Major SVC upgrade in the Canadian 735 kV transmission system Emerging Technologies for Power System Applications

摘要

Two older analog Static Var Compensators (SVCs), part of Hydro-Quebec's 735 kV transmission system in Canada, were replaced by new digital ones and put into commission by ABB in the autumn of 2013 and 2014 respectively. This project was riddled with challenges, the first being the short time frame for completion. For both replacements, an eight-month window was given to demolish the old SVC and install the new one. A second hurdle was the required parallel operation mode between a new digital SVC and an old analog SVC. As these SVCs are crucial to Hydro-Quebec's transmission system during peak demand in winter, the parallel mode was necessary to allow the proper operation of both SVCs in the year between the installation of the first and the second new SVC. This paper highlights the key elements in this project. The characteristics of the Nemiscau SVCs are given, as well as background information and the design philosophy for their operation and controls for all phases of the project. During the winter of 2013-2014 an old and a new SVC, with two different susceptance control strategies, had to work in parallel, controlling the same 735 kV busbar. The approach used to interfacing both SVCs as well as requirements for accuracy and delay are discussed in this paper together with the testing approach, e.g. in ABB and IREQ laboratories. The testing of the controls prior to commissioning was a key element in the success of this project. The operation of the SVCs and the challenges faced since the completion of the project will also be discussed.