GE 2.x Zero Power Voltage Regulation Measurement Results Vincent Schellings

1. GE Energy GE 2.xZero Power Voltage Regulation Measurement ResultsVincent Schellings

2. Introduction • Voltage Regulation • Zero Power Voltage Regulation Concept • Measurement Results • Conclusions

3. Voltage Regulation To support the network voltage, GE wind turbines supply reactive power The GE Wind Farm Management System controls the wind farm voltage (or power factor) by measuring voltage and current at the substation The Wind Farm Management System then compares the actual wind farm output to the voltage or parameter settings

4. Voltage at POI Wind farm power output Individual WTG Collector Bus Utility ~20 km Transmission Bus (POI) SCR ~3.5 75km Voltage Regulation Example - Colorado Green 20% variability in real power <1% variability in voltage

5. Zero Power Voltage Regulation (ZPVR) Concept • Wind turbines generally operate unless: • Low wind speeds • High wind speeds, resulting in sudden loss of power • Abnormal grid conditions Through appropriate controls in the GE 2.x its converter can deliver reactive power (kVAR) without wind (kW)

6. ZPVR Benefits for the Grid • Voltage support and regulation continues without active power generation • Adverse voltage impact due to tripping wind turbines is greatly reduced or eliminated

7. ZPVR benefits for the grid Benefits are greatest in: • Weak grids (e.g. geographically remote systems, end of long lines) • Systems with high wind penetration Alternatives are: • Separate dynamic VAR sources within the farm • Grid reinforcements

8. 2 3 1 2 3 1 Measurement results Turbine out of operation Turbine supplies 200 kVAR reactive power and no active power Turbine supplies 1100 kVAR reactive power and no active power Mean value of 6025.8 V Mean value of 6033.4 V Mean value of 6083.7 V, an increase in grid voltage of 1% Grid voltage can be influenced with a non-operating turbine

9. Measurement results Turbine continues constant supply of reactive power during operation of the turbine

10. Wind turbines can stabilize the grid voltage by supplying and absorbing reactive power The GE 2.x wind turbine contains a “Zero Power Voltage Regulation“ feature to provide reactive power without active power generation Zero Power Voltage Regulation is benificial for weak grids and systems with high wind penetration As a result of Zero Power Voltage Regulation, considerable savings can be achieved on the need for grid reinforcements or VAR sources in the wind farm Conclusions

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