Summary In this article, a high step‐up interleaved boost converter topology is proposed for renewable energy applications. The proposed converter utilizes two‐phase interleaved configuration, to increase the power capability of converter while reducing the input current ripples. The output side formation enhances the voltage gain with the help of coupled inductors. It produces high voltage conversion ratio with least voltage stress on the switches. The switches are relieved from the voltage spikes by reclaim the energy leakage of the coupled inductors, which minimizes reverse recovery problem in diodes. The conduction losses of the switches are reduced due to small on state resistance. Finally, a prototype of 200 W proposed converter is developed in the laboratory to verify the both theoretical analysis and simulation results.

Grid-connected photovoltaic (PV) systems impose challenges like voltage fluctuations, low system inertia and power quality issues. The need to tackle these challenges led to the introduction of flexible power point tracking (FPPT), where the PV power output is controlled by an energy management system (EMS), rather than solely operating the PV systems on the maximum power point (MPP). The requirement of fast transient response implies that algorithms such as the one proposed in this paper are desirable. The proposed algorithm uses the secant method to achieve significantly improved results in comparison to the existing methods. The method also simplifies the prediction of variations during changes in the environment and power reference, hence, results in reduced oscillation around the set-point and faster convergence. Experimental validation is presented in this paper for supporting the claims. The results in terms of accuracy, convergence rate, steady state oscillations and cumulative error are bench-marked against one of the most recent FPPT methods. Index Terms-Active power control, flexible power point tracking, grid connected photovoltaic systems, secant method. I. INTRODUCTIONT HE desire to reduce the reliance on the conventional fossil fuel resources is one of the driving forces behind the widespread utilization of renewable energy sources (RESs) for electricity generation [1]. In this regard, owing to the widespread abundance, solar energy emerges as a promising alternative [2]. Conventionally, maximum power Manuscript

This study proposes a suitable DC-DC converter topology with improved power quality at the input side for micro-butt welding machine by evaluating different power factor correction (PFC) techniques and DC-DC converter topologies. Firstly, different control strategies of boost converters such as peak current controlled PFC, average current controlled PFC and hysteresis current controlled PFC are discussed for minimising input current distortions and improving the power quality. Also, the current loop gain stability analyses are presented using small-signal model for selecting the best model and optimisation of the same. Secondly, the important key parameters such as cost, size, weight, complexity in implementation and other application dependent parameters of various isolated type of DC-DC converter topologies are compared and the best DC-DC converter topology is selected for the proposed application. Finally, the modelling and stability analysis is performed on the DC-DC converter and optimisation is achieved for the welding current controller. The software packages MATLAB/Plecs/OrCAD PSpice are used for simulation and implementation of the desired circuitry with optimised design. A prototype has been developed based on optimised design, hysteresis current controller for PFC and DC-DC converter; and the control algorithm is implemented DSP TMS320F2812 and the experimental results were discussed. 2 DC-DC converter topologies for micro-butt welding The DC-DC converter consists of inverter, high frequency transformer (HFT), rectifier and filter. The primary requirements of welding power supply are galvanic isolation from main supply, DC current (150-600 A) regulation with max of 5 V and capability to withstand during the short-circuit condition. The general criteria for selection of DC-DC converter are cost, weight, size and ease of

No abstract

No abstract