The Technology of Instrument Transformers


Book Description

Existing instrument transformer technologies as well as new measuring principles for current and voltage measurement are described in this book. The properties of conventional current and voltage transformer as well as the dimensioning are discussed in details out of the long experience of the authors. Especially the dielectric dimensioning and the used materials are discussed. Beside this an overview over new modern measuring principles is given and the technology of low-power instrument transformer, and RC-dividers are shown.










Test bench design for power measurement of inverter-operated machines in the medium voltage range


Book Description

This thesis gives an overview of test bench design for inverter operated Medium Voltage (MV) drives with the focus on the active power measurement. The sources of measurement setup uncertainty are analysed and methods are shown to assess these uncertainties. Further, a possibility is shown to do quantitative uncertainty estimations which are verified with measurements through different measurement setups for MV drives operated with multilevel converters. The influence of measurement transducers, voltage dividers, power meters and data acquisition boards are considered. The digital signal processing is analysed and the possibilities to reduce its uncertainty contribution on an active power measurement is shown. An analysis is made with the conventional measurement devices in the MV-range. The transfer behaviour of the devices and the characteristics of the uncertainty are investigated. Measurements are done on typical medium voltage drives with an uncertainty analysis, which shows the essential aspects of active power measurement. The results show the significance of a measurement setup performance. The investigations on the drives are used to indicate the impact on the determination of the drive efficiency and gives a significant input for further standardisation processes. The handling of measurement uncertainties during active power measurement of drives is shown concerning the permanent topic of energy saving and its efficient use. The work proposes a way of categorising electrical drives in energy efficiency classes and to make their determination comparable. Die vorliegende Dissertation gibt einen Überblick über den Prüfstandsaufbau von umrichtergetriebenen Mittelspannungsantrieben. Die Unsicherheitsquellen werden analysiert und Methoden werden aufgezeigt um die Messunsicherheit zu bewerten. Des Weiteren werden die Machbarkeit von Unsicherheitsabschätzungen gezeigt, welche mit Messungen an typischen Mittelspannungsantrieben mit Umrichterspeisung verglichen werden. Der Einfluss von Messwandlern, Spannungsteilern, Leistungsmessern und Messkarten zur Signalerfassung wird berücksichtigt. Die digitale Signalverarbeitung wird analysiert um den Unsicherheitsbeitrag zur Wirkleistungsmessung zu reduzieren. Es werden konventionellen Messwandler und -teiler im Mittelspannungsbereich bezüglich ihres Übertragungsverhal- tens sowie Messunsicherheiten untersucht. Die Ergebnisse der Untersuchungen verdeutlichen die Signifikanz eines performanten Messaufbaus. Des Weiteren werden Auswirkun- gen auf die Bestimmung der Effizienz aufgezeigt. Die Arbeit liefert einen wesentlichen Beitrag für weitere Standardisierungsprozesse. Der Umgang mit Messunsicherheiten der Wirkleistungsmessung wird betrachtet im Hinblick auf Energieeinsparpotenziale und deren effiziente Nutzung. Die Arbeit schlägt eine Möglichkeit vor, wie elektrische Antriebe in Energieeffizienzklassen kategorisiert werden können um diese vergleichbar zu machen.




Springer Handbook of Power Systems


Book Description

This handbook offers a comprehensive source for electrical power professionals. It covers all elementary topics related to the design, development, operation and management of power systems, and provides an insight from worldwide key players in the electrical power systems industry. Edited by a renowned leader and expert in Power Systems, the book highlights international professionals’ longstanding experiences and addresses the requirements of practitioners but also of newcomers in this field in finding a solution for their problems. The structure of the book follows the physical structure of the power system from the fundamentals through components and equipment to the overall system. In addition the handbook covers certain horizontal matters, for example "Energy fundamentals", "High voltage engineering", and "High current and contact technology" and thus intends to become the major one-stop reference for all issues related to the electrical power system.




Technical Report


Book Description




Gas Insulated Substations


Book Description

GAS INSULATED SUBSTATIONS An essential reference guide to gas-insulated substations The second edition of Gas Insulated Substations (GIS) is an all-inclusive reference guide to gas insulated substations (GIS) and its advanced technologies. Updated to the latest technical developments and applications, the guide covers basic physics of gas insulated systems, SF6 insulating gas and its alternatives, safety aspects and factors to choose GIS. GIS technology, its modular structure, control and monitoring systems, testing, installation rules and guidelines for operation, specification, and maintenance. Detailed information on various types for GIS, with 14 reference project explanations and three extensive case studies give information for the best solutions of practical applications. Special solutions using mobile substations concepts, mixed technology switchgear (MTS) with air and gas insulated technology, underground substations, and the use of special GIS substation buildings e.g., shopping centers, parking lots, city parks, business complexes’ or subway stations are explained. Future developments of GIS technology are shown for the next steps in alternatives to SF6, low power instrument transformers, and digitalization of substations. A new chapter explains advanced technologies applied to GIS projects which cover the following; environmental issues for the substation permission process, insulation coordination studies for the network requirements including very fast transients, project scope development, risk-based asset management, health and safety impact, electromagnetic fields, SF6 decomposition byproducts and condition assessment. Disruptive development steps in gas insulated substations technologies are also covered in this second edition. Vacuum breaking and switching technology for rated voltages of up to 500 kV is explained in detail with its physical background. Principle function and possible implementation of low power instrument transformers (LPIT) are explained and examples of applications are given. The principles of digital twin for gas insulated substations (GIS) and gas insulated transmission lines (GIL) are explained in theory and project applications show the practical use and advantage. The wide and fast-growing technical field of offshore GIS applications for AC and DC is explained on many examples and gives information on special requirements when getting offshore. Theoretical requirements on DC gas insulated systems, methods of testing, prototype installation tests, modular design features, and advantages in applications are given. Finally, impact and advantages of digital substations using GIS are explained. Key features: Written by leading GIS experts involved in development and project applications Discusses practical and theoretical aspects Detailed material of GIS for new and experienced GIS users, and project planners Invaluable guide to practicing electrical, mechanical and civil engineers as well as third- and fourth-year electric power engineering students