Itinerant drives specialist peers into his crystal ball
13 November 2015
Andy Gardener looks back over twenty years of working with drives, taking inverter drive technology into developing markets across the globe, and makes some predictions.
In November 1995, a few months after I had departed the IMO family as a young man with a full head of hair, the illustrious Edward Kirk penned an article for this very publication predicting the future for ac drives. Having then spent the next couple of decades travelling the world taking inverter drive technology into developing markets across the globe, in a career path as circular as the planet we live on, I now ironically find myself occupying the same chair and pondering the same question that Eddie was pondering all those years ago.
The original article highlighted the technical advancements in open loop torque vector technology, which has indeed reached a point now where we can develop the kind of torque required to drive an extruder with the same kW rated ac motor as the dc one it is replacing. Faster processors, faster output transistors and an increased understanding of how to squeeze every ounce of performance from a squirrel cage motor has led to improvements in the algorithms that control the inverter drives of today.
There is no doubt that in order to slow the pace of both climate change and in order to protect the supply of natural resources, we, as an industry must continue on the path to developing more power with less resource. So where are we going to see the performance improvements in drive technology moving forwards?
This has to be considered on two fronts. Firstly, the inverter fed motor efficiency needs to improve further. In all likelihood this will come from an increase in the use of permanent magnet motors or synchronous motor technology. This type of motor offers a reduction in frame size and an increase in efficiency, resulting in lower heat loss. Controlling these synchronous motors accurately requires much more from the drive. The new products we are bringing to market now offer both open loop and the traditional closed loop operation for PM motors.
Secondly we must look at the efficiency of the drive itself. The current figure of around 98 percent is a pretty good achievement. We believe that 45 percent of energy globally is consumed by electric motors, many of which are controlled by inverters. Even 1 percent improvement in the efficiency of the drive would therefore have a huge impact on global energy consumption.
Over the next few years we are focusing on further improvements in switching technology. Better efficiency in these components will result in lower heat losses, smaller heatsinks, smaller drives, and an end to the age-old problem of dissipating large amounts of generated heat by the drive within an enclosed control panel.
Looking at today’s drives I don’t think any of us could have predicted the volume and breadth of features that we would eventually see included in the standard products. Over 500 user parameters and a manual stretching to over 700 pages is a far cry from the days when the whole system was commissioned using half a dozen PCB mounted potentiometers. That’s not to say that those features are not used on a daily basis by somebody somewhere in the world, it’s just that that someone doesn’t necessarily need all of them.
It is becoming possible now with modern drive designs to have a common hardware platform and to customise the software to suit the requirements of certain market segments. We are already doing this with software tailored specifically to suit the requirements of the building services industry, or the specific features required by the water industry.
I’m certain that this type of customisation will develop further in the years to come. We may even see the day when the customer defines his own feature set using a common hardware platform - after all, what would a crane company need dry pump detection for? Does an air handling unit manufacturer really need a triple redundancy brake release circuit?
The last decade has seen the coming of the Internet Age, the growth in mobile communications and our unending desire for more and more information. There are great advancements in data acquisition happening right now that are going to take smart drive users up to the next level in years to come.
With the recent launch of IMO’s iConnect products and cloud services, it is now possible to collect data from drive systems into an HMI or PLC and upload them to a cloud server via 4G/3G networks anywhere in the world. That data can then be analysed and accessed by mobile phone, tablet or PC.
In its simplest form you might want to alert an off-site engineer to a trip or fault in the system, but that is just the tip of the data iceberg. Maybe you’re an automotive manufacturer looking at real time energy usage of every fan and pump drive in your paint shop to understand where savings can be made. Or perhaps an oil company monitoring the number of barrels produced each day by each nodding donkey in a remote oil field. There could even be opportunities in the future for companies that lease out plant and bill the end user automatically based on machine usage or throughput.
How long will it be before we are monitoring drives in the field in the same way that Rolls-Royce monitors its aero engines as they ferry passengers and freight around the world? Well, in theory we could do that right now. IMO Jaguar drives do monitor and log data on such things as capacitor condition and life expectancy, hours run, energy used, and so on. So, you could install a drive system today that will send you an email in 15 years or so to tell you that it needs replacing on the next planned shutdown.
Bluetooth communications and mobile phone and tablet apps could easily be adapted for use in commissioning and fault finding in the drives of the future. Such a lot can be done now with a smart phone that it must surely be a natural progression for more industrial applications to emerge over time.
All in all we have exciting times ahead for those of us at the cutting edge of industrial technology. But it is unfortunate that we are not seeing enough talented school leavers choosing to have a career in engineering. So I will sign off with a final thought for the potential young engineers of the future:
“It is a lot more exciting standing out in the middle of a Cumbrian lake fault finding on an automated dredger that pulls 12 tons of shingle from 5 meters down at high speed, than it is to sit in a darkened room writing computer code that serves no other purpose than moving a bunch of pixels from one side of a screen to the other.”
Andy Gardener is a drives specialist at IMO Precision Control
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