scholarly journals High Gain Transformer-less DC/AC Inverter for PV System

2021 ◽  
Vol 2129 (1) ◽  
pp. 012065
Author(s):  
I A Zunnurain ◽  
M F Hariz ◽  
S M Ilham ◽  
N Kimpol ◽  
M N K Anuar ◽  
...  

Abstract Investigation interests on many scientific aspects of photovoltaic (PV) trans-former-less inverter system has improved over the past decade. Using step-up transformer or high frequency transformer in electrical system has made the entire system expensive and voluminous. There is alternative topology to replace the transformer by implementing DC/DC quadratic boost converter to expand the voltage from 12VDC to 325VDC from the photovoltaic (PV) solar and convert it to AC applying H-bridge inverter circuit. This method will replace the conventional method of bulky transformer into a lighter converter with the same performance. The circuit is simulated using Power Sim (PSIM) software to initiate the design and study the circuit capability. The experimental result will project the exact voltage in the range of 230VACrms . The harmonic profile of the inverter is studies and compared with the normal inverter configuration.

In the present scenario photovoltaic (PV) systems feature resonant interest in the recent researches. The amount from the PV frame is highly oscillated due to temperature variation. In this proposed work, the ANN based MPPT algorithm extracts maximum energy from the PV system by benefit of high gain DC-DC Luo converter, the Luo converter produced voltage is given to the single phase grid through reduced switch seven level inverter. The proposed seven level inverter is controlled by high frequency technique multicarrier modulation technique. The PI controller based closed loop grid synchronization is implemented for solving the power quality issues. The multilevel inverter reduce the total harmonics distortion in the output AC voltage waveform. The developed work is carried out using Matlab software-based simulation with various solar irradiation and degree. Keywords: Artificial Neural Network


2013 ◽  
Vol 2013 ◽  
pp. 1-18 ◽  
Author(s):  
Denizar Cruz Martins

This paper presents a grid-connected PV system in a centralized configuration constructed through a three-phase dual-stage inverter. For the DC-DC stage the three-phase series resonant converter is chosen thanks to the advantages that it exhibits. However, it is inadequate for the accomplishment of MPPT, due to its efficiency strongly depending on the implemented deadtime and switching frequency. Then, this paper proposes a conceptual modification, that is, a modified dual-stage inverter in which the inverter stage is responsible for both the MPPT and the grid-current control. In addition, the DC-DC converter operates with constant duty cycle and frequency. Such configuration requires a new concept, introduced as Behavior Matching. It serves as a fundamental feature for the DC-DC converter to reproduce the PV array I–V characteristic when they are connected, without control action. The maximum power operating point is found by maximizing the direct axis current, obtained by Park's transformation from the inverter, through the perturbation and observation algorithm. Any specific measurement to realize the MPPT is needed. The galvanic isolation is achieved by using a high-frequency transformer. The structure is appropriate for high power applications, above 10 kW.


2014 ◽  
Author(s):  
Nicholas A. Bishop ◽  
Mohammod Ali ◽  
Jason Miller ◽  
David L. Zeppettella ◽  
William Baron ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1943
Author(s):  
Bader N. Alajmi ◽  
Mostafa I. Marei ◽  
Ibrahim Abdelsalam ◽  
Mohamed F. AlHajri

A high-frequency multi-port (HFMP) direct current (DC) to DC converter is presented. The proposed HFMP is utilized to interface a photovoltaic (PV) system. The presented HFMP is compact and can perform maximum power point tracking. It consists of a high-frequency transformer with many identical input windings and one output winding. Each input winding is connected to a PV module through an H-bridge inverter, and the maximum PV power is tracked using the perturb and observe (P&O) technique. The output winding is connected to a DC bus through a rectifier. The detailed analysis and operation of the proposed HFMP DC-DC converter are presented. Extensive numerical simulations are conducted, using power system computer aided design (PSCAD)/electromagnetic transients including DC (EMTDC) software, to evaluate the operation and dynamic behavior of the proposed PV interfacing scheme. In addition, an experimental setup is built to verify the performance of the HFMP DC-DC converter.


1990 ◽  
Vol 39 (3) ◽  
pp. 279-293 ◽  
Author(s):  
A.W. Eriksson

AbstractA study was conducted on twinning in relatives of consecutive triplet sets in the Åland Islands in the years 1740-1939. The incidence of twinning in sibships of triplets was extremely high, 80/1000 (56/1000 before and 143/1000 after the triplet maternity). In Finland as a whole, 1905-1954, the twinning rate was among mothers of triplets 38/1000, ie, about 2.6 times the rate in general population, and was higher after (48/1000) than before the triplet maternity (34/1000). In the sibships of fathers of triplets there was a low rate of twinning (below 10/1000) both of same-sexed (SS) and of opposite-sexed (OS) triplets. Among sibships of mothers of OS triplets the twinning rate was 18/1000 and among mothers' sibships of SS triplets 26/1000. The series of triplet families from both Åland and Finland as a whole indicate a considerably higher frequency of twinning on the maternal than on the paternal side. The sibships of OS triplets in Finland have higher twinning rates than sibships of SS triplets (50/1000 vs 27/1000). In sibships of triplets, not only the DZ but also the MZ twinning rates were approximately twice as high as those in the general population. The triplet rates in Finland were increasing strongly with maternal age and were in the last century among mothers of 30-39 years of age considerably higher than among mothers from this century. This, in combination with higher mean parity, may explain the high rates of multiple maternities in sibships of triplets in the past. The rate of triplet maternities seems to be more sensitive to sociodemographic changes than the rate of twin maternities. Mothers of triplets in Finland had a high frequency (more than 40%) of prenuptially conceived firstborn children. This, and a short protogenesic interval indicate that triplet-prone mothers are more fecundable, ie, they conceive with greater ease and/or may have a better physical condition than other women for completing a gestation with multiple embryos.


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