๐ Case Study
Industrial Plant Power Design: Aluminum Smelter Load Flow Optimization
Severe voltage sag during anode changing cycles causing PLC trip cascades
๐๏ธ Project Overview
Greenfield 320 MW aluminum smelter in Iceland with 100% renewable hydro supply
๐ฏ Challenge
Severe voltage sag during anode changing cycles causing PLC trip cascades
๐ง Design Approach
Integrated STATCOM + dynamic tap changer coordination with load flow-driven reactive reserve allocation
๐ Design Diagram
AI-generated project design illustration
๐ Key Calculations
Short Circuit Ratio at Rectifier Bus
SC_MVA / Converter_MVA
Result: 2.8
Determines STATCOM sizing for voltage support
Voltage Sag Depth During 200ms Load Step
Z_line ร I_step / V_base
Result: 6.2%
Triggered protective undervoltage lockout
๐ Results
Zero trips over 18-month operation; 12% reduction in reactive energy penalties๐ก Lessons Learned
- โขStatic VAR compensation must be sized for worst-case dI/dt, not steady-state
- โขTap changers require coordinated delay logic to avoid counteracting STATCOM action
โ Key Takeaways
- 1Static VAR compensation must be sized for worst-case dI/dt, not steady-state
- 2Tap changers require coordinated delay logic to avoid counteracting STATCOM action