Aluminium

The “current efficiency” of the aluminum smelting process (how much current it takes to convert alumina to aluminum) is the key cost element of production. Improving process efficiency, increasing process current, upgrading of power conversion equipment and industry consolidations make accurate measurements crucial for maintaining competitiveness.

Process Applications

DynAmp focuses on two key parts of this process:

1. Conversion of electrical power to be useable in the process
2. Delivery and consumption of power in the process.

With process efficiencies increasing, tenths of a percent have a significant impact on competitiveness. With individual pot-lines energy costs from $11m to over $75m at current levels approaching 600kA, even small measurement errors can hide large losses.

High accuracy measurement of voltage and current is needed to…

• Provide current data to process systems for optimum control performance
• Detect unexpected changes in process efficiency
• Accurately evaluate impact of intended/trial process changes
• Objectively compare multiple process lines and smelters
• Improve visibility of process energy utilization and costs

Power Conversion Applications

Aluminum processes require the highest stability and reliability from power conversion equipment. Current instability leads to numerous process efficiency problems which increase costs. Reliability of power is paramount. Short-term disruptions increase costs by running the pot-line at less than optimal capacity. Long-term disruptions can be catastrophic requiring an entire pot-line to be rebuilt. Finally, catastrophic power conversion equipment failures are extremely hazardous and endanger both staff and facility.

Highly dependable and responsive measurement systems are needed to…

• Provide current data to rectifier control systems for optimum performance and stability
• Provide overall multi-rectifier balance indication
• Provide a backup “totalized” current measurement signal for total mainline current
• Sense power conversion equipment failure modes quickly to protect process, equipment, and personnel
• Analyze a rectifier’s condition to determine internal balance for capacity analysis and maintenance actions