Power measuring for 3 phase boiler Topic is solved

[RonkA]

Hello,

Im trying to create a 3 phase energy meter for my waterheater using actual resistance of the heating elements, P1-port data, and a 'klikaanklikuit'
AWMT-230 transmitter.

The AWMT-230 is connected over 1 of the resistors of the boiler and sends a inverted signal to my RFXcom tranceiver.
(so when the boiler kicks in it transmits 'off' and when boiler is ready it transmits 'on'. i use a blocky to invert to real state in dummy switch)
You could take the time the boiler was active and multiply this by the rated power to give the used power.
But there is a catch:
Here in the Netherlands the mains is rated at 230v per Phase. So Ohms law gives us (voltage x voltage)/resistance=power and this gives the rated
power of the boiler.
Example: a 2000w boiler has a internal resistance of 26,45 ohm, Ohm law: power=(230v x 230v)/ 26,45 ohm is 2000w
All nice if this was true but the mains fluctuates by law max. 10% so the mains voltage range is between 207v and 253v!!
So for the example boiler the real power can be as low as (207v x 207v)/26,45ohm is 1620w and as high as (253v x 253v)/26,45ohm is 2420w!

For today i got this from the log of phase 1:

netspanning.jpg (59.48 KiB) Viewed 696 times

The former is no bueno to use...

My solution: i want to use the values from the P1-port of my housemeter to calculate the used power.
My boiler is 3 phase star-wired so the individual resistors have 230v over them.
I measured the 3 individual resistors from the boiler: 1st phase = 27.8 ohm 2nd phase = 27.9 ohm 3nd phase = 29.9 ohm
From the P1-port of my housemeter i collect 'Net - Voltage L1' 'Net - Voltage L2' 'Net - Voltage L3' every 10 seconds
A dummy counter 'Boiler usage' set to 'compute' is created to count the power.

[RonkA]

This is how far i got with making a script:

Code: Select all

commandArray = {}
debug = true

-- Update these lines before use

trigger = "Boiler boven inverteerd"		-- name of the meter to trigger the dummy meter update.
fase_1_voltage = "Net - Voltage L1"		-- name of smart meter device
fase_2_voltage = "Net - Voltage L2"		-- name of smart meter device
fase_3_voltage = "Net - Voltage L3"		-- name of smart meter device
resistor_1 = 27.8				-- Ohm value of resistor
resistor_2 = 27.9				-- Ohm value of resistor
resistor_3 = 29.9				-- Ohm value of resistor
dummymeter0 = "Boiler boven - Verbruik"		-- name of virtual sensor
dummymeter_id0 = 133		   			-- ID of virtual sensor

-- loop 

for deviceName,deviceValue in pairs(devicechanged) do

    if (deviceName == trigger) then
       
	fase1 = otherdevices_svalues[fase_1_voltage]            -- Voltage fase 1
	fase2 = otherdevices_svalues[fase_2_voltage]            -- Voltage fase 2
	fase3 = otherdevices_svalues[fase_3_voltage]            -- Voltage fase 3

	power_L1 = (fase1 * fase1) / resistor_1			-- power used fase 1
	power_L2 = (fase2 * fase2) / resistor_2			-- power used fase 2
	power_L3 = (fase3 * fase3) / resistor_3			-- power used fase 3			
	power_total = power_L1 + power_L2 + power_L3		-- totaal power used
	power_total_a = math.floor(power_total)                	-- remove value after comma

--end
            
            
if (debug) then
print('Voltage fase 1 = ' .. fase1 .. ' Voltage fase 2 = ' .. fase2 .. ' Voltage fase 2 = ' .. fase3)		
print('power_L1 = ' .. power_L1 .. ' power_L2 = ' .. power_L2 .. ' power_L3 = ' .. power_L3)
print('total power = ' .. power_total .. ' total power rounded = ' .. power_total_a)
end

	-- Populate commandArray with update command
		
        commandArray[1] = {['UpdateDevice'] = dummymeter_id0 .. "|0|" .. power_total_a .. ";" .. (power_total_a/1000)}	 

    end
end
return commandArray

This gives a log output like:
2022-06-15 12:01:51.162 Status: LUA: Voltage fase 1 = 238.200 Voltage fase 2 = 237.000 Voltage fase 2 = 239.000
2022-06-15 12:01:51.162 Status: LUA: power_L1 = 2040.9798561151 power_L2 = 2013.2258064516 power_L3 = 1910.4013377926
2022-06-15 12:01:51.162 Status: LUA: total power = 5964.6070003594 total power rounded = 5964

And this is where i need some support, the script has to trigger if the boiler is heating(AWMT-230 states 'off') AND THEN update wattage when one of the voltages is changing.

[RonkA]

Anybody???

[boum]

I'm more of a dzVents user but in classic lua, this would be something like:
(not tested at all, not even for syntax)

Code: Select all

commandArray = {}
local debug = true

-- Update these lines before use
local trigger = "Boiler boven inverteerd"		-- name of the meter to trigger the dummy meter update.
local fase_1_voltage = "Net - Voltage L1"		-- name of smart meter device
local fase_2_voltage = "Net - Voltage L2"		-- name of smart meter device
local fase_3_voltage = "Net - Voltage L3"		-- name of smart meter device
local resistor_1 = 27.8				-- Ohm value of resistor
local resistor_2 = 27.9				-- Ohm value of resistor
local resistor_3 = 29.9				-- Ohm value of resistor
local dummymeter0 = "Boiler boven - Verbruik"		-- name of virtual sensor
local dummymeter_id0 = 133		   			-- ID of virtual sensor

local fase1Changed = devicechanged[fase_1_voltage]
local fase2Changed = devicechanged[fase_2_voltage]
local fase3Changed = devicechanged[fase_3_voltage]
if not (fase1Changed or fase2Changed or fase3Changed) then
  -- not one of the interesting devices
  return commandArray
end

if debug then
  if fase1Changed then print('Phase ' .. fase_1_voltage .. ' changed to ' .. fase1Changed) end
  if fase2Changed then print('Phase ' .. fase_2_voltage .. ' changed to ' .. fase2Changed) end
  if fase3Changed then print('Phase ' .. fase_3_voltage .. ' changed to ' .. fase3Changed) end
end

-- just return if AWMT-230 is activated
if otherdevices[trigger] == 'On' then
  if debug then
	print('skipping power update because state of ' .. trigger .. ' is ' .. otherdevices[trigger])		
  end
  return commandArray
end
-- loop 

local fase1 = otherdevices_svalues[fase_1_voltage]            -- Voltage fase 1
local fase2 = otherdevices_svalues[fase_2_voltage]            -- Voltage fase 2
localfase3 = otherdevices_svalues[fase_3_voltage]            -- Voltage fase 3

local power_L1 = (fase1 * fase1) / resistor_1			-- power used fase 1
local power_L2 = (fase2 * fase2) / resistor_2			-- power used fase 2 
local power_L3 = (fase3 * fase3) / resistor_3			-- power used fase 3
local power_total = power_L1 + power_L2 + power_L3		-- totaal power used 
local power_total_a = math.floor(power_total)                	-- remove value after comma
            
if (debug) then
print('Voltage fase 1 = ' .. fase1 .. ' Voltage fase 2 = ' .. fase2 .. ' Voltage fase 2 = ' .. fase3)		
print('power_L1 = ' .. power_L1 .. ' power_L2 = ' .. power_L2 .. ' power_L3 = ' .. power_L3)
print('total power = ' .. power_total .. ' total power rounded = ' .. power_total_a)
end

-- Populate commandArray with update command
commandArray[1] = {['UpdateDevice'] = dummymeter_id0 .. "|0|" .. power_total_a .. ";" .. (power_total_a/1000)}	 

return commandArray

Note sure about the "trigger" device. Also I used early exit with return rather than having several if depths.

[RonkA]

Merci!!

I will test this shortly.

----

Code: Select all

localfase3 = otherdevices_svalues[fase_3_voltage] (missing space)
localfase 3 = otherdevices_svalues[fase_3_voltage]

----

The code works ok for the first time. If the trigger == off then the device is updated correct, if the triger goes back to 'on' the last value stays on and gets counted in the total.
I've modified this in the code and now its looking great!!

Code: Select all

-- just return if AWMT-230 is activated
if otherdevices[trigger] == 'On' then
  if debug then
	print('skipping power update because state of ' .. trigger .. ' is ' .. otherdevices[trigger])		
  end
  return commandArray
end

to:

Code: Select all

-- just return if AWMT-230 is activated
if otherdevices[trigger] == 'On' then
  if debug then
	print('skipping power update because state of ' .. trigger .. ' is ' .. otherdevices[trigger])	
  end
 power_total_a = 0
 commandArray[1] = {['UpdateDevice'] = dummymeter_id0 .. "|0|" .. power_total_a .. ";" .. (power_total_a/1000)}	  
  return commandArray
end

[RonkA]

Still going strong, this is the code right now:

Code: Select all

commandArray = {}
local debug = false

-- My boiler nominal power is 5.568 Watt at 230 Volt.

-- Update these lines before use
local trigger = "Boiler boven inverteerd"	-- name of the meter to trigger the dummy meter update.
local fase_1_voltage = "Net - Voltage L1"	-- name of smart meter device
local fase_2_voltage = "Net - Voltage L2"	-- name of smart meter device
local fase_3_voltage = "Net - Voltage L3"	-- name of smart meter device
local resistor_1 = 27.8				-- Ohm value of resistor
local resistor_2 = 27.9				-- Ohm value of resistor
local resistor_3 = 29.9				-- Ohm value of resistor
local dummymeter0 = "Boiler boven - Verbruik"	-- name of virtual sensor
local dummymeter_id0 = 133			-- ID of virtual sensor

local fase1Changed = devicechanged[fase_1_voltage]
local fase2Changed = devicechanged[fase_2_voltage]
local fase3Changed = devicechanged[fase_3_voltage]
if not (fase1Changed or fase2Changed or fase3Changed) then
  -- not one of the interesting devices
  return commandArray
end

if debug then
  if fase1Changed then print('Phase ' .. fase_1_voltage .. ' changed to ' .. fase1Changed) end
  if fase2Changed then print('Phase ' .. fase_2_voltage .. ' changed to ' .. fase2Changed) end
  if fase3Changed then print('Phase ' .. fase_3_voltage .. ' changed to ' .. fase3Changed) end
end
-- My triggerdevice sends 'Off' when boiler is activated. 'On' updates 0 Watt to virtual sensor.
if otherdevices[trigger] == 'On' then
  if debug then
	print('skipping power update because state of ' .. trigger .. ' is ' .. otherdevices[trigger])	
	
  end
local power_total_a = 0
 commandArray[1] = {['UpdateDevice'] = dummymeter_id0 .. "|0|" .. power_total_a .. ";" .. (power_total_a/1000)}	  
  return commandArray
end
-- loop 

local fase1 = otherdevices_svalues[fase_1_voltage]      -- Voltage fase 1
local fase2 = otherdevices_svalues[fase_2_voltage]      -- Voltage fase 2
local fase3 = otherdevices_svalues[fase_3_voltage]      -- Voltage fase 3

local power_L1 = (fase1 * fase1) / resistor_1		-- power used fase 1
local power_L2 = (fase2 * fase2) / resistor_2		-- power used fase 2 
local power_L3 = (fase3 * fase3) / resistor_3		-- power used fase 3
local power_total = power_L1 + power_L2 + power_L3	-- totaal power used 
local power_total_a = math.floor(power_total)          	-- remove value after comma
            
if (debug) then
print('Voltage fase 1 = ' .. fase1 .. ' Voltage fase 2 = ' .. fase2 .. ' Voltage fase 2 = ' .. fase3)		
print('power_L1 = ' .. power_L1 .. ' power_L2 = ' .. power_L2 .. ' power_L3 = ' .. power_L3)
print('total power = ' .. power_total .. ' total power rounded = ' .. power_total_a)
end

-- Populate commandArray with update command
commandArray[1] = {['UpdateDevice'] = dummymeter_id0 .. "|0|" .. power_total_a .. ";" .. (power_total/1000)}	 

return commandArray