Operational experience of 800 kV series capacitors
In Brazil, series compensation has been used since 1989 in the Furnas 765 kV AC power transmission to safeguard stable transmission of large amounts of hydro power. Today, a total of nine series capacitors are in operation, eight of which were supplied by ABB, six at Ivaipora and two at Itabera, the substations located about one third from each end of the tie. Ratings vary between 1017 MVAr (Ivaipora) and 1242 MVAr (Itabera). When introduced, the series capacitors were the first in the world to be installed at 765 kV. The paper gives a description of the series capacitor banks and comment on the operational performance of the banks
Study on system operation voltage characteristics of UHV transmission lines with series capacitors
Adopting series capacitors (SC) on 1000kV UHV AC transmission line can further uprate its transmission capacity, and it can also make impact on operation voltage characteristics of UHV system. Especially for heavy-load mode, as the large voltage step-up caused by SC, the issues on system operation voltage control may be more prominent. The layout manner for SC on lines and the relative fixed position between high voltage shunt reactors (SR) and SC can make great difference. Based on the planned Huainan-Wannan-Zhebei-Huxi 1000kV UHV AC double circuits transmission project, this paper researched the steady-state voltage distribution characteristics of Huainan-Wannan lines which are fixed with 40% series capacitors. Two kinds of simulation tools such as PSD-BPA and EMTPE are adopted in this study. The suggestions on the layout manner for SC and the relative layout manner between SR and SC are put forward, which can supply technique basis for the project implementation.
Effectiveness of Series Capacitors in Long Distance Transmission Lines
The effectiveness of series capacitors used with long distance transmission lines in improving system stability is analyzed. Compensation efficiency is defined as the effectiveness of series capacitors. The influence of various factors on compensation efficiency such as capacitor location, line length, and degree of series compensation is investigated. Proper use of shunt reactors with series capacitors, in addition to limiting power frequency over- voltages, increases the maximum power transfer. Analytical expressions are included to aid in the calculation of compensation efficiency for a few typical cases. Curves are also presented indicating the critical value of shunt Mvar required for various degrees of series compensation and line lengths.