JMK_Engineering_Inc/JEPL
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Adding parallel circuits to calculate conductors

Browse source
This commit is contained in:
Jeff MacKinnon 2024-12-15 20:19:11 -04:00
parent 790fec2920
commit 8784a2ba89
4 changed files with 136 additions and 15 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

41
example_notebook.ipynb
View file

@ -114,6 +114,43 @@
"jmk.voltage_drop(240, 100, '2/0', material='al', num_runs=4)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### Calculate conductors for specified voltage drop\n",
"\n",
"This next function will specify the conductor size based on the specified:\n",
"\n",
"- System voltage\n",
"- Load in Amps\n",
"- Distance in meters\n",
"- Voltage drop percent (default 3%)\n",
"- Number of parallel runs (default 1 run)\n"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {},
"outputs": [
{
"ename": "TypeError",
"evalue": "unsupported operand type(s) for /: 'function' and 'int'",
"output_type": "error",
"traceback": [
"\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
"\u001b[1;31mTypeError\u001b[0m Traceback (most recent call last)",
"Input \u001b[1;32mIn [5]\u001b[0m, in \u001b[0;36m<cell line: 1>\u001b[1;34m()\u001b[0m\n\u001b[1;32m----> 1\u001b[0m \u001b[43mjmk\u001b[49m\u001b[38;5;241;43m.\u001b[39;49m\u001b[43mvoltage_drop_conductors\u001b[49m\u001b[43m(\u001b[49m\u001b[38;5;241;43m120\u001b[39;49m\u001b[43m,\u001b[49m\u001b[38;5;241;43m200\u001b[39;49m\u001b[43m,\u001b[49m\u001b[38;5;241;43m100\u001b[39;49m\u001b[43m,\u001b[49m\u001b[43mv_drop_percent\u001b[49m\u001b[43m \u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43m \u001b[49m\u001b[38;5;241;43m0.03\u001b[39;49m\u001b[43m,\u001b[49m\u001b[43mruns\u001b[49m\u001b[43m \u001b[49m\u001b[38;5;241;43m=\u001b[39;49m\u001b[43m \u001b[49m\u001b[38;5;241;43m1\u001b[39;49m\u001b[43m)\u001b[49m\n",
"File \u001b[1;32mc:\\Business\\JMKEngineering\\Engineering\\Active\\TEP Group\\24xx_TEP_Shubie-tower-project\\eng\\resources\\JEPL\\jepl\\jepl_circuits.py:124\u001b[0m, in \u001b[0;36mvoltage_drop_conductors\u001b[1;34m(voltage, current, distance, v_drop_percent, runs, material)\u001b[0m\n\u001b[0;32m 96\u001b[0m \u001b[38;5;250m\u001b[39m\u001b[38;5;124;03m'''\u001b[39;00m\n\u001b[0;32m 97\u001b[0m \u001b[38;5;124;03m Calculates the minimum conductor size to accomodate for voltage drop based on:\u001b[39;00m\n\u001b[0;32m 98\u001b[0m \n\u001b[1;32m (...)\u001b[0m\n\u001b[0;32m 119\u001b[0m \n\u001b[0;32m 120\u001b[0m \u001b[38;5;124;03m'''\u001b[39;00m\n\u001b[0;32m 123\u001b[0m \u001b[38;5;66;03m# Determine the resistivity needed in ohms/km\u001b[39;00m\n\u001b[1;32m--> 124\u001b[0m resistivity \u001b[38;5;241m=\u001b[39m ((\u001b[43mvd\u001b[49m\u001b[38;5;241;43m/\u001b[39;49m\u001b[43mcurrent\u001b[49m)\u001b[38;5;241m/\u001b[39mruns)\u001b[38;5;241m/\u001b[39m((\u001b[38;5;241m2\u001b[39m \u001b[38;5;241m*\u001b[39m distance)\u001b[38;5;241m/\u001b[39m\u001b[38;5;241m1000\u001b[39m)\n\u001b[0;32m 125\u001b[0m \u001b[38;5;28mprint\u001b[39m(resistivity)\n\u001b[0;32m 127\u001b[0m \u001b[38;5;28;01mimport\u001b[39;00m \u001b[38;5;21;01mos\u001b[39;00m\n",
"\u001b[1;31mTypeError\u001b[0m: unsupported operand type(s) for /: 'function' and 'int'"
]
}
],
"source": [
"jmk.voltage_drop_conductors(120,200,100)"
]
},
{
"cell_type": "markdown",
"metadata": {},
@ -132,7 +169,7 @@
},
{
"cell_type": "code",
"execution_count": 5,
"execution_count": null,
"metadata": {},
"outputs": [
{
@ -159,7 +196,7 @@
},
{
"cell_type": "code",
"execution_count": 6,
"execution_count": null,
"metadata": {},
"outputs": [
{

102
jepl/jepl_circuits.py
View file

@ -13,9 +13,20 @@ import math
import sqlite3
def vd(current,length,resistance):
def vd(current,length,resistance,runs=1):
vd=2*current*length*resistance/1000
'''
Calculates the voltage drop across the conductor length.
If there are parallel runs we assume that they are approximately the same length.
Therefore from the general equation of:
1/Req = 1/R1 + 1/R2 ... and all R1-Rn are the same.
Req = R/n or in the equation below r = resistance / runs.
'''
r = (length*resistance/1000) / runs
vd=round(2*current*r,8)
return vd
def percentvd(vd,nominal):
@ -24,7 +35,7 @@ def percentvd(vd,nominal):
return percent
def voltage_drop(nominal_voltage, current, conductor_size, material ='cu', code = 'CEC'):
def voltage_drop(nominal_voltage, current, conductor_size, material ='cu', num_runs = 1, code = 'CEC'):
'''
This function will return the drop in voltage and in percent of the supply.
@ -53,19 +64,21 @@ def voltage_drop(nominal_voltage, current, conductor_size, material ='cu', code
if (material == 'al'):
try:
with sqlite3.connect("cable.db") as con:
with sqlite3.connect("jepl-cable.db") as con:
cur = con.cursor()
cur.execute('SELECT "AC Resistance" FROM "SW-Spec 25055" WHERE "Conductor Size"=?', (conductor_size,))
cur.execute('SELECT "AC Resistance" FROM "SW-Spec 25051" WHERE "Conductor Number" = 3 AND "Conductor Size"=?', (conductor_size,))
resistance = cur.fetchone()[0]
#print(resistance)
except sqlite3.OperationalError as e:
print(e)
elif (material == 'cu'):
try:
with sqlite3.connect("cable.db") as con:
with sqlite3.connect("jepl-cable.db") as con:
cur = con.cursor()
cur.execute('SELECT "AC Resistance" FROM "SW-Spec 25051" WHERE "Conductor Number=3" AND "Conductor Size"=?', (conductor_size,))
cur.execute('SELECT "AC Resistance" FROM "SW-Spec 25055" WHERE "Conductor Number" = 3 AND "Conductor Size"=?', (conductor_size,))
resistance = cur.fetchone()[0]
except sqlite3.OperationalError as e:
@ -74,16 +87,87 @@ def voltage_drop(nominal_voltage, current, conductor_size, material ='cu', code
else:
return (print("error, choose material as cu or al"))
voltage = vd(nominal_voltage,current,resistance)
voltage = vd(nominal_voltage,current,resistance,num_runs)
percent = percentvd(voltage,nominal_voltage)
return [voltage, percent]
#
# voltage_drop_conductors is wrong
#
#
def voltage_drop_conductors(voltage,current,distance,v_drop_percent = 0.03,runs = 1,material='cu'):
'''
Calculates the minimum conductor size to accomodate for voltage drop based on:
voltage -> system nominal voltage
current -> the peak/design load for the circuit
distance -> meters
v_drop_percent -> The design voltage drop (default 0.03 or 3%)
runs -> number of parallel runs (default 1)
material -> the conductor material, either 'al' or 'cu'. (default 'cu')
First we calculate the necessary resistivity:
resistivity = ohms/km
but the distance is 2x (there and back)
resistivity = ohms/[(2 * distance)/1000] {ohms/km}
ohms = v/I or v_drop_percent/current
resistivity = (v_drop_percent/current)/[(2 * distance)/1000]
This works for 1 run, but for parallel runs Rtot = R/n where n is the number of runs.
in this equation we are looking for R, not Rtot, so we multiply the top by the number of runs.
therefore:
resistivity = [(v_drop_percent/current)*runs]/[(2 * distance)/1000]
'''
'''
# Determine the resistivity needed in ohms/km
resistivity = ((v_drop_percent/current)*runs)/((2 * distance)/1000)
if resistivity < 0.1214:
print("add parallel runs")
print(resistivity)
else:
print(resistivity)
import os
import sys
if os.path.isfile('jepl-cable.db') == False:
return (print("Run init. \nCopy jeplinit.py to the same folder as this file and add \n%run jeplinit.py jepl/folder/location/\nto the notebook. Make sure there is a trailing slash."))
# Lookup the conductor size that meets this resistivity.
if (material == 'al'):
try:
with sqlite3.connect("jepl-cable.db") as con:
cur = con.cursor()
cur.execute('SELECT "Conductor Size" FROM "SW-Spec 25055" WHERE "Conductor Number" = 3 AND "AC Resistance"<?', (resistivity,))
conductor = cur.fetchone()[0]
print(conductor)
except sqlite3.OperationalError as e:
print(e)
elif (material == 'cu'):
try:
with sqlite3.connect("jepl-cable.db") as con:
cur = con.cursor()
cur.execute('SELECT "Conductor Size" FROM "SW-Spec 25051" WHERE "Conductor Number" = 3 AND "AC Resistance"<?', (resistivity,))
conductor = cur.fetchone()[0]
print(conductor)
except sqlite3.OperationalError as e:
print(e)
else:
return (print("error, choose material as cu or al"))
return (conductor)
# These functions need to be re-written with the databases.
'''

4
jepl/jeplinit.py
View file

@ -60,8 +60,8 @@ create_database('jepl-cec21.db',CEC21_database)
cable_database = [
['jepl-cable.db','SW-Spec 25055',location+'Tables/Manufacturer/SW-Spec-23055.csv'],
['jepl-cable.db','SW-Spec 25051',location+'Tables/Manufacturer/SW-Spec-25055.csv'],
['jepl-cable.db','SW-Spec 25055',location+'Tables/Manufacturer/SW-Spec-25055.csv'],
['jepl-cable.db','SW-Spec 25051',location+'Tables/Manufacturer/SW-Spec-25051.csv'],
]
create_database('jepl-cable.db',cable_database)

2
jepl/jeplpv.py
View file

@ -47,4 +47,4 @@ def panels_per_string(Vmax,Voc,beta=-0.5,temp = 25,STCtemp = 25):
panels_per_string_max = Vmax // Vocadj
return panels_per_string_max
return int(panels_per_string_max)