📋 Case Study

Texas ERCOT West Texas Wind Cluster Stability Upgrade

Repeated voltage collapse during summer peak load + low-wind conditions

🏗️ Project Overview

3 GW wind farm cluster connected via 345 kV weak line (SCR ≈ 1.8)

🎯 Challenge

Repeated voltage collapse during summer peak load + low-wind conditions

🔧 Design Approach

Deployment of 4× 150 Mvar STATCOMs with dynamic reactive power scheduling and Q-V droop tuning

📐 Key Calculations

Q-V Droop Setting

ΔQ = k × ΔV

Result: k = −300 Mvar/pu

Prevents reactive power starvation during voltage sag

Voltage Stability Margin

VSM = (V_critical − V_operating)/V_critical

Result: 0.14 pu

Below 0.15 pu threshold requiring mitigation

📊 Results

Zero voltage collapse events over 24 months; improved recovery time from 4.2 s to 0.8 s post-fault

💡 Lessons Learned

• •Q-V droop must be coordinated across all reactive support devices
• •STATCOM placement requires modal participation factor analysis

✅ Key Takeaways

• 1Q-V droop must be coordinated across all reactive support devices
• 2STATCOM placement requires modal participation factor analysis