scholarly journals Direct Coupled PV Panel with ĆUK Converter for DC Load Applications

The PV systems are becoming gradually more common in distribution and generation systems. The direct coupled CUK converter for DC load applications is connected with PV panel. The ĆUK converter convert DC- DC voltage, in which magnitude of voltage output is not more than or higher than the magnitude of voltage input also the input voltage polarity is reverse to that of output voltage. The ĆUK converter is frequently customized for additional functions like simple transformer separation, high current protection, less ripple current and transfers the power regularly through capacitor. As per the research on the ĆUK converters has rigorous minor switching loss, capable to give unity power factor, decrease in element size, improving efficiency of the system, etc. Operation of ĆUK converter is relatively unusual with that of PWM converters. The effectiveness of proposed methods is to validate ĆUK converter in MATLAB/ SIMULINK.

The use of solar energy as source of power is becoming not a choice but a necessity due to the unprecedented growth in the demand and consumption of electrical power for various applications. The solar power from the Photovoltaic (PV) systems is currently used as a standalone PV system or integrated with the electric grid. However, the generated DC power from PV systems is not stable due to weather, atmospheric and environmental conditions, which requires the design of a DC power supply to produce a stable and regulated DC voltage output. In this paper, a new design of power supply is presented that provides a stable output voltage (Vout = +12 V, 0 V, -12V) over significant range of input voltage variations (Vin = +15 V to +50 V) emulating the variation of output voltage of PV systems. The stabilization of the output voltage reflects the effectiveness of the proposed design for photovoltaic systems applications. The system is simulated using NI-MULTISIM software. A satisfactory simulation result is obtained showing a strong promise to practically implement using discrete components.


Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1464
Author(s):  
Marcin Walczak ◽  
Leszek Bychto

DC/DC converters are widely used in photovoltaic (PV) systems to maximize the power drained from solar panels. As the power generated by a PV panel depends on the temperature and irradiance level, a converter needs to constantly modify its input resistance to remain at the maximum power point (MPP). The input resistance of a converter can be described by a simple equation that includes the converter load resistance and the duty cycle of the switching signal. The equation is sufficient for an ideal converter but can lead to incorrect results for a real converter, which naturally features some parasitic resistances. The goal of this study is to evaluate how the parasitic resistances of a converter influence its input resistance and if they are relevant in terms of MPPT system operation.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2536
Author(s):  
Bor-Ren Lin ◽  
Yi-Kuan Lin

A full-bridge converter with an additional resonant circuit and variable secondary turns is presented and achieved to have soft-switching operation on active devices, wide voltage input operation and low freewheeling current loss. The resonant tank is linked to the lagging-leg of the full bridge pulse-width modulation converter to realize zero-voltage switching (ZVS) characteristic on the power switches. Therefore, the wide ZVS operation can be accomplished in the presented circuit over the whole input voltage range and output load. To overcome the wide voltage variation on renewable energy applications such as DC wind power and solar power conversion, two winding sets are used on the output-side of the proposed converter to obtain the different voltage gains. Therefore, the wide voltage input from 90 to 450 V (Vin,max = 5Vin,min) is implemented in the presented circuit. To further improve the freewheeling current loss issue in the conventional phase-shift pulse-width modulation converter, an auxiliary DC voltage generated from the resonant circuit is adopted to reduce this freewheeling current loss. Compared to the multi-stage DC converters with wide input voltage range operation, the proposed circuit has a low freewheeling current loss, low switching loss and a simple control algorithm. The studied circuit is tested and the experimental results are demonstrated to testify the performance of the resented circuit.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3863
Author(s):  
Tiago Alves ◽  
João Paulo N. Torres ◽  
Ricardo A. Marques Lameirinhas ◽  
Carlos A. F. Fernandes

The effect of partial shading in photovoltaic (PV) panels is one of the biggest problems regarding power losses in PV systems. When the irradiance pattern throughout a PV panel is inequal, some cells with the possibility of higher power production will produce less and start to deteriorate. The objective of this research work is to present, test and discuss different techniques to help mitigate partial shading in PV panels, observing and commenting the advantages and disadvantages for different PV technologies under different operating conditions. The motivation is to contribute with research, simulation, and experimental work. Several state-of-the-artsolutions to the problem will be presented: different topologies in the interconnection of the panels; different PV system architectures, and also introducing new solution hypotheses, such as different cell interconnections topologies. Alongside, benefits and limitations will be discussed. To obtain actual results, the simulation work was conducted by creating MATLAB/Simulink models for each different technique tested, all centered around the 1M5P PV cell model. The several techniques tested will also take into account different patterns and sizes of partial shading, different PV panel technologies, different values of source irradiation, and different PV array sizes. The results will be discussed and validated by experimental tests.


2014 ◽  
Vol 24 (11) ◽  
pp. 1450142 ◽  
Author(s):  
Mohammed M. Al-Hindawi ◽  
Abdullah Abusorrah ◽  
Yusuf Al-Turki ◽  
Damian Giaouris ◽  
Kuntal Mandal ◽  
...  

Photovoltaic (PV) systems with a battery back-up form an integral part of distributed generation systems and therefore have recently attracted a lot of interest. In this paper, we consider a system of charging a battery from a PV panel through a current mode controlled boost dc-dc converter. We analyze its complete nonlinear/nonsmooth dynamics, using a piecewise model of the converter and realistic nonlinear v–i characteristics of the PV panel. Through this study, it is revealed that system design without taking into account the nonsmooth dynamics of the converter combined with the nonlinear v–i characteristics of the PV panel can lead to unpredictable responses of the overall system with high current ripple and other undesirable phenomena. This analysis can lead to better designed converters that can operate under a wide variation of the solar irradiation and the battery's state of charge. We show that the v–i characteristics of the PV panel combined with the battery's output voltage variation can increase or decrease the converter's robustness, both under peak current mode control and average current mode control. We justify the observation in terms of the change in the discrete-time map caused by the nonlinear v–i characteristics of the PV panel. The theoretical results are validated experimentally.


2018 ◽  
Vol 7 (2.24) ◽  
pp. 177
Author(s):  
Elangovan P ◽  
Kamatchi . ◽  
Nandhini . ◽  
Kamaatchi Devi ◽  
Kokila .

Grid integrated photovoltaic (PV) system is capable of maximizing solar energy conversion by minimizing power losses. Conventionally, the grid integrated PV system uses boost or buck-boost DC-DC converters in the DC link for lifting up the PV output. Also, a separate complex circuit is used for active power compensation in the grid end. This paper proposes an advanced DC-DC converter by name Super-Lift Converter (SLC) in the DC link of grid integrated PV system. Unlike the conventional DC-DC converters, the proposed converter lifts up the DC link voltage thrice that of the input voltage. In addition, the proposed SLC is regulated using a PI controlled active front end (AFE) topology, which results in operation of unity power factor at grid end. The suggested system is simulated using MATLAB software. The presented results such as grid end voltage and current, input and output power of SLC and DC link voltage validates the effectiveness of the developed system.  


Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1843 ◽  
Author(s):  
Leopoldo Gil-Antonio ◽  
Belem Saldivar ◽  
Otniel Portillo-Rodríguez ◽  
Juan Carlos Ávila-Vilchis ◽  
Pánfilo Raymundo Martínez-Rodríguez ◽  
...  

Solar energy harvesting using Photovoltaic (PV) systems is one of the most popular sources of renewable energy, however the main drawback of PV systems is their low conversion efficiency. An optimal system operation requires an efficient tracking of the Maximum Power Point (MPP), which represents the maximum energy that can be extracted from the PV panel. This paper presents a novel control approach for the Maximum Power Point Tracking (MPPT) based on the differential flatness property of the Boost converter, which is one of the most used converters in PV systems. The underlying idea of the proposed control approach is to use the classical flatness-based trajectory tracking control where a reference voltage will be defined in terms of the maximum power provided by the PV panel. The effectiveness of the proposed controller is assessed through numerical simulations and experimental tests. The results show that the controller based on differential flatness is capable of converging in less than 0.15 s and, compared with other MPPT techniques, such as Incremental Conductance and Perturb and Observe, it improves the response against sudden changes in load or weather conditions, reducing the ringing in the output of the system. Based on the results, it can be inferred that the new flatness-based controller represents an alternative to improve the MPPT in PV systems, especially when they are subject to sudden load or weather changes.


Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 321 ◽  
Author(s):  
Dmitry Baimel ◽  
Saad Tapuchi ◽  
Yoash Levron ◽  
Juri Belikov

This paper proposes two new Maximum Power Point Tracking (MPPT) methods which improve the conventional Fractional Open Circuit Voltage (FOCV) method. The main novelty is a switched semi-pilot cell that is used for measuring the open-circuit voltage. In the first method this voltage is measured on the semi-pilot cell located at the edge of PV panel. During the measurement the semi-pilot cell is disconnected from the panel by a pair of transistors, and bypassed by a diode. In the second Semi-Pilot Panel method the open circuit voltage is measured on a pilot panel in a large PV system. The proposed methods are validated using simulations and experiments. It is shown that both methods can accurately estimate the maximum power point voltage, and hence improve the system efficiency.


Sign in / Sign up

Export Citation Format

Share Document