Yokogawa has released the HXS10 controller, designed to control the actuation systems that move heliostats and photovoltaic panels.

The HXS10 helps to maximize power generating efficiency by controlling the angles of a system’s heliostats – its reflectors – or its solar panels so that they stay pointed at the sun as it moves across the sky.

In a solar thermal power generation system, sunlight is concentrated onto a receiver that uses the heat to turn water into steam, which rotates a turbine and generates electricity. By controlling the angle of the heliostat so it tracks the movement of the sun, it is possible to precisely focus the sunlight onto the receiver.

Although most solar panels used today are of the fixed type, the power generating efficiency of photovoltaic systems can be improved if panels are kept directed at an optimal angle towards the sun. Control technologies that can precisely orient the heliostats and panels to follow the movement of the sun are crucial.

Yokogawa has developed the HXS10 to control the actuation systems of solar thermal and photovoltaic power generation systems. Based on the facility location, date and time, the HXS10 calculates the position of the sun through a high-resolution (64-bit) solar position algorithm, and operates motors or hydraulic actuators to adjust the angle of the heliostats and solar panels so they stay pointed toward the sun.

The HXS10 has been designed specifically for controlling solar tracking systems. Yokogawa also claims that its new controller has lower initial costs and requires less engineering time than general-purpose controllers such as PLCs.

The HXS10 is built of environmentally resistant and durable components and can withstand temperatures ranging from -20 °C to +70 °C, according to Yokogawa.

This makes the device optimal for controlling solar power generating facilities installed in deserts and other harsh locations, says its maker. The HXS10 also has a communication function that allows it to be monitored by a host system in a central control room. Moreover, to eliminate communication traffic overload and create a more secure and stable communication environment, each HXS10’s communications can be routed to the host system via another HXS10 unit.



Santee Cooper modernizes its Winyah coal fired power plant with GE Energy’s Mark VIe TMR digital control system for turbines

South Carolina’s Santee Cooper Winyah coal fired power plant has been working with GE Energy to modernize its Westinghouse Control System with GE’s most advanced digital control system for turbines – the Mark VIe Triple Modular Redundant (TMR).

Santee Cooper is South Carolina’s state-owned electric and water utility. The state’s largest power provider, Santee Cooper uses a diverse fuel and energy supply of coal, nuclear, oil, gas, hydro and renewables to directly serve more than 165 000 residential and commercial customers in Berkeley, Georgetown and Horry counties. Santee Cooper also supplies power indirectly to all of South Carolina’s 46 counties through wholesale customers.

When it was built, the Winyah plant – located between Myrtle Beach and Charleston – was Santee Cooper’s most ambitious generating project. Unit 3 and Unit 4 in the plant were the first in the Southeast of the US with scrubbers to reduce emissions.

Next spring, the current Westinghouse EHC control system on the Winyah plant’s Unit 4 steam turbine generator will be migrated to a Mark VIe TMR control system. GE claims this is the first time a Mark VIe Control System will replace an existing Westinghouse Control System, although the company has been working to modernize other systems at Santee Cooper. On 9 June, 2010, a Mark II was replaced with a Mark VI at Santee Cooper’s Cross Station.

The Mark VIe TMR is a custom-programed, expandable, digital control system. It will be mounted and pre-wired in new cabinetry, then installed. The Mark VIe TMR is the latest turbine control system from GE’s Control Solutions business. It has been designed to provide modules for interfacing with nearly every type of sensor on the market today.

The Mark VIe TMR modernization will extend the life of the Winyah plant and improve its equipment’s reliability, reducing downtime and expensive maintenance, according to GE.

The new digital control system should also enable Santee Cooper to improve its turbine control by introducing modern instrumentation as well as more robust and precise control of the equipment.

The base scope of the Westinghouse conversion includes a Mark VIe TMR Cabinet, two HMIs with four network switches, a primary emergency overspeed kit, a Watt/VAR transducer, a factory acceptance test, on-site training, and on-site technical direction.

Control Techniques inverters help Aquamarine Power’s Oyster marine energy device generate clean output to the grid

The latest installation of the Oyster hydroelectric wave energy device – one of the most promising machines in its field – incorporates a 315 kW high-efficiency grid connected inverter system from Control Techniques.

Aquamarine Power’s Oyster marine energy generator sits off the shore of Orkney, in northern Scotland, and comprises a large buoyant steel flap hinged to a base on the sea bed.

Waves cause the flap to oscillate, driving two hydraulic pistons attached to each side. High pressure water from these two pumping cylinders – clean, salt-free water in an enclosed system – is pumped ashore, driving a Pelton wheel with spoon-shaped buckets that harness the energy of the high pressure water.

This is attached to a flywheel (to smooth out variations) that powers a standard induction generator. Control Techniques inverters then take the generated power and provide an interface with the grid.

Testing of a demonstration-scale wave energy device commenced at Narec, the UK’s national centre for developing renewable and low-carbon energy, in March last year. The device is now installed and working offshore at Billia Croo near Stromness, in Orkney. The Oyster was officially turned on in November 2009 to generate power for the national grid and local homes in Orkney and beyond.

Devices such as the Oyster could generate their maximum output in winter, as waves become more powerful, coinciding with maximum demand. Large waves are estimated to carry potential energy of 200 kW per metre and, in the long term, some researchers believe marine energy could meet up to 20 per cent of the UK’s energy demands.

Control Techniques’ early involvement in the development came through its close working relationship with the Narec centre in Blyth, in the north of England, where the Oyster concept was under test in a dry dock facility.

Oyster is now installed at the European Marine Energy Centre’s test site in Orkney, where two Control Techniques inverters provide a clean supply to the grid, with low harmonic distortion. The AC output from the generator is normally equally split via sharing chokes, to produce a clean output to the grid.

As the Oyster is a demonstration unit, Aquamarine Power has fitted strain gauges, pressure monitoring and other feedback devices at all key points to give a complete picture of the system’s performance and all these signals are fed back to the PLC. The Pelton turbine’s speed is monitored by encoder and this is fed back to the inverter.

“The next generation of Oyster drives, which will have three operating ‘flaps’, are already in development, and we are looking at an output of 2.4 MW per unit,” says Paul Smith, lead electrical engineer at Aquamarine Power.

“We have been very pleased with the support we’ve had from Control Techniques.”

The units that make up the system are from the Unidrive SPM range, which can be used to implement high efficiency grid-tie inverters for renewable energy systems including wave, tidal, photovoltaic and wind.

Megger’s new MT0210 offers easy measurement of DC resistance

Incorporating patented Fast Test technology, Megger’s new MTO210 transformer ohmmeter has been launched to faciliate rapid, safe and accurate measurement of DC resistance of all types of magnetic winding.

The unit is also ideal for checking the operation of on-load tap changers, which are one of the most common causes of transformer problems, claims its manufacturer.

The Fast Test technology in the MTO210 has been specifically developed to stabilize the test current in the shortest possible time, significantly reducing test times, says Megger.

Further time-saving features include dual channel operation, which allows the resistances of transformer primary and secondary windings to be measured simultaneously, and bi-directional current output capabilities, so users can take advantage of any existing magnetization in the winding core to aid rapid current stabilization.

When used to check the contact resistance of make-before-break tap changes and voltage regulators, the MTO210 provides fast, dependable indication of pitted or misaligned contacts, says Megger. As a further aid to the convenient testing of tap changers, a remote probe is available so the user can operate the tap changer while the tester is in operation.

To ensure safe operation, circuitry automatically discharges the winding or windings under test when the test is completed, if a lead is accidentally disconnected or a power failure occurs. Provision is also made for driving a warning beacon, and for interlocking the operation of the instrument with, for example, a safety fence.

The MTO210 offers facilities for demagnetizing winding cores before or after resistance testing is carried out, and it can also be used as a standalone core demagnetizer. Its versatility is further increased by its wide resistance range of 1 µΩ to 2000 Ω, which allows it to be used for heat-run testing of many types of transformer.

Test results are shown on large liquid crystal displays, and can also be stored in the instrument’s internal memory for later printing or downloading. The MTO210 is fully compatible with Megger’s PowerDB software, which provides uniform test result analysis and reporting features for all types of power equipment tests.

Weighing less that 13 kg, and built into a rugged case with a hinged lid and carrying handle, the MTO210 is equally suitable for use on site and in the workshop. It is supplied complete with a set of 10-metre test leads, and accessory 20-metre leads are available as an option. All leads feature ruggedized Kelvin clamps that eliminate the need for bushing adaptors.

Scottish and Southern Energy picks Nlyte Softwarein its relocation and upgrade of data centres

Scottish and Southern Energy has used Nlyte Software’s Data Centre Performance Management (DCPM) suite in replacing its data centres with two purpose-built facilities in Hampshire, UK, says the software house.

Nlyte’s software helped Scottish and Southern Energy move its operations into these facilities, which will facilitate delivering best practice services in a highly regulated industry and maximizing efficiency and reliability with minimum environmental impact.

Scottish and Southern Energy decided to review the way it manages its data centre assets, and to establish a source of real-time insight.

“We identified three main priorities. These were to understand and gain better control of the data centre environment, to introduce centralized planning and change management, and to be able to immediately identify any potential risks to the operational environment,” said Simon Davis, Scottish and Southern Energy’s data centre manager.

“When evaluating competitive tools, it was clear that Nlyte’s software would be the right solution to help us do this, by giving us a real-time dashboard view of all of our assets and connectivity across the new data centres.”

By providing a centralized repository with a single version of the ‘truth’ across all data centres, Nlyte has aimed to give Scottish and Southern Energy full control over its operations, ensuring that all critical assets are appropriately managed and eliminating all risk associated with system and process failures and energy supply threats.

Since deploying Nlyte’s DCPM suite, Scottish and Southern Energy has already experienced massive benefits, according to Nlyte.

For instance, with a single point of knowledge – from hardware and software to power and cooling – Davis and his team can properly plan and provision for new resources, says Nlyte.

In some cases, by being able to accurately see and map real-time power usage with the DCPM suite – rather than going by manufacturers’ plate values – Scottish and Southern Energy has also been able to plan for up to 50 per cent less power usage than previously thought, according to the software company.

New generation of power transmission coupling extends John Crane’s power industry offering

John Crane has launched a new power transmission coupling which builds on the company’s history as a supplier to the power generation market.

The new Metastream M Series ZMH flexible membrane coupling improves on the high levels of performance safety and reliability provided by John Crane’s existing ZMC coupling and is specifically intended for cooling tower installations. The corrosion-resistant ZMH has been designed to withstand the hot, humid and hostile environments typically found in cooling towers and to improve on its predecessor’s performance.

Designed for infinite life, it has no wearing parts, requires no lubrication and so represents a genuine fit-and-forget solution.

A composite fibre spacer piece makes the easy-to-install ZMH up to 80 per cent lighter than alternative ‘all metal’ designs and it incorporates a stainless steel radial spoke membrane designed to provide outstandingly reliable performance.

Emerson to install Ovation expert control system at Saudi Arabia’s Rabigh oil fired power plant

Emerson Process Management has been selected to install its Ovation expert control system at Units 1 and 2 of the Rabigh Power Plant in the Western Province of Saudi Arabia.

The contract for the new 1320 MW(2 x 660 MW) oil fired plant was awarded by SEPCO III, the first Chinese company to secure an EPC (Engineer Procure Construct) contract to build a power plant in Saudi Arabia.

At each unit, an Ovation control system will perform data acquisition, and also monitor and control the boiler, turbine and heat recovery steam generator (HRSG), all supplied by Donfang Electric Corp.

The Ovation system will also control the modulation control system, sequence control system, furnace safety supervisory system, electric control system, flue gas desulphurization (FGD) system, feedwater pump turbine and balance-of-plant processes.

In addition, Ovation technology will manage systems common to Units 1 and 2 using multi-networking technology. For additional efficiency, operators will be able to monitor and control operations of both units from a central control room.

All told, the Ovation control systems will manage approximately 18 700 I/O points. The contract calls for Emerson to supply a total of 44 Ovation redundant controllers (20 per unit, as well as four that will be common to both units) and 22 workstations. Unit 1 is currently slated for startup in July 2012, and Unit 2 in April 2013.

Atlas Copco proves superior energy efficiency of screw technology for air blowers

The introduction of air blowers using internal compression instead of external compression raises energy efficiency in the low-pressure market, according to research by Atlas Copco.

This is the main conclusion of a technical whitepaper published by Atlas Copco’s Oil-free Air Division, explaining the differences between screw technology and the traditional ‘Roots’ type lobe technology.

Screw technology – which is claimed to average 30 per cent more energy efficient – is used in the manufacturer’s recently introduced full range of ZS screw blowers to improve energy efficiency for low-pressure applications and industries such as wastewater treatment and pneumatic conveying.

“Over the past 50 years the blower market for small volume flows has not seen any major technical improvements,” says Chris Lybaert, president of Atlas Copco’s Oil-free Air Division. “The only considerable development we have seen with the ‘Roots’ type lobe blowers was the reduction of pulsation levels. There were still significant steps to be made in the area of energy efficiency. Atlas Copco achieved this by developing the twin screw design for a low-pressure blower.”

ZS screw blowers use the concept of internal compression, while the traditional ‘Roots’ type lobe blowers rely on external compression to obtain an external system pressure. The technical whitepaper finds that internal compression is more efficient than external compression from 0.4 bar(e)/5.8 psi(g) upwards.

Tests, witnessed and certified by the independent Technischer Überwachungs-Verein (TÜV) – German’s technical inspection association – found the ZS is 23.8 per cent more energy-efficient than a tri-lobe blower at 0.5 bar(e)/7 psig, and 39.7 per cent at 0.9 bar(e)/13 psig.

Biach’s self-contained tensioner targets improved safety and less downtime

The launch of the Biach self-contained tensioner (SCT) will improve safety, reduce manpower and cut the downtime required for a critical task, according to Hydratight.

An advanced reactor pressure vessel stud tensioner, the SCT is a self-contained unit that requires a power source, but no hydraulic connections or remote pump-control unit or operator.

In live tests, the SCT has reduced typical tensioning time from up to four hours to under an hour, with 40 per cent less manpower, meaning lower potential radiation exposure time and greatly reduced reactor downtime, according to its maker.

“The unit has been in development for over three years: the Biach SCT is a major advance in RPV tensioning and operator safety,” said Jon Slocum of Hydratight, a supplier of bolted joint solutions and machining services.

“The new system eliminates the separate control unit: each of the tensioners has its own 10 000 psi pump unit and can be easily moved into position by two men. Most importantly, each SCT networks to the other units, and each one displays the readings of the others in use. This means one operator can control all devices in a typical setup.”

In other systems, tensioners must be connected to a central control unit, which reduces the crew’s speed to that of its slowest member, while bringing potentially dangerous hydraulic cables and manifolds onto the reactor floor, with one person, usually out of the immediate area, operating the control unit. The SCT streamlines the process.

The recent acquisition of Biach Industries – a leading nuclear reactor equipment companies – by global engineering and joint integrity specialist Hydratight is expected to give the SCT a wide, global market.

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