Author Topic: Reverse your smart energy meter with this simple trick!  (Read 12904 times)

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Offline Jeroen3Topic starter

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Reverse your smart energy meter with this simple trick!
« on: August 13, 2021, 07:26:45 am »
So, apparently several Smart Energy Meters in the Netherlands read incorrect in certain conditions.
It was already established a few years ago that some LED lamps could cause some meters to read high.
However, today I found this, fool the smart meter in your advantage!

Research paper: How to Earn Money with an EMI Problem: Static Energy Meters Running Backwards.

News item (dutch): Gelderlander.

Apparently, Chris bought a dimming wireless socket from KlikAanKlikUit (a brand in the netherlands) and used it for his TV.

tldr: This caused significant current pulses at specific phase angles fooling the meter in thinking he was backfeeding power.
Some others meters increased the power reading.

Interesting find. Soon the dodgy technology "power savings plug" will contain power corruptors...
« Last Edit: August 13, 2021, 09:20:53 am by Jeroen3 »
 

Offline Halcyon

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Re: Reverse your smart energy meter with this simple trick!
« Reply #1 on: August 13, 2021, 10:08:01 am »
Until they flash a firmware update over-the-air, rendering the "hack" useless.
 

Offline Zero999

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Re: Reverse your smart energy meter with this simple trick!
« Reply #2 on: August 13, 2021, 10:28:28 am »
It's also quite likely against the law.
 

Offline Berni

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Re: Reverse your smart energy meter with this simple trick!
« Reply #3 on: August 13, 2021, 10:36:03 am »
Is it still illegal if the meters are so crappy that a normal load with terrible power factor can cause it to read this wrong?

This is sort of like your ISP used a crappy bandwith limiter solution that would let you get 2x the amount of internet bandwidth if you sent packets with just the right packet size. Then they sue you for using more internet than they allowed you to use.

If they power company wants the accurate electricity usage reading, how about they pony up and buy some meters that actually work.
 
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Offline Alti

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Re: Reverse your smart energy meter with this simple trick!
« Reply #4 on: August 13, 2021, 10:48:37 am »
So, apparently several Smart Energy Meters in the Netherlands read incorrect in certain conditions.(..)
I'd say that every measurement instrument imaginable can only be expected to return results within conditions it has been designed and tested for. This not only applies to power meters.

In case of power meters the error bound (both plus and minus) is characterised but again, only in certain test conditions. Of course one cannot create test condition that includes "all possible current draw patterns" because a production test would have taken quite a long time then. Instead, a product is tested against standardised shape but you cannot infer from that the measurement error never exceeds boundaries - this has not been tested.

I suspect these meters are only designed to deal with EMC-compliant loads. Had someone used not-so-compliant load, the returned results could have included errors out of specified bounds.

Now the question is: is this a problem of a meter design and should any meter be robust against eBay jammers? Because then someone would have to prove non-existance of a pattern for which the error exceeds specified bounds.

 

Offline Zero999

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Re: Reverse your smart energy meter with this simple trick!
« Reply #5 on: August 13, 2021, 11:36:59 am »
Is it still illegal if the meters are so crappy that a normal load with terrible power factor can cause it to read this wrong?
If you're intentionally hacking it then yes, it is illegal.
 

Offline CJay

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Re: Reverse your smart energy meter with this simple trick!
« Reply #6 on: August 13, 2021, 11:40:31 am »
Is it still illegal if the meters are so crappy that a normal load with terrible power factor can cause it to read this wrong?
If you're intentionally hacking it then yes, it is illegal.

Intent is everything yes.

I wonder if this would have the effect of lowering the metered power consumption so be unnoticeable in a normal household?
 

Offline Red Squirrel

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Re: Reverse your smart energy meter with this simple trick!
« Reply #7 on: August 13, 2021, 11:49:25 am »
Wow that's pretty bad.  I could see that easily happen accidentally and lot of people getting screwed over by that once they are "caught".   
 

Offline Jeroen3Topic starter

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Re: Reverse your smart energy meter with this simple trick!
« Reply #8 on: August 13, 2021, 12:39:04 pm »
Well yes of course tampering with metering equipment is against the law. Especially intentionally!
But the thing is, these type of loads are not at all that uncommon today.

The standard doesn't explicitly tell you to test these waveforms. Only how much you may be wrong with what harmonics and such.
It does suggest some test setups, like half wave rectification and phase angle dimming, not the kind of pulses seen here, yet.
 

Offline Zero999

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Re: Reverse your smart energy meter with this simple trick!
« Reply #9 on: August 13, 2021, 02:48:08 pm »
Wow that's pretty bad.  I could see that easily happen accidentally and lot of people getting screwed over by that once they are "caught".
As mentioned above, intent is everything. If it's caused by a fault in the meter and a load, which just happens to emit the right kind of noise for it to roll backwards, then you'll probably get away with it. On the other hand, if it can be proven you designed a device, specifically to emit noise, with the intention of causing the meter to roll backwards, then you can be done for fraud.

I also wouldn't be surprised if the power company could theoretically, get you to pay them, for any electricty they gave you for free, even if it was their error, but they would have a hard time proving it and it would have to be split up into reasonable, instalments, over a fair time period.
 

Offline langwadt

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Re: Reverse your smart energy meter with this simple trick!
« Reply #10 on: August 13, 2021, 03:35:38 pm »
Wow that's pretty bad.  I could see that easily happen accidentally and lot of people getting screwed over by that once they are "caught".
As mentioned above, intent is everything. If it's caused by a fault in the meter and a load, which just happens to emit the right kind of noise for it to roll backwards, then you'll probably get away with it. On the other hand, if it can be proven you designed a device, specifically to emit noise, with the intention of causing the meter to roll backwards, then you can be done for fraud.

I also wouldn't be surprised if the power company could theoretically, get you to pay them, for any electricty they gave you for free, even if it was their error, but they would have a hard time proving it and it would have to be split up into reasonable, instalments, over a fair time period.

I'd expect that if the bill is high the power company will say the meter is has been tested so pay up, if it bill is low they
will assume you cheat and tell you to pay up an estimate based on previous bills
 

Online Kleinstein

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Re: Reverse your smart energy meter with this simple trick!
« Reply #11 on: August 13, 2021, 03:53:14 pm »
The old article about meters reading high with LED lamps was a case of a load outside the permitted limits. It this can the meter is allowed to read a little higher than normal. For normal loads this does not make a difference, as normal loads are usually much more well behaved. Even if it reads some 10% high an a poor designed Chinese LED lamp this would not make a big different (maybe $1). It would still read OK with the significant consumers like water heating, cooking, washing mashine or air conditioning.

A poor load could also cause an error to the other side - but still, what is the savings if it reads the poor power factor LED low and still gets it right with the main part. It is illigal to manipulate / fool the meter and it is also illegal to cause such EMI. It can effect neighbors and they may complain about poor grid quality and find the culprit.  Modern smart meters may detect and report excessive EMI,  very poor power factor or similar.
 

Offline TheSteve

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Re: Reverse your smart energy meter with this simple trick!
« Reply #12 on: August 13, 2021, 05:27:41 pm »
I lost one leg of the power coming into my house, the smart meter didn't notice or generate any fault. I'm not convinced they are very smart.
VE7FM
 

Online coppice

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Re: Reverse your smart energy meter with this simple trick!
« Reply #13 on: August 13, 2021, 05:55:00 pm »
The article is pretty vague. It would be interesting to see a proper description of the type of dimmer causing this, and the waveforms it produces.
 

Online coppice

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Re: Reverse your smart energy meter with this simple trick!
« Reply #14 on: August 13, 2021, 06:03:01 pm »
I suspect these meters are only designed to deal with EMC-compliant loads. Had someone used not-so-compliant load, the returned results could have included errors out of specified bounds.
These meters are generally only tested in accordance with WELMEC, OIML, IEC62052-xx and related specs (except in the US, which has its own ANSI specifications). If the IEC specs don't call for a test, and the utility doesn't lay down the test as an additional requirement, it won't be done. Good meter developers do a lot of additional internal testing for a variety of potential problems, but there is no commonality in those tests, and no requirement to publish results.
 
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Offline amyk

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Re: Reverse your smart energy meter with this simple trick!
« Reply #15 on: August 14, 2021, 02:02:29 am »
Does anyone else get reminded of the old ads in the back of some electronics magazines that told you how to make a device that would cause the meter to run backwards? I always thought those were just scams for the gullible... this was decades ago.
 

Offline station240

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Re: Reverse your smart energy meter with this simple trick!
« Reply #16 on: August 14, 2021, 03:16:42 pm »
The article is pretty vague. It would be interesting to see a proper description of the type of dimmer causing this, and the waveforms it produces.

Huh ?
Read the linked PDF, page 4 onwards, figure 6 in particular.
 

Online coppice

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Re: Reverse your smart energy meter with this simple trick!
« Reply #17 on: August 14, 2021, 03:58:43 pm »
The article is pretty vague. It would be interesting to see a proper description of the type of dimmer causing this, and the waveforms it produces.

Huh ?
Read the linked PDF, page 4 onwards, figure 6 in particular.
Ah, I missed that there was a detailed document as well as the news article.

The measurements seem interesting, but the conclusion is bogus. They assume this must be an EMI issue, without investigation. If you look at the design of various measuring techniques used in meters, there could well be problems with the power measurement algorithm being fooled by the waveforms. I wonder if the 4 meters giving funky results all use the same measurement front end, and what that front end might be?
« Last Edit: August 14, 2021, 04:42:00 pm by coppice »
 

Offline Jeroen3Topic starter

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Re: Reverse your smart energy meter with this simple trick!
« Reply #18 on: August 14, 2021, 08:22:48 pm »
I think that maybe the big short current pulse is being flattened and delayed by the digital filtering.
Can't make perfect filters...
 

Offline Zero999

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Re: Reverse your smart energy meter with this simple trick!
« Reply #19 on: August 14, 2021, 08:30:01 pm »
Wow that's pretty bad.  I could see that easily happen accidentally and lot of people getting screwed over by that once they are "caught".
As mentioned above, intent is everything. If it's caused by a fault in the meter and a load, which just happens to emit the right kind of noise for it to roll backwards, then you'll probably get away with it. On the other hand, if it can be proven you designed a device, specifically to emit noise, with the intention of causing the meter to roll backwards, then you can be done for fraud.

I also wouldn't be surprised if the power company could theoretically, get you to pay them, for any electricty they gave you for free, even if it was their error, but they would have a hard time proving it and it would have to be split up into reasonable, instalments, over a fair time period.

I'd expect that if the bill is high the power company will say the meter is has been tested so pay up, if it bill is low they
will assume you cheat and tell you to pay up an estimate based on previous bills
That's why we have courts.

If I were running a power company and I genuinely thought a customer had cheated, then I wouldn't be just looking at reclaiming the money, but they also received a suitable penalty from the authorities to deter them and others.
 

Offline Cyberdragon

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Re: Reverse your smart energy meter with this simple trick!
« Reply #20 on: August 14, 2021, 11:02:17 pm »
I lost one leg of the power coming into my house, the smart meter didn't notice or generate any fault. I'm not convinced they are very smart.

Fun fact, cheap digital meters extract power from only one leg, no redundancies. If you loose that leg, the meter goes out, the remaining leg is free power. ;D :palm:
*BZZZZZZAAAAAP*
Voltamort strikes again!
Explodingus - someone who frequently causes accidental explosions
 

Offline Alti

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Re: Reverse your smart energy meter with this simple trick!
« Reply #21 on: August 15, 2021, 11:31:24 am »
The solution could have been to split counting of energy into several harmonics ranges (digitally).
Then first counter integrates sub-harmonics, second integrates around main 50Hz, third all other higher harmonics. Then the metering could have been tested for tight <1% errors only around main frequency. Designing a 1% power meter frontend for MHz eBay jammers would have been expensive and unnecessary so maybe let the third meter integrate higher harmonics with +-30% error and just apply higher charge on this counter. This could have been relatively easy to design and to test.
 

Offline Berni

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Re: Reverse your smart energy meter with this simple trick!
« Reply #22 on: August 16, 2021, 07:19:49 am »
No need for any fancy FFT or anythyng.

You just need to sample the current and voltage about 1000 times per the 50Hz cycle, multiply them together to get instantaneous power then average out the power across the cycle. With some more analysis you can also extract the reactive power and power factor from this.

It's just a matter of sampling fast enough to catch all the relevant harmonics while having proper low pass filtering on the voltage and current sense inputs to keep out any high frequency or RF noise. This keeps the noise from perhaps demodulating itself in the current shunt amplifier or alias in the ADC.

Test the thing with a large frequency sweep from Hz to high MHz and if the ADC readings don't twitch or move at all then it will be resilient to pretty much anything you could reasonably throw at it (So this does not include pointing a microwave oven magnetron at it)
 

Offline SeanB

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Re: Reverse your smart energy meter with this simple trick!
« Reply #23 on: August 16, 2021, 08:09:45 am »
Does anyone else get reminded of the old ads in the back of some electronics magazines that told you how to make a device that would cause the meter to run backwards? I always thought those were just scams for the gullible... this was decades ago.

No, those were easy, you just use a iron core welding transformer, or three, which was essentially a near perfect inductive load. The high out of phase current would saturate the current sense coil, and then cause the meter to either not read correctly, or to run backwards as the core came out of saturation and generated a magnetic field that appeared to be a return current flow. The solution from the power companies was to simply include a small non reverse cam and pawl on the meter movement shaft, so it would not run backwards more than a single revolution in this case.  For those who were using the arc welders to weld, the meter simply did not move while they were connected but not welding, though when you welded the meter would run forward as usual, as the resistive load overwhelmed the inductive current flow.

Modern meters will simply measure the inductive current flow as reactive power, and will ignore it. Also why you need a second meter in series for solar feed in, the flow of reactive power is not counted, only resistive current flow.
 

Offline Alti

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Re: Reverse your smart energy meter with this simple trick!
« Reply #24 on: August 16, 2021, 01:19:35 pm »
You just need to sample the current and voltage about 1000 times per the 50Hz cycle (..)
If the sample is made at that frequency then conditioning circuit starts from anti-aliasing filter (it has to attenuate all frequencies above F/2) otherwise you get junk. At higher frequencies you can happily draw power in between ADC samples. And that is what this dumb eBay jammer does I suspect. I think it (unintentionally) locks fast rising edge with ADC, offset with zero crossing.

With this brute force approach and keeping within 1% accuracy you would have to increase sampling to more than 2*some frequencies limited by RLC bandwidth of a piece of cable that separates power meter and jammer. Otherwise a purposely built jammer can be/will be created that locks into ADC sampling and extracts 1.01kWh when ADC counts 1.00kWh (thus defying your concept). That is essentially a proposition of a 1% accurate measurement instrument with DC to tens of MHz bandwidth.
 


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