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Dear PAC World Editor,
Unfortunately, sometimes the PAC World magazine needs to communicate sad news to our readers. We are very sorry to inform our community that our dear friend and colleague Rui M. de Moraes passed away on February 5 after a long fight with cancer. This is an enormous loss not only to his family and friends, but to our whole industry.  His contribution to the Brazilian Power Sector and CIGRE/IEEE world-wide community was remarkable. He was a wonderful person and fought his illness bravely, always caring more about others than himself.

Rui was an industry leader on many technical subjects in the areas of power system protection and control and system planning and operations. His recent work with deployment of synchrophasor measurement technology provided leadership and guidance to the electrical power sector in Brazil and all around the world.
Rui worked up to the last possible moment, so, together with his brother Rogério, we will submit a paper on Rui's behalf to be published in the next issue of the magazine

Jorge Ordacgi and Damir Novosel
PAC World Advisory Board Members

Dear PAC World Editor,
Itaipu Hydro busbar arrangement really paid off!  Itaipu hydro power plant is jointly operated by Brazil and Paraguay. The 50 Hz generators (10 x 700 MW) are connected to Paraguay through a 500/220 kV AC System and to Brazil through a HVDC System. The 60 Hz generators (10 x 700 MW) are connected to Brazil through a 500/765 kV AC System.
Both 50 Hz and 60 Hz substations inside the power house are rated 500 kV and built as gas insulated (SF6) installation. The busbar configuration is the same, as summarized in the diagram below: four busbar sections with double-breaker bays for transmission lines and the auxiliary service transformer with breaker-and-a-half bays for the generating units.  Each busbar section is protected by a high impedance differential scheme and a phase comparison differential scheme.

These GIS installations were the 2nd experience with 500 kV rated voltage. The application was difficult due to the large and complex power systems connected to each GIS. Many internal and external busbar faults took place during the childhood period of these substations. Table 1 describes the protection performance and shows that no generation was lost thanks to the busbar arrangement.
The protection system which uses the phase comparison differential scheme is more modern and has an automatic testing device, which performs periodic internal tests. This system has presented problems in Itaipu Right Bank aerial substation 500kV busbars protection when the automatic testing device is locked which leads to protection unavailability.

José Benedito Mota Jr.


pac world

Editor in chief: dr. Alexander Apostolov (USA)
Editors: Christoph Brumer (Switzerland),
Yana St. Clair (USA)
Design Layout Concept: Marek Knap (Poland)
Graphic Design: Terry McCoy (USA),
Iagoda Lazarova (USA), Dan-Andrei Serban (Romania)
Web Masters: Ognian Samokovliiski (Bulgaria)

Advisory Board: dr. Damir Novosel (USA), 
prof. Peter Crossley (UK),  prof. Paul Lee (Korea),
prof. Xinzhou Dong (China),  
prof. Mohindar Sachdev (Canada),
Jorge Miguel Ordacgi Filho (Brazil),
Rodney Hughes (Australia),
Graeme Topham (South Africa)



PAC World  (Email: editor@pacw.org)
8 Greenway Plaza, Suite 1510
Houston, TX  77046, USA
PAC World magazine is published quarterly by PAC World.  All rights reserved.  All published articles express solely the opinion of the authors. Reproduction in whole or in part of any material in this publication is allowed.
Parent company: OMICRON electronics Corp. USA



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