Electric cars and voltage drops and hifi

[gingermrkettle]

Maybe time to move this to OT?

Anyway, unless the neighbour has 3 phase (which is unlikely) the maximum draw through the standard socket is 7kW. Fast charging is DC and will use batteries/supercapacitors.

 

[Whaleblue]

7.5kW draw to charge an EV is actually less than most domestic electric showers in the UK (9 kW or so usually - 40-45A draw, more tna teh nominal '32A' EV domestic charger)
Such a large voltage drop as the OP is seeing, therefore looks to me to be worth following-up on; something is not right.

ON mains frequency - yeah, well, being a measurist-weirdo I actually have a frequency meter hooked-up and have been watching; on the UK mains you get v short term changes in the 0.05Hz range, and total deviation - over last three months is typ less than +/-0.1Hz in say about a 3-5min window, and rarely worse than that. It is observably, very much more stable in terms of short term frequency deviations on days when wind output is low, and remaining traditional (Nuclear/CCGT generation, with large spinning mass) is delivering >50%.

eta: mains voltage/freq at time of post: that's 49.xxx Hz

Living on the south coast near to the Rampion wind farm I’m wondering whether we are likely to be consuming that wind generated electricity, when available, which seems to be most of the time? In other words, does generated electricity all go to the national grid in such a way as to get consumed evenly across the country, or is it set up so that generators feed local demand first before any “spare” gets into the wider grid?

 

[davidsrsb]

Old gear like the MK1 Quad 405 has 220/230/240V mains selection, so dips like the OP has are a pain

The UK grid is nationwide, one frequency everywhere, and essentially a single load pool

 

[toprepairman]

The 405 will run perfectly happily on 200 V when set to 240V. The only difference will be a marginal drop in power which very few will ever notice as Jez pointed out.

 

[MJS]

Your local electricity distributor should check this out.

A couple of years back I noticed my CDI was making a weird clicking noise. The mute relays were dropping in and out. The linear regulators had stopped working but everything inside was also out of spec. I then hooked up a meter to the mains a saw that we had 199V RMS mains.

To be fair to Western Power they were straight out to my property thinking that the main fuse was the culprit (and fire risk) and it wasn't until they swapped it out and saw no difference they they started checking all the other phases. They were all low. Then they got a message from the call centre that one of our neighbours had been trying to cook something for 4 hours - it was a Sunday.

Anyway, it turned out that a low voltage cable had burned out on one of the village's two transformers in the summer and they'd wired the affected properties to the other one. All was well until winter when all the heating and cooking dropped the voltage too far. The cable fault had been flagged as repaired when it hadn't been so no-one was aware until I reported it. Apparently the red phase fuse on the remaining transformer was 'a little hot'.

 

[mindlagoon]

It's car manufacturers I pity. Rather than being allowed to develop new tech at a sensible pace they are being forced into radical upheaval by political whims. How are they supposed to invest when the ground keeps changing and it takes so long to see a return?

Pity?? Jeez. They've had plenty of time to prepare and invest. Read up about the General Motors EV1. Thankfully Tesla and Musk came along and have embarrassed them all. Those who shorted Tesla shares, especially with the backing of the oil and auto industry, deserve the huge losses they have suffered. The days of burning dinosaur juice to propel ourselves and freight about are coming to an end and not before time. If rhe infrastructure needs up-rating it will be up-rated.

 

[Rodrat]

So a follow up to my earlier post reply, if you want to upgrade the main fuse, you have to contact your electricity supplier to install 2.5mm tails if they are not already fitted. It cost me about £35 via British Gas my supplier. Once they are done you contact the National Grid who will come out and replace the fuses for free. As it is a shared supply you may not be able to go as high as 100amps though. It was all very efficiently done.

 

[Barrymagrec]

I think you mean 25mm ?

 

[Sue Pertwee-Tyr]

I found these numbers on fast charging a Tesla:

300 amps at 400 Volts (3 phase, I presume), a peak value during the 1 hour cycle. Thats 120 kW! But are fast charges drawing directly from the grid or do they use batteries to even out the loading?

I suppose this redefines the 'bad mains day' discussion...

Fast charging like this only happens at Supercharger points AFAIK, and these must surely be connected to 3 phase supply. As has been mentioned above, most domestic ‘fast chargers’ are 7.5kW and connect to the domestic single phase supply. IIRC most housing developments tend to connect adjacent houses to different phases, so this shouldn’t really be much of an issue unless and until electric cars become more commonplace.

Slightly surprised the OP’s neighbours are charging at early evening peak times, they’d be better off setting the timer to charge in off peak, overnight.

 

[Rodrat]

Sorry, yes.

 

[Arkless Electronics]

I found these numbers on fast charging a Tesla:

300 amps at 400 Volts (3 phase, I presume), a peak value during the 1 hour cycle. Thats 120 kW! But are fast charges drawing directly from the grid or do they use batteries to even out the loading?

I suppose this redefines the 'bad mains day' discussion...

Those are the kind of figures I had in mind yes!

 

[hal9001]

Just think this problem is going to get worse with time. The quality of the mains will deteriorate to such an extent without major investment and anyone running current hungry amps will need to invest in some form of regen designed for this particular application, or they are eventually banned and we have to move to SMPS. Or a big battery (can't beat them, join them). At the moment I'm placing my faith in the protection circuitry until I get hold of a multimeter and confirm what I am seeing on the regen display. Then I can have another conversation with Northern Powergrid.

 

[Arkless Electronics]

Just think this problem is going to get worse with time. The quality of the mains will deteriorate to such an extent without major investment and anyone running current hungry amps will need to invest in some form of regen designed for this particular application, or they are eventually banned and we have to move to SMPS. Or a big battery (can't beat them, join them). At the moment I'm placing my faith in the protection circuitry until I get hold of a multimeter and confirm what I am seeing on the regen display. Then I can have another conversation with Northern Powergrid.

It has nothing to do with "current hungry amps" and they will be unaffected other than as I said up thread.

For the third bleedin time... linear regs are what will be most effected.

 

[cctaylor]

The mains distribution system is designed to cope with a wide range of loads. The engineers can adjust taps at substations to correct voltages. In future it will be that as the loads increase due to EV chargers and the increase in electric heating systems such as heat pumps the network and local distribution systems will need to be reinforced and upgraded

As stated earlier standard chargers do not create more load than an electric shower but of course it is over a longer period.

If the voltages are as the OP reports there is a problem on his local network which needs to be checked out.

 

[matt j]

Fast charging like this only happens at Supercharger points AFAIK, and these must surely be connected to 3 phase supply.

Public Tesla Superchargers are DC.

I think the highest rated home AC charging option is 22kw but I don't know how popular they are due to cost, like you say the 7kw option is the most common.

 

[clivem2]

Public Tesla Superchargers are DC.

I think the highest rated home AC charging option is 22kw but I don't know how popular they are due to cost, like you say the 7kw option is the most common.

The output may be DC but probably the input needs 3 phase. Certainly that’s the understanding of the AC requirements from a pal who considered a Tesla.

 

[Mr Pig]

Pity?? Jeez. They've had plenty of time to prepare and invest.

But you can only invest when the technology and market is ready. That's sensible business, which is not what's happening just now. Politicians are dictating pace of change rather than allowing the EV market to develop naturally.

My question on how you defrost an EV wasn't a rhetorical one. Your Tesla might be just super in California but what if you're unfortunate enough to live in Scotland? Live in a city and can't park your car at your house on charge over night. Maybe you're a long-distance driver, a rep or something.

How do you unfreeze your car? Ten minutes with the electric heater on full? Then you head off but you're getting about half the range you should because you've got the heater and all the lights on and the batteries don't work properly in the cold!

These are real problems, the tech is not ready, not for everyone, but the politicians are just ignoring the them.

Electric cars will be great, the solutions will be found, they are the future. But can we not just let them develop at their own pace? When they're good enough you won't have to push people into buying them, they'll want them.

 

[John Phillips]

... These are real problems, the tech is not ready, not for everyone, but the politicians are just ignoring the them. ...

You are being realistic but naïve. One of the defining characteristics I observe in Politicians (or politicians) is the "I've got a great idea. You're going to solve it" attitude.

 

[Mr Pig]

One of the defining characteristics I observe in Politicians (or politicians) is the "I've got a great idea. You're going to solve it" attitude.

Quite. They're like middle managers who have never done the job they're managing. There is so much about our political and governmental system that's broken and i don't see how it can be fixed.

Anyway, off to run our block of ice diesel car for fifteen minutes until it's movable...

 

[forester]

Politicians are useless at being managers at any level, Anyway they (or their advisers) have left some hybrid vehicles as a get out. Be more concerned about the RF rubbish that solar, wind and chargers are putting back into the system.