Peak load limiter

[Erwin van der Zwart]

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:

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-- 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