Changes
/* Control patents */
| <center>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6278211.PN.&OS=PN/6278211&RS=PN/6278211 US6278211B1]</center>
| <center>02/08/01</center>
| <center>SWEO EDWIN Sweo Edwin A</center>
| Brushless doubly-fed induction machines employing dual cage rotors
| <center>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6954004.PN.&OS=PN/6954004&RS=PN/6954004 US6954004B2]</center>
| <center>11/10/05</center>
| <center>SPELLMAN HIGH VOLTAGE ELECTRONSpellman High Voltage Electron</center>
| Doubly fed induction machine
| <center>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7411309.PN.&OS=PN/7411309&RS=PN/7411309 US7411309B2]</center>
| <center>12/08/08</center>
| <center>XANTREX TECHNOLOGY INCXantrex Technology Inc</center>
| Control system for doubly fed induction generator
| <center>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7485980.PN.&OS=PN/7485980&RS=PN/7485980 US7485980B2]</center>
| <center>03/02/09</center>
| <center>HITACHI LTDHitachi Ltd</center>
| Power converter for doubly-fed power generator system
| <center>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7800243.PN.&OS=PN/7800243&RS=PN/7800243 US7800243B2]</center>
| <center>21/09/10</center>
| <center>VESTAS WIND SYS ASVestas Wind Systems </center>
| Variable speed wind turbine with doubly-fed induction generator compensated for varying rotor speed
| <center>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7830127.PN.&OS=PN/7830127&RS=PN/7830127 US7830127B2]</center>
| <center>09/11/10</center>
| <center>WIND TO POWER SYSTEM S LWind To Power Systems</center>
| Doubly-controlled asynchronous generator
|}
