スイス全土の基幹送電網を所有・運営する株式会社。電力の安定供給を確保するため、グリッドの周波数制御や需給調整、欧州他国との電力取引の管理を行っている。FlexBaseの巨大蓄電プロジェクトとの接続を計画しており、民間蓄電施設との直接接続は同機関初の試みとなる。
The flexibility of distributed energy resources (DERs) accommodated in active distribution networks (ADNs) can be aggregated and then used to provide ancillary services to the transmission system. In this context, this paper presents a linear optimization method for the transmission system operator (TSO) to allocate its required active power reserve from aggregated resources installed in active distribution systems (ARADSs) as well as dispatchable bulk power plants (DBPPs). It consists in a linear optimization problem that minimizes the sum of the expected cost of active power reserve allocated from all possible providers (including ARADSs and DBPPs) and the expected cost of load not served over a desired time horizon. The value of lost load (VOLL) index is used as a criterion to realize an economical balance between the expected cost of allocated reserve and expected cost of load not served. The method leverages scenarios of power system contingencies and forecast errors of loads and renewable generation to represent typical operational uncertainties. A simulation proof-of-concept using real-data from the transmission system operator of Switzerland, Swissgrid, is provided to illustrate the performance of the method.
Um von den Kraftwerken zu den Verbrauchern zu gelangen, muss der elektrische Strom durch das 6700 km lange Übertragungsnetz fliessen. Ohne dieses wäre die Versorgung mit elektrischer Energie nicht möglich. Eigentümerin und Betreiberin des Übertragungsnetzes ist Swissgrid – eine privat-rechtliche Aktiengesellschaft. Swissgrid ist von Gesetzes wegen dafür verantwortlich, dass schweizweit dauernd und jederzeit die nötige Menge Strom zu angemessenen Preisen erhältlich ist. Doch was geschieht, wenn Swissgrid dies nicht mehr gewährleisten kann? Die Auswirkungen auf die gesamte Bevölkerung und die Wirtschaft wären drastisch: Ein Blackout verursacht einen Schaden von vier Milliarden Franken – pro Tag. Für diesen Schaden würde zwar in erster Linie die privat-rechtliche Swissgrid haften. Doch den Bund trifft stets die letzte Verantwortung. Das vorliegende Werk zeigt deshalb nicht nur detailliert das Haftungsregime auf, sondern geht auch der Frage nach, wie sinnvoll es ist, die sichere Stromversorgung der Schweiz in die Hände einer AG zu legen.
Employee rostering is a process of assigning available employees to open shifts. Automating it has ubiquitous practical benefits for nearly all industries, such as reducing manual workload and producing flexible, high-quality schedules. In this work, we develop a hybrid methodology which combines Mixed-Integer Linear Programming (MILP) with scatter search, an evolutionary algorithm, having as use case the optimization of employee rostering for Swissgrid, where it is currently a largely manual process. The hybrid methodology guarantees compliance with labor laws, maximizes employees' preference satisfaction, and distributes workload as uniformly as possible among them. Above all, it is shown to be a robust and efficient algorithm, consistently solving realistic problems of varying complexity to near-optimality an order of magnitude faster than an MILP-alone approach using a state-of-the-art commercial solver. Several practical extensions and use cases are presented, which are incorporated into a software tool currently being in pilot use at Swissgrid.
