Peak load limiter - Printable Version

Peak load limiter - Printable Version

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Peak load limiter - tomnord - 07.12.2018

Hello, has anybody got any good ideas on how to make a peak load limiter based on current KW usage or kwh? Scalable to varius amount of loads to be controlled.

RE: Peak load limiter - buuuudzik - 07.12.2018

I think firstly you should create a list of your controllable loads with their power and priority.

RE: Peak load limiter - Erwin van der Zwart - 07.12.2018

Hi,

I created this a while ago, maybe it could help you in your task.

Code:
-- Set adresses

address_max = '1/1/2'

address_hyst = '1/1/3'

address_relais1 = '1/1/4'

address_relais2 = '1/1/5'

address_relais3 = '1/1/6'

address_relais4 = '1/1/7'

-- Get measured power

power = event.getvalue()

-- Get limit value

max = grp.getvalue(address_max)

-- Get Hysteresis

hyst = grp.getvalue(address_hyst)

-- Calculate floor value

hyst_floor = math.floor((max - hyst) + 0.5)

-- Check if chanels need to be turned on

if power < hyst_floor then

    -- get current state of relais 4

  current_state_relais4 = grp.getvalue(address_relais4)

  if current_state_relais4 == false then

    grp.write(address_relais4, true)

    -- exit script and after that cascade to chanel 3

      return

  end

    -- get current state of relais 3

  current_state_relais3 = grp.getvalue(address_relais3)

  if current_state_relais3 == false then

    grp.write(address_relais3, true)

    -- exit script and after that cascade to chanel 2

      return

  end

   -- get current state of relais 2

  current_state_relais2 = grp.getvalue(address_relais2)

  if current_state_relais2 == false then

    grp.write(address_relais2, true)

    -- exit script and after that cascade to chanel 1

      return

  end

  -- get current state of relais 1

  current_state_relais1 = grp.getvalue(address_relais1)

  if current_state_relais1 == false then

    grp.write(address_relais1, true)

    -- exit script

      return

  end

end

-- Check if chanel 1 need to be turned off, after that cascade to chanel 2, then cascade to chanel 3 etcetera

if power > max then

  -- get current state of relais 1

  current_state_relais1 = grp.getvalue(address_relais1)

  if current_state_relais1 == true then

    grp.write(address_relais1, false)

  else

      -- get current state of relais 2

      current_state_relais2 = grp.getvalue(address_relais2)

      if current_state_relais2 == true then

        grp.write(address_relais2, false)

    else

          -- get current state of relais 3

          current_state_relais3 = grp.getvalue(address_relais3)

          if current_state_relais3 == true then

            grp.write(address_relais3, false)

        else

              -- get current state of relais 4

              current_state_relais4 = grp.getvalue(address_relais4)

              if current_state_relais4 == true then

                grp.write(address_relais4, false)

              end

          end

      end

  end

end

BR,

Erwin

RE: Peak load limiter - tomnord - 07.12.2018

(07.12.2018, 21:19)Erwin van der Zwart Wrote: Hi,

I created this a while ago, maybe it could help you in your task.

Code:
-- Set adresses address_max = '1/1/2' address_hyst = '1/1/3' address_relais1 = '1/1/4' address_relais2 = '1/1/5' address_relais3 = '1/1/6' address_relais4 = '1/1/7' -- Get measured power power = event.getvalue() -- Get limit value max = grp.getvalue(address_max) -- Get Hysteresis hyst = grp.getvalue(address_hyst) -- Calculate floor value hyst_floor = math.floor((max - hyst) + 0.5) -- Check if chanels need to be turned on if power < hyst_floor then -- get current state of relais 4 current_state_relais4 = grp.getvalue(address_relais4) if current_state_relais4 == false then grp.write(address_relais4, true) -- exit script and after that cascade to chanel 3 return end -- get current state of relais 3 current_state_relais3 = grp.getvalue(address_relais3) if current_state_relais3 == false then grp.write(address_relais3, true) -- exit script and after that cascade to chanel 2 return end -- get current state of relais 2 current_state_relais2 = grp.getvalue(address_relais2) if current_state_relais2 == false then grp.write(address_relais2, true) -- exit script and after that cascade to chanel 1 return end -- get current state of relais 1 current_state_relais1 = grp.getvalue(address_relais1) if current_state_relais1 == false then grp.write(address_relais1, true) -- exit script return end end -- Check if chanel 1 need to be turned off, after that cascade to chanel 2, then cascade to chanel 3 etcetera if power > max then -- get current state of relais 1 current_state_relais1 = grp.getvalue(address_relais1) if current_state_relais1 == true then grp.write(address_relais1, false) else -- get current state of relais 2 current_state_relais2 = grp.getvalue(address_relais2) if current_state_relais2 == true then grp.write(address_relais2, false) else -- get current state of relais 3 current_state_relais3 = grp.getvalue(address_relais3) if current_state_relais3 == true then grp.write(address_relais3, false) else -- get current state of relais 4 current_state_relais4 = grp.getvalue(address_relais4) if current_state_relais4 == true then grp.write(address_relais4, false) end end end end end
BR,

Erwin

Thanks Erwin, this looks like it could work good as a startingpoint.
I'm new to LM5 and scripting, so trial and error will be nessesary, it's great to have some place to start.

RE: Peak load limiter - Erwin van der Zwart - 08.12.2018

Hi,

I also created something for EV chargers that the max output power is set by the number of active loaders and available power.

I could share that so you can see how that works, it’s a bit more complex.

BR,

Erwin

RE: Peak load limiter - tomnord - 08.12.2018

Sure, do share. Anything helps.

RE: Peak load limiter - Domoticatorino - 10.12.2018

(07.12.2018, 21:19)Erwin van der Zwart Wrote: Hi,

I created this a while ago, maybe it could help you in your task.

Code:
-- Set adresses address_max = '1/1/2' address_hyst = '1/1/3' address_relais1 = '1/1/4' address_relais2 = '1/1/5' address_relais3 = '1/1/6' address_relais4 = '1/1/7' -- Get measured power power = event.getvalue() -- Get limit value max = grp.getvalue(address_max) -- Get Hysteresis hyst = grp.getvalue(address_hyst) -- Calculate floor value hyst_floor = math.floor((max - hyst) + 0.5) -- Check if chanels need to be turned on if power < hyst_floor then -- get current state of relais 4 current_state_relais4 = grp.getvalue(address_relais4) if current_state_relais4 == false then grp.write(address_relais4, true) -- exit script and after that cascade to chanel 3 return end -- get current state of relais 3 current_state_relais3 = grp.getvalue(address_relais3) if current_state_relais3 == false then grp.write(address_relais3, true) -- exit script and after that cascade to chanel 2 return end -- get current state of relais 2 current_state_relais2 = grp.getvalue(address_relais2) if current_state_relais2 == false then grp.write(address_relais2, true) -- exit script and after that cascade to chanel 1 return end -- get current state of relais 1 current_state_relais1 = grp.getvalue(address_relais1) if current_state_relais1 == false then grp.write(address_relais1, true) -- exit script return end end -- Check if chanel 1 need to be turned off, after that cascade to chanel 2, then cascade to chanel 3 etcetera if power > max then -- get current state of relais 1 current_state_relais1 = grp.getvalue(address_relais1) if current_state_relais1 == true then grp.write(address_relais1, false) else -- get current state of relais 2 current_state_relais2 = grp.getvalue(address_relais2) if current_state_relais2 == true then grp.write(address_relais2, false) else -- get current state of relais 3 current_state_relais3 = grp.getvalue(address_relais3) if current_state_relais3 == true then grp.write(address_relais3, false) else -- get current state of relais 4 current_state_relais4 = grp.getvalue(address_relais4) if current_state_relais4 == true then grp.write(address_relais4, false) end end end end end
BR,

Erwin

Hi Erwin,
I have some question about this script.

1. Is this a resident script or event base script?
2 If is it a resident script which is the refresh time? In case it was a event base script, what is the event base object?
3 Power, hyst and power limit are 4 byte floating point object as per Watt?

Thank you for your help.

regards.

RE: Peak load limiter - Erwin van der Zwart - 10.12.2018

Hi,

1. Event based on the measured power
2. NA
3. Doesn’t matter, 1, 2, 4 byte is fine as all is numeric

BR,

Erwin

RE: Peak load limiter - Domoticatorino - 12.12.2018

(10.12.2018, 18:10)Erwin van der Zwart Wrote: Hi,

1. Event based on the measured power
2. NA
3. Doesn’t matter, 1, 2, 4 byte is fine as all is numeric

BR,

Erwin

Thank you Erwin. Works very good.

(10.12.2018, 18:10)Erwin van der Zwart Wrote: Hi,

1. Event based on the measured power
2. NA
3. Doesn’t matter, 1, 2, 4 byte is fine as all is numeric

BR,

Erwin

Thank you Erwin. Works very good.

RE: Peak load limiter - Erwin van der Zwart - 12.12.2018

Hi,

Here is a more complex script for load balancing, i use it for EV chargers, they can use max 63 Amp and need minimal 8 Amp, based on active chargers and available power the chargers are set to a maximum loader output over modbus (for our EVLink)

All works with TAG's on the binary state (active/not active) object and a offset of 1 in the main address (32/1/1 = State -> 32/1/1 = Set max charging output) so you can easily add multiple chargers (:

Code:
-- Get maximal available amperage

Max_Amp = grp.getvalue('35/0/10')

-- Get current messured amperage

Current_Amp = grp.getvalue('35/0/11')

-- Calculate available amperage for loaders

Available_Amp = Max_Amp - Current_Amp

-- Minimal amperage output on loader

Min_Loader_Amp = 8

-- Maximal amperage output on loader

Max_Loader_Amp = 63

-- Get all loaders on/off states 

All_Loaders = grp.tag('LoaderState')

-- Function to sort table by updatetime

local function tableSortCat (a,b)

  return a.updatetime < b.updatetime

end

-- Sort table All_Loaders by updatetime

table.sort(All_Loaders, tableSortCat)

-- Create table with active loader

Active_Loaders = {}

-- Determine amount of active loaders

Number_Active_Loaders = 0

-- Ceeate new table with values and only loader tagged bit objects

for _, item in pairs(All_Loaders) do

  if item.datatype == 1 or (item.datatype > 999 and item.datatype < 2000) then

    if item.value == true then

      Number_Active_Loaders = Number_Active_Loaders + 1

    end

    table.insert(Active_Loaders, {id = item.id, updatetime = item.updatetime, datatype = item.datatype, address = item.address, value = item.value})

  end

end

-- Sort table Active_Loaders by updatetime

table.sort(Active_Loaders, tableSortCat)

-- Determine maximum loaders based on available power

Max_Number_Loaders_Possible =  math.floor(Available_Amp / Min_Loader_Amp)

-- Check if more loaders are active then max possible loaders 

if Number_Active_Loaders < Max_Number_Loaders_Possible then

  Max_Number_Loaders_Possible = Number_Active_Loaders

end

--Set available amperage per loader

Available_Amperage_Loader_Per_Unit = math.round(Available_Amp / Max_Number_Loaders_Possible, 2)

--Check if output exceeds loaders Max_Amp

if Available_Amperage_Loader_Per_Unit > Max_Loader_Amp then

  Available_Amperage_Loader_Per_Unit = Max_Loader_Amp

end

-- Set loaders to 0 when current amperage exceeds max amperage 

if Current_Amp > Max_Amp then

    Max_Number_Loaders_Possible = 0

  Available_Amperage_Loader_Per_Unit = 0

end

-- Write values to the output of each loader

Number_Loaders_Value_Written = 0

for _, item in pairs(All_Loaders) do

  Address_Table = string.split(item.address, "/")

  New_Address = Address_Table[1]+1 .. '/' .. Address_Table[2] .. '/' .. Address_Table[3]

  if item.value == true then

    if Number_Loaders_Value_Written < Max_Number_Loaders_Possible then

        grp.checkupdate(New_Address,Available_Amperage_Loader_Per_Unit)

      Number_Loaders_Value_Written = Number_Loaders_Value_Written + 1

    else

      grp.checkupdate(New_Address,0)

    end

  else

    grp.checkupdate(New_Address,0)

  end

end

BR,

Erwin

RE: Peak load limiter - BMA - 19.02.2021

(07.12.2018, 21:19)Erwin van der Zwart Wrote: Hi,

I created this a while ago, maybe it could help you in your task.

Code:
-- Set adresses address_max = '1/1/2' address_hyst = '1/1/3' address_relais1 = '1/1/4' address_relais2 = '1/1/5' address_relais3 = '1/1/6' address_relais4 = '1/1/7' -- Get measured power power = event.getvalue() -- Get limit value max = grp.getvalue(address_max) -- Get Hysteresis hyst = grp.getvalue(address_hyst) -- Calculate floor value hyst_floor = math.floor((max - hyst) + 0.5) -- Check if chanels need to be turned on if power < hyst_floor then -- get current state of relais 4 current_state_relais4 = grp.getvalue(address_relais4) if current_state_relais4 == false then grp.write(address_relais4, true) -- exit script and after that cascade to chanel 3 return end -- get current state of relais 3 current_state_relais3 = grp.getvalue(address_relais3) if current_state_relais3 == false then grp.write(address_relais3, true) -- exit script and after that cascade to chanel 2 return end -- get current state of relais 2 current_state_relais2 = grp.getvalue(address_relais2) if current_state_relais2 == false then grp.write(address_relais2, true) -- exit script and after that cascade to chanel 1 return end -- get current state of relais 1 current_state_relais1 = grp.getvalue(address_relais1) if current_state_relais1 == false then grp.write(address_relais1, true) -- exit script return end end -- Check if chanel 1 need to be turned off, after that cascade to chanel 2, then cascade to chanel 3 etcetera if power > max then -- get current state of relais 1 current_state_relais1 = grp.getvalue(address_relais1) if current_state_relais1 == true then grp.write(address_relais1, false) else -- get current state of relais 2 current_state_relais2 = grp.getvalue(address_relais2) if current_state_relais2 == true then grp.write(address_relais2, false) else -- get current state of relais 3 current_state_relais3 = grp.getvalue(address_relais3) if current_state_relais3 == true then grp.write(address_relais3, false) else -- get current state of relais 4 current_state_relais4 = grp.getvalue(address_relais4) if current_state_relais4 == true then grp.write(address_relais4, false) end end end end end
BR,

Erwin

Hello,

A well working script, but is it a easy way to get the outputs to stay off only for 10-15 minutes a time and gets blocked to turn off for a 30-60min or something afterwards? So the it loops trough all the relay channels befor the first channel turns off again.

Bjørn