Coupling of Real-Time and Co-Simulation for the Evaluation of the Large Scale Integration of Electric Vehicles into Intelligent Power Systems

This paper addresses the validation of electric vehicle supply equipment by means of a real-time capable co-simulation approach. This setup implies both pure software and real-time simulation tasks with different sampling rates dependent on the type of the performed experiment. In contrast, controller and power hardware-in-the-loop simulations are methodologies which ask for real-time execution of simulation models with well-defined simulation sampling rates. Software and real-time methods are connected one to each other using an embedded software interface. It is able to process signals with different time step sizes and is called "LabLink". Its design implies both common and specific input and output layers (middle layer), as well as a data bus (core). The LabLink enables the application of the co-simulation methodology on the proposed experimental platform targeting the testing of electric vehicle supply equipment. The test setup architecture and representative examples for the implemented co-simulation are presented in this paper. As such, a validation of the usability of this testing platform can be highlighted aiming to support a higher penetration of electric vehicles.Comment: 2017 IEEE Vehicle Power and Propulsion Conference (VPPC

Development and evaluation of open-source IEEE 1547.1 test scripts for improved solar integration

Distributed Energy Resources (DERs) equipped with standardized, interoperable, grid-support functionality have the capability to provide a range of services for power system operators. These requirements have been recently codified in the 2018 revision of the American DER interconnection and interoperability standard, IEEE Std. 1547, as well as the revised Canadian interconnection standard, CSA C22.3 No. 9. Currently, the IEEE standards committee is drafting a new revision of the IEEE Std. 1547.1 test standard, which outlines the test procedures for certifying equipment compliant to IEEE Std. 1547. In addition, it is often referenced as a test standard in CSA C22.3 No. 9. This draft test standard has not been fully exercised yet to identify mistakes, redundancies, and/or implementation challenges. In this work, an international community of research laboratories developed open-source IEEE Std. 1547.1 test scripts. The scripts are used to evaluate grid-support functions – such as constant-power-factor, volt-var, volt-watt, and frequency-watt functions – of several DER devices to the draft standard, EEE1547.1. Sample test results are presented and discussed, and recommendations are offered to improve the draft standard during the balloting process

Entwicklung eines echtzeitfähigen Batteriemodells für Power Hardware-in-the-Loop Simulationen

Abweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in dt. SpracheIm Stromnetz der Zukunft wird Erneuerbare Energie eine große Rolle spielen, um dem Klimawandel entgegen zu wirken und die Emission von Treibhausgasen zu reduzieren. Mit dem vermehrten Einsatz von volatilen Energieträgern wie Wind und Photovoltaik steigt auch der Bedarf an Speichersystemen. Neben effizienteren und kostengünstigeren Batterien ist auch die Entwicklung von dazugehöriger Leistungselektronik, wie zum Beispiel Batteriewechselrichter, essentiell. Das Testen solcher Leistungselektronik ist zeitintensiv und teuer. Batterien müssen zwischen Experimenten langwierig ge- bzw. entladen werden, was Laborzeit beansprucht und dadurch Geld kostet. Außerdem sind oft unterschiedliche Batterietypen, -spannungen und -kapazitäten notwendig. Eine Lösung dieses Problems ist es, echte Batterien durch emulierte zu ersetzen. Diese bestehen aus einem Echtzeitcomputer, der das Verhalten der Batterie anhand eines internen Batteriemodells berechnet, sowie aus einem Leistungsverstärker, der die berechnete Batteriespannung in eine reale Spannung umwandelt. Damit können verschiedene Batterietypen modelliert, bzw. deren Spannung, Kapazität und der Ladezustand beliebig vorgegeben werden. Diese Arbeit beschäftigt sich mit der Entwicklung eines solchen Batterie-Emulators. Hierfür wird ein passendes Batteriemodell entwickelt, dessen Parametrisierung zuerst diskutiert und danach mithilfe realer Messungen aus einem standardisierten Fahrzyklus validiert. Anschließend wird das Batteriemodell auf ein Echtzeitsystem portiert und der Batterie-Emulator implementiert. Mithilfe einer Kombination aus konstanter Last und programmierbarer Stromquelle werden die Messungen des Fahrzyklus reproduziert und so der Batterie-Emulator verifiziert. Dabei erreicht der Batterie-Emulator eine Übereinstimmung von 95% im Vergleich zu den Messungen. Der entwickelte Batterie-Emulator kommt am Forschungsprüfstand des Austrian Institute of Technology zum Einsatz und ermöglicht dort schnellere und reproduzierbare Tests von Batteriewechselrichtern, Ladesäulen von Elektrofahrzeugen u.v.m., ohne die jeweilige Batterie kaufen zu müssen.Renewable energy will play an important role in the grid of the future in order to fight climate change and reduce greenhouse gas emissions. The increased use of volatile energy sources like wind and photovoltaic goes along with an enlarged demand of battery energy storage systems. Besides more efficient and cost-effective batteries, the development of battery related power electronics like battery inverters is vital. The test of such power electronics is time-consuming and expensive. Batteries have to be charged and discharged between experiment, a protracted procedure that costs time and hence also money. Furthermore, various battery types with different voltages and capacities are necessary. A solution to this problem is replacing a real with an emulated battery. These consist of a real time system that computes the behavior of the battery on the basis of an internal battery model, and of a power amplifier that converts the calculated battery voltage into a real voltage. That way various battery types can be modeled, as well as whose voltage, capacity and state of charge can be set arbitrary. This work deals with the development of such a battery emulator. Therefore a suitable battery model is developed, its parametrization discussed and afterwards validated by means of measurements form a standardized driving cycle. Then, the battery model is ported onto a real time system and the battery emulator is implemented. The measurements of the driving cycle are reproduced with a combination of a constant load and a programmable current source in order to verify the battery emulator. Here, the battery emulator achieves accuracy of 95% in comparison to the measurements. The developed battery emulator is deployed at the research test bed of the Austrian Institute of Technology and makes faster, more cost-effective and reproducible tests of battery related power electronics possible without the need of buying the particular batteries12

Investigating Cyber-Physical Attacks against IEC 61850 Photovoltaic Inverter Installations

Cyber-attacks against Smart Grids have been found in the real world. Malware such as Havex and BlackEnergy have been found targeting industrial control systems (ICS) and researchers have shown that cyber-attacks can exploit vulnerabilities in widely used Smart Grid communication standards. This paper addresses a deep investigation of attacks against the manufacturing message specification of IEC 61850, which is expected to become one of the most widely used communication services in Smart Grids. We investigate how an attacker can build a custom tool to execute man-in-the-middle attacks, manipulate data, and affect the physical system. Attack capabilities are demonstrated based on NESCOR scenarios to make it possible to thoroughly test these scenarios in a real system. The goal is to help understand the potential for such attacks, and to aid the development and testing of cyber security solutions. An attack use-case is presented that focuses on the standard for power utility automation, IEC 61850 in the context of inverter-based distributed energy resource devices; especially photovoltaic (PV) generators

Comparison of Power Hardware-in-the-Loop Approaches for the Testing of Smart Grid Controls

The fundamental changes in the energy sector, due to the rise of renewable energy resources and the possibilities of the digitalisation process, result in the demand for new methodologies for testing Smart Grid concepts and control strategies. Using the Power Hardware-in-the-Loop (PHIL) methodology is one of the key elements for such evaluations. PHIL and other in-the-loop concepts cannot be considered as plug’n’play and, for a wider adoption, the obstacles have to be reduced. This paper presents the comparison of two different setups for the evaluation of components and systems focused on undisturbed operational conditions. The first setup is a conventional PHIL setup and the second is a simplified setup based on a quasi-dynamic PHIL (QDPHIL) approach which involves fast and continuously steady state load flow calculations. A case study which analyses a simple superimposed voltage control algorithm gives an example for the actual usage of the quasi-dynamic setup. Furthermore, this article also provides a comparison and discussion of the achieved results with the two setups and it concludes with an outlook about further research

Towards Holistic Power Distribution System Validation and Testing – An Overview and Discussion of Different Possibilities

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