Cosim of Python and Eplus

This document show how to specify the path of python script and conduct co-simulation with EnergyPlus .

Here is the python code

"""
    This python script is the example of CosimR to show how to do co-simulation with EnergyPlus
    Package: CosimR
    Github: https://github.com/jywang2016/CosimR
    Author: Jiangyu Wang
    Date: 11th Dec, 2018
    Email: jywang_2016@hust.edu.cn
    Reference: schedule example in BCVTB
"""

import re
import sys

string = sys.argv[1]
time = sys.argv[2]
iter = sys.argv[3]

m = re.findall(r"\d+\.?\d*",string)

tout = float(m[0])

# input const -----------------------
dayStart = 6*3600
nightStart = 16*3600
TCNight = 30
TCRooLow = 22
TCRooHig = 26

TCOutLow = 20
TCOutHig = 24

THDay = 20
THNight = 16

# temp set logic ----------------------
time = int(float(time))

ToutDif = tout - TCOutLow

TSetCooOn = TCRooLow + ToutDif * (TCRooHig - TCRooLow)/(TCOutHig - TCOutLow)
TCDay = max(TCRooLow,min(TCRooHig,TSetCooOn))

if time % 86400 > dayStart and time % 86400 < nightStart:
    THSetPoi = THDay
    TCSetPoi = TCDay
else:
    THSetPoi = THNight
    TCSetPoi = TCNight

strs = [str(THSetPoi),str(TCSetPoi),' ']

sys.stdout.write(','.join(strs))

Suppose the python code Cosim.py will be placed into the python folder under the xmlpath = 'D:/bcvtb/examples/CosimRtest'.

Co-simulation by using CosimR

library(CosimR)

Step1: generate the .xml file

xmlpath = 'D:/bcvtb/examples/CosimRtest'
copy_xml(xmlpath = xmlpath)

## CosimR.xml is copied to D:/bcvtb/examples/CosimRtest successfully!

Step2: modify the .xml file

file.copy(from = system.file("extdata/Cosim.py", package = "CosimR"),
          to = paste0(xmlpath,'/python'),
          overwrite = TRUE)

## [1] TRUE

xmlroot<- modify_xml(xmlpath = xmlpath,
                     timeStep = 15*60, 
                     beginTime = 3*24*3600,
                     endTime = 4*24*3600,
                     extractLength = 2,
                     idf = paste0(xmlpath,'/SmOffPSZ.idf'),
                     epw = 'D:/bcvtb/examples/ePlusWeather/USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw',
                     outname = 'eplusout',
                     programname = 'python',
                     programArgs = 'Cosim.py',
                     workingDir = paste0(xmlpath,'/python'),
                     cpp = FALSE)

## Part1: Cosim time set modify >>>>>>>>>

## timeStep: 900 beginTime: 259200 endTime: 345600

## Part2: ArrayExtract actor pram.args modify >>>>>>>>>

## extractLength: 2 outputArrayLength: 2

## Part3: EnergyPlus Simulator pram.args modify >>>>>>>>>

## energyplus command: " -w D:/bcvtb/examples/ePlusWeather/USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.epw -p eplusout -s C -x -m -r D:/bcvtb/examples/CosimRtest/SmOffPSZ.idf "

## Part4: SystemCommand pram.args modify >>>>>>>>>

## programname: python 
## programArgs: "D:/bcvtb/examples/CosimRtest/python/Cosim.py $input $time $iteration" 
## workingDir: D:/bcvtb/examples/CosimRtest/python 
## simulationLog: D:/bcvtb/examples/CosimRtest/python/simulation.log

## ---------------- Modification End ----------------

Step3: save the .xml file

write_xml(rootnode = xmlroot,
          xmlpath = xmlpath,
          output = 'new.xml')

## new.xml is written successfully!

Step4: run the .xml file

run_Cosim(bcvtbpath = 'D:/bcvtb',
          xmlpath = xmlpath,
          output = 'new.xml')

Add plotter in BCVTB manually

Plotter block is not included in the .xml template file provided in the CosimR package. If you want see the results in real time, add plotter block in BCVTB manually is a good choice.