With even larger 7.5 MW and 10 MW output wind turbines under development, developers and manufacturers of this next generation of turbines need to test new turbine blade designs and prototype platforms.

This includes measuring and monitoring the loads on the platform and individual turbine blades. To carry out these tests, small-scale wind turbine models are normally constructed.

For wind turbine load testing, UK company Applied Measurements has recently seen a significant rise in demand for its standard and custom-designed bolt-on load cells. The company’s BOSS series of bolt-on strain sensors is designed to be attached directly to steel structures, including wind turbines, and are capable of detecting tensile, compressive and bending stresses. These forces can then be converted to a useable electrical signal, either using instrumentation provided by Applied Measurements or by the customer’s own systems.

Peter Lewis, Managing Director at Applied Measurements said: “We’ve designed a number of load cells recently for wind energy applications. As well as load cells that measure vertical and horizontal forces on the turbine platform, we recently supplied a customer with a six-axis measurement system for monitoring the loads on the turbine blades.

“The system was fairly simple and comprised of our very robust, bolt-on load cells, which were positioned in the head of the wind turbine. Blocks were welded onto the head of the turbine, which the load cells were then attached to. The load cells monitor the stresses on the root of each turbine blade. We originally supplied four units, but the customer was so pleased that they ordered 30 more.”

Utilizing the latest strain gauge technology, each BOSS strain sensor is manufactured from specifically selected high-grade alloy steel, with thermal coefficients of expansion matched to the structural steel of the wind turbine platform or blade. Each unit is temperature-cycled to ensure that the effects of temperature fluctuations are minimized. In addition, to ensure complete protection from harsh environments, including high winds, rain and stormy weather, each sensor is fully encapsulated (potted) with a high strength waterproof compound and sealed to IP65.

Lewis added: “To install the sensors to a wind turbine, each unit is supplied with a template to which the two mounting blocks are attached using high tensile cap head bolts.

“The mounting blocks are welded into position using the template, which is then removed and the bolt-on sensor attached in its place. The solution is simple but robust and the sensors are guaranteed for three years.”

According to Lewis, in another wind turbine testing application, four of the company’s load cells were positioned underneath each corner of a rectangular-shaped wind turbine platform. Each load cell measures the vertical and horizontal forces on the structure, including the reaction and thrust forces present. These forces are quite unique in wind turbines and are constantly trying to tip over the structure whilst in operation. Hence, testing the loads at the prototype phase is critical.

As well as load cells for this project, Applied Measurements also supplied supporting instrumentation in the form of eight amplifiers. Each load cell was set up to measure two axes on each corner of the platform. The load cells were custom-designed and protected from the elements.


Hard hats a headache? New ESAB adapter may relieve the pain


Leading manufacturer of welding equipment and consumables, ESAB, is now stocking a new type of hat adaptor that will save the wearer the time and bother of changing safety wear for different working situations.

The Hard Hat Adaptor has been developed for sites where welders need to use both a hard hat on health and safety grounds as well as a welding helmet. The equipment is ideal for use in areas such as shipyards and construction sites, where fear of falling objects requires a hard hat, simultaneously with welding equipment, becomes an issue.

Now, rather than carrying two hats around, the hard hat adaptor is simply attached to a New-Tech Helmet – after the removal of the internal head harness – in a matter of seconds.

For extra safety, the user does not even have to remove the hat from the head to attach or detach the adaptor, and can even undertake the operation while wearing heavy work gloves. For total flexibility, the hard hat adaptor can be utilized with any of the New-Tech range of auto darkening welding helmets which features the latest technology developed by ESAB.

All four ESAB models in the range are lightweight and well-balanced to provide maximum comfort, but additionally, they offer a wide viewing area and provide protection to the ears and neck, as well as just the face.

The area in front of the mouth is larger for a good flow of fresh area – importantly, this feature also ensures there is no build up of carbon monoxide. For that personalized touch or corporate feel, hard hats are available in a choice of colours, these being yellow, white, blue, green and red.

ESAB has made ordering the correct helmet and adaptor as straightforward as possible, with just three easy steps involved – the first being the selection of the New-Tech Helmet. The second part of the process involves looking at the adaptor order number alongside to ensure the correct hard hat adaptor is chosen, while step three involves choosing the colour of the hard hat.

The maximum operational parameters of the test plants in the Thermo-Hydraulic Platform are based on heating capacities of up to 22 MW, electrical currents of up to 80 kilo amperes, pressures of up to 300 bar and temperatures of up to 600 °C. The accreditation thereby covers tests and assessments as well as expert concept evaluations with appropriate support programmes. Areva also offers the appropriate on-site inspections in power plants.


Schaeffler launches large size bearings technical compendium


A 1100-page technical compendium on large size bearings is now available from Schaeffler (UK) Ltd.

Catalogue GL1 provides OEMs, distributors and end users with a comprehensive overview of the range of large size bearings available from Schaeffler for heavy machinery and equipment.

The catalogue provides technical information on more than 10 000 bearings under the INA and FAG brands with outside diameters (OD) up to 2800mm. It is a valuable complement to Schaeffler’s existing HR1 rolling bearings catalogue, which includes rolling bearings up to 1300mm OD.

The new catalogue also contains useful bearing accessories, special rolling bearings, spherical plain bearings and bearing housings.

When it comes to large size bearings, Schaeffler offers considerable expertise and technical guidance. For many years, the company’s INA and FAG branded large size bearings have been the preferred choice for heavy industry applications, including steel, paper, mining and mineral processing, industrial power transmission, wind turbines, rail, production machinery and the energy sector.

In most of these industries, large size bearings are critical in ensuring the high reliability, energy efficiency and correct functioning of drive systems and other important machine components.

Catalogue GL1 shows which products are suitable for specific bearing arrangements and which factors need to be considered during the design process, the tolerances required of the adjacent structures, and how the bearing can be sealed effectively in light of the application conditions. The catalogue also provides information on service life calculations, operating temperatures and loads, and lubricant selection.


Megger makes relay testing yet more portable


Megger’s Sverker 760 and Sverker 780 protection relay test sets can now optionally be ordered with a rugged protective case that makes them even easier and more convenient to store, transport and use.

The case, which is constructed entirely from non-conductive materials, incorporates a robust hinged carrying handle, and is also fitted with a second extendable handle and wheels, allowing it to be moved around easily and with a minimum of effort.

To allow unimpeded access to the instrument, the lid of the case can be removed completely and, as a further aid to convenience, provision is made within the case for the storage of test leads. When closed, the new case has an IP67 ingress protection rating to safeguard the instrument against damage by water, dust or other contaminants while it is being stored or transported.

The Sverker 760 and 780 single-phase protective relay test sets for which the new case is suitable are designed to maximize testing efficiency while minimizing complexity. Both models feature logical front panel layouts that make setting up straightforward, and they have easy to read displays that can be used to show Z, R, X, S, P, Q, phase angle and cos, as well as time, voltage and current.

As a further aid to testing efficiency, the voltmeter function of the instruments can be configured as a second ammeter, which is particularly useful when testing differential relays, and the display incorporates a freeze function for capturing short duration voltage and current transients.

As well as all of these facilities, the recently introduced Sverker 780 also incorporates a wide-range variable voltage source that can be adjusted in frequency from 15 Hz to 500 Hz, and that has a continuously variable phase-shift facility. This makes the Sverker 780 useful for testing directional protective equipment and protection schemes that involve phase shifting.


Emerson improves Ovation


Emerson Process Management has integrated machinery protection and prediction of critical mechanical equipment into its Ovation control system, directly supporting power generators’ drive for improved plant availability and performance by providing machinery health feedback to operators and simplifying the integration from days to minutes.

As turbines, generators, boiler feedpumps and other mechanical equipment deteriorate, plant performance and efficiency decrease, while the risk of unplanned outages increases. When plant operators have visibility into the performance of their critical generating assets, they can take action before failures occur, avoiding costly plant shutdown as well as the potential for equipment damage and personnel injury.

In traditional control systems, integrating machinery protection can be complex and expensive, requiring Modbus and system expertise as well as specific machinery knowledge. Typical machinery protection systems can require more than 2000 steps and up to five days to complete the integration process. With this many steps, network issues, additional testing time and nuisance alarms are easily introduced. Until now, the economic barriers to undertaking integration have been prohibitive.


Nexans wins €13m power cable contract for the Linth-Limmern pumped-storage hydropower plant project in Switzerland


Nexans has been awarded a €13m ($17.64m) contract to supply the power cables for the new Kraftwerke Linth-Limmern pumped storage hydropower plant currently under construction in eastern Switzerland.

This contract covers the design, manufacture, supply, installation, connection and commissioning of about 30 km of extra high voltage (EHV) cables. Nexans will supply six 380 kV XLPE-insulated underground cables, each 5 km in length, which corresponds to the length of the underground access tunnel in which they will be installed.

Laid in parallel to connect the new plant to the EHV power transmission grid, these cables will comprise copper core conductors with a cross-section of 1600 mm².

The Limmern pumped-storage project in the Linthal Valley will utilize the proximity of two existing water holding reservoirs – the Muttsee Lake (elevation: 2474 m; new capacity: 25m m3 water) and the Limmernsee Lake (elevation: 1857 m; capacity: 92m m3 water) – by building an underground pumped-storage plant between the two lakes. During the day, when power demand is at its peak, water will be released through the turbines of the new Limmern plant to generate electric power for the coverage of demand peaks. At night, as demand decreases, a larger amount of electric power is available on the grid, and this will be used by the new Limmern plant to pump back water “upstream”, from Limmernsee into Muttsee. For these pump-and-turbine operations, the Limmern plant will be supplied with some 1000 MW power through an underground access tunnel which is about 5 km long.

With its ability to pump back water from the lower into the higher reservoir, the plant acts like a huge rechargeable battery, using readily available night-time power to provide a very reliable and flexible power supply which can cover peak demand during the day.

The same power lines, connected to the Swiss national EHV power transmission grid, will provide the electric power required to pump back water as well as exporting the power generated by the plant when it is operating in turbine mode.


Areva Thermo-Hydraulic Platform gains accreditation as an independent test and inspection body


As market leaders in the field of nuclear power plant technology, Areva runs an internationally-unique test and qualification infrastructure for nuclear plant components.

The associated Thermo-Hydraulic Platform with different test facilities in Karlstein and Erlangen has already been recognized as a testing laboratory according to ISO 17025. The Deutsche Gesellschaft für Akkreditierung (DGA – German Society for Accreditation) has now also certified the same organization as an independent inspection body according to ISO 17020.

The accreditation confirms for Areva and their customers the high standard of inspections carried out in the numerous test facilities. Not only that, but it is also appropriate for the opening of the Thermo-Hydraulic Platform to sub-suppliers, engineering companies, operators and research institutions who are subject to inspections or qualifications, but do not themselves possess a suitable infrastructure for this purpose. In a similar way to an independent institution, Areva obligates itself to protecting all inspection results for its clients gained in the test and inspection body.

The accreditation by the DGA accords with an internationally-agreed standard, recognized in all countries belonging to the International Laboratory Accreditation Cooperation (ILAC) – including the USA, Canada, China, India, Japan, Korea, the United Arab Emirates, Brazil, Argentina and most of Europe.

The Areva Thermo-Hydraulic Platform contains integral test facilities, on which accident scenarios, with interaction of all relevant systems, are tested for pressurized water reactors and boiling water reactors. For another, special effects such as possible blockage of filters or methods of heat dissipation are inspected on separate effect test loops. In addition, qualification test facilities.

All over the world, its says, Areva provides its customers with solutions for carbon-free power generation and electricity transmission. With its knowledge and expertize in these fields, the group has a leading role to play in meeting the world’s energy needs.

Ranked first in the global nuclear power industry, Areva’s unique integrated offering covers every stage of the fuel cycle, reactor design and construction, and related services. In addition, the group is developing a portfolio of operations in renewable energies. Areva also offers its customers a complete range of solutions for greater grid stability and energy efficiency.


Siemens Energy launches Turloop control system for industrial steam turbines


Siemens has launched a control system (CS) for steam turbines, named Turloop, which its claims offers a control system for industrial steam turbines that is based on proven standard components to provide high operating safety and reliability, flexibility and user friendliness based on proven components.

The Turloop control system, with global sales of more than 400 systems to date, provides Siemens Energy Service with a successful automation system for industrial steam turbine applications. To supplement this, Turloop CS was developed as a compact, budget variant.

The system platform is based on proven Simatic S7 standard components, allowing flexible use for industrial steam turbines including extraction turbines with up to two extractions and irrespective of whether these are used as generator, compressor or pump drives. Further high performance features of Turloop CS include provision for up to five configurable process controls and a maximum of eight final control elements with position controllers.

The new control system also implements limit controllers for generator load, inlet pressure and backpressure, as well for extraction and wheel chamber pressure. Linearization curves can be parameterized for all final control elements. The system also permits automatic startup of the turbine and runup to nominal speed, while distinguishing between cold, warm and hot starts.

The system features on-board two-channel speed measurement for eddy-current sensors. Turloop SMM-DP speed measurement allows connection of all standard eddy-current sensors and proximitors, as well as interfacing with electronic overspeed protection systems via an adapter module. Where eddy current sensors are used, continuous monitoring of gap between speed sensor and pulse wheel is possible. Speed actual values are transmitted to the central computing unit fast and error-free along a Profibus link.

Parameterization menus are used to adapt the system to the turbine via a 12-inch touchscreen, this also permitting comfortable system operation during turbine operation. Customer designations and tags from standard identification systems can be stored and displayed in the system. No additional software or hardware is required here for parameterization.

Use of standardized and tested hardware and software ensures operating safety and reliability. Parameterization errors are detected, thus preventing “impossible” configurations. Self-diagnostic features are integrated in the control system. Provision is also made for backup of configuration data to a USB drive.


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