Madeira River Complex consists of the hydroelectric plants of Santo Antonio and Jirau, which have a total installed capacity of about 6,500 MW in their final phase. For the disposal of the energy produced by these plants, a transmission system composed of two DC dipoles at ± 600 kV were designed, covering a distance of 2,375 km from São Paulo, and two converters back to back, 2 x 400 MW, located in Porto Velho to the local supply.

The project incorporated new technologies, both in generating, using bulb type turbines, as in converter stations for direct current transmissions. As in any large project, the entry into operation of its components takes place in stages, being necessary to evaluate each one in detail, to ensure the electrical security of the BIPS, as well as the integrity of the equipment involved - the new and the existing ones.

The work begins with an analysis of the compliance of basic projects to the operational requirements set in the bidding documents, involving approximately 550 documents, including reports, studies, project drawings, equipment characteristics, definition of protection, command and control systems, supervision and telecommunication system. In 2011, it was approved the compliance of the basic projects A (back to back) and C (dipole 1).

The operational studies were initially conducted for the previous configuration to the entry into operation of the DC transmission. In this context, the anticipation of the entry into operation of the first generating units at the plant in San Antonio brought a great challenge for the system operation, since these units come up with an incomplete transmission system, with only one of three circuits of 230 kV planned between the substations Vilhena and Samuel. This incomplete setting limits the power exchange limits between the área Acre-Rondônia and the rest of the BIPS, becoming a major challenge to ensure the integration of Santo Antonio plant, with its maximum generation, without reducing the reliability of power supply to the states of the area.  

The operational studies carried out for this initial stage were aimed at defining bands of operational security, considering the combination of several variables involved: exchanges with the rest of the BIPS; load levels, local plants generation, implementation of new Special Protection Systems; restoration procedures, and the settings of the controllers of the generating units connected in Acre-Rondônia area.

The implementation of operational measures identified in the studies provide benefits for the area supply, allowing explore with security the energy generated in Santo Antonio plant and thus reduce dependence on local thermal generation, increase operational flexibility, and provide better supply conditions in normal operation and in emergency conditions.

The operating studies will continue with the analysis of the next steps until the full deployment of plants and the associated transmission system. In this sense, since the studies are in progress to the next step, which includes commissioning and the entry into operation of Porto Velho back to back converters, scheduled for the first half of 2012.

In 2011, ONS staff continued to be trained on DC transmission technology, involving about 150 professionals and with the participation of experts from ANEEL, MME and EPE. It was also given continuity to the installation of the real time digital simulator, discussed in section 2.7.