Efficiently generating electric power without polluting the environment becomes increasingly important in times of high commodity prices and growing environmental awareness among consumers. Within the scope of the OGOWin research project for building up a first prototype of a jacket-construction-type offshore wind power plant, HBK supplies and installs test and measurement equipment for a test plant in Bremerhaven, Germany. The challenge is to install the equipment such that it also withstands the extreme stresses to which the production models will be subjected later when used in rough sea conditions.
Has the wind turbine the ability to withstand the loads it is subjected to at sea? That was the challenge facing HBK, when the company provided testing and measuring equipment for the first prototype of an offshore wind turbine with a jacket support structure within the framework of the OGOWin research project.
Offshore wind farms comprise many wind turbines installed far off shore in the open sea and permanently producing clean current. This is an attractive concept which, however, is not easy to implement because of the stresses resulting from wind, waves and saltwater to which the materials used are subjected. For this reason, the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) subsidizes the research and optimization of disarrayed foundation structures for offshore wind power plants (OGOWin) regarding material usage, the assembly process and new manufacturing methods for the carrying structure of wind power plants.
Prior to the actual use of the foundation structures on the sea bed, the OGOWin project focuses on onshore research of the offshore plants. The two main components of a wind power plant are the carrying structure (jacket + tower) and the actual nacelle with the rotor blades for generating electric power from the wind. The OGOWin project focuses on the jacket as the object of study. Researchers aim at minimizing material usage, because steel is expensive and a jacket weighs about 350 tons. In addition, the status of the wind power plant is to be continuously monitored. Maintenance cycles and the residual service life are inferred from the results.
The Fraunhofer Center for Wind Energy and Marine Technology (SWMT) in Bremerhaven, Germany, is responsible for the design and layout of the test and measurement equipment at the carrying structure. HBK has built up and installed the test and measurement equipment on behalf of the Fraunhofer CWMT.
HBK was chosen, not least because of the positive experiences and convincing results with FINO1, a research platform for offshore wind power for which HBK provided the test and measurement equipment (electrical strain gages installed fully waterproof) already in 2003. It had been used without any problems for several years until an exceptionally strong storm destroyed parts of the platform.
Moreover, HBK has a competent and international service team enabling problems to be quickly and reliably eliminated on site. And last but not least, HBK offers both technologies from a single source so that reproducibility is guaranteed.
HBK's tasks in the framework of the OGOWin project include installing electrical and fiber-optical strain gages at the "stressed" points of the jacket, cabling the HBK amplifiers and transmitting the measured values to the Fraunhofer Center.
The goal is to test both technologies (optical, fiber-Bragg-grating-based strain gages and electrical strain gages) with respect to reproducibility of test results and suitability for use in offshore wind power plants.
For implementing the test and measurement concept, HBK provided the required hardware and software (MGC amplifier, opto-electric interrogators, catman software) and installed about 70 strain gages on the jacket.
Many measuring points were doubly configured - i.e. strain gages of both technologies were installed.
The focus is on analyzing the static and dynamic behavior of the newly developed cast-iron nodes used in this design for the first time.
The measuring points were covered with multiple layers to enable them to withstand many years of continuous use in a water depth of up to 40 meters. Test data is transmitted by saltwater-proof cables to the amplifier located at the foot of the tower and sent to Fraunhofer at periodic intervals. There, data is visualized, converted and analyzed using HBK's catman software.
The Fraunhofer-Gesellschaft promotes and engages in internationally networked, application-based research for the direct benefit of the business community and to the advantage of society. Customer satisfaction is a crucial success indicator for Fraunhofer institutes.
Unlike research institutions that concentrate more heavily on basic research, direct assignments from industry constitute a central element of the organisation's funding and are the precondition for growth and success. The consistent focus on the needs of industry and its timing lie at the heart of the organisation's research activities. Ensuring the confidentiality of information and results is therefore of paramount importance.
For an industry organisation like IWES, which focuses entirely on wind energy, a close alliance with industrial partners is a matter of existential importance. In order to exactly understand the needs of industry and to develop methods and solutions for acute and future problems, numerous interfaces have been created for a regular exchange of ideas.
Os medidores de tensão são o principal recurso para medir a fadiga e testar materiais para produtos melhores e mais seguros. Seja em testes de durabilidade estrutural, monitoramento de integridade estrutural ou para a produção de transdutores OEM, os strain gauges ópticos e elétricos da HBK são a primeira escolha.
