# US 9,752,560 B2 · Wind turbine generator system and lightning protection device thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,752,560 B2 - Document ID: US9752560B2 - Status: Granted - Kind: B2 - Application number: 14/366,753 - Filed: 2012-07-26 - Published: 2014-11-27 - Granted: 2017-09-05 - Earliest claimed: 2011-12-23 - Assignees: Xinjiang Goldwind Science & Technology Co., Ltd. - Applicants: Jinpeng Huang; Uwe Hinz; Qiang Li; Junhao Ge; Wei Yang - Inventors: Jinpeng Huang; Uwe Hinz; Qiang Li; Junhao Ge; Wei Yang - Web page: https://patentgrep.com/patent/US9752560B2 ## CPC - F03D 80/30: Lightning protection - H02G 13/80: {Discharge by conduction or dissipation, e.g. rods, arresters, spark gaps} - Y02E 10/72: Wind turbines with rotation axis in wind direction - F03D: WIND MOTORS - H02G: INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A lightning protection device for a wind turbine generator system includes at least a blade arrester, a down lead of a blade connected to the blade arrester, a lightning-proof element of a pitch bearing, a lightning-proof element of a rotor bearing. The lightning-proof element of the pitch bearing is arranged at the blade root, with one end connected to the down lead of blade and the other end connected to the lightning-proof element of the rotor bearing. The lightning protection device forms a lightning current conducting path passing through a cavity of the pitch bearing, a hollow of a rotor shaft and a cavity of the rotor bearing. A wind turbine generator system having the above mentioned lightning protection device is provided. ## Claims ### Claim 1 A lightning protection device for a wind turbine generator system including a rotor connected with a hub and at least one rotor blade, wherein the at least one rotor blade is connected to the hub via a blade pitch bearing, the hub is connected to a hollow rotor shaft and the hollow rotor shaft is supported by at least one rotor bearing, and wherein the blade pitch bearing has a cavity therein and the at least one rotor bearing has a cavity defined by an inner diameter of the rotor bearing, the lightning protection device includes: a blade arrester located near a blade tip and at a side of the at least one rotor blade, a down lead of the at least one rotor blade connected to the blade arrester, a lightning protection element of the blade pitch bearing and a lightning protection element of the at least one rotor bearing, wherein the lightning protection element of the blade pitch bearing is provided at a blade root, one end of the lightning protection element of the blade pitch bearing is connected to the down lead of at least one rotor blade and another end is connected to the lightning protection element of the rotor bearing; wherein, the lightning protection device forms a lightning current conducting path which is passing through the cavity of the blade pitch bearing, a hollow portion of the hollow rotor shaft and the cavity of the rotor bearing; the lightning protection element of the rotor bearing includes a slip ring with at least one brush; and the slip ring of the lightning protection element of the rotor bearing is arranged around an electrical or hydraulic slip ring unit of the wind turbine generator system. ### Claim 2 (depends on 1) A lightning protection device according to claim 1, wherein, the lightning protection element of the blade pitch bearing includes a flexible insulated cable. ### Claim 3 (depends on 2) A lightning protection device according to claim 2, wherein, the lightning protection element of the blade pitch bearing includes a tensioned rope for limiting a position of the flexible insulated cable, wherein two ends of the tensioned rope are connected to a fixed point at the at least one rotor blade and a fixed point at the hub respectively, and the flexible insulated cable has at least one point fixed to the tensioned rope. ### Claim 4 (depends on 3) A lightning protection device according to claim 3, wherein, the flexible insulated cable of the lightning protection element of the blade pitch bearing is tensioned between the fixed point at the at least one rotor blade and the fixed point at the hub along a direction of an axis of the blade pitch bearing. ### Claim 5 (depends on 2) A lightning protection device according to claim 2, wherein, the lightning protection element of the blade pitch bearing further includes a tube for position limitation arranged in the cavity of the blade pitch bearing, the flexible insulated cable passing through the tube and capable of rotating in the tube. ### Claim 6 (depends on 1) A lightning protection device according to claim 1, wherein, the lightning protection element of the blade pitch bearing includes a slip ring with at least one brush. ### Claim 7 (depends on 1) A lightning protection device according to claim 1, wherein, the at least one brush of the lightning protection element of the rotor bearing rotates along with the hub and is fixed to the hub or to the hollow rotor shaft, and the slip ring of the lightning protection element of the rotor bearing is fixed to an axle or to a base frame of a generator. ### Claim 8 (depends on 1) A lightning protection device according to claim 1, wherein, the slip ring of the lightning protection element of the rotor bearing rotates along with the hub and is fixed to the hub or to the hollow rotor shaft, and the at least one brush of the lightning protection element of the rotor bearing is fixed to an axle or to a base frame of a generator. ### Claim 9 (depends on 1) A lightning protection device according to claim 1, wherein, one end of the lightning protection element of the rotor bearing is electrically connected to an axle or a base frame of a generator. ### Claim 10 (depends on 1) A lightning protection device according to claim 1, wherein, one end of the lightning protection element of the rotor bearing is electrically connected to a lightning protection element of a yaw bearing, and the lightning protection element of the yaw bearing is electrically connected to a tower. ### Claim 11 (depends on 10) A lightning protection device according to claim 10, wherein, the lightning protection element of the yaw bearing includes a flexible insulated cable, wherein one end of the flexible insulated cable is fixed to a base frame and electrically connected to the lightning protection element of the rotor bearing, and another end is fixed to the tower, and wherein the flexible insulated cable has at least one point fixed to a cavity on a top of the tower or fixed at a position on a base frame near a center on the top of the tower. ### Claim 12 (depends on 10) A lightning protection device according to claim 10, wherein, the lightning protection element of the yaw bearing includes at least one brush, which is in slidable contact with the tower or a yaw brake disk. ### Claim 13 (depends on 1) A wind turbine generator system, including a tower, a nacelle, at least one generator, a hub and at least one rotor blade, wherein, including the lightning protection device according to claim 1. ### Claim 14 (depends on 13) The wind turbine generator system according to claim 13, wherein, the wind turbine generator is a direct-driven permanent magnetic generator.