The Impact of Grid-connected Photovoltaic Voltage Sourced Converter with Negative Sequence Decoupling Control on Protection Scheme Behavior - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook The Impact of Grid-connected Photovoltaic Voltage Sourced Converter with Negative Sequence Decoupling Control on Protection Scheme Behavior write by Fahad Ata Allah Alhajeri. This book was released on 2018. The Impact of Grid-connected Photovoltaic Voltage Sourced Converter with Negative Sequence Decoupling Control on Protection Scheme Behavior available in PDF, EPUB and Kindle. This thesis focuses on grid-connected PV systems and their impact on protection scheme performance during system fault conditions. The main objective of this work is to design a simulation model that can simulate the response of the system during different fault applications. The ATP program is used to model the grid-connected PV system along with the VSC control schemes based on the decoupled double synchronous reference frame method. The ATP model can be used as a teaching tool in courses and for research purposes. Different types of faults are applied to the power distribution system, with a distance protection element (21) proposed to protect the distribution system. An inverse-time overcurrent element (51) is used to protect the collector system on the ac-side of the VSC. Due to the characteristics of the VSC, it is controlled to limit the fault current contribution to less than 1.2 pu of the maximum current value. This causes the protection elements to either not trip or not trip correctly. In addition, due to the limited fault current and the weak source of the grid-connected PV system compared to the grid system source, the mho distance element mislocates the fault location. It calculates that the apparent fault location is much closer to the PCC than it actually is. This study indicates that the performance of the supervised distance element and the inverse-time overcurrent element are impacted by the grid-connected PV system. Therefore, in the fault analysis study and the protection schemes settings, this type of system should not be modeled as a conventional power generator.
Grid Converters for Photovoltaic and Wind Power Systems
Grid Converters for Photovoltaic and Wind Power Systems - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Grid Converters for Photovoltaic and Wind Power Systems write by Remus Teodorescu. This book was released on 2011-07-28. Grid Converters for Photovoltaic and Wind Power Systems available in PDF, EPUB and Kindle. Grid converters are the key player in renewable energy integration. The high penetration of renewable energy systems is calling for new more stringent grid requirements. As a consequence, the grid converters should be able to exhibit advanced functions like: dynamic control of active and reactive power, operation within a wide range of voltage and frequency, voltage ride-through capability, reactive current injection during faults, grid services support. This book explains the topologies, modulation and control of grid converters for both photovoltaic and wind power applications. In addition to power electronics, this book focuses on the specific applications in photovoltaic wind power systems where grid condition is an essential factor. With a review of the most recent grid requirements for photovoltaic and wind power systems, the book discusses these other relevant issues: modern grid inverter topologies for photovoltaic and wind turbines islanding detection methods for photovoltaic systems synchronization techniques based on second order generalized integrators (SOGI) advanced synchronization techniques with robust operation under grid unbalance condition grid filter design and active damping techniques power control under grid fault conditions, considering both positive and negative sequences Grid Converters for Photovoltaic and Wind Power Systems is intended as a coursebook for graduated students with a background in electrical engineering and also for professionals in the evolving renewable energy industry. For people from academia interested in adopting the course, a set of slides is available for download from the website. www.wiley.com/go/grid_converters
Modeling, Analysis and Advanced Control of Voltage- and Current-source Converters in Renewable Energy-based Active Distribution Systems
Modeling, Analysis and Advanced Control of Voltage- and Current-source Converters in Renewable Energy-based Active Distribution Systems - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Modeling, Analysis and Advanced Control of Voltage- and Current-source Converters in Renewable Energy-based Active Distribution Systems write by Amr A. A. Radwan. This book was released on 2015. Modeling, Analysis and Advanced Control of Voltage- and Current-source Converters in Renewable Energy-based Active Distribution Systems available in PDF, EPUB and Kindle. This thesis addresses the integration of renewable energy resources into the grid-connected and isolated distribution systems using voltage- and current-source converters. Motivated by its promising potential and attractive features, a one-stage current-source converter (CSC) is selected as an effective interfacing device for the photovoltaic (PV) generators to the utility-grid. The operation of the grid-connected CSC-based PV system is investigated under different operating conditions, parameters variation, and control topologies. From the dc-side, it is found that the variation in the weather conditions, e.g., solar irradiance levels, might affect the dynamic performance of the vector-controlled grid-connected CSCs. Small-signal dc-side impedance models for the CSC and the PV generators are developed to investigate the system stability. Active compensation techniques are proposed so that the system performance is well maintained under different operating points. From the ac-side, a susceptible potential to instabilities is yielded under the very weak grid conditions. This potential significantly increases in the vector-controlled converters. The implementation of the phase-locked loop (PLL) is found to have a detrimental impact on the system stability as the grid impedance increases. Two solutions for the very weak grid integration have been proposed. Firstly, the power synchronization control (PSC) scheme is developed for CSCs in PV applications so that the PLL is no longer needed, and hence a seamless integration to the very weak grid is achieved. Secondly, supplementary compensation loops are proposed and added to the conventional PLL-based vector-controlled CSC so that the negative impacts of the PLL are completely alleviated. In both cases, small-signal state-space models are developed to investigate the system stability and provide a detailed design approach for the proposed controllers. A larger system level integration is considered in this thesis by interfacing multiple distributed generation (DG) units to the conventional distribution system. A generalized hybrid alternating-current (ac)/direct-current (dc) system that constitutes ac and dc subgrids is created to efficiently accommodate the dc-type renewable sources (such as PVs, batteries, fuel cells, etc.) to the ac-type conventional distribution system. Both subgrids are interconnected using voltage-source converters (VSCs) to facilitate a bidirectional power exchange via multiple inversion-rectification processes. To achieve an accurate and efficient operation, a supervisory power management algorithm is proposed. The algorithm operates successfully regardless of the control mode of the individual DG units. However, the integration of severe dynamic loads, such as direct online inductions motors (IMs) into the ac-side of the hybrid system reflects very lightly damped modes, which in turns induce instabilities, particularly in the isolated mode of operation. Therefore, active compensation techniques have been proposed to increase the system damping. Throughout this thesis, time domain simulations under Matlab/Simulink® environment for the systems under study are presented to validate the analytical results and show the effectiveness of the proposed techniques.
Voltage, Current and Fault Control of a Multi-port Power Converter for a Grid-connected Photovoltaic System
Voltage, Current and Fault Control of a Multi-port Power Converter for a Grid-connected Photovoltaic System - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Voltage, Current and Fault Control of a Multi-port Power Converter for a Grid-connected Photovoltaic System write by Thilo Janssen. This book was released on 2016. Voltage, Current and Fault Control of a Multi-port Power Converter for a Grid-connected Photovoltaic System available in PDF, EPUB and Kindle. New smart power grids apply automatically controlled power systems that require a modernization of existing technologies. Renewable energy systems such as Photovoltaic power plants convert solar energy into electricity. Conventional 60Hz transformers in such systems can be replaced by novel power converter systems, which reduce production costs, size, and improve efficiencies. This thesis presents a power interface for a large scale solar power plant, utilizing an innovative power balance and fault tolerance control to feed electricity reliably and efficiently to the medium voltage 13.8kV utility grid. This interface consists of a multi-port converter configuration which achieves a high power DC-AC conversion. Each port consists of an array of PV solar panels, a multi-level dual active bridge, a neutral point clamped inverter, and a connection circuit to the grid. This combination of ports is arranged for a three phase output. A connection to the grid entails a system level controller, which can be achieved by a voltage and current balancing control, using a nonlinear concept with integrated feedback loops. Autonomous operation requires the establishment of a fault-tolerant control algorithm, attained by a continuously monitored fault detection circuit. A novel multi-port control is proposed to realize a voltage, current and fault control strategy among cascaded ports. This control is verified in Matlab/Simulink; detailed analysis and simulation results are provided.
Predictive Control of Grid-Connected Voltage-Sourced Converters
Predictive Control of Grid-Connected Voltage-Sourced Converters - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Predictive Control of Grid-Connected Voltage-Sourced Converters write by Younes Sangsefidi. This book was released on 2015. Predictive Control of Grid-Connected Voltage-Sourced Converters available in PDF, EPUB and Kindle.
