Use of the Power Line Communication System (PLC) at Low Voltage (0.4 kV)

Use of the Power Line Communication System (PLC) at Low Voltage (0.4 kV)

Noisy Electrical Networks – Introducing a New Concept at Power Quality

István SZÉN1, Ervin RÁCZ (PhD)1

1 Institute of Power Engineering

Kandó Kálmán Faculty of Electrical Engineering, Óbuda University

Bécsi út 94-96A, 1039 Budapest (Hungary)

Phone/Fax number:+0036/1-666-5828,

e-mail: szen.istvan@kvk.uni-obuda.hu

e-mail: racz.ervin@kvk.uni-obuda.hu

EXCERPTS:

Installing of these new energy sources new challenges will be outcroped. New challenges must be solved by

electrical engineers and other professionals. For example, it is important to know that how these small power plants

connect to the central power system. Parallel to the advantages of the small systems they can introduce

significant electric noises in the central electric system. Figure 3. shows an example how a mini solar cell power

supply system connect to a 0.4 kV main central electric line.

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PLCs are very sensitive for electric noises.

Unfortunately, high frequency electric noises can affect their operations. The power line communication works at

frequency range of 9 – 95 kHz (CENELEC A-band). This frequency range is endangered by electric noises.

Another important factor is: the PLCs cannot be substituted by other parts. They must be protected!

The aim of the present research work was mapping the noise effect on PLCs. In order to investigate the role of

the high frequency noises on PLC operation, some test measurements on PLCs with different inverters have

been made. Figure 4. presents the actual experimental setup used for the measurements.

Measurements were started at flow meter installed closest to the data concentrator. This flow meter was installed 50

meters far from the data concentrator device. Next measurements were made 200 meters, than 150 meters

and than another 150 meters far at different direction from the data concentrator, respectively.

Fig. 12.: Measurement data shows significant noise level at PLC region in case of measurement at household #2.

Carriers can not be observed due to strong noise level. Finally, communication resulted incorrect transmission of

information and interrupted connection (measurement position #4). [4]

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noise diagram showed fluctuations causing statistical errors. Signal – noise ratio depends on the daylight time period.

For example: afternoons and night times stronger noises were detected than in the morning. Weekends and in the

night periods noise signals were significantly stronger influecting read out cycle of flow meters.

ARIZONA-ACC Confession: “More and more often” APS ‘Smart’ Meters Don’t Work

ACC Confession: “More and more often” APS ‘Smart’ Meters Don’t Work

Information & Perspective by Warren Woodward

Sedona, Arizona ~ June 21, 2015

           Last April I made another Public Records Request of the Arizona Corporation Commission (ACC). I asked for all “smart” meter related emails and documents from January 1st, 2015 to the date of my request, April 28th.

           Since the lawless and scandal-ridden ACC has so much to hide, what I received last Friday was mostly redacted. However, there were a few noteworthy unredacted email exchanges. Below is one such exchange.

           This email exchange is between employees of the ACC Utility Division’s so-called “Consumer Services” section. Mike Buck works there, and Connie Walczak is the manager of Consumer Services. The other people listed in the “To” heading of the emails are all Consumer Services workers.

           Connie is explaining to Buck and the others that “more and more often” APS’s “smart” meters are not communicating, that the problem can “go on for months,” and so APS is estimating customers’ bills as a result.

           This news is not without irony since, in the past, APS has claimed that one of the advantages of “smart” meters was cutting down on the number of estimated bills due to meter access problems. Is anyone surprised that another APS “smart” meter claim turns out to be a lie?

           Last October, APS admitted to replacing some 32,000 faulty “smart” meters between January 1st and August 31st of last year alone (see: http://images.edocket.azcc.gov/docketpdf/0000156835.pdf ). With this new revelation in the ongoing “smart” meter fiasco, one wonders how many more “smart” meters have been replaced since then. Of course the ACC wouldn’t know because, as with APS’s “smart” meter related fires, the ACC is simply too negligent to investigate. After all, laws don’t mean a thing at the ACC, especially A.R.S. 40-361.B which states:

“Every public service corporation shall furnish and maintain such service, equipment and facilities as will promote the safety, health, comfort and convenience of its patrons, employees and the public, and as will be in all respects adequate, efficient and reasonable.”

           Are APS’s “smart” meters “adequate, efficient and reasonable” “in all respects?” No, not in any respect.

From: Connie Walczak

Sent: Wednesday, April 01, 2015 1:32 PM

To: Al Amezcua; Carmen Madrid; Deborah Reagan; Jenny Gomez; Michael Buck; Richard Martinez; Tom Davis; Trish Meeter

Subject: FW: APS SMART METERS

FYI

What you might hear from APS is….. the meter stopped ‘communicating’ with the company. Seems the Smart Meters are doing this more and more often. It may be for only a brief period or a week or a month. APS seems to not have a problem with this ‘non’ communication, they have Schedule 8, 3.1 to rely on which enables them to estimate the bills. This can go on for months. They do not check the meter when they could retrieve the data, rather, they estimate usage. They do not feel the meter is malfunctioning if it begins communicating again. Even when it continues doing this for more than one month.

From: Michael Buck

Sent: Wednesday, April 01, 2015 11:04 AM

To: Richard Martinez; Jenny Gomez; Al Amezcua; Deborah Reagan; Carmen Madrid; Trish Meeter; Tom Davis

Cc: Connie Walczak

Subject: APS SMART METERS

Per Connie,

Has anyone in Consumer Services had any complaints concerning APS’s inability to read their Smart Meter’s and estimating the bill? Appreciate the information.

Thank you

Mike Buck