38 I E E E E l e c t r i f i cati o n M agaz ine / SEPTEMBER 2015 Tref 13.2/ 3.3 kV dc 7 MVA ac 7 MVA ac 3.3/13.2 kV Soft-Starter GRC 750-kW Drive Train Two-Speed Induction Generator GB GB GE 2.75-MW Drive Train PM Generator dc 7 MVA ac dc dc 600 V 690 V ac dc ac ac 2-MW PV Inverter dc 2 MW/1 MWh Up to ±1,000Vdc PV Array Simulator dc Future Energy Storage and PV Inverter Testing Capability 2.5-MW Dynamometer Dyno Control 5-MW Dynamometer ac 7 MVA Figure 10. NWTC simulated grid capability. Grid dc 7 MVA ac Future RLC Load Bank 13.2-kV CGI Test Bus CGI Bus Gamesa 2 MW Gearbox Gearbox Siemens 2.3 MW Gearbox Alstom 3 MW Gearbox DFIG: Doubly-Fed Induction Generators RLC: Resistor, Inductor, Capacitor DFIG DFIG DFIG GE 1.5 MW NWTC Row Four Wind Turbines