Sigma Monitoring System Installed At Aluminium Plant

• 12/02/2010
• Cases

Alumar, Aluminum Consortium of Maranhão, located in the city of São Luis, is one of the world’s largest alumina and aluminum production complexes. Construction of the complex started in 1980 and operations began in 1984. Today, the complex is responsible for approximately 1% of Brazilian exports. The industrial complex is comprised of a large infrastructure set: port, refinery (that transforms bauxite in alumina), and reduction, that transforms alumina into metal aluminum in the cube lines (electrolytic kilns).

The energy requirements of this facility are met by Eletronorte. The tie in to the base network is at the São Luis II Substation through two 230kV transmission lines with independent towers and from there, to the reduction and refinery substations, where it is stepped down to distribution and consumption levels (13.8 / 34.5 kV), with installed power on the order of 1700 MVA and average demand of 650 MVA at the reduction facility and 32 MVA, at the refinery.

The facility’s average monthly overall consumption of 460 GWh makes Alumar one of Latin America’s largest and most electricity intensive industries. This industry’s main inputs are bauxite and electricity, with sudden and unforeseen prolonged interruption of power to the smelting cubes causing, in  addition to  loss of production, irreversible damage to the cubes due to the aluminum solidified on the refractory lining. This feature characterizes the requirement for high availability in energy supply.

In order to address the availability criteria, the reduction substation went through capacity increase and, among other equipment, a special transformer was ordered from ABB which received the integration of a voltage regulation transformer to the step down transformer, creating a single 343 MVA, 230 / 34.5 kV unit with two taps under load – the first one on the HV side that, through variation in induction, delivers to the LV side additional voltage regulation to the regulation obtained by the second tap, installed on the LV side by way of a transformer in series.

In this case also and due to the importance of the delivery, the ABB substation department chose Treetech to supply the complete on-line command, supervision, sensing and monitoring solution deploying the specialist software Sigma.