A wind powered turbine with low voltage ride-through capability. An inverter is connected to the output of a turbine generator. The generator output is conditioned by the inverter resulting in an output voltage and current at a frequency and phase angle appropriate for transmission to a three-phase utility grid. A frequency and phase angle sensor is connected to the utility grid operative during a fault on the grid. A control system is connected to the sensor and to the inverter. The control system output is a current command signal enabling the inverter to put out a current waveform, which is of the same phase and frequency as detected by the sensor. The control system synthesizes current waveform templates for all three-phases based on a sensed voltage on one phase and transmits currents to all three-phases of the electrical system based on the synthesized current waveforms.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. patent application Ser. No. 10/981,364, which was filed on Nov. 3, 2004, now U.S. Pat. No. 7,233,129, and which itself was a Continuation In Part of U.S. patent application Ser. No. 10/773,851, which was filed on Feb. 4, 2004, now U.S. Pat. No. 7,042,110, and which claimed priority under 35 U.S.C. .sctn. 119(e) to U.S. Provisional Patent Application No. 60/468,899 Variable Speed Wind Turbine Technology which was filed on May. 7, 2003 and which is incorporated herein by reference.
This application is related to U.S. Pat. Nos. 6,304,002, 6,731,017 6,653,744, and U.S. patent application Ser. No. 10/426,287 Kevin L. Cousineau: Distributed Static VAR Compensation (DSVC) System For Wind And Water Turbine Applications" filed Apr. 30, 2003, and U.S. patent application Ser. No. 10/449,342 of Amir S. Mikhail and Edwin C. Hahlbeck entitled "Improved Distributed Power Train (DGD) With Multiple Power Paths" filed May 31, 2003, all of which are assigned to Clipper Windpower Technology, Inc. and are incorporated herein by reference.
