General Electric Co now claims Vestas Wind Systems A/S and Vestas-American Wind Technology Inc. infringed on another wind turbine technology patent, according to the recently amended suit against the Danish wind turbine manufacturer.
On Oct. 2, GE filed an updated suit alleging that Vestas infringed on its Low Voltage Ride Through patent, which helps turbine generators stay connected to the grid and keeps the blade pitch system going during low-voltage events.
Using information from Vestas' brochures and website, GE claims at least four wind turbine models have a similar design, composed of a wind turbine generator with a blade pitch control system that is designed to stay online during low-voltage events for up to three seconds. GE claims Vestas has known about the patent since 2009, when it filed for a patent for a method to control wind turbines connected to the grid and detect problems within the grid. Vestas references GE's Low Voltage Ride Through technology patent in at least four other patent applications, according to court documents.
The updated complaint reasserts GE's previous claim from July that Vestas violated the company's patent on its Zero Voltage Ride Through technology, a similar mechanism that pairs a wind turbine generator with an electric power system so the turbine continues to produce electricity when the voltage drops to zero due to events like lightning strikes. Three of the four turbine models listed in that complaint also allegedly violated GE's Low Voltage Ride Through patent, according to the amended suit.
The company wants the U.S. District Court for the Central District of California to place an injunction against Vestas making, using or selling wind turbines within the U.S. that violate the two GE patents. Vestas has until Nov. 1 to respond to the complaint.
This is not the first time GE has filed a lawsuit against a wind turbine manufacturer for patent infringement. The company won a case against Mitsubishi Heavy Industries Ltd. and Mitsubishi Power Systems for using similar technology in their turbines and was originally awarded $166.8 million in lost profits and $3.4 million in royalty damages by the court. The two companies ended up settling in 2013.
A Vestas spokesperson provided a statement that said the company "considers the amended Complaint to be without merit, and will vigorously defend itself.