Real-Time Implementation of a STATCOM on a Wind Farm Equipped with Doubly Fed Induction Generators

Voltage stability is a key issue to achieve the uninterrupted operation of wind farms equipped with doubly fed induction generators (DFIGs) during grid faults. A Static Synchronous Compensator (STATCOM) is applied to a power network which includes a DFIG driven by a wind turbine, for steady state voltage regulation and transient voltage stability support. The control schemes of the DFIG rotor-side converter, grid-side converter and the STATCOM are suitably designed and coordinated. The system is implemented in real-time on a Real-Time Digital Simulator (RTDS®). Results show that the STATCOM improves the transient voltage stability and therefore helps the wind turbine generator system to remain in service during grid faults

Offshore Wind Farm-Grid Integration: A Review on Infrastructure, Challenges, and Grid Solutions

Recently, the penetration of renewable energy sources (RESs) into electrical power systems is witnessing a large attention due to their inexhaustibility, environmental benefits, storage capabilities, lower maintenance and stronger economy, etc. Among these RESs, offshore wind power plants (OWPP) are ones of the most widespread power plants that have emerged with regard to being competitive with other energy technologies. However, the application of power electronic converters (PECs), offshore transmission lines and large substation transformers result in considerable power quality (PQ) issues in grid connected OWPP. Moreover, due to the installation of filters for each OWPP, some other challenges such as voltage and frequency stability arise. In this regard, various customs power devices along with integration control methodologies have been implemented to deal with stated issues. Furthermore, for a smooth and reliable operation of the system, each country established various grid codes. Although various mitigation schemes and related standards for OWPP are documented separately, a comprehensive review covering these aspects has not yet addressed in the literature. The objective of this study is to compare and relate prior as well as latest developments on PQ and stability challenges and their solutions. Low voltage ride through (LVRT) schemes and associated grid codes prevalent for the interconnection of OWPP based power grid have been deliberated. In addition, various PQ issues and mitigation options such as FACTS based filters, DFIG based adaptive and conventional control algorithms, ESS based methods and LVRT requirements have been summarized and compared. Finally, recommendations and future trends for PQ improvement are highlighted at the end

Large Grid-Connected Wind Turbines

This book covers the technological progress and developments of a large-scale wind energy conversion system along with its future trends, with each chapter constituting a contribution by a different leader in the wind energy arena. Recent developments in wind energy conversion systems, system optimization, stability augmentation, power smoothing, and many other fascinating topics are included in this book. Chapters are supported through modeling, control, and simulation analysis. This book contains both technical and review articles

Role of FACTS devices in enhancing integration of renewable energy sources to the grid: a review

2018 Conference paper. Theme (Renewable Energy and Energy Efficiency)The modern power system is facing challenges such as exponential growth in demand, constrained infrastructure and deregulation of electricity markets. For a sustainable energy system, it is necessary to meet energy need by utilizing renewable energy sources (RES), which have minimum environmental impact. Over the last two decades, renewable energy generation and integration into the grid has received a lot of attention worldwide. In 2017 alone, more than half of all new electricity capacity installed globally was from RES. However, RES such as solar photovoltaic and wind energy are intermittent in nature. Integrating variable generating sources into the grid can cause problems such as voltage fluctuations and interruptions, which affect the performance of utility equipment as well as end user. Over the years, flexible AC transmission system (FACTS) device utilization in power systems has been on the rise. FACTS refer to the application of power semi-conductor devices to control electrical variables, thus influencing power flow and enhancing power system security. This paper investigates the role of FACTS devices in expediting renewable energy integration in power systems. Challenges associated with renewable energy injection into the grid, and how FACTS devices can mitigate these issues is presented. We conclude that the penetration rate of renewable energy will be accelerated if FACTS devices are incorporated in RES integration projects.Jomo Kenyatta University of Science and Technology, Kiambu, Keny

Grid integration of variable renewable energies in Ghana: assessment of the impact on system stability

This research analyses the impact of renewable energies (RE) generation in Ghana’s national interconnected transmission system (NITS) and how its stability is affected. Integrating RE, particularly solar and wind in Ghana’s power system has been discussed at the national level with the intention to diversify the energy mix and reduce the dependency on thermal energy. RE integration introduces operational and infrastructural challenges in Ghana’s network, to which novel measures are required. Using the DIgSILENT PowerFactory simulation tool and MATLAB, simulation scenarios are created to capture diverse network conditions including different RE penetration levels, load demand and infrastructural expansion for three separate years. The ‘optimum’ penetration level of RE in the NITS considering voltage and loading limits is also identified using optimization techniques. The simulation results show that the target scenario is the most prone to both static and dynamic voltage instability. The transient stability analysis however reveals the post-target scenario to be unstable. Furthermore, methods of optimization are used to determine the reactive power deficient nodes in the NITS, which serve as the basis for the stability enhancement measures. The simulations and analysis additionally indicate that implementing the proposed measures indeed enhances the stability of the NITS. Finally, this research shows that RE integration is ‘technically’ feasible in Ghana if the required network reinforcements and operational changes are accordingly considered