Design of single switch-boosted voltage current suppressor converter for uninterrupted power supply using green resources integration

Introduction. Uninterrupted power supply is the major requirement in the areas since it involves human lives. In the current scenario the demand and price of fossil fuels is increasing rapidly and availability also is not sufficient to the needs, an alternative identification to power generation is solar and wind energies. The purpose of designing an aimed, single switch boosted voltage and current suppressor (SS-BVCS) converter topology that interfaces both the wind and solar hybrid model. The method involves in the proposed chopper converter is derived by simply merging a switch and a pair of diodes and CLC filter which is used in realization of zero voltage switching for the main switch and a reversing diode to extract high voltage gain. The designed SS-BVCS converter topology can able to have a tight self-control on two power-processing paths. The novelty of the SS-BVCS converter module is designed to ensure maximum throughput, feeding to the load with high quality uninterrupted output, by boosting the DC voltage to a required amount and thereby supressing the current. Practical value obtained by the developed model utilizes both the sources for supply to the load individually or combined based on the extraction availability of the feeder. Also, the proposed SS-BVCS module delivers with efficient lesser component count and gaining maximum power from the harvest of green energy.Вступ. Джерело безперебійного живлення є основною вимогою в галузях, що пов'язані з людськими життями. У поточній ситуації, коли попит та ціна на викопне паливо швидко зростають, а їх доступність також недостатня для задоволення потреб, альтернативною технологією виробництва електроенергії є сонячна та вітрова енергія. Метою є розробка цільової топології перетворювача з підвищеною напругою та пригнічувачем струму з одним перемикачем (SS-BVCS), яка взаємодіє як з вітровою, так і з гібридною моделлю сонячної енергії. Метод включає запропонований перетворювач переривника, отриманий шляхом простого злиття перемикача, пари діодів і CLC-фільтра, який використовується для реалізації перемикання при нульовому напрузі для основного ключа і реверсивного діода для вилучення високого коефіцієнта посилення по напрузі. Розроблена топологія перетворювача SS-BVCS може забезпечити жорсткий самоконтроль на двох ланцюгах обробки енергії. Новизна модуля перетворювача SS-BVCS призначена для забезпечення максимальної пропускної здатності, живлення навантаження з якісним безперебійним виходом шляхом підвищення напруги постійного струму до необхідної величини і, таким чином, придушення струму. Практична цінність, отримана завдяки розробленій моделі, дозволяє використовувати як джерела живлення навантаження окремо, так і комбіновано залежно від можливості відбору фідера. Крім того, запропонований модуль SS-BVCS забезпечує ефективне використання меншої кількості компонентів та отримання максимальної потужності за рахунок збирання зеленої енергії

A Current-Source Modular Converter for Large-Scale Photovoltaic Systems

The world is shifting toward renewable energy sources (RESs) to generate clean energy and mitigate the stress of global warming caused by CO2 emissions in recent decades. Among several RES types, large-scale photovoltaic (LSPV) plants are a promising source for meeting ambitious clean energy targets and being part of power generation. With the progress of high-power modular inverters, new opportunities have arisen to integrate them into LSPV systems connected to medium-voltage (MV) grids to obtain high efficiency and reliability, better system flexibility, and improved electrical safety compared with string or central inverters. This thesis presents and implements a new current source three-phase modular inverter (TPMI) based on a novel dual-isolated SEPIC/CUK (DISC) converter. The TPMI is designed with a single power processing stage comprised of seriesconnected DISC submodules (SMs) to deliver MV into the utility grid. It outperforms conventional high-power inverters in terms of modularity, scalability, galvanic isolation compliance, and distributed maximum power point tracking (MPPT) capabilities. The DISC converter employed as an SM in the proposed TPMI generates bipolar output (i.e., both positive and negative voltages). In addition to having step-up and step-down capabilities with a continuous input current, this converter shares an input side inductor, thereby reducing the number of components. The DISC structure, modulation method, operation, novel state-space model, and parameter design procedure are analysed in details. Then, simulation results are presented to validate the theoretical and analytical analyses of the DISC converter. The proposed TPMI inverter is subsequently integrated into the LSPV grid connection to prove its suitability for such applications. In the theoretical analysis, the advantages of TPMI structure over conventional topologies are discussed. Then, the modulation technique, and operational concept are presented, followed by a dedicated control strategy is implemented by adding a system and SM-level controllers. The system controller is required for the generation of uniform duty ratios for all SMs in order to regulate the power transfer. The SM level controller is introduced to ensure equal current and voltage distribution between SMs and to compensate for minor discrepancies between the various parameters. The entire TPMI system is demonstrated through MATLAB and Simulink simulations, with the objective being to deliver the rated (1 MW) power from the PV modules under normal operation, uniform shading, and partial shading conditions and to match PV generation with the grid’s power demands. A downscaled 3-kW TPMI inverter was developed in the laboratory to validate its feasibility experimentally with its control strategy in different operating conditions. Finally, the TPMI performance is compared with selected current source inverter topologies, which shows that TPMI obtains good efficiency within the context of existing state-of-the-art current source converters. Then, the TPMI structure is modified by redesigning its DISC SMs, which provides several benefits, including a reduction in the number of switch devices operating at high frequency, thus decreasing switching losses, and an increase in efficiency. In this study, a half-cycle modulation (HCM) scheme is developed for the switches, and the operation of a modified DISC SM is analysed. Simulation and experimental results validate the performance of the modified TPMI topology and demonstrate its suitability for LSPV applications. According to the results of the comparison, the maximum power efficiency of the modified TPMI structure is 95.5%, which represents an improvement over the original TPMI structure