LONDON — A new power supply has been developed to charge the latest super-capacitors used to power wind turbine pitch control systems. Super-capacitors (electrical double-layer capacitors) are rapidly replacing lead acid batteries previously used for pitch drives.
Pitch control systems are housed within the spinner of the turbine and rotate at around 30 RPM, so using lead acid batteries can risk acid spillage and poor reliability, says PULS UK, the company responsible for the new power supply.
PULS says its PAS395 delivers a high-charging current – a two-Farad capacitor will be fully charged in five minutes. Once charging is complete the charger has been designed to automatically switch to energy saving mode. The company says the unit can operate in temperatures between -40°C and +65°C and at up to 6000 metres, and comes with remote monitoring and control as standard features.
Safety Guidance Issued
The Energy Institute (EI), in collaboration with DNV (Det Norske Veritas), has published new guidance to help non-specialists manage human factors analysis of safety-critical tasks. This analysis can help reduce the chance of human failure, which otherwise could lead to a major accident, they say.
Reducing human error (Source:Yi Zhang)
Although the importance of human failures in accidents is well known, historically analysis of technical failures in major accident hazard safety reports has dominated. There are some signs this is beginning to change, with a higher volume of human factors analyses being conducted. Regulators are also responding to public expectations concerning proactive risk management, with requirements that safety critical human tasks are comprehensively analysed and their risk appropriately assessed.
While there are benefits in encouraging deeper analysis of safety critical tasks, there has been a lack of available information to help those without a human factors background effectively identify and manage safety risks in the workplace.
Innovation in Turbine Design
A new book, Innovation in Wind Turbine Design, based on over 30 years’ experience working on wind technology, has been published. The volume addresses the fundamentals of design, the reasons behind design choices, and how to apply existing engineering knowledge to further advance this technology.
The author, Peter Jamieson, has been involved with wind technologies, their assessment and concept design throughout his career. His background in maths and physics, rather than engineering, has seen him work across the entire turbine design process.
Andrew Garrad, president of GL Garrad Hassan, says of Peter Jamieson and the book: ‘He is a real blue sky thinker unimpeded by convention and driven by a strong sense of rigour. Innovation in wind turbine design is what he has been doing for the last 30 years. Anyone interested in the technical aspects of both the past developments and the exciting future of wind turbines should read this book carefully and be inspired. This is no arid technical text or history – this is real intellectual capital and, of course, innovation.’
Innovation in Wind Turbine Design covers design background, technology evaluation, design themes and examples of innovative technology.
Wake Effect Study
A Colorado-based research team recently completed a major wind study using Second Wind’s Triton Sonic Wind Profiler to learn more about one of wind power’s biggest unknowns, the wake effect, and its impact on turbine productivity.
Triton is one of several remote sensing technologies that TWICS (the Turbine Wake and Inflow Characterisation Study) has used to create a detailed, 3D model of the turbulence caused when wind passes over rotating turbine blades. The turbine inflow and wake observations will be integrated into a wind energy forecasting model.
The study is aimed at capturing turbulence and other wake effects in a broad wedge of air up to 7 km long and 1 km high in front of and behind a multi-MW wind turbine. Triton, along with tower-mounted sensors and other remote sensing systems, profiles the winds in front of and behind a 130 metre high wind turbine located at the National Renewable Energy Laboratory’s (NREL’s) National Wind Technology centre near Boulder, Colorado.
Triton is a remote sensing system that uses sodar (sound detection and ranging) technology to measure wind in the areas that most affect a turbine’s performance. Triton machines are being used throughout the wind industry, alone or in conjunction with met towers, to streamline the wind farm development process and to improve operations.
Turbine access design system
Houlder and BMT Nigel Gee have been awarded a contract from the UK’s Carbon Trust as one of the selected participants in the Offshore Wind Accelerator Access (OWA-A) Competition. The competition, backed by the Trust and eight wind farm developers, challenges the industry to think beyond traditional approaches, to enable access to the turbine structures for engineering personnel and equipment in windfarms currently under development further offshore.
Turbine access further offshore (Source: Sean Gallup/Getty Images)
The Houlder/BMT Nigel Gee team has been selected to develop the existing Turbine Access System (TAS) design to extend the concept’s operability further offshore and into more onerous conditions.
The TAS is a lightweight motion compensated gangway that will provide access to turbine structures in seas of up to two metres significant wave height. The TAS is currently being fabricated and utilises a damped roller system which allows the vessel a degree of vertical movement at the foundation. In contrast to other systems, the TAS does not require dynamic positioning (DP) of the vessel and neither the TAS nor the vessel is connected to the turbine at any point, its developers say. The first sale of the system, to operator Turbine Transfers Ltd, has recently been announced with sea trials expected before the new year, the company revealed.
Bolt Tensioning Simulator
Oilennium Ltd, a provider of training programmes for the international oil and gas industry, has announced that it is poised to enter the wind energy industry with a first-of-its-kind online wind turbine bolt tensioning simulator.
As construction of wind energy projects continues to escalate, global demand for efficient training in wind turbine operation and maintenance has skyrocketed. Because correct tensioning of bolts is essential to every wind turbine, Oilennium says it decided to focus first on this aspect. Orbis Energy and EEDA awarded a grant to Oilennium to develop the system’s associated courses.
Correct bolt tensioning is essential (Source: Infrastructurist)
To ensure that the bolting simulator provides aspiring wind turbine technicians with all requisite aspects of bolting and tensioning the blades to the hub of a turbine, Oilennium sought the expertise of Hydratight, which provides bolting and machining solutions to the power generation and oil and gas industries.
The programme uses Hydratight’s multi-stud tensioners which can be configured to provide up to 100% simultaneous tightening.
With its spring-return pistons and geared nut rotation, these tools have proven time savings of up to 65% when tightening ‘blade to bearing’ or ‘bearing to hub’, Oilennium says.
New Signals for Ormonde
Tideland Signal has supplied Burntisland Fabrications (BiFab) of Fife with the first aids to navigation to warn shipping in the vicinity of the new Ormonde windfarm which is currently under construction 10 km off Barrow-in-Furness in the Irish Sea.
The Tideland equipment is supplied in kit form ready to install on turbines in accordance with IALA 0-139, which calls for flashing yellow lights with a range of 5 NM on the significant peripheral structures (SPS) at intervals of not more than 3 NM around the perimeter of the field. Each Tideland kit consists of an MLED-155 MaxiHALO 60 main lantern, MLED-120E 1T secondary lantern (both with a range of 5 NM), AB-560 fog signal and Sentry visibility detector, all complete with power supply, battery backup, and monitor and control systems.
In the Ormonde application, the MLED-155 is fitted with a yellow MaxiHalo 60 multi-code LED flasher, sunswitch and on-board GPS to synchronise the flash code. The MLED-120 is also equipped with GPS and Tideland Signal’s SyncMaster circuitry which enables two or more MLED-120E lanterns to flash in unison without interconnecting cables or radio links between lanterns.
New Ways To De-ice
Ice formation leads to production losses and the risk of ice throws. Over the past winter, a few such ice throws occurred at wind power plants operated by Vattenfall, though none of them caused any injuries or damage.
A study analysing measured icing and comparing the figures to model data started in 2010. This study is now being followed up by an analysis of production data and ice problems on othersites in northern Sweden. The study is based on data from ice measurements and data from metrological models.
The project will also investigate available mitigation technology, various solutions and their costs. This will be done in cooperation with turbine producers. ‘In all phases of the project we measure, analyse, and evaluate various solutions, but each phase carries us further in understanding and acting on the problem,’ says project leader Daniel Gustafsson.
The usual approach to de-icing is to install heating in the rotor blades. However, that is not enough to eliminate the production loss entirely or to completely eliminate the risk of ice throws, but it does decrease the risk, Vattenfall says. Other measures may include replacing sensors, adding new sensors and mounting of cameras. The project will be completed by the end of June 2012, with further data being recorded over the coming winter.’