scholarly journals Improvement of Static Voltage Gain of a Non-Isolated Positive Output Single-Switch DC-DC Converter Structure Using a Diode-Capacitor Cell

2021 ◽  
Vol 8 (4) ◽  
pp. 583-590
Author(s):  
D. Murali ◽  
S. Annapurani

There are different low switching stress non-isolated DC-DC power converter structures developed for Photo-Voltaic (PV) applications with a view to achieve high voltage conversion ratio. The work proposed in this research article investigates the performance analysis of a coupled inductor and diode-capacitor multiplier cell based non-isolated high gain single-switch DC–DC conversion scheme with a single-ended primary-inductor on the input side. The presented converter suitable for renewable energy applications has the merits such as continuous input current, high voltage conversion ratio, and reduced voltage stress across the power switch. The multiplier cell consisting of two diodes and two capacitors is mainly used to enhance the converter output voltage level. A MATLAB / SIMULINK model of the suggested topology has been developed to validate its performance. During the simulation of the converter, a DC voltage of 50 V was given at the input side. The load end received a DC voltage of approximately 900 V. Thus, through this study, it was found that the addition of diode-capacitor cell can significantly improve the static gain of the suggested converter. The findings of this research may serve as a base for future studies on improvement of voltage gain of DC-DC converters.

Author(s):  
S. Nagaraj ◽  
R. Ranihemamalini ◽  
L. Rajaji

Bidirectional high gain DC-DC buck boost converter is a virtual interface among PV source and inverter fed motor drive. In this article, a PV panel integrating a non-isolated bidirectional DC/DC converter that has high voltage gain voltage and a 3 phase three level DC/AC inverter is projected. It highlights the comparison between proportional integral controller (PIC), fractional order proportional integral derivative Controller (FOPIDC) and fuzzy logic controller (FLC) based Bidirectional DC/DC Power Converter System (BDDPCS). The design, model and simulation using SIMULINK of open loop BDDPCS and closed loop PIC, FOPIDC and FLC based BDDPCS are done and the results are discussed. The findings indicate higher performance for FLC based control of BDDPCS. The proposed BDDPCS has merits such as bidirectional power transferability, lesser hardware count with enhanced dynamic response. The hardware of BDDPCS is tested and the experiment result is compared in association with simulation results.


Author(s):  
Christophe Raoul Fotso Mbobda ◽  
Alain Moise Dikandé

To provide a high votage conversion ratio, conventional non-isolated DC-DC boost topologies, which have reduced voltage boost capability, have to operate with extremely high duty cycle ratio, higher than 0.9. This paper proposes a DC-DC converter which is mainly based on the narrow range of duty cycle ratio to achieve extra high voltage conversion gain at relatively reduced voltage stress on semiconductors. In addition, it does include any magnetic coupling structure. The structure of the proposed converter combines the new hybrid SEPIC converter and voltage multiplier cells. From the steady-state analysis, this converter has wide conversion ratio and cubic dependence with respect to the duty ratio and then, can increase the output voltage several times more than the conventional and quadratic converters at the same duty cycle ratio. However, the proposed dual-switch cubic SEPIC converter must withstand higher voltage stress on output switches. To overcome this drawback, an extension of the proposed converter is also introduced and discussed. The superiority of the proposed converter is mainly based on its cubic dependence on the duty cycle ratio that allows it to achieve extra high voltage gain at reduced voltage stress on semiconductors. Simulation results are shown and they corroborate the feasibility, practicality and validity of the concepts of the proposed converter.


Author(s):  
P. Nithin and Dr. R. Rajeswari

In this paper, a novel high voltage gain DC-DC converter based on coupled inductor and voltage multiplier technique is proposed. The benefits of the proposed converter are ultra-high voltage gain, low voltage stress across the power switch and very low input current ripple by employing a low current ripple structure (LCR) at the input side. A low on state resistance (RDS(on)) of the power switch can be employed since the voltage stress is a maximum of 25% of the output voltage and the conduction losses of the switch is also reduced. Design of a 1.9kW, 48V at the low voltage side and 430V at the high voltage side is done and verified by simulation. Simulation results show an efficiency of over 93% when operating in continuous conduction mode (CCM).


In this paper, a non-isolated two interleaved modified step up KY Converter is analyzed and designed, whose efficiency, the voltage conversion ratio is high. There are various types of non -isolated converters such as buck-boost, Cuk, SEPIC, ZETA converters, etc but the voltage gain of these converters is less compare to the proposed interleaved KY converters. The voltage gain, efficiency of the proposed converter is enhanced compared to the previous converters. The voltage stress on semi-conductor devices and the ripple in the input current is reduced because of this interleaving technique. Switches with low on-state resistance are used due to which the conduction losses are reduced. Steady-state analysis and the operating principle are studied in continuous conduction mode (CCM) at ideal conditions. Simulation is also carried out in MATLAB/Simulink for the proposed interleaved KY converter.


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