Control of a DSTATCOM Coupled with a Flywheel Energy Storage System to Improve the Power Quality of a Wind Power System

Wind power generation is considered the most economic viable alternative within the portfolio of renewable energy resources. Among its main advantages are the large number of potential sites for plant installation and a rapidly evolving technology. However, the lack of controllability over the wind and the type of generation system used cause problems to the electric systems. Among such problems are those produced by wind power short-term fluctuations, e.g., in the power quality and in the dynamics of the system (Slootweg & Kling, 2003; Ackermann, 2005; Suvire & Mercado, 2008; Chen & Spooner, 2001; Mohod & Aware; 2008; Smith et al., 2007). In addition, the reduced cost of power electronic devices as well as the breakthrough of new technologies in the field of electric energy storage makes it possible to incorporate this storage with electronic control into power systems (Brad & McDowall, 2005; Carrasco, 2006; Barton & Infield, 2004; Hebner et al., 2002). These devices allow a dynamic control to be made of both voltage and flows of active and reactive power. Therefore, they offer a great potential in their use to mitigate problems introduced by wind generation. Based on the results obtained by analyzing different selection criteria, a Distribution Static Synchronous Compensator (DSTATCOM) coupled with a Flywheel Energy Storage System (FESS) has been proposed as the most appropriate system for contributing to the smoothing of wind power short-term fluctuations (Suvire & Mercado, 2007).Fil: Suvire, Gaston Orlando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; ArgentinaFil: Mercado, Pedro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentin

Power flow stabilization and control of microgrid with wind generation by superconducting magnetic energy storage

High penetration of renewable energy sources such as wind generation in microgrids (MGs) causes fluctuations of power flow and significantly affects the power system (PS) operation. This can lead to severe problems, such as system frequency oscillations, and/or violations of power lines capability. With the proper control, superconducting magnetic energy storage (SMES) is able to significantly enhance the dynamic security of the PS. In an SMES system, the power conditioning system (PCS) is the crucial component that directly influences the validity of the SMES in the dynamic control of the PS. This paper proposes the use of an improved SMES controller for the stabilization and control of the power flow of wind-hybrid MGs. In this sense, the design and implementation of a novel high-performance PCS scheme of the SMES is described. Moreover, a detailed model of the SMES unit is derived and a novel three-level control scheme is designed, comprising a full decoupled current control strategy in the d-q reference frame and an enhanced PS frequency controller. The dynamic performance of the proposed systems is fully validated by computer simulation.Fil: Molina, Marcelo Gustavo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Mercado, Pedro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Modelling and Control Design of Pitch-Controlled Variable Speed Wind Turbines

This chapter provides an overall perspective of modern wind power systems, including a discussion of major wind turbine concepts and technologies. More specifically, of the various wind turbine designs, pitch-controlled variable speed wind turbines controlled by means of power electronic converters have been considered. Among them, direct-in-line wind turbines with full-scale power converter and using direct-driven permanent magnet synchronous generators have increasingly drawn more interests to wind turbine manufactures due to its advantages over the other variable-speed wind turbines. Based on this issue, major operating characteristics of these devices are thoroughly analyzed and a three-phase grid-connected wind turbine system, incorporating a maximum power point tracker for dynamic active power generation is presented. Moreover, a simplified state-space averaged mathematical model of the wind turbine system is provided. An efficient power conditioning system of the selected wind turbine design and a new three-level control scheme by using concepts of instantaneous power in the synchronous-rotating d-q reference frame in order to simultaneously and independently control active and reactive power flow in the distribution network level are proposed. Dynamic system simulation studies in the MATLAB/Simulink environment is used in order to demonstrate the effectiveness of the proposed multi-level control approaches in d-q coordinates and the full detailed models presented. The fast response of power electronic devices and the enhanced performance of the proposed control techniques allow taking full advantage of the wind turbine generator.Fil: Molina, Marcelo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; ArgentinaFil: Mercado, Pedro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentin

Stabilization and control of tie-line power flow of microgrid including wind generation by distributed energy storage

High penetration of wind generation in electrical microgrids causes fluctuations of tie-line power flow and significantly affects the power system operation. This can lead to severe problems, such as system frequency oscillations, and/or violations of power lines capability. With proper control, a distribution static synchronous compensator (DSTATCOM) integrated with superconducting magnetic energy storage (SMES) is able to significantly enhance the dynamic security of the power system. This paper proposes the use of a SMES system in combination with a DSTATCOM as effective distributed energy storage (DES) for stabilization and control of the tie-line power flow of microgrids incorporating wind generation. A new detailed model of the integrated DSTATCOM-SMES device is derived and a novel three-level control scheme is designed. The dynamic performance of the proposed control schemes is fully validated using MATLAB/Simulink. © 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.Fil: Molina, Marcelo Gustavo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Mercado, Pedro Enrique. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentin

Analysis of integrated STATCOM-SMES based on three-phase three-level multi-pulse voltage source inverter for high power utility applications

This paper is aimed to investigate the operating characteristics of a static synchronous compensator (STATCOM) integrated with superconducting magnetic energy storage (SMES) for high power applications in the transmission network level. The STATCOM controller topology comprises multi-level multi-pulse neutral-point clamped-type (NPC) voltage source inverters (VSIs) using the harmonics cancellation technique, and incorporates a SMES coil. An innovative two-quadrant multi-level dcdc converter is proposed to effectively interface the STATCOM with the superconducting coil using a buck-boost topology with neutral point voltage control capabilities; thus enabling to simultaneously control both active and reactive power exchange with the high voltage power system. A detailed analysis of major system variables is presented, including analytical results and digital simulations using the MATLAB/Simulink environment. Moreover, a three-level control scheme is designed, including a full decoupled current control strategy in the dq reference frame with a novel controller to prevent the STATCOM dc bus capacitors voltage drift/imbalance and an enhanced power system frequency controller.Fil: Molina, Marcelo Gustavo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Mercado, Pedro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Watanabe, Edson H.. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentin

Dynamic Modelling of Advanced Battery Energy Storage System for Grid-Tied AC Microgrid Applications

In the last decade, power generation technology innovations and a changing economic, financial, and regulatory environment of the power markets have resulted in a renewed interest in on-site small-scale electricity generation, also called distributed, dispersed or decentralized generation (DG). Other major factors that have contributed to this evolution are the constraints on the construction of new transmission lines, the increased customer demand for highly reliable electricity and concerns about climate change. Along with DG, local storage directly coupled to the grid (aka distributed energy storage or DES) is also assuming a major role for balancing supply and demand, as was done in the early days of the power industry. All these distributed energy resources (DERs), i.e. DG and DES, are presently increasing their penetration in developed countries as a means to produce in-situ highly reliable and good quality electrical power. Incorporating advanced technologies, sophisticated control strategies and integrated digital communications into the existing electricity grid results in Smart Grids (SGs), which are presently seen as the energy infrastructure of the future intelligent cities. Smart grids allow delivering electricity to consumers using two-way (full-duplex) digital technology that enable the efficient management of consumers and the efficient use of the grid to identify and correct supply-demand imbalances. Smartness in integrated energy systems (IESs) which are called microgrids (MG) refers to the ability to control and manage energy consumption and production in the distribution level. In such IES systems, the grid-interactive AC microgrid is a novel network structure that allows obtaining the better use of DERs by operating a cluster of loads, DG and DES as a single controllable system with predictable generation and demand that provides both power and heat to its local area by using advanced equipments and control methods. This grid, which usually operates connected to the main power network but can be autonomously isolated (island operation) during an unacceptable power quality condition, is a new concept developed to cope with the integration of renewable energy sources (RESs). Grid connection of RESs, such as wind and solar (photovoltaic and thermal), is becoming today an important form of DG. The penetration of these DG units into microgrids is growing rapidly, enabling reaching high percentage of the installed generating capacity. However, the fluctuating and intermittent nature of this renewable generation causes variations of power flow that can significantly affect the operation of the electrical grid. This situation can lead to severe problems that dramatically jeopardize the microgrid security, such as system frequency oscillations, and/or violations of power lines capability margin, among others. This condition is worsened by the low inertia present in the microgrid; thus requiring having available sufficient fast-acting spinning reserve, which is activated through the MG primary frequency control. To overcome these problems, DES systems based on emerging technologies, such as advanced battery energy storage systems (ABESSs), arise as a potential alternative in order to balance any instantaneous mismatch between generation and load in the microgrid. With proper controllers, these advanced DESs are capable of supplying the microgrid with both active and reactive power simultaneously and very fast, and thus are able to provide the required security level. The most important advantages of these advanced DESs devices include: high power and energy density with outstanding conversion efficiency, and fast and independent power response in four quadrants. Much work has been done, especially over the last decades, to assess the overall benefits of incorporating energy storage systems into power systems. However, much less has been done particularly on advanced distributed energy storage and its utilization in emerging electrical microgrid, although major benefits apply. Moreover, no studies have been conducted regarding a comparative analysis of the modeling and controlling of these modern DES technologies and its dynamic response in promising grid-interactive AC microgrids applications. In this chapter, a unique assessment of the dynamic performance of novel BESS technologies for the stabilization of the power flow of emerging grid-interactive AC microgrids with RESs is presented. Generally, electrochemical batteries include the classic and well-known lead-acid type as well as the modern advanced battery energy storage systems. ABESSs comprise new alkaline batteries, nickel chemistry (nickel-metal hydride?NiMH, and nickel-cadmium?NiCd), lithium chemistry (lithium-ion?Li-Ion, and lithium?polymer-Li-po), and sodium chemistry (sodium-sulfur?NaS, and sodium-salt?NaNiCl). In this work, of the various advanced BESSs nowadays existing, the foremost ones are evaluated. In this sense, the design and implementation of the proposed ABESSs systems are described, including the power conditioning system (PCS) used as interface with the grid. Moreover, the document provides a comprehensive analysis of both the dynamic modeling and the control design of the leading ABESSs aiming at enhancing the operation security of the AC microgrid in both grid-independent (autonomous island) and grid-interactive (connected) modes...Fil: Sarasua, Antonio Ernesto. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; ArgentinaFil: Molina, Marcelo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; ArgentinaFil: Mercado, Pedro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentin

A New Control Strategy to Integrate Flow Batteries into AC Micro-Grids with High Wind Power Penetration

The penetration of wind generation into AC micro-grids (MGs) has been increasing in recent years. Wind generation is uncontrollable, variable in nature, and uncertain. If the penetration level is high, the random variations of the wind power generation could cause problems for MGs to maintain the nominal system frequency. A typical solution is to employ energy storage systems (ESS) into the MG in order to compensate the wind power fluctuations. In this chapter, the use of a vanadium redox flow battery (VRFB) coupled with a power conditioning system (PCS) is suggested to enhance the frequency stability of a MG with high wind power penetration. A new control system is developed for the PCS/VRFB. The control system performs the load leveling of the wind generation and carries out the primary and secondary frequency control of the MG. Dynamic simulations of the proposed device are performed and demonstrate that the new control system improves the transient responses of the PCS/VRFB and the MG, during minor and/or severe disturbances

Improved Superconducting Magnetic Energy Storage (SMES) Controller for High Power Utility Applications

Superconducting magnetic energy storage (SMES) systems are getting increasing interest in applications of power flow stabilization and control in the transmission network level. This trend is mainly supported by the rising integration of large-scale renewable energy power plants into the high-power utility system and by major features of SMES units. In a SMES system, the power conditioning system (PCS) is the crucial component for controlling the power exchange between the superconducting coil and the ac system. The dynamics of the PCS directly influences the validity of the SMES in the dynamic control of the power system. This paper describes a novel PCS scheme of SMES to simultaneously perform both active and reactive power flow controls. Moreover, a detailed model of the SMES unit is derived and a three-level control scheme is designed, comprising a full decoupled current control strategy in the dq reference frame with a novel controller to prevent PCS dc bus capacitors voltage drift/imbalance. The dynamic performances of the proposed systems are fully validated by computer simulation.Fil: Molina, Marcelo Gustavo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Mercado, Pedro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hirokazu Watanabe, Edson. Universidade Federal do Rio de Janeiro; Brasi

Compensation of Wind Generator Power Fluctuations in Microgrid Applications by Superconducting Magnetic Energy Storage

Grid connection of wind power generation (WPG) is becoming today an important form of distributed generation (DG). The penetration of these DG units into AC microgrids (MGs) is growing rapidly, enabling reaching high percentage of the installed generating capacity. However, the fluctuating and intermittent nature of this renewable generation causes variations of power flow that can bring both power quality and reliability issues to the electrical grid. To overcome these problems, superconducting magnetic energy storage (SMES) arises as a potential alternative to compensate these power flow fluctuations and thus to significantly enhance the MG dynamic security. To this aim, the management of the energy stored in the SMES device is crucial for optimizing the storage capacity as well as for preventing the device from becoming overcharged or uncharged. This paper proposes the use of an improved SMES controller for the stabilization of the fluctuating active power injected into the microgrid by wind generators. In this sense, the design and implementation of a high performance active power controller of the SMES is described. The control is based on fuzzy logic techniques and uses an enhanced fuzzy inference system (FIS) combined with a unique filter block. Moreover, a detailed model of the SMES unit and its power conditioning system (PCS) for connecting to the electric grid is derived. The dynamic performance of the proposed system and its impact on the MG operation is validated by computer simulation.Fil: Molina, Marcelo Gustavo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Energía Eléctrica. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; ArgentinaFil: Suvire, Gaston Orlando. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Energía Eléctrica. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; ArgentinaFil: Mercado, Pedro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Energía Eléctrica. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentin