Superconducting Magnetic Energy Storage Application Research Articles

Adaptive Model Predictive Control Scheme for Application of SMES for Load Frequency Control

The use of superconducting magnetic energy storage (SMES) has been widely reported in the literature to mitigate various load frequency control (LFC) issues in a multi-area power system. Most of these are thyristor based SMES, employing proportional type controllers. In this paper, a supervisory adaptive model predictive control scheme (AMPC) is proposed for a voltage source converter based relatively small rating SMES for LFC application. The reference power command for the SMES is derived from the AMPC in such a manner that it effectively handles the operational constraints of the SMES system. A representative first-order system emulating the inner loop dynamics of the SMES chopper system, is tuned offline via genetic algorithm (GA) and is used to derive dynamic constraints for the cost function in AMPC. The effectiveness of the scheme is demonstrated through simulations.

Application of EV aggregators and SMES for frequency deviation control using fractional fuzzy controller

<span lang="EN-US">Secondary controllers are implemented in the alternator control loop to take care of the swinging of frequency initiated due to inequality of load and demand. A fractional fuzzy-PID controller (FFPID) is projected in this work for frequency deviation control in unified system including EV aggregators and superconducting magnetic energy storage (SMES). EVs and SMES are given primacy because of their ecofriendly nature. Proper adjustment of gains of FFPID is also required to extract the best performance of the secondary controllers. Here a recent tuning process named as artificial rabbits optimization (ARO) is applied for proper tuning of projected controller. The implemented dual area power system includes time varying delay-based EV aggregators, SMES, and thermal generating units. The ARO technique is applied in the model to tune the controller constraints with abrupt increment of demand in one of the control areas. A time-based function is treated as fitness function to evaluate the system performance. The dominance property of the projected FFPID controller over conventional PID and FPID controller in terms of different response specifications like maximum positive deviation (overshoot), settling time and minimum negative deviation (undershoot). The robust nature of the projected controller is also confirmed by multiple analysis like random load deviations and system constraint alteration.</span>

Technical challenges and optimization of superconducting magnetic energy storage in electrical power systems

The main motivation for the study of superconducting magnetic energy storage (SMES) integrated into the electrical power system (EPS) is the electrical utilities' concern with eliminating Power Quality (PQ) issues and greenhouse gas emissions. This article aims to provide a thorough analysis of the SMES interface, which is crucial to the EPS. This article also discusses the development of SMES as a reliable energy storage system (ESS). Delivering outstanding performance to support the EPS in any upsetting scenario can help SMES achieve its goals. A few of the fascinating aspects of the application of SMES in this context are microgrids, transmission and distribution (T&D) grids, renewable energy sources (RES), and plug-in hybrid energy storage systems (HESS). However, power utilities must evaluate the effectiveness and enhance a better performance on PQ when presenting a highly efficient energy technology. This article examines the difficulties of integrating SMES into the electricity network as well as the performance effects of HESS and RES. Finally, by outlining the current state of knowledge and highlighting any gaps in the literature, the power protection strategies and difficulties for power networks using SMES are evaluated.

Investigation on the structural behavior of superconducting magnetic energy storage (SMES) devices

Superconducting Magnetic Energy Storage (SMES) devices are being developed around the world to meet the energy storage challenges. The energy density of SMES devices are found to be larger along with an advantage of using at various discharge rates. Superconducting tapes such as YBCO (Tc = 90 K) are wound around a mandrel to construct the solenoid type SMES. This SMES is cooled with Liquid Nitrogen (LN2) at 77 K. However, challenges pertaining to the development of mandrel which gives structural supports to the superconducting tapes and compatibility at cryogenic temperatures are still to be investigated. In the present work, hybrid composite material is proposed to be used as a mandrel in solenoid type SMES. In this work, different composite samples such as Double Layered Carbon, Single and Double Layered Kevlar and Hybrid Composite made of Carbon and Kevlar are treated in Liquid Nitrogen (LN2) and tested for mechanical behavior. An experimental investigation is carried out to investigate the mechanical behavior of composite samples to be compatible for SMES applications. From the investigation, it is observed that the strength of composites increased when treated in LN2. Further, Cryo-treated Double Layered Carbon and Kevlar are found to be desirable for SMES applications.

Development of design for large scale conductors and coils using MgB2 for superconducting magnetic energy storage device

MgB2 wires are commercially available, and their superconducting characteristics have been continuously developed in the last decade. The relatively high critical temperature of these wires has attracted the attention of researchers, especially in the field of superconducting magnetic energy storage (SMES) coil applications in terms of its relatively high critical temperature, as it enables the use of liquid hydrogen for cooling the coils. The sensitivity of multi-filament MgB2 wires to bending strain makes the design of large-scale conductors and coils for an SMES system technologically difficult, and the careful investigation of the applied strains during manufacturing is required. Two-conventional methods have been introduced for the fabrication of the coils: wind-and-react (W&R) and react-and-wind (R&W). These methods have been demonstrated to be suitable for the production of large-scale MgB2 magnets to maximize the coil performance. The W&R and R&W methods have been successfully applied to the designs of conductors and coils, and small W&R test coil fabrication, as well as stability demonstrations are performed in this study. Our study is the first to demonstrate the feeding of hundreds of amperes of transport current using multifilamentary MgB2 wires at around liquid hydrogen temperature in the practical background magnetic field of 2 T. The minimum quench energy and normal zone propagation velocity are also experimentally investigated for the protection of the actual coils for SMES application.

Application of Superconducting Magnetic Energy Storage in Microgrid Containing New Energy

Superconducting magnetic energy storage (SMES) system can be long-term, efficient, non-destructive electric energy storage, the decoupling control can run in four quadrant, can achieve power active power and wattless power real-time fast independent adjustment. It is applied to the microgrid implemented through the SMES dynamic power compensation so as to greatly increase the initiative control of power grid operation. In this paper, the current source type SMES as the research object, the SMES system based on microgrid operation research. A microgrid PSCAD model including SMES system, SMES respectively provide short-term electricity, fault time buffer, improve microgrid power quality, micro smoothing grid and main network switching, optimization of DG improve the operation of microgrid operation economy of simulation study, provide a reference for SMES application in microgrid.

Coordinated Control Strategy of Scalable Superconducting Magnetic Energy Storage

Superconducting magnetic energy storage (SMES) has the characteristics of high power density and zero impedance that helps to develop renewable energy generation and micro-grid. A coordinated control for large capacity SMES application is proposed in this paper, which can improve power quality and system robustness effectively. Based on the topology and mathematical model of large capacity SMES, the coordinated control of outer power and inner current double closed loops control for power conditioning system is desired and vector switching automatic current sharing control method for multiphase chopper is developed. A low-pass filter and repetitive controller are included in the inner current loop controller to suppress periodic disturbance and increase robustness of the system. Simulation based on MATLAB/Simulink and experimental results demonstrate the effectiveness of large-capacity SMES coordinated control.

Superconducting magnetic energy storage and superconducting self-supplied electromagnetic launcher

Superconductors can be used to build energy storage systems called Superconducting Magnetic Energy Storage (SMES), which are promising as inductive pulse power source and suitable for powering electromagnetic launchers. The second generation of high critical temperature superconductors is called coated conductors or REBCO (Rare Earth Barium Copper Oxide) tapes. Their current carrying capability in high magnetic field and their thermal stability are expanding the SMES application field. The BOSSE (Bobine Supraconductrice pour le Stockage d’Energie) project aims to develop and to master the use of these superconducting tapes through two prototypes. The first one is a SMES with high energy density. Thanks to the performances of REBCO tapes, the volume energy and specific energy of existing SMES systems can be surpassed. A study has been undertaken to make the best use of the REBCO tapes and to determine the most adapted topology in order to reach our objective, which is to beat the world record of mass energy density for a superconducting coil. This objective is conflicting with the classical strategies of superconducting coil protection. A different protection approach is proposed. The second prototype of the BOSSE project is a small-scale demonstrator of a Superconducting Self-Supplied Electromagnetic Launcher (S3EL), in which a SMES is integrated around the launcher which benefits from the generated magnetic field to increase the thrust applied to the projectile. The S3EL principle and its design are presented.

Status Evaluation Method for SMES Used in Power Grid

Superconducting magnetic energy storage (SMES) is expected to be utilized in the power grid for dynamic power compensation. However, a SMES status such as magnet current (including parameters of power conditioning system) and temperature of superconducting (SC) magnet will restrict the output capability of SMES. This paper proposes a new method to evaluate SMES status, which will guarantee the dynamic thermal stability of SC magnet applied in power grid. First, it is generally analyzed that the output capability $(P_{\max})$ of a SMES is restricted by the initial (standby) current $(I_0)$ in the SC magnet for a specific application of SMES. To prove that $P_{\max}$ also depends on the temperature $(T_0)$ of the SC magnet, the thermal characteristics of the SC magnet is simulated with a 5 MJ SMES model. Based on these restricted conditions and the simulation results, a SMES status evaluation method (SSEM)is constructed and implemented. Then, with combination of test data gotten from open-loop experiments of a real 150-kJ/100-kW conduction-cooled SMES, the presented SSEM is realized by simulation in MATLAB/Simulink, the simulation results preliminarily verify the feasibility and effectiveness of SSEM. Furthermore, SSEM is applied to dynamic experiments, whereas the 150-kJ/100-kW SMES is set for damping power oscillation after the short-circuit fault in a physical simulated power grid. The proposed SSEM presents a potential way to optimize SMES operation in the power system.

Cryogenic Power Conversion for SMES Application in a Liquid Hydrogen Powered Fuel Cell Electric Vehicle

Cryogenic power conversion for superconducting magnetic energy storage (SMES) application in a liquid hydrogen (LH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) powered fuel cell electric vehicle (FCEV) is investigated. Principle and operation strategy of the SMES-based onboard energy system are presented for various operational models. A typical FCEV system equipped with a 720-kJ SMES device is conceptually designed and theoretically modeled with a bridge-type cryogenic chopper, which consists of four metal-oxide- semiconductor field-effect transistors (MOSFETs) cooled by low-temperature gas hydrogen (GH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ). The bridge-type cryogenic chopper has higher energy storage and utilization efficiencies than the conventional one because the MOSFETs have much less thermal loss compared with normal operations of the MOSFETs and diodes. Both the start-up time and the regenerative braking time of the FCEV are significantly reduced with the introduction of the SMES. The design and tests of an experimental energy exchange prototype are also presented to verify the feasibility of the proposed high-efficiency SMES system incorporated with the FCEV.

Design and Analysis of a Fuzzy Logic Controlled SMES System

Superconducting magnetic energy storage (SMES) becomes enabling technology and emerging to power systems. Its dynamic and steady-state characteristics in various power systems are largely related to the control strategies employed. This work investigates the feasibility to implant a fuzzy logic control method to a bridge-type chopper controlled SMES system, and theoretically validates the control method for SMES application.

Integrated SMES Technology for Modern Power System and Future Smart Grid

Superconducting magnetic energy storage (SMES) technology has been progressed actively for use in modern power system. Principal application schemes of a sole SMES system, a hybrid energy storage system (HESS) consisting of small-scale SMES and other commercial energy storage systems (ESSs), a distributed SMES (DSMES) system, and a distributed HESS (DHESS) are presented and compared. The concept of the SMES-based HESS provides an economical way to apply medium-scale SMES systems in daily load leveling and to apply small-scale SMES systems in power quality improvement. A dc power distribution network case with superconducting dc cables and SMES devices is conceptually designed to evaluate the performance of the proposed four SMES application schemes. The results show that the novel concept of the SMES-based DHESS can be particularly expected to achieve efficient and economical power management. Finally, the application prospects and possible schemes implanting SMES devices for power generation, transmission, distribution and utilization are explored for use in future smart grid.

Electric Energy Exchange and Applications of Superconducting Magnet in an SMES Device

A unified energy exchange system with an equivalent dc circuit topology is presented for superconducting magnetic energy storage (SMES) study. The principle and experimental prototype design have been carried out to study the dynamic energy exchange characteristics of SMES for both voltage sag and swell compensations, with a new bridge-type I/V chopper and relevant digital control method introduced and compared with the conventional chopper. The bridge-type I/V chopper has been demonstrated to be more suitable for low-voltage power applications because of its high energy storage and exchange efficiencies. The integrated SMES application solutions and characteristics in the modern power systems have also been discussed using two sample cases of daily load leveling and voltage fluctuation compensation presented.

Experiment and Numerical Simulation on Quench Detection in Cryocooler-Cooled YBCO Coil for SMES Application

In the real application of high-temperature superconducting (HTS) coils to a superconducting magnetic energy storage (SMES) system, coated conductors are cyclically subjected to tensile strain due to electrical charging and discharging. A quench is not only caused by failure in the power supply and cooling system but also could be induced by local deterioration of the superconducting characteristics because of the cyclic strain during operation. In such a local deterioration case, the conventional detection method using voltage signal for low-temperature superconducting (LTS) coils is not applicable for the HTS coils because of the significantly slow velocity of normal-zone propagation. Furthermore, the voltage detection method is considered to be extremely difficult because the noise of the converters and other equipment is much larger than the local normal-zone voltage of the HTS coils. Therefore, a new quench-detection method for HTS coils is required. In our previous studies, a current detection method was developed for a cryocooler-cooled SMES coil wound with a kA-class laminated bundle conductor composed of four electrically insulated coated conductors. In the present study, experiments and numerical simulations were carried out on a double pancake model coil that assumes real SMES operation to verify the validity of the current detection method.

Stability of a Wind Farm with Superconducting Magnetic Energy Storage

ABSTRACTElectric networks will experience deep changes due to the emergence of dispersed generation. Variability in power output is a characteristic of wind energy and increased penetration of wind power will present significant operational challenges in ensuring grid security and power quality. This paper addresses the integration of large wind farms into the grid through the beneficial role of superconducting magnetic energy storage (SMES) systems. Although originally conceived as a load-leveling device for nuclear power plants, today’s utility-industrial realities emphasize other applications of SMES in the development of wind energy. In the industrial section, concerns about power quality and stability have driven the development of a market for micro-SMES devices for power quality applications. The paper reviews the recent history of SMES, performs analysis in terms of the quantity of superconductor required and cost associated with both toroid and solenoid shaped coil using Bi-2223, YBCO and MgB2. The energy storage is optimized by properly designing the bandwidth of SMES. The ultimate aim of this paper is to influence the optimal design and configuration of SMES for land and offshore wind power generation and to propose a roadmap for the resolution of technical barriers related to the integration of wind energy to the electric grid.

Study on the Application of SMES to Improve Power Quality

With the development of modern technology, high quality power supply becomes more desirable in everyday life. Among problems related with the power quality, the most urgent is the voltage dip; with the application of power electronics devices, the power system is polluted by harmonics. SMES (Superconducting Magnet Energy Storage) system can not only compensate the voltage dip, but also provide a load-fluctuation compensation and active power filter. In the paper the main structure of SMES system is introduced; the necessity to use SMES are demonstrated by analyzing the problem of power quality. The analysis shows that SMES system is effective in improving the power quality.

Digitalization Control and Characteristic Analysis of a Superconducting Inductive Energy Management System

In past decades, the technique of superconducting magnetic energy storage (SMES) has received substantial attention both by academia and industry with the great improvement of applicable high temperature superconductors and relevant control technologies. A bridge-type inductive energy management system topology is presented for SMES applications by using a concept of digitalization. The inductive power charging, storing and discharging status are modelled, and then digitalized for the advanced control implementation. As a consequence, an inductive energy control method can be realized by the digitalized models to satisfy relative project requirements by high efficiency and control precession. New principles and methodologies provide the theoretical foundation to achieve digital power inductor energy control and superconducting inductive energy storage device operation.

Application of SMES and Grid Code Compliance to Wind/Photovoltaic Generation System

This paper describes a study on the application of superconducting magnetic energy storage (SMES) and grid code compliance to a wind and photovoltaic (PV) generation system. When a grid operates under instantaneous outage or surge condition, the distributed generation systems such as wind and PV systems must remain connected to the grid during a certain period of time. Therefore, the distributed generation system should be able to operate under abnormal conditions, such as reactive power or current fluctuations, which can damage the system and critical loads. The SMES can significantly enhance the dynamic security of such distributed power systems due to its high energy density and quick response characteristics. In this paper, the SMES control strategies for a wind and PV generation system during a fault ride through condition are examined, and the dynamic performance of SMES is evaluated by a case study based on the PSCAD/EMTDC simulation.

A Fast Algorithm for Initial Design of HTS Coils for SMES Applications

Superconducting magnetic energy storage (SMES) is characterized by low-energy density but high-power density, making this an unfeasible approach for bulk energy storage. Nevertheless, there are applications where high amounts of power must be available for a short period of time, like power quality applications. The core element of SMES is the superconducting coil. Different approaches are found in the literature considering the modeling of this component, either for design or simulation purposes. These usually consist of analytical or numerical approaches. The former allows fast results, but only considers geometric effects. The latter provides accurate results, considering, besides electromagnetic, also mechanical and thermal effects. In this paper, a review of these models is performed, and analytical models are used in an algorithm that allows optimizing equivalent inductance for a specified length of tape. Two small prototypes are fabricated, and experimental measurements carried out, in order to validate the models that are in the base of the proposed algorithm.

Application of SMES to Enhance the Dynamic Performance of DFIG During Voltage Sag and Swell

The integration of wind turbines into modern power grids has significantly increased during the last decade. Wind turbines equipped with doubly fed induction generators (DFIGs) have been dominating wind power installation worldwide since 2002. In this paper, a superconducting magnetic energy storage (SMES) unit is proposed to improve the dynamic performance of a wind energy conversion system equipped with DFIG during voltage sag and voltage swell events. The converter and the chopper of the SMES unit are controlled using a hysteresis current controller and a fuzzy logic controller, respectively. Detailed simulation is carried out using MATLAB/SIMULINK software to highlight the impact of the SMES unit in improving the overall system performance under voltage sag and voltage swell conditions.