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Advanced Meter Infrastructure...

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potteryshard

Electrical
Joined
Sep 29, 2010
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152
Location
US
The small southwestern US utility for which I work is embarking on the specification, purchase, and implementation of an automated advanced metering infrastructure, and is now in the throes of deciding upon which system to select for our water and electric systems.

This is an arena in which by means of diligent denial I've managed to learn even less than in other topics. Worse, until yesterday afternoon, I've not been invited to participate in the process. Now with the decision point looming a few weeks away, I've been requested to learn all I can on the subject.

So; this thread is a request for guidance regarding such AMI topics as meters, meter problems, communications preferences, (star or mesh) backhaul considerations and required collector installations, software, vendor performance issues, quality control issues, hardware support, and all other relevant topics.

In particular, references to vendor-neutral studies, comparisons, and capabilities would be of tremendous help.
 
This is a very sensitive topic. These are, in general, highly proprietary systems that are sold as a complete package. Once a purchase decision is made, your company will be completely locked in to this technology unless you choose to completely replace everything.

Once a utility has made the sizable investment in whatever technology they have selected, there is reluctance to air problems in public and they are often restricted by terms of the NDA from discussing these issues with third-parties. From my limited experience, every single installation I am aware of, from a variety of vendors, has experienced problems of one type or another and the implementation costs seem to always exceed whatever is estimated.

Without knowing more about your utility it would be difficult to make any specific recommendations. One suggestion I would make is make sure you do an initial pilot installation to make sure whatever system you select will meet your needs before buying the entire system.

Unbiased comparison data will be hard to obtain, in my experience.

Good luck.
 
There are many different communication principles available. From the very slow, but considered safe, Turtle with bandwidths in the mHz range via common PLC (Power Line Communication working in the sub 150 kHz band) to ADSL, WiFi and RF modems.

I have been involved in the evaluation and faultfinding on Turtle and PLC and my experience is that Turtle works very well until the grid is polluted from CSI frequency inverters. Then the whole system can be blocked and, since a transmission takes around 24 hours, the chances that a disturbing frequency sweeps through the communication band are very real. There are some indications that PWM inverters do the same thing. Especially large ones used as tie inverters for wind turbines.

The sub 150 kHz PLC is sensitive to ordinary HVAC inverters and the sad thing is that when you put filters on the inverters, you also filter away a good deal of the PLC carrier. So, you have to be very careful and select filters with care. Phase compensation capacitors have the same effect.

I have no experience with ADSL, WiFi or RF modems in AMR aplications. I think that it works well. But others may have other experiences.

One thing that is worth noting is that the (European) meter specifications do not deal with distorted current waveforms like the ones you get from dimmers. The consequence is that there are meters (a very well-known brand) that record hundreds of percent too much consumption if you have much triac controlled load. I made an investigation for a utility almost one year ago to find out why some of their customers paid a lot more than they should. The utility had put other meters in series with the offending ones and had seen the difference themselves. They said it was around 50 percent too much, but we found much larger deviations in lab tests with thyristor controlled incandescent lamps.

The result of this investigation is now with the authoritites. The have uttered nil so far. But they have also not denied that the results are correct. We are still waiting for their reaction.

My best bet is that you contact nearby utilities and get their opinion on the matter.

Gunnar Englund
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
 
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