Wind energy today is the principal moving force of renewable energy development. According to REN21 international association and its latest report named RENEWABLES 2016 GLOBAL STATUS REPORT, in 2015 wind energy capacities exceeded 430 GW, which comprises about 55% of all electrical power generating renewable energy facilities in the world, excluding hydro power. The innovative activities of inventors make considerable contribution to this development. This article, alongside the previously published ones, examines recent technical solutions in the field of wind energy through the examples of specific patent applications published in 2015 in the leading patent offices of the world.
Almost 33% of patent applications are related to control systems and equipment, and slightly more than 23% are related to wind turbine blades. Another important aspect of the industry, which is also widespread in patent documents, is related to maintenance, repair and replacement of equipment – it was mentioned in approximately 11% of cases.
The greatest attention to wind turbine control systems was paid in that year by Vestas Wind Systems A/S company (190 documents found) and General Electric (159 documents). The problem of high costs related to maintenance, repair and replacement of equipment was mentioned the most in this group of patent documents – in 800 documents. In our opinion, particular attention should be paid to patent application by Siemens Aktiengesellschaft company that was filed in the United States Patent and Trademark Office Detecting a pitch angle adjustment fault / A: US20150176570A1 / IPC: F03D11/00, F03D7/04, F03D7/02 /Egedal Per, Hoegh Gustav, Kallesoee Bjarne Skovmose / SiemensAktiengesellschaft / Appl. date: 05.12.2014; Publ. date: 25.06.2015, and a series of applications by Vestas Wind Systems A/S company that were filed under one title in the United Kingdom, namely - Improvements relating to lightning protection systems for wind turbine blades / A: GB2519331A /IPC: F03D1/06, F03D11/00, H02G13/00 / WHITEHOUSE Daniel, BAKER Richard / Vestas Wind Systems A/S /Appl. date: 17.10.2013; Publ. date: 22.04.2015. The first of these documents describes a method and device for detecting a malfunctioning in the pitch angle control system of a wind turbine, while the second document represents a method and device for wind turbine blade lightning protection. These documents complemented the previously existing patent families and have the highest bibliographical rating in this group of patent applications, as calculated in accordance with our methodology. This rating doesn't directly evaluate the technical excellence of patent documents; however, it can be used to grade the documents by the total of bibliographical parameters, which include among others: number of claims; document kind; declared problems and technological belonging; breadth of distribution of a document and its family members across different countries; activity of authors, etc. Taking into consideration the fact that bibliographical parameters indirectly concern the technical essence of invention and substantially disclose its legal claims, an aggregate bibliographical rating can be considered as an important tool for preliminary evaluation of patent documents. Among other applications with the highest rating score, which were designated as wind turbine control systems, the following document should be mentioned: METHODS AND SYSTEMS FOR DETECTING WIND TURBINE ROTOR BLADE DAMAGE / A: US20150050143A1 / IPC: F03D11/00 / Kammer Leonardo Cesar / General Electric Company /Appl. date: 19.08.2013; Publ. date: 19.02.2015, in which the applicant (General Electric company) discloses a control system for detecting rotor blade damage (method and device thereof), which system uses a comparison of frequency component amplitudes in different working conditions of the wind turbine. Maximum number of claims in this group of patent documents is 71, they belong to an application filed in the World International Patent Office – Turbine fluid velocity field measurement / A: WO2015001301A1 / IPC: G01S17/58,G01S17/95, G01P5/26, F03D7/04, F03D11/00 / HOLTOM Theodore / WIND FARM ANALYTICS LTD / Appl. date:09.06.2014; Publ. date: 08.01.2015.
The most active applicants proposing different technical solutions related to wind turbine blades virtually equally were Siemens AG and Wobben Properties GmbH from Germany. Wobben Properties GmbH proposed several interrelated documents filed in various patent offices, particularly in WIPO - ROTOR BLADE FOR A WIND TURBINE / A: WO2015155079A1 / IPC: F03D1/06 /HOFFMANN Alexander / WOBBEN PROPERTIES GMBH / Appl. date: 31.03.2015; Publ. date:15.10.2015, which concern important aspects of production and operation of wind turbine blade and, in particular, a method of preventing icing. In a nutshell, the document proposes to apply a set of cavities in different portions of the blade for this purpose and a method for differentiated heating thereof. In total the document comprises 68 claims. In our opinion, attention should also be directed to a group of documents published in various offices (WIPO, Australia, Taiwan, Canada) that belong to one patent family and disclose a special coating for wind turbine blades: Novelcoating composition / A: WO2015049260A1 / IPC: C08G18/50, C08G18/60, C08G18/79, C09D175/12,C08G18/46, F03D11/00 / WOULDHAVE Matthew, KANATT Bijoy, HESSELINK Sebastiaan J A, DONKIN Michael David / AKZO NOBEL COATINGS INTERNATIONAL B.V / Appl. date:01.10.2014; Publ. date: 09.04.2015. The invention simultaneously proposes a complex polymer coating composition, a method for efficient production of this coating and, a blade with such coating. A list of this document's claims contains 14 paragraphs.
Sometimes it can be useful to take a glance at the list of inventions that are assigned to several sections of International Patent Classification simultaneously, inasmuch as some truly interesting solutions can appear at the intersection of different disciplines. For instance, a group of applications, represented by Canadian document WIND TURBINE HAVING A REDUCED RADAR CROSS SECTION / A: CA2919935A1 / IPC: F03D80/00, F03D13/20, C09D5/32, E04H12/02, G01S7/41 / FIXTER GREG PETER WADE, SPOONER CHRISTOPHER DOUGLAS JAMES, PERRY CHRISTOPHER JAMES, SAVAGE VINCEN / QINETIQ LIMITED / Appl. date: 30.07.2014; Publ. date: 05.02.2015, contains three different IPC sections: F, C and E. The document discloses a special composition of radiation absorbent material and a production method thereof, which composition is intended for the loadbearing structure of a wind turbine with a decreased radar cross section. The largest number of claims in the group of patent applications related to the production and operation of wind turbine blades was found in the application filed in the European Patent Office - Efficient wind turbine blades, wind turbine blade structures, and associated systems and methods of manufacture, assembly and use / A: EP2358998A4 / IPC: B29D99/00, F03D1/06, F03D3/06, B29L31/08 / Baker Myles L, Arendt Cory P, Madrid Bernard G, Vilhauer Sheldon / Vestas Wind Systems A/S / Appl. date: 04.12.2009; Publ. date: 30.12.2015. This application has 150 claims and it complements the list of documents of a previously existing patent family.
Wobben Properties GmbH company became the unconditional leader in terms of the number of registered documents related to the technological group of maintenance, repair and replacement, with 93 documents found. The following documents had the highest bibliographical rating score in this group: Synchronous generator of a gearless wind energy turbine / A: US20150288267A1 / IPC: H02K19/16, H02K15/00, F03D9/00 / Gudewer Wilko, GiengielWojciech / Wobben Properties GmbH / Appl. date: 05.04.2013; Publ. date: 08.10.2015, with Wobben Properties GmbH named as the applicant; and a group of applications by VESTAS WIND SYSTEMS A/S that can be represented by: RAIL APPARATUS FOR WIND TURBINE BLADE CONSTRUCTION / A: US20150298403A1 / IPC: B29C70/54, B29C70/34, B66C19/00 / HEDGES Andrew, LEE Byungwoo / VESTAS WIND SYSTEMS A/S / Appl. date: 19.12.2013; Publ. date: 22.10.2015.
Almost all of the patent applications mentioned above complement previously registered priority documents, which define patent family groups. However, another part of patent applications doesn't have such family background and therefore may be of exceptional originality. As an example, the following application can be named: WIND TURBINE OPERATING METHOD AND DEVICE BASED ON LOAD AND ACCELERATION MEASUREMENTS IN THE BLADE / A: WO2015014366A1 / IPC: F03D7/02, F03D11/00 / OLESEN IbSvend / Vestas Wind Systems A/S / Appl. date: 04.07.2014; Publ. date: 05.02.2015. It is dedicated to a particularly important topic – wind turbine operation with the possibility to prevent excessive loads on the blades of the rotor.
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