High Efficient Maximum Power Point Tracking for Multiple Solar Strings with GaN-Based HiLEM Circuit

This paper discusses the potentials of string based Maximum Power Point Tracking (MPPT) in ground-mounted solar power plants using the HiLEM topology. First, the functionality of the HiLEM circuit is described, then the planned setup with the HiLEM topology is presented. Finally, the operating principle is illustrated by a simulated shading scenario

A review of grid-tied converter topologies used in photovoltaic systems

This study provides review of grid-tied architectures used in photovoltaic power systems, classified by the granularity level at which maximum power point tracking (MPPT) is applied. Grid-tied PV power systems can be divided into two main groups, namely centralized MPPT (CMPPT) and distributed MPPT (DMPPT). The DMPPT systems are further classified according to the levels at which MPPT can be applied, i.e. string, module, submodule, and cell level. Typical topologies for each category are also introduced, explained and analyzed. The classification is intended to help readers understand the latest developments of grid-tied PV power systems and inform research directions

PV inverters for module level applications

Dissertação para obtenção do Grau de Mestre em Energias Renováveis – Conversão Eléctrica e Utilização SustentáveisNowadays, the photovoltaic (PV) energy is presented as one of the most promising source of clean energy, and so a good way for greenhouse gas emissions mitigation and reduce the fossil fuel dependence. Within it, the photovoltaic energy has caused a huge interest in the electronic converters, and the need to improve their efficiency and reducing their cost. With this work I present a solution for a module scale grid-connected single-phase inverter. The solution consists in a two-stage inverter insolated with a grid line transformer. The two-stage inverter is composed by a DC-DC converter and a DC-AC converter connected through a DC-link capacitor. The DC-DC converter in case is a boost converter used to elevate the voltage from the PV module to a higher level. For the DC-AC converter it is used a full-bridge inverter, and both the DC-DC and the DC-AC converters use the IGBTs form an integrated module with its respective drivers. To the boost control it is implemented a Maximum Power Point Tracking algorithm that can optimize the power extraction from the PV source and for the inverter it is used a sliding mode hysteretic control. Once this inverter is conceived to work connected to the grid, a single-phase PLL system is used to synchronize the injected current to grid voltage. All the control part is made digitally using an Arduino Uno board, which uses an Atmel microcontroller

Power quality and electromagnetic compatibility: special report, session 2

The scope of Session 2 (S2) has been defined as follows by the Session Advisory Group and the Technical Committee: Power Quality (PQ), with the more general concept of electromagnetic compatibility (EMC) and with some related safety problems in electricity distribution systems. Special focus is put on voltage continuity (supply reliability, problem of outages) and voltage quality (voltage level, flicker, unbalance, harmonics). This session will also look at electromagnetic compatibility (mains frequency to 150 kHz), electromagnetic interferences and electric and magnetic fields issues. Also addressed in this session are electrical safety and immunity concerns (lightning issues, step, touch and transferred voltages). The aim of this special report is to present a synthesis of the present concerns in PQ&EMC, based on all selected papers of session 2 and related papers from other sessions, (152 papers in total). The report is divided in the following 4 blocks: Block 1: Electric and Magnetic Fields, EMC, Earthing systems Block 2: Harmonics Block 3: Voltage Variation Block 4: Power Quality Monitoring Two Round Tables will be organised: - Power quality and EMC in the Future Grid (CIGRE/CIRED WG C4.24, RT 13) - Reliability Benchmarking - why we should do it? What should be done in future? (RT 15

Photovoltaic and Wind Energy Conversion Systems

In the first decades of the current millennium, the contribution of photovoltaic and wind energy systems to power generation capacity has grown extraordinarily all around the world; in some countries, these systems have become two of the most relevant sources to meet the needs of energy supply. This Special Issue deals with all aspects of the development, implementation, and exploitation of systems and installations that operate with both sources of energy

A study of the solar energy systems and storage devices

Includes abstract.Includes bibliographical references.Following the 2008 severe electricity shortage in South Africa, domestic and industrial users faced incessant periods of blackouts. It is generally believed to be associated with lack of generation capacity. Since then research efforts have been directed towards boosting the generation capacity of the South African network by investing in a mix of power generation projects which include coal, nuclear and renewable energy schemes such as solar and wind. The renewable energy resources are considered a more viable option because of their many advantages such as lower greenhouse gas emissions, inexhaustible, reliable and even cheaper energy cost on the long term. Africa has huge potentials of solar power because of the abundance of direct sunshine in most days of the year. The rising cost of the fossil electricity has made the solar power an attractive option bearing in mind that the cost of the solar power has plummeted steadily in the past few years. Two main technologies are prevalent in the solar power research. These are photovoltaic (PV) systems and the concentrated solar power (CSP). The PV systems are made of solar panels and power electronic circuits. They are mostly economical in small residential units. The CSPs on the other hand which are made of solar field, thermal storage and steam turbine/generator units are economical only in large scale. In this thesis, a 2.5 kW Residential PV system and a 100 MW Molten Salt Power Tower Concentrated Solar Power were developed. The technical model of the photovoltaic panel and the power electronic circuits that connect it to the grid were also developed with Matlab/Simulink while the economic simulation of the PV, as well as the Concentrated Solar Power were carried out with Systems Advisor Model (SAM) using the climate data of Cape Town. The simulation results of this work compared the cost of PV electricity first with Renewable Energy Feed-in Tariff (REFIT) of National Energy Regulator of South Africa (NERSA), and then with the residential tariff charged by the City of Cape Town. Also the cost of electricity using CSP is compared NERSA`s REFIT. Finally the cost of PV electricity is compared with that of CSP. We therefore conclude that, with government incentives, CSP and PV are viable technologies however electricity produced by CSP is cheaper than that of the PV

EXPERIMENTAL MODEL OF SINGLE-PHASE DC–DC BOOST CONVERTER FOR 1000 WP PHOTOVOLTAIC APPLICATION

The photovoltaic system is used and utilized as electricity demand in many developed countries, including Indonesia. Nowadays, the photovoltaic system is an alternative source of inexpensive, reasonably priced electricity and easily applied in public facilities until laboratory usage. In Electrical Engineering Laboratory (EEL), Faculty of Engineering (FoE), Universitas Jenderal Achmad Yani is 1 kWp peak photovoltaic application available. The PV system is planned to be connected to the grid and produces 220VAC / 50Hz characteristics to meet the existing load capacity. The PV systems modeled include Pulse Width Modulation (PWM) controlled DC/DC Boost Converter, and DC/AC converter circuit. This study's experimental architecture is proposed to meet the electrical load following the characteristics of the photovoltaic device. The three types of electronic switching control, namely Metal Oxide Semiconductor Field Effect Transistor (MOSFET), Insulated Gate Bipolar Transistor (IGBT) and Gate Turn-off Thyristor (GTO), are used to achieve the highest performance. Based on the 1 kWp photovoltaic system's simulation results from the three types of electronic power switching, a minimum output voltage range of 210-230 VDC is produced. DC/AC Converter testing has been carried out and can be tested on a grid-connected 220VAC/50Hz single phase with the highest output using MOSFET equal to 96.7%

Hardware Approach To Mitigate The Effects Of Module Mismatch In A Grid-Connected Photovoltaic System: A Review

This study reviews the hardware approach to mitigate the effects of module mismatch in a grid-connected photovoltaic (PV) system. Unlike software solutions, i.e. the maximum power tracking algorithm, hardware techniques are well suited to enhance energy yield because of their inherent ability to extract energy from the mismatched module. Despite the extra cost of the additional circuitry, hardware techniques have recently gained popularity because of their long-term financial benefits. Notwithstanding the growing interest in this topic, review papers that provide updates on the technological developments of the three main hardware solutions, namely micro inverter,DC power optimizer, and energy recovery circuits, are lacking. This is in contrast to software solutions, which have had a considerable number of reputable reviews. Thus, a comprehensive review paper is appropriate at this juncture to provide up-to-date information on the latest topologies, highlight their merits/drawbacks, and evaluate their comparative performance

A Review on Control Strategies and Topologies of Multi Level Converter System

In recent decades, high-performance and medium voltage energy management for academia and industry have been attracted by multi-level converter topologies. In addition, the multi-level principle is used without decreasing the inverter power output to synthesise the harmonic distortion on the output waveform. For the reduction of harmonic distortion in the output waveform, the multi-level principle is used. The following topologies are presented: diode clamped inverters (neutral point clamped), condenser clamped (flying condenser), multi-level cascading (dc source, etc.) and the most effective modulation methods built for this converter category: multi-level, selective harmonic removal and space m vectors. A series of different topologies are given in this paper. Multi-level inverters have been gaining popularity in research teams and in the production of industrial applications for high and medium voltage applications for 20 years. Moreover, compared to a conventional converter, multi-level inverters can generate switched waveforms with reduced harmonic slopes. Recently, multi-level inverters have increased interest in their ability to generate high-quality wave forms at lower frequencies; the multi-level topology used in dynamic restaurant voltages reduces the harmonic distortion of the inverter output waveform without inverter output losses. By integrating control techniques for multi-level inverters, this paper discusses the most common topologies, making their implementations flexible in some power applications in many industrial areas