Modern trends in long distance power links

Many of the changes in the way the world works lead to new opportunities for different technologies. This has led to a new approach to electricity distribution using HVDC – High Voltage Direct Current – transmission lines, operating at up to 800 kV. Such power transfer lines are now installed particularly around Europe, and across China.

When power stations were smaller, and based near the major population centres, they tended to serve a local area with electric power, and this was best delivered using AC transmission, via local transformers, to produce the 110–240 VAC power distributed to each street. (As an aside, even more locally around the power station, district heating schemes could distribute some of the power using thermal transmission.) To provide the electrical energy transmission further afield, higher voltage AC transmission lines were used to feed a major substation, then distributing the power to local transformers, creating local networks – like the branches of a tree.

Currently, the new solar farms and wind power sources have been built well away from the major centres of population, where the land (or sea) space is available, and the conditions are right. Plus, hydroelectric plants are necessarily placed near the river or water flows, naturally located in the hills. All these sites are at the end of the thinnest branches of the old ‘distribution tree’, so new transmission lines are needed to take the power back to the population centres.

Long distance transmission

China also faced this problem, with economic development and a growing demand for power by the population in the west of the country, with the major new power stations and hydro plants located in the east. For transmission of power over distances like 500 km or more, the reactive power flow due to the large cable capacitance limits the maximum possible transmission distance, as the power loss becomes high. The installation and maintenance costs for the necessarily taller and wider dual pylon AC overhead transmission lines, also becomes excessive.

For such long distance transmission, HVDC comes into its own economically because the line losses are much lower, as are the line installation and maintenance costs, since HVDC (at around 600 kV) can use a single overhead pylon carrying just two conductors, or can use a buried cable. The higher costs of the HVDC terminal equipment, needed at both ends to convert the power back to AC for local distribution, are more than offset by the savings in the transmission line costs. Plus the environmental impact of the HVDC underground cables is insignificant, compared to overhead AC transmission. The possibility of using underground cables means HVDC links can deliver power into cities and urban areas where the use of pylons and overhead cables would not be tolerated.

So, over the last few years China has installed 24 projects using HVDC power transmission: one of these used a 1670 km line carrying 8000 MW of power to the east. The supplier for 19 of these projects, including the largest one, was ABB Power Systems. ABB also claims to be the major supplier of recent HVDC power transmission projects throughout Europe, and the rest of the world.

Undersea links

In Europe there are many power networks, based around different standards that were developed by the different countries: these AC networks can run at different frequencies, and are not often synchronised. It makes sense to wish to trade power between networks, to make use of surpluses when these are available, and cover for power outages or other unforeseen events. Transferring power using HVDC links makes sense, firstly because the receiving terminal can convert the DC to an AC power source running at the same frequency as the receiving network, plus the local ­engineers can phase synchronise the generated AC power with their other sources.

The second big advantage of HVDC links is that they can run in economically constructed underwater cables, to islands and across major sea routes, such as from the UK to France, or Norway and Sweden to Denmark, Germany and Finland. The NorNed link, from Norway to the Netherlands, is the world’s longest submarine power cable, at 580 km length. Similar HVDC links are used to supply power from hydro schemes and wind farms in the north of Scotland, across the estuary of the Moray Firth to the heavily populated Inverness/Aberdeen area.

The growth of offshore wind farms has led to this green energy being sent onshore using an HVDC submarine cable, and also vice versa, in the sense that offshore oil production platforms are now being supplied with power from onshore, delivered by cable, and just converted to AC power on the platform – saving weight and complexity offshore. Plans are being made to extend this European network, with possible hydro-electric power being delivered by cable from Iceland to Scotland, and from Norway via the Shetland Islands, then also to Scotland.

More importantly, in an African context perhaps, solar farms in North Africa will be able to transmit power to Europe via Spain from Morocco and to Italy from Tunisia and Libya.

This article first appeared in my column in the South African Journal of Instrumentation and Control, November 2017 issue. SAIC is published by Technews in South Africa.

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ABB automation increases capacity 10x for Tate & Lyle food additive plant

When Tate & Lyle acquired Biovelop, a Swedish manufacturer of oat based food ingredients in 2013, the factory in Kimstad, Sweden was modernized and expanded by installing automation systems, variable speed drives, motors, motor control cabinets  and valve positioners from ABB Automation. In 2016 the remodeled plant celebrated the first anniversary of operations with the new systems and significantly increased production capacity.

The global market for specialty food ingredients, including health and wellness products, is growing, with annual sales of $51 billion and annual growth rate of 4-5%. Oat ingredients have been actively involved with this trend as they offer some key nutritional and functional benefits. In particular, oat contains beta glucan, a soluble fiber that has been shown to lower cholesterol and reduce post prandial glycaemic response – claims that have been approved by the European Food Safety Authority (EFSA). In fact, it was these properties of the grain that made the sector an attractive one to Tate & Lyle, and triggered the decision to diversify its portfolio into this sector.

“We have seen a more than tenfold increase in capacity with the same number of shift operators compared to four years ago,” said Annika Werneman, Tate & Lyle plant manager. “It’s a huge change in such a short time, and it means that we’ve gone from a low-level facility to one that can deliver high quality product to our customers globally.”

Advanced automation technologies in the plant run critical food processing equipment -including pumps and decanters: material handling machinery is also used to transport the dry food products. ABB delivered automation equipment that included 85 variable speed drives (VSDs), with power ratings ranging from 0.37 kW to 55 kW, as well as ABB MNS 3.0 motor control cabinets and low voltage motors. ABB also delivered 44 Digital Electro pneumatic positioners (TZID-C) , which use the Hart protocol to communicate with the control valves.

“We needed a process that was highly automated and could run 24 hours, seven days a week, all year long,” Werneman continued. This meant building a system that enabled Tate & Lyle engineers to digitally interact with the system, commission (start) devices, and diagnose performance deviations or failures from anywhere in the world. This not only helps ensure operational consistency, but also reduce the total cost of ownership by enabling staff to manage the processes without being physically present at each site.

Such interactivity was enabled by the ABB fieldbus automation for the drive controls, providing flexibility as well as remote monitoring of the plant performance. “I like that ABB designed the system so that the fieldbus responsible for device control is split from the fieldbus used for asset management,” explained Leo Dijkstra, power & controls team leader Europe at Tate & Lyle. “This ensures that I can make any changes to the configuration of the devices without the risk of the whole network going down.”

At Tate & Lyle, they place great importance not just on what they do, but how they do it. “We are working continuously wherever we can to reduce the environmental footprint of our operations,” said Dijkstra. ABB was well placed to help as it has developed a portfolio of products and solutions that improve industrial energy efficiency.

“In our pump applications alone, we are using up to 50 percent less energy thanks to the variable speed drives, and these have been running non-stop for the last two years without a single failure,” Dijkstra continued. “What’s more, ABB was so quick to deliver products that we even had the first VSD delivered in just a few days.”

Although the nearest ABB support is only a ten-minute drive away from the Kimstad factory, the fieldbus flexibilities in the drives enable Tate & Lyle to rely on its own staff to handle the ABB equipment remotely. “Our work with Tate & Lyle illustrates the benefits of digitization, which can yield immense productivity and output gains from existing facilities,” said Petter Hollertz, area sales manager at ABB. “The improvements at this plant also show what great teamwork between the equipment supplier and the user can accomplish, as we worked together as true partners on this project.”

600,000 flowmeters measure beer and lager flow

Titan Enterprises has established a long-standing working relationship with Vianet plc (formerly Brulines) for the supply of beer flowmeters for pub and bar automation projects. Over the last 20 year period Titan have delivered, and Vianet has installed, over 600,000 of these meters for beer and other bar flow measurement and automation applications.

Brulines, was formed in 1993 with the intention of providing pub chain owners with data on their bar activity via an electronic point of sale (EPOS) system. After trialling several other flowmeters, the company sought a solution to resolve flowmeter bearing lifespan problems and to overcome the unreliability of the optical detection method in beer.

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The beer flowmeter

Following a collaborative approach to developing the solutions needed for the Vianet customer base, Titan Enterprises proposed an adapted version of its 800-series turbine flowmeter as the design included durable sapphire bearings proven reliable for many thousand hours operation, and a Hall effect detector which was not subject to problems with discolouration inside the pipe. After successful tests, a trial order for 400 units was placed in 1997, which after the subsequent field trials, was followed by an order for >5000 meters which were all delivered to the clients required timescales.

To ensure the flowmeter was ‘fit for purpose’, Titan additionally adapted the cable type as well as the body and increased the length to 10 metres. These adaptions enabled Brulines installations to be maintained in beer cellars with differing wire runs to the control panel without any junction boxes.

Twenty Years of Collaboration

With the widespread reliability of this product, Vianet turned again to Titan Enterprises in 1999 to develop for them an “intelligent” flowmeter (IFM) for their enhanced iDraught retail product. The specification for the IFM required that it should additionally measure temperature as well as determining the type of fluid in the line to detect line cleaning cycles which are essential for the dispensing of a good pint.

At the time, Titan did not have the technology to provide sensing electronics at a reasonable price so we produced a revised version of the beer flowmeter with the capability of being matched to a PCB designed, manufactured and installed by a third party.

After trialling and testing, this new IFM was introduced in June 2000 and supplied to Vianet at the rate of up to 3500 units a week. Mark Fewster, product manager at Vianet commented “Titan’s supply chain has always delivered to our quality and timescale needs”.

IoT Developments

ifm latest

An intelligent flowmeter design

Since this first IFM introduction, close collaboration between the two parties has resulted in 5 iterations of the product with revised features as end user requirements have developed and evolved with the growth of the IOT (Internet of Things). Drawing upon this close working relationship, over a long period of time, Titan continue to work with Vianet on new solutions and offerings as the Vianet customer offering further develops.

This Titan Enterprises application story is based on a report in the Autumn issue of Flowdown, the regular news bulletin published by Trevor Forster, MD of Titan, from their Dorset, UK base.

Roxtec transits ensure safety on “Mein Schiff 6”

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On cruise liner Mein Schiff 6 of TUI Cruises, thousands of Roxtec transits provide certified protection against fire, gas, water and electromagnetic disturbance. Co-owner Royal Caribbean and shipyard Meyer Turku in Finland continue to cooperate with Roxtec to enable the use of more plastic and composite pipes.   “Roxtec transits make it cost-efficient to install light-weight and long-lasting plastic pipes,” says Berth Strömborg, senior superintendent of Royal Caribbean.

One sealing system

Over 6000 openings for cables and pipes in decks, bulkheads and cabinets are sealed with Roxtec transits. The seals are used in the engine room as well as in passenger areas, and many of them include spare capacity for additional cables and pipes.  “It is good to have one supplier for all pipe systems,” says Antti Laaksonen, system responsible for HVAC and catering design at Meyer Turku.

Optimizing logistics

Mika Tuokko, head of electrical outfitting at Meyer Turku, says one hundred installers have been working with Roxtec cable seals on the new cruise liner:  “The most important thing is to keep up the speed by handling fewer items. By using Roxtec instead of other systems we avoid 50 items in stock for each transit.”

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Roxtec Mulltidiameter bulkhead seals in-situ

About Roxtec and Multidiameter

The Swedish Roxtec Group is the world-leading provider of modular-based cable and pipe seals. The company’s invention for adaptability to cables and pipes of different sizes, the Roxtec Multidiameter, is based on sealing modules with removable rubber layers and allows for a perfect sealing, regardless of the outside dimension of the cable or pipe.  The technology simplifies design, speeds up installation and reduces the need for stock, material and logistics. It also provides spare capacity for upgrades. Roxtec serves and supports customers in more than 80 markets through subsidiaries and distributors.

False alarms from safety sensors?

So I do know about sensors and control systems, from the supplier point of view. But maybe like many suppliers I’ve only been on site to troubleshoot a sensor that is reported to be giving incorrect data. So someone else made the decision to question the validity of the sensor outputs.

These days, the nearest I get to regular sensor monitoring is at home, typically with smoke alarms, a CO monitor, and a flammable gas alarm. Plus the plant manager, my wife, is always demanding an immediate solution to any alarm system going off, to continue production.

The problem

A flammable gas alarm was positioned above the gas hob: perhaps in retrospect not the best place, as the instructions said humidity and steam should be avoided. But very quickly we realised that the detector was not very tolerant of any wine added to dishes being cooked on the hob. Then, surprisingly, it alarmed whenever we had bread dough baking in the (electric) oven. Since the detector was said to be set to alarm at 25% of the LEL this was surprising.

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The instruction came down – ‘Get me a switch in that alarm circuit, so I can switch the piercing noise of the alarm off!’ So, there was my solution, and a task, so that was done. I did not think it through any further.

Time passes

This system worked well for maybe 3 years. The alarm switch changed power from the alarm to a lamp over the worktop, so we knew to switch it back on after a problem event. But such sensors must have a life, and so when the alarm started going off when the kettle boiled and steam drifted up past the detector, I thought the unit was failing. There were then several late evening alarms, for no apparent reason, and we could not smell any gas (it is difficult to detect these days), nor see anything untoward. Like every engineer I guess, I felt the sensor, to find it very hot. This seemed to confirm the problem, that the sensor was failing, so take the thing out – ‘it was not that hot before!’ Something had changed.

Six months later, this Summer, we had a new gas meter – a Smart unit – installed on the domestic gas supply. Ultrasonic measurement of the flow, wifi connection to the indoor display, and mobile network reporting usage figures to the supplier. That would all be great, except the fitter refused to reconnect the gas to the house, because of a slight leak detected indoors. We had to call out a plumber to deal with our in-house problems. Good job it was Summer, as that took over a week.

Finding the gas leak

The leak was located as somewhere in the piping to the gas hob. The plumber tightened up the connections under the hob, and repeated the pressure loss checks. Still a slight leak, but within allowable tolerances. OK, so he checks once more, to be sure, and starts his paperwork. A last twist of the 90 degree bend directly on the hob (supplied by the Chinese supplier) produced an interesting result: the threaded part of this connector sheared off, almost in two half-round pieces. It looks like steel, but low grade steel, and showed a brittle type fracture all around the fitting.

Presumably the crack that had been there before, allowing a slow leak, had led to the fracture on tightening the connection. That was installed 10 years before, and no-one had done any checks of that or the system post installation. OK, I had never had the systems tested for gas leaks.

What had happened?

The conclusion at this point was that the slow leak presumably collected gas in the lower cupboards, and when this escaped it combined with the wine vapours to trip the alarm. Possibly the steam from the kettle just accelerated the rise of the gas past the detector. The detector was presumably a Pellistor, and got hot because it was burning the gas off. The dough rising in the oven? I don’t know much about bread and dough – but the leak was directly above the oven, so maybe the gas and air, warmed from the sides of the oven, helped the gas rise up past the detector. If that fitting had actually failed totally one night, there would have been a major blast, as I had removed the gas detector.

We now have installed a new detector, further from the cooking (3 metres). Plus the old one is re-installed, as a back-up unit: it is working OK still, next to the boiler. The bad news: the new alarm went off last weekend, when simmering a Paella laced with white wine….

Yesterday the plant manager produced a batch of dough and made bread. Both flammable gas alarms went off, first the unit 3 metres away then the old reserve unit, now even further away in the utility room, with the boiler.

Legislation

In any rented accommodation the landlord has to have a gas system safety check once a year. Because we own our own house there is no such requirement, and the boiler service man, who checks the gas boiler and heating system once a year, is not required to, and does not include, a system gas leak test in his inspection.

Product or system failure?

The gas hob was made by Proline, and installed around 8 years ago by a registered installer. It was a Chinese manufactured unit supplied by Comet as a low-cost own-brand hob to many retail outlets in the UK. The 90 degree bend that failed was supplied as a part of the hob, the gas inlet port. It is not steel, it could be an aluminium or zinc alloy. It appears the design was such that this port could be stressed during installation or tightening, as the bend itself would not rotate to suit the angle of the delivery pipework. It seems the break was on the hob side of the fitting. A combination of a poor quality fitting and a poor design.

The flammable gas alarm seems to work OK in detecting natural gas, but is even more sensitive to alcohol vapours, bread and dough making, and using any window cleaning spray that has any hydrocarbons in the fluid. So beware of using them in a brewery, distillery, bakery, bread shop, pub, restaurant and so on!

There was undoubtedly a small gas leak, around the hob, which has now stopped. Possibly this was from the 90 degree bend fitting, which then completely broke apart on tightening the joint. It remains possible that this failure was an accident waiting to happen.

The domestic plant manager is none too pleased at the moment. So do I leave the sensors installed, take both or one of them away, or fit switches to suppress the noise and turn off the alarm(s)?

Postscript

The supplier of the unit is surprised and upset. He considers these sensors do not give false alarms, when exposed to wine fumes from simmering a paella, or from baking bread in the oven. He has asked me to return the newest one to allow him to test it.

This has been done so we will see what results!

UV keeps bottled water safe

Hanovia UV has supplied Cott Beverages UK, based in Derby, with a PureLine intelligent UV system to keep its production process water pure.

PureLine range

In an increasingly regulated and safety-conscious market, legislation such as the EU Directive for Bottled Water 98/88/EC (1998) drives the beverage industry to meet ever more stringent standards of quality. Microbial growth due to contaminated water or ingredients can cause discolouration, off flavours and shortened shelf-life. The threat of contamination is further increased as manufacturers respond to demands for less chemical additives and preservatives. Effective microbial disinfection of the whole process is therefore essential.

To meet this requirement, Cott Beverages has been using Hanovia UV disinfection technology to treat process water used in the production process. The company decided to use UV technology to ensure final product security prior to mixing and bottling and has been very satisfied with the performance of the UV systems.

“The Hanovia UV systems have been easy to integrate, maintain and operate,” said Chris Prentice, site service engineer at Cott Beverages. “They provide us with absolute insurance before bottling by making sure that we are producing and maintaining a high-quality product, which is essential for our brand.”

PureLine UV from Hanovia is an intelligent system that is optimised for the beverage industry to simplify the treatment of water, sugar syrup, brine and even reducing chlorine and ozone. Critically, there are no microorganisms known to be resistant to UV – this includes pathogenic bacteria such as listeria, legionella and cryptosporidium (and its spores, which are resistant to chlorination). Unlike chemical treatment, UV does not introduce toxins or residues into process water and does not alter the chemical composition, taste, odour or pH of the fluid being disinfected.

UV is used for both primary disinfection or as a back-up for other purification methods such as carbon filtration, reverse osmosis or pasteurisation. Because UV has no residual effect, the best position for a treatment system is immediately prior to the point of use. This ensures incoming microbiological contaminants are destroyed and there is a minimal chance of post-treatment contamination.

UV disinfection systems are easy to install, with minimum disruption to the plant. They need very little maintenance, the only requirement being the replacement of the UV lamps every 9-12 months, depending on use. This is a simple operation that takes only a few minutes and can be carried out by trained general maintenance staff. The Hanovia UVCare training programme supports businesses like Cott Beverages to make sure servicing is carried out by certified engineers at all UK production sites.

Battery Energy Storage Systems help UK power efficiency

Nidec ASI, of Milan in Italy, part of the appliance, commercial and industrial motor business of Nidec in Japan, has won an order from the UK-based EDF Energy Renewables business for the installation and supply of a second Battery Energy Storage System (BESS), for use on the British National Grid.

EDF ER, a renewable energy developer, is a JV company between EDF Energy in the UK and EDF Energies Nouvelles in France. As a result of this new contract, Nidec ASI will act as an EPC (engineering, procurement, and construction) contractor to supply the 49 MW BESS system that EDF ER is building to serve the National Grid, the British electricity distribution company. The contract, which follows closely after an earlier large-scale deal for a 10 MW battery energy storage system (also for National Grid) makes Nidec ASI reach a 33% market share in the British BESS systems market.

As renewable energy resources are more widely used – to reduce the environmental impact of power generation – investments in battery energy storage systems are becoming increasingly prominent. These stabilise the power grid by temporarily storing any surplus electricity generation, and discharging the saved electricity during power shortages. Last November Nidec ASI delivered the world’s largest (90 MW) BESS system to major electricity firm STEAG of Germany. As a leader in the BESS market, Nidec is committed to stabilizing the world’s power grids and contributing to realizing a low-carbon society via the spread and expansion of battery energy storage systems and high-quality state-of-the-art equipment.

EDF West Burton 2

The BESS will be installed at the EDF Energy West Burton site in Nottinghamshire, pictured above, to support the UK’s National grid.