πŸ“‹ Case Study

Wind Farm Grid Connection Study

Steady-state overvoltage (>1.08 p.u.) during light-load night conditions; reactive power absorption causing instability warnings

πŸ—οΈ Project Overview

320 MW onshore wind farm connecting to 220 kV transmission node in low-inertia region

🎯 Challenge

Steady-state overvoltage (>1.08 p.u.) during light-load night conditions; reactive power absorption causing instability warnings

πŸ”§ Design Approach

Dynamic reactive compensation using wind turbine AVRs + switched shunt reactors; inclusion of aggregated WTG models with Type IV converter controls

πŸ“ Design Diagram

Grid\nSubstation 132 kV\nLine Wind Farm\n(50 Γ— 4.5 MW) Type IV WTGs Dynamic\nCompensation AVR + SSR P = +225 MW Q_abs = βˆ’128 MVAR Ξ”V = +0.0023 p.u./MW Steady-state overvoltage > 1.08 p.u.\n(Reactive absorption β†’ instability) Q_abs_max = βˆ’128 MVAR

AI-generated project design illustration

πŸ“ Key Calculations

Reactive Power Absorption Margin

Q_abs_max = S_rated Γ— √(1 βˆ’ PFΒ²)
Result: βˆ’128 MVAR
Set upper absorption limit to avoid grid code violations

Voltage Rise per MW Injection

Ξ”V β‰ˆ (P Γ— R + Q Γ— X)/V_base
Result: +0.0023 p.u./MW
Predicted 0.74 p.u. rise at full outputβ€”triggered reactor switching logic

πŸ“Š Results

Max voltage limited to 1.068 p.u.; zero reactive curtailment events; successful ENTSO-E compliance verification

πŸ’‘ Lessons Learned

  • β€’Aggregate modeling must preserve reactive capability envelopesβ€”not just active power dispatch
  • β€’Night-mode reactive scheduling requires separate load flow initialization

βœ… Key Takeaways

  • 1Aggregate modeling must preserve reactive capability envelopesβ€”not just active power dispatch
  • 2Night-mode reactive scheduling requires separate load flow initialization