Advanced laboratory testing methods using real-time simulation and hardware-in-the-loop techniques : a survey of smart grid international research facility network activities

The integration of smart grid technologies in interconnected power system networks presents multiple challenges for the power industry and the scientific community. To address these challenges, researchers are creating new methods for the validation of: control, interoperability, reliability of Internet of Things systems, distributed energy resources, modern power equipment for applications covering power system stability, operation, control, and cybersecurity. Novel methods for laboratory testing of electrical power systems incorporate novel simulation techniques spanning real-time simulation, Power Hardware-in-the-Loop, Controller Hardware-in-the-Loop, Power System-in-the-Loop, and co-simulation technologies. These methods directly support the acceleration of electrical systems and power electronics component research by validating technological solutions in high-fidelity environments. In this paper, members of the Survey of Smart Grid International Research Facility Network task on Advanced Laboratory Testing Methods present a review of methods, test procedures, studies, and experiences employing advanced laboratory techniques for validation of range of research and development prototypes and novel power system solutions

Design and Implementation of a True Decentralized Autonomous Control Architecture for Microgrids

Microgrids can serve as an integral part of the future power distribution systems. Most microgrids are currently managed by centralized controllers. There are two major concerns associated with the centralized controllers. One is that the single controller can become performance and reliability bottleneck for the entire system and its failure can bring the entire system down. The second concern is the communication delays that can degrade the system performance. As a solution, a true decentralized control architecture for microgrids is developed and presented. Distributing the control functions to local agents decreases the possibility of network congestion, and leads to the mitigation of long distance transmission of critical commands. Decentralization will also enhance the reliability of the system since the single point of failure is eliminated. In the proposed architecture, primary and secondary microgrid controls layers are combined into one physical layer. Tertiary control is performed by the controller located at the grid point of connection. Each decentralized controller is responsible of multicasting its status and local measurements, creating a general awareness of the microgrid status among all decentralized controllers. The proof-of concept implementation provides a practical evidence of the successful mitigation of the drawback of control command transmission over the network. A Failure Management Unit comprises failure detection mechanisms and a recovery algorithm is proposed and applied to a microgrid case study. Coordination between controllers during the recovery period requires low-bandwidth communications, which has no significant overhead on the communication infrastructure. The proof-of-concept of the true decentralization of microgrid control architecture is implemented using Hardware-in-the-Loop platform. The test results show a robust detection and recovery outcome during a system failure. System test results show the robustness of the proposed architecture for microgrid energy management and control scenarios

Tasasähkövoimalaitoksen mallinnus Hardware-in-the-Loop ympäristöön

Ever increasing requirements for increased fuel efficiency and reduced emissions on board a ship has prompted designers to turn their interest towards a distribution system where the main energy carrier is DC instead of AC. A DC power plant offers significantly reduced fuel consumption and easier integration of an increasing number of DC based sources and consumers, but also requires a more complicated control system for smart operation of the power plant. Therefore, the role of testing these control systems becomes even more important than before. This work introduces a Hardware-in-the-Loop (HIL) simulation technique for modeling and simulating a DC power plant on board a ship. In HIL simulation technique, a control-loop is built by using components, of which some are real hardware and some are simulated. This thesis work explores the possibilities for using the HIL simulation technique to perform real-time system level tests for a DC power plant on board a ship. The interfaces required to connect the real hardware components to the HIL simulator, and that way to the software component models as required by the simulation, will be examined. These interfaces consist of fieldbus communication (IEC61850 and Modbus) and a combination of digital and analog input and output signals. The goal of the HIL model of this work, is to offer an environment where different control schemes of the DC power system and the operation of the upper level power management and energy management systems can be tested safely and in a controlled manner. This requires that at least the controllers in the generating units are modeled using real hardware. The rest of the system can be modeled using virtual component models in the HIL software. A HIL model for modeling and simulating a complete DC power plant will be proposed and finally, the possibility to expand the model to include larger systems with more hardware will be discussed.Kasvavat vaatimukset polttoaineen kulutuksen ja päästöjen vähentämiseksi on saanut suunnittelijat kääntämään katseensa kohti sähkönjakelujärjestelmää, jossa sähkön jakelu kuluttajille toteutuu tasavirtana vaihtovirran sijasta. Tasasähkövoimalaitos mahdollistaa huomattavasti pienemmän polttoaineen kulutuksen ja helpottaa erilaisten DC lähteiden ja kuluttajien integroimista sähköverkkoon, mutta vaatii myös monimutkaisemman ohjausjärjestelmän voimalaitoksen älykkäälle toiminnalle. Tästä syystä ohjausjärjestelmän testauksen merkitys kasvaa jopa entuudestaan. Tämä työ esittelee Hardware-in-the-Loop (HIL) simulointimenetelmän tasasähkövoimalaitoksen mallintamiseksi ja simuloimiseksi. HIL mallinnustavassa säätöpiiri muodostetaan komponenteista, joista osa ovat oikeita komponentteja ja osa virtuaalisesti mallinnettuja komponentteja. Tämä diplomityö tutkii HIL mallinnustavan mahdollisuuksia suorittaa reaaliaikaisia järjestelmätason kokeita laivan tasasähkövoimalaitoksesta. Rajapinnat, jotka vaaditaan oikeiden komponenttien ja HIL simulaattorin yhteen liittämiseen tutkitaan tässä työssä. Nämä rajapinnat koostuvat kenttäväyläkommunikaatiosta (IEC61850 ja Modbus) sekä digitaalisten ja analogisten signaalien yhdistelmästä. Tämän työn HIL mallin tavoitteena on tuottaa testiympäristö, jossa tasasähkövoimalaitoksen säätöjärjestelmät ja ylemmän tason tehonhallinnan ja energianhallinnan järjestelmät voidaan testata turvallisesti ja hallitusti. Tämä vaatii, että ainakin sähköä tuottavien yksiköiden ohjaimet mallinnetaan oikeina komponentteina. Loput järjestelmästä voidaan mallintaa virtuaalisina komponentteina HIL simulaattorin ohjelmistossa. Työssä ehdotetaan mahdollinen HIL malli, jolla voidaan mallintaa ja testata koko tasasähkövoimalaitos. Lopuksi keskustellaan vielä mahdollisuuksista laajentaa mallia koskemaan laajempaa järjestelmää, jossa on enemmän oikeita komponentteja kytketty säätöpiiriin

Advancements in Real-Time Simulation of Power and Energy Systems

Modern power and energy systems are characterized by the wide integration of distributed generation, storage and electric vehicles, adoption of ICT solutions, and interconnection of different energy carriers and consumer engagement, posing new challenges and creating new opportunities. Advanced testing and validation methods are needed to efficiently validate power equipment and controls in the contemporary complex environment and support the transition to a cleaner and sustainable energy system. Real-time hardware-in-the-loop (HIL) simulation has proven to be an effective method for validating and de-risking power system equipment in highly realistic, flexible, and repeatable conditions. Controller hardware-in-the-loop (CHIL) and power hardware-in-the-loop (PHIL) are the two main HIL simulation methods used in industry and academia that contribute to system-level testing enhancement by exploiting the flexibility of digital simulations in testing actual controllers and power equipment. This book addresses recent advances in real-time HIL simulation in several domains (also in new and promising areas), including technique improvements to promote its wider use. It is composed of 14 papers dealing with advances in HIL testing of power electronic converters, power system protection, modeling for real-time digital simulation, co-simulation, geographically distributed HIL, and multiphysics HIL, among other topics

An islanded microgrid energy management controller validated by using Hardware-In-the-Loop Emulators

A novel microgrid emulator used to test multiple microgrid configurations and energy management control strategies is presented. The system includes Hardware-In-the-Loop (HIL) emulators for geothermal and biogas energy sources. It also includes actual photovoltaic energy together with a lead acid battery bank for storage and it is controlled by a two level control system. The control system consists of a primary level voltage-reactive power and frequency-active power and a secondary level energy management algorithm based on the balance between the power produced by the renewable energy generators, state of charge of the battery bank and the loads. The energy management control strategy is based on cycle-charging the batteries at a reference value in order to efficiently use the available resources. The primary energy source is considered the geothermal energy, while the most cost effective one is the photovoltaic energy. A buffer zone is kept in the battery bank in order to store as much energy produced by the photovoltaic system as possible. The presented microgrid, used for testing the energy management strategies, employs emulators for the geothermal and biogas generators; however, the results are relevant and can be scaled for a real-life microgrid

Real-Time Simulation of a Smart Inverter

abstract: With the increasing penetration of Photovoltaic inverters, there is a necessity for recent PV inverters to have smart grid support features for increased power system reliability and security. The grid support features include voltage support, active and reactive power control. These support features mean that inverters should have bidirectional power and communication capabilities. The inverter should be able to communicate with the grid utility and other inverter modules. This thesis studies the real time simulation of smart inverters using PLECS Real Time Box. The real time simulation is performed as a Controller Hardware in the Loop (CHIL) real time simulation. In this thesis, the power stage of the smart inverter is emulated in the PLECS Real Time Box and the controller stage of the inverter is programmed in the Digital Signal Processor (DSP) connected to the real time box. The power stage emulated in the real time box and the controller implemented in the DSP form a closed loop smart inverter. This smart inverter, with power stage and controller together, is then connected to an OPAL-RT simulator which emulates the power distribution system of the Arizona State University Poly campus. The smart inverter then sends and receives commands to supply power and support the grid. The results of the smart inverter with the PLECS Real time box and the smart inverter connected to an emulated distribution system are discussed under various conditions based on the commands received by the smart inverter.Dissertation/ThesisMasters Thesis Electrical Engineering 201

Power conversion for a modular lightweight direct-drive wind turbine generator

A power conversion system for a modular lightweight direct-drive wind turbine generator has been proposed, based on a modular cascaded multilevel voltage-source inverter. Each module of the inverter is connected to two generator coils, which eliminates the problem of DC-link voltage balancing found in multilevel inverters with a large number of levels.The slotless design of the generator, and modular inverter, means that a high output voltage can be achieved from the inverter, while using standard components in the modules. Analysis of the high voltage issues shows that isolating the modules to a high voltage is easily possible, but insulating the generator coils could result in a signicant increase in the airgap size, reducing the generator effciency. A boost rectier input to the modules was calculated to have the highest electrical effciency of all the rectier systems tested, as well as the highest annual power extraction, while having a competitive cost. A rectier control system, based on estimating the generator EMF from the coil current and drawing a sinusoidal current in phase with the EMF, was developed. The control system can mitigate the problem of airgap eccentricity, likely to be present in a lightweight generator. A laboratory test rig was developed, based on two 2.5kW generators, with 12 coils each. A single phase of the inverter, with 12 power modules, was implemented, with each module featuring it's own microcontroller. The system is able to produce a good quality AC voltage waveform, and is able to tolerate the fault of a single module during operation. A decentralised inverter control system was developed, based on all modules estimating the grid voltage position and synchronising their estimates. Distributed output current limiting was also implemented, and the system is capable of riding through grid faults

Hybrid System of Distributed Automation

One of the most important tendencies in the development of the industrial automation is the application of intelligent control systems within factories, which focuses heavily on networked architectures. Following this line of thinking, the goal of this dissertation resumes itself in the implementation of a distributed system that controls two physical processes, where the system components not only trade information between each other, but also have that same information be accessible remotely and within HMI equipment. The controllers were conceptualized to offer different functional modes with high customization available. This system also takes resource of an OPC server, so it allows, not only the communication between different manufacturer PLC controllers but also the connection with remotes clients The implemented remote clients hold the intent of demonstrating the versatility of this architecture and are, namely, an operational historian that registers information and a data viewer, which allows the use of more advanced methods of monitoring