environment, is used. The paper describes the modulation strategies implementation, the test bench set-up, and the experimental investigations carried out. The results obtained in terms of Total Harmonic Distorsion (THD) and efficiency are analyzed, compared, and discussed.

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-phase cascaded H-bridge inverters, has been applied at a single-phase five-level cascaded H-bridge multilevel inverter (CHBMI). Through a very basic methodology, the polynomial equations that drive the control angles were detected for a single-phase five-level CHBMI. The acquired polynomial equations were implemented in a digital system to real-time operation. The paper presents the preliminary analysis in simulation environment and its experimental validation.It is well known that the fundamental multilevel topologies include the diode-clamped [4-6], flying capacitor [7], and cascaded H-bridge (CHB) structures [8]. Diode-clamped technology employs diodes to separate direct current (DC) voltage levels from one DC source at its midpoint. The flying capacitor technique substitutes diodes with capacitors. The cascaded H-bridge technique employs different DC sources to create different DC voltage levels.An interesting review can be found in the literature [9], which also takes into account the inverter's cost, by taking the factors numbers sources, switches, and variety. In the works of [10][11][12], good reviews are also performed.Inverters can also be classified according to their applications [10]: renewable energy applications [11][12][13][14][15][16][17][18][19][20][21], automotive [22][23][24][25][26][27], heavy traction [28,29], power quality [30,31], and industrial drives [32,33]. In the literature [13], the performance in terms of harmonics distortion rates were faced in order to extract maximum power from the PV modules. Again, that authors of [14,15] face the harmonics distortion by implementing a fast switching modulation, but without considering power losses. The authors of [16] recommend a single phase multilevel inverter configuration with three series connected full bridge inverter and a single half bridge inverter. In this case, a reduction of harmonics in terms of total harmonic distortion rate (THD) is evaluated around 9.85%. In another paper [17], a spice model considers not only the THD, but also the storage element. Again, in the literature [18], a simulation of the performance of multilevel inverter is made taking into account the partial shaded condition of PV panels. In the work of [19], a multilevel invert is used to reduce the THD. The simulation generates a 15-level output voltage with 8.12% of total har...

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The diffusion of electric vehicles in Italy has started but some complications weight its spread. At present, hybrid technology is the most followed by users, due particularly to socioeconomic factors such as cost of investment and range anxiety. After a deep discussion of the Italian scenario, the aim of the paper is to recognize whether fuel cell technology may be an enabling solution to overcome pollution problems and respect for the environment. The opportunity to use fuel cells to store electric energy is quite fascinating—the charging times will be shortened and heavy passenger transport should be effortless challenged. On the basis of the present history and by investigating the available information, this work reports the current e-mobility state in Italy and forecasts the cities in which a fuel cell charging infrastructure should be more profitable, with the intention of granting a measured outlook on the plausible development of this actual niche market.

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