In action
unlicensed, some licensed. But I just want to add another string to the bow. “We’ve got, essentially, 600–700 primary
Scada devices in the bigger substations. Ten you jump up to several thousand devices look- ing after the pole-mounted equipment and the smaller ground-mounted. And I guess that in the next generation it will have to be 100000 even smaller substations to connect up. “We are doing some work now to try and
look forward to see the scalability of some of these networks, bearing in mind that the chan- nels were put together for the PMR system back in the 1980s when smart grids weren’t even a vague concept.”
Engineering Kevan is keen to stress that Western Power runs its own team of radio technicians. If something goes wrong, they repair it themselves. “We don’t rely on a contract for a supplier to use their own prioritizing of the faults”, he says. “And that’s why we didn’t go on the mobile phone network. It was because we couldn’t get a better category than number 19 in the list of users, behind the Queen and the special services and all the rest of it, to be any more important than Joe Public. If the network is full, we would have to wait. Whereas, with our network, if we want to restrict users or we want to shut whole areas of it off, if we need resource in other areas, we can do that. It is under our own control.
“If a device goes off, my team get a call and
they go and sort it out, and they do it now. Not tomorrow or the next day.” Yet much of the company’s automation in
the Midlands is now based on GPRS. And there have been instances when a message has taken two days to travel from a remote device back into the central computer. “We need to operate things within three minutes”, Kevan protests. “We’ve got a measure on us that if we leave customers off for more than three min- utes, we get penalized!” Kevan traces his company’s reliability-ori-
ented culture right to the top. “Te difference between our company and other companies, without saying anything derogatory about any of them, is that our company is run by an engi- neer”, he says. “Te boss is an engineer. Other companies are run by accountants. To main- tain a network of radio sites and all the comms that go with it is expensive, and all they could see was the monthly charge that they would get from a mobile phone. Tey didn’t really look at the consequences of that system not being available to them.”
Traffic loads In the existing Xfin network, the 103 sites are each equipped with a control channel and two or three voice channels. A normal working month will usually see 7000–8000 calls, but that has ramped up to 12000 in a few hours at the busiest times.
Xfin blades installed for Western Power Distribution’s South West of England and Wales network
Design work on the Midlands network
is already well advanced, and the plan is to complete the roll-out by the end of next year. “We’ve done all the hard work already, essen- tially: we know the technology works”, Kevan says. “I guess Andy’s guys know a bit more about the system, and so we’ve got no problem at all. It should fly in.” But the geography of the areas WPD has to deal with ensures that there will always be
At one of the sites in Western Power Distribution’s network, Team Simoco engineers prepare to install the new Xfin radio rack LAND mobile September 2012 19
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