Projects

1. Recently Finished

Project of Rehabilitation and Automation of the South Central - REABSUL

In 2003, considering the increase in the number of failures, the notable interruption on the manufacturing of certain spare parts and the need for modernization, the implementation of a project of rehabilitation, automation and remote control operating to the Southern Central (REABSUL) was decided. This project ended in 2007.The REABSUL results were noticed in 2005, when the first production record of 13.064 GWh was broken, having since then increased production from year to year (2006 with 14.490, 70GWh and 2007 with 15.846, 58GWh). The maximum theoretical production is probably of 18.000 GWh and the project had a cost of around 100 millions of Euros.

Main aisle of the Central, before rehabilitation		Main aisle of the Central, after rehabilitation

2. From the Present and Future

2.1 – Researches aiming to the possible increase on generation capacity from the South Central

The growing increase in electric energy demand both it the national and regional markets, leads the maximization of energy production to being a factor that needs attention, without disregarding the components of hydraulic safety and generating units. In this range emerges the decision of reevaluating the possibility of increasing the generation capacity of the five generating groups from the South Central (in the order of approximately 6%), which after being implemented would result in a greater availability of electrical energy, which would increase HCB’s contribution to the suppression of the increasing national and regional demand.

Francis Turbine		Generator’s rotating part

2.2 – Project of Discharger Rehabilitation – REABDESC

This project consists on the rehabilitation of the 8 flood dischargers plus 1 superficial discharger in the dam, according to their age and operation time, for an operational improvement of the fence elements and its surface. It will include the automation and remote control operation of the maneuver equipment.

2.3 – Project to the Construction of the North-central

The reactivation of the studies for the installation of a new central in the north margin is essential in view of the recent regional energetic market situation. A feasibility of the central north has as foundations the fact that a potential extra drain off already exists and was identified in the Cahora Bassa reservoir, and also the fact that it already has a regional demand. An installed power of 1.200MW is predicted, which could increase the installed capacity of the Cahora Bassa hydroelectric enterprise to 3.275MW.

Flood Gate in activity, frontal view		Aerial view of the dam, north and south margin		Rehabilitation Project

2.4 - Project of Rehabilitation of the Converting Substation – REABSUB

The Songo Substation comprises the HVDC system (High Voltage Direct Current) and a HVAC System. (High Voltage Alternate Current).

The HVDC set, consists of a Bipolar Transmission System, which is formed by an Alternate Current Park with Cutting and Maneuver equipment, 8 Converter Bridges of 240MW each, (four Converter Bridges by pole), Single-phase Converting Transformers, by a Continuous Current Park with Cutting and Maneuver equipment and by two Single-polar Transportation Lines. The total of the installed power is around 1.920 MW.

If on one side the manufacturing of this equipment has stopped long ago, it becomes very difficult to find qualified labor in the market to work on them. In the same perspective with these factors, the increasing rate of breakdowns was the key factor for the whole rehabilitation and modernization of the converting system to be decided, with a possible increase on the transmission capacity from 1.920 to 3.600 MW. It must be referred that this capacity increase goes from the revision of the isolation level on the respective transportation lines.

Substation, High Voltage Direct Current Park (transformers and e converter valves)		Substation, High Voltage Direct Current Park (cutting, maneuver and protection equipment)

The transportation lines play an important role, in the electric energy transportation chain, and also the transportation lines, which can be formed by a choking knot, which has been testified during the armed conflict with the fall down of the towers and the 2000 floods as well as the fall down of many others.

The rebuilding of the electric energy transportation lines towers to Apollo, in the first phase, consists of the treating anti-corrosive protection of protection of metallic elements.

With the increase in the converting substation’s capacity and having in perspective the future need of draining the energy that comes from new generation sources, such as north central and others, studies are being carried out to the probable increase of electrical energy transportation lines.

Tower of electrical energy transportation in direct current