DC-DC Converter For Photovoltaic Applications Research Articles

A new non-isolated high-gain DC-DC converter for the PV application

Small, distributed types of generation like solar photovoltaic (PV) played a significant part in shifting to a clean energy future due to economic factors and governmental laws. DC-DC converters are essential in the generation of solar PV electricity because they regulate the output voltage relying on the input voltage. The conventional boost converter (CBC) has minimal output voltage gain, and voltage stress at a switch is typically equivalent to the output voltage. The voltage produced by distribution generation (DG) sources is minimal, necessitating the use of high-gain boost converters. This proposed study is concerned with the development of an improved architecture of non-isolated high-gain DC-DC converters for PV applications, which provides quadratic output voltage gain and reduced voltage stress across a switch. The proposed configuration of the converter is comprised of a conventional quadratic boost converter with a voltage lift cell, which provides a high gain. The topological benefit is the use of a single switch with a lower number of inductors which reduces the circuit bulkiness. The developed topology was contrasted in terms of voltage gain, number of passive components used, and other parameters with other recently presented topologies. The simulation was performed using MATLAB/SIMULINK, and the output voltage gain was verified by prototype experimental results employing the simulation data.

A multi-input, multi-stage step-up DC-DC converter for PV applications

The paper introduces a step-up multiple-input multi-stage dc-dc converter with a soft-switching for Photovoltaic (PV) applications. The proposed topology is constructed from series connection of switched capacitor circuits to minimize the effects of partial shading and mismatch between PV modules. A soft switching is achieved for the entire switches in the converter with no need for additional components. The applied technique utilizes the stray inductance of PCB traces to create a LC circuit so that the zero current switching is achieved for all switches. Moreover, the converter will take advantage of the superior features of Wideband gap devices in order to operate at high switching frequency. As a result, bulky capacitors in switched-capacitor circuits are significantly reduced, hence, small size multilayers ceramic capacitors with high temperature capability will be employed. Furthermore, with the lower losses and the higher temperature capability of Wideband gap devices, the thermal requirements will be reduced and with fast reverse recovery time, the snubber circuit are not required. Simulation results are presented, laboratory prototype is constructed, and experimental results are given at rated power to validate the feasibility of proposed dc-dc converter under soft switching operation.

Control and monitoring of a Flyback DC-DC converter for photovoltaic applications using embedded IoT system

In this article, the authors present an Internet of Things (IoT) solution for controlling and monitoring a low power photovoltaic system (250 W). Power conditioning is performed by a DC-DC Flyback converter with active clamping. An ESP32 microcontroller is used to implement an output voltage control loop and to communicate, online and in real time, with an internet server. The effectiveness of voltage regulation is proven with experimental results and the authors present evidence that the IoT features work properly.

Computationally Efficient Modeling of DC-DC Converters for PV Applications

In this work, a computationally efficient approach for the simulation of a DC-DC converter connected to a photovoltaic device is proposed. The methodology is based on a combination of a highly efficient formulation of the one-diode model for photovoltaic (PV) devices and a state-space formulation of the converter as well as an accurate steady-state detection methodology. The approach was experimentally validated to assess its accuracy. The model is accurate both in its dynamic response (tested in full linearity and with a simulated PV device as the input) and in its steady-state response (tested with an outdoor experimental measurement setup). The model detects automatically the reaching of a steady state, thus resulting in lowered computational costs. The approach is presented as a mathematical model that can be efficiently included in a large simulation system or statistical analysis.

A Multistage DC-DC Step-Up Self-Balanced and Magnetic Component-Free Converter for Photovoltaic Applications: Hardware Implementation

This article presents a self-balanced multistage DC-DC step-up converter for photovoltaic applications. The proposed converter topology is designed for unidirectional power transfer and provides a doable solution for photovoltaic applications where voltage is required to be stepped up without magnetic components (transformer-less and inductor-less). The output voltage obtained from renewable sources will be low and must be stepped up by using a DC-DC converter for photovoltaic applications. 2 K diodes and 2 K capacitors along with two semiconductor control switch are used in the K-stage proposed converter to obtain an output voltage which is (K + 1) times the input voltage. The conspicuous features of proposed topology are: (i) magnetic component free (transformer-less and inductor-less); (ii) continuous input current; (iii) low voltage rating semiconductor devices and capacitors; (iv) modularity; (v) easy to add a higher number of levels to increase voltage gain; (vi) only two control switches with alternating operation and simple control. The proposed converter is compared with recently described existing transformer-less and inductor-less power converters in term of voltage gain, number of devices and cost. The application of the proposed circuit is discussed in detail. The proposed converter has been designed with a rated power of 60 W, input voltage is 24 V, output voltage is 100 V and switching frequency is 100 kHz. The performance of the converter is verified through experimental and simulation results.

A Novel High Step-up DC-DC Converter for Photovoltaic Applications

This paper proposes a new topology of a high step-up dc-dc converter for photovoltaic system applications. The proposed converter can boost up the low input voltage, about 20 V, generated from the PV array to the high output voltage level of approximately 400 V. The proposed converter employs only one power switch to achieve a high step-up voltage conversion ratio, approximately 20 times, without the extremely large duty cycle. The operating principles and steady-stage analyses of continuous conduction mode are described in detail. The relationship between the step-up voltage ratio and the duty cycle of the proposed converter is analyzed. The simulation and experimental results are shown to demonstrate the effectiveness of the proposed high step-up single-switch dc-dc converter for low-input and high-output voltage systems.

Coupled Inductor Based Soft Switched Interleaved DC-DC Converter for PV Applications

Interleaved DC-DC converter topologies are gaining popularity for their use as an interface between photovoltaic (PV) source and load. In this paper, a family of coupled inductor (CI) based novel soft switched interleaved DC-DC converter topologies has been proposed to be used for PV application. The topology has been developed from the interleaved stage so as to reduce the input current ripple. The CI stage has been introduced to enhance the power handling capability of the converter. In addition, diode-capacitor multiplier (DCM) cells are connected to obtain higher voltage gain. Since voltage gain extension is obtained through DCM cells and the turns-ratio of the CI, the voltage stress on the main power switches is only a fraction of the output voltage. Further, the diodes present in each DCM cell need to withstand only a low reverse voltage. To enhance the operating power conversion efficiency, the power switches are turned ON under zero voltage switching (ZVS) condition. Experimental results obtained from a 20V-360V, 200W prototype converter validate the operating principle and the advantageous features of the developed topology.