Will this flow work regards to automatically change charge speeds?

Questions & Help
1

Flow_1
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Hello folks! :slight_smile:

Will this flow work?

When i come home from work i plug in the charger and the charger will automatically charge with full load (30A) until the main load gets over 14.000W.

When the main load goes under 10.000W the charger starts again and increase the charge speed based on the main load in the house.

Is the timer sat right?

Thanks :slight_smile:

2

I don’t think it is going to work as you want with this setup.

Now the flow will stop charging, and also start charging on 10A, 20A and 30A all at once when the timer stops. Not sure what the flow will choose, but it will not work as intended.

Firstly you need to make a timer for each thing you want. One timer to stop the carging (e.g. elbil_lader_stop), and one for start charging at 10A, one for start charging at 20A and so one (e.g. elbil_lader_start10A).

Also I would consider removing the “Is not charging” card under each charging setup. If you are charging at 10A and the power drops below 8000 it wont start charging at 20A like it is now.

3

Thanks alot for your help! :slight_smile:

Is this a better flow regards to the charge limiting?

I have made one timer for each flow etc. and removed “car is charging” card.

In my head i think this flow will not work. Because the main power usage also measures the car charge load?

PS! I have only taken screenshot of a part of the flow here. For all the flow look at the first post :slight_smile:

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4

If I understand your situation correctly you want to keep the maximum powerconsumption under 14000 Watts and when plugging in your car it will always start charging at 30 Amps.

At 30 Amps you are charging with P = V*I = 240 * 30 = 7200 Watts.

So when your are using, let’s say, 15000 Watts it’s 1000 Watts to much. So you want to reduce the Amps with 1000/240 = 4,17 Amps. To be save set the charge speed at 25 Amps.

So I would create a number variable ‘Target Amps’

In general ‘Target Amps’ = ‘Target Amps’ + (14000-power)/ 240

So:

WHEN

every 2 minutes

AND

car is charging

THEN

calculate ‘Target Amps’ as {{‘Target Amps’ + (14000-power)/240}}

WHEN

variable ‘Target Amps’ has changed

AND

car is charging

THEN

Set current limit to ‘Target Amps’ A

Set initial charging Amps back to 30

WHEN

charging has stopped

THEN

set ‘Target Amps’ to 30

5

Thanks for replying and helping me out. :slight_smile:

I think i have found an better solution. I have made a card that calculates netto power usage where Charge load is substracted from main house power etc.

I have also made som minor changes.

Please take a look at this flow and tel me what you think? :slight_smile:

PS! I have 230V 3-fas in my house with 3x63A circuit breaker, and i can load the main fuse with around 25.0000W, so it’s not the end of the world if the power goes over 14000W. :slight_smile:

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6

I have tried the last flow now, and nothing happend when i turned on stove etc. and main power increased from 3000W to 6000W.

No message to my phone and no difference in charge speed etc.

Some ideas?

PS! Note that the real flow has more cards etc. but all is the same as the picture over. Just changes inn low/high cards. Etc.

7

Say the house is using 15000W and carcharger 7200W.
The ‘netto-load’ is 15000W - 7200W = 7800W

That is always lower then 14000W, so nothing happens.

8

But the calculation is based on netto load. My car charged with 6.200W. My house main load (without the car) was around 7.000W. One of my rules should have kicked in i think….?

9

So the calculation shouldbe power PLUS power = 6000 +7200 = 13200. Still below 14000

10

Think i have to show the last flow i tested with that did not work. This is the whole flow.

I have donme some stitching in photoshop.

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11

I found two errors and corrected it.

The errors is shown in image under marked red.

I changed the timer to 30A and removed the “less than 14.000” card”.

I have not tested the flow yet….

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12

Here is screenshot from my last flow after the correcting showed over.

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13

Some thoughts:

  • The first in each of the last four set of flows depends on the netto_load variable calculated in the first flow. Since all five flows have the same trigger, they will be initiated at (almost) the same time. You might run into the issue that the first flow has not yet completed calculating, while the other flows are already checking the netto_load variable. That will still contain the old value, resulting in unexpected behavior of the flow. An option is to add a 1 sec wait card after the trigger of the first in each of the last four set of flows.
  • I am not sure how often the ‘power changed’ flowcard is triggered. Ideally you would only use this trigger once and daisy chain the other cards in series so that you control the flow sequence, instead of being dependent on the order in which Homey decides to execute the flows. So creating one flow - triggered by the ‘power changed’ card, instead of five - that is executed always in the same order.
14

Wery good points! Thanks alot :slight_smile:

But if i set 1 sec. delay behind all four triggers… Isn’t that giving the same problem?

I will try that and come back :slight_smile:

15

That would only solve the dependency between the first and the set of last four flows that are triggered based on the power changed-flowcard.

The better option is the one I mentioned at my second bullet: combine the five flows into one and daisy chain the flowcards. Then you also don’t have to use the 1 sec delay, as the flow does not continue before a flowcard that calculates the netto_load has been completed.

16

Something like that?

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17

Yes. And you can skip the ‘netto_load is less than 9000 / 7500’ checks/cards, because that is automatically the case if it is not greater than those numbers, which you check in the preceding card.

18

Thanks :slight_smile:

I will try the flow later to day :slight_smile:

19

Good remark, its even worse…

It will cause the flow bot to run whe. Its exactly 9000

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1 Like
20

For inspiration, you can take a look at the flow I created to charge my car.

Puspose is a bit different (I want to use all surplus solar power to charge my car)

But in the end that also comes down to following the neasured power on my meter (insteps of 1A)