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
TRV Phenomenon in Chinese 1100 kV UHV Series Compensated System
Based on the planned Ximeng-Beijingdong UHV project in China, this paper mainly focuses on the TRV phenomenon in UHV series compensated system. The results show that, without countermeasure, the peak value of TRV during clearing single phase to ground fault in XimengBeijingdong UHV series compensated lines may exceed 2.7p.u.(1p.u.=1100kV* 2 / 3 ) and the TRV during clearing multi-phase fault may exceed 3.0p.u., which are much larger than the amplitude of TRV in present circuit breaker (CB) standards. This phenomenon may result in the failure of clearing system fault and the damage of circuit breaker. Several influencing factors for TRV in UHV series compensated transmission lines are analyzed. In order to limit the TRV, different countermeasures are investigated. The investigation indicates that, for Ximeng-Beijingdong UHV series compensated system, fast bypass series capacitors during system fault can effectively reduce the TRV peak value of line CBs, but the peak value still statistically exceeds related standards. Through the discussion with purchasers, manufacturers and test labs of UHV CBs, a common view of increasing the withstand capability for TRV of UHV CBs used for series compensated system is reached and a new higher test requirement for 1100kV CB is suggested.
Physical Chemistry for the Life Sciences
PART 1 - BIOCHEMICAL THERMODYNAMICS PART 2- THE KINETICS OF LIFE PROCESSES PART 3 - BIOMOLECULAR STRUCTURE PART 4 - BIOMOLECULAR SPECTROSCOPY