Adding parallel circuits to calculate conductors
This commit is contained in:
Jeff MacKinnon
parent
790fec2920
commit
8784a2ba89
4 changed files with 136 additions and 15 deletions
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@ -114,6 +114,43 @@
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"jmk.voltage_drop(240, 100, '2/0', material='al', num_runs=4)"
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"jmk.voltage_drop(240, 100, '2/0', material='al', num_runs=4)"
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]
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]
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},
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### Calculate conductors for specified voltage drop\n",
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"\n",
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"This next function will specify the conductor size based on the specified:\n",
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"\n",
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"- System voltage\n",
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"- Load in Amps\n",
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"- Distance in meters\n",
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"- Voltage drop percent (default 3%)\n",
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"- Number of parallel runs (default 1 run)\n"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [
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{
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"ename": "TypeError",
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"evalue": "unsupported operand type(s) for /: 'function' and 'int'",
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"output_type": "error",
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"traceback": [
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"\u001b[1;31m---------------------------------------------------------------------------\u001b[0m",
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"\u001b[1;31mTypeError\u001b[0m Traceback (most recent call last)",
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"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",
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"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",
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"\u001b[1;31mTypeError\u001b[0m: unsupported operand type(s) for /: 'function' and 'int'"
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]
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}
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],
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"source": [
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"jmk.voltage_drop_conductors(120,200,100)"
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]
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},
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{
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{
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"cell_type": "markdown",
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"cell_type": "markdown",
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"metadata": {},
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"metadata": {},
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@ -132,7 +169,7 @@
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},
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},
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{
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{
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"cell_type": "code",
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"cell_type": "code",
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"execution_count": 5,
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"execution_count": null,
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"metadata": {},
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"metadata": {},
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"outputs": [
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"outputs": [
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{
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{
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@ -159,7 +196,7 @@
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},
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},
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{
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{
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"cell_type": "code",
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"cell_type": "code",
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"execution_count": 6,
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"execution_count": null,
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"metadata": {},
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"metadata": {},
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"outputs": [
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"outputs": [
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{
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{
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@ -13,9 +13,20 @@ import math
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import sqlite3
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import sqlite3
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def vd(current,length,resistance):
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def vd(current,length,resistance,runs=1):
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vd=2*current*length*resistance/1000
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'''
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Calculates the voltage drop across the conductor length.
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If there are parallel runs we assume that they are approximately the same length.
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Therefore from the general equation of:
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1/Req = 1/R1 + 1/R2 ... and all R1-Rn are the same.
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Req = R/n or in the equation below r = resistance / runs.
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'''
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r = (length*resistance/1000) / runs
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vd=round(2*current*r,8)
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return vd
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return vd
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def percentvd(vd,nominal):
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def percentvd(vd,nominal):
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@ -24,7 +35,7 @@ def percentvd(vd,nominal):
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return percent
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return percent
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def voltage_drop(nominal_voltage, current, conductor_size, material ='cu', code = 'CEC'):
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def voltage_drop(nominal_voltage, current, conductor_size, material ='cu', num_runs = 1, code = 'CEC'):
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'''
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'''
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This function will return the drop in voltage and in percent of the supply.
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This function will return the drop in voltage and in percent of the supply.
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@ -53,19 +64,21 @@ def voltage_drop(nominal_voltage, current, conductor_size, material ='cu', code
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if (material == 'al'):
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if (material == 'al'):
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try:
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try:
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with sqlite3.connect("cable.db") as con:
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with sqlite3.connect("jepl-cable.db") as con:
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cur = con.cursor()
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cur = con.cursor()
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cur.execute('SELECT "AC Resistance" FROM "SW-Spec 25055" WHERE "Conductor Size"=?', (conductor_size,))
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cur.execute('SELECT "AC Resistance" FROM "SW-Spec 25051" WHERE "Conductor Number" = 3 AND "Conductor Size"=?', (conductor_size,))
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resistance = cur.fetchone()[0]
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resistance = cur.fetchone()[0]
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#print(resistance)
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except sqlite3.OperationalError as e:
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except sqlite3.OperationalError as e:
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print(e)
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print(e)
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elif (material == 'cu'):
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elif (material == 'cu'):
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try:
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try:
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with sqlite3.connect("cable.db") as con:
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with sqlite3.connect("jepl-cable.db") as con:
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cur = con.cursor()
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cur = con.cursor()
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cur.execute('SELECT "AC Resistance" FROM "SW-Spec 25051" WHERE "Conductor Number=3" AND "Conductor Size"=?', (conductor_size,))
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cur.execute('SELECT "AC Resistance" FROM "SW-Spec 25055" WHERE "Conductor Number" = 3 AND "Conductor Size"=?', (conductor_size,))
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resistance = cur.fetchone()[0]
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resistance = cur.fetchone()[0]
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except sqlite3.OperationalError as e:
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except sqlite3.OperationalError as e:
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@ -74,16 +87,87 @@ def voltage_drop(nominal_voltage, current, conductor_size, material ='cu', code
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else:
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else:
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return (print("error, choose material as cu or al"))
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return (print("error, choose material as cu or al"))
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voltage = vd(nominal_voltage,current,resistance)
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voltage = vd(nominal_voltage,current,resistance,num_runs)
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percent = percentvd(voltage,nominal_voltage)
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percent = percentvd(voltage,nominal_voltage)
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return [voltage, percent]
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return [voltage, percent]
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#
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# voltage_drop_conductors is wrong
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#
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#
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def voltage_drop_conductors(voltage,current,distance,v_drop_percent = 0.03,runs = 1,material='cu'):
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'''
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Calculates the minimum conductor size to accomodate for voltage drop based on:
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voltage -> system nominal voltage
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current -> the peak/design load for the circuit
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distance -> meters
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v_drop_percent -> The design voltage drop (default 0.03 or 3%)
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runs -> number of parallel runs (default 1)
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material -> the conductor material, either 'al' or 'cu'. (default 'cu')
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First we calculate the necessary resistivity:
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resistivity = ohms/km
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but the distance is 2x (there and back)
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resistivity = ohms/[(2 * distance)/1000] {ohms/km}
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ohms = v/I or v_drop_percent/current
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resistivity = (v_drop_percent/current)/[(2 * distance)/1000]
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This works for 1 run, but for parallel runs Rtot = R/n where n is the number of runs.
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in this equation we are looking for R, not Rtot, so we multiply the top by the number of runs.
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therefore:
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resistivity = [(v_drop_percent/current)*runs]/[(2 * distance)/1000]
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'''
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# Determine the resistivity needed in ohms/km
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resistivity = ((v_drop_percent/current)*runs)/((2 * distance)/1000)
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if resistivity < 0.1214:
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print("add parallel runs")
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print(resistivity)
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else:
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print(resistivity)
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import os
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import sys
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if os.path.isfile('jepl-cable.db') == False:
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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."))
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# Lookup the conductor size that meets this resistivity.
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if (material == 'al'):
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try:
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with sqlite3.connect("jepl-cable.db") as con:
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cur = con.cursor()
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cur.execute('SELECT "Conductor Size" FROM "SW-Spec 25055" WHERE "Conductor Number" = 3 AND "AC Resistance"<?', (resistivity,))
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conductor = cur.fetchone()[0]
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print(conductor)
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except sqlite3.OperationalError as e:
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print(e)
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elif (material == 'cu'):
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try:
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with sqlite3.connect("jepl-cable.db") as con:
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cur = con.cursor()
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cur.execute('SELECT "Conductor Size" FROM "SW-Spec 25051" WHERE "Conductor Number" = 3 AND "AC Resistance"<?', (resistivity,))
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conductor = cur.fetchone()[0]
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print(conductor)
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except sqlite3.OperationalError as e:
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print(e)
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else:
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return (print("error, choose material as cu or al"))
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return (conductor)
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'''
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'''
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# These functions need to be re-written with the databases.
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# These functions need to be re-written with the databases.
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'''
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'''
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@ -60,8 +60,8 @@ create_database('jepl-cec21.db',CEC21_database)
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cable_database = [
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cable_database = [
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['jepl-cable.db','SW-Spec 25055',location+'Tables/Manufacturer/SW-Spec-23055.csv'],
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['jepl-cable.db','SW-Spec 25055',location+'Tables/Manufacturer/SW-Spec-25055.csv'],
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['jepl-cable.db','SW-Spec 25051',location+'Tables/Manufacturer/SW-Spec-25055.csv'],
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['jepl-cable.db','SW-Spec 25051',location+'Tables/Manufacturer/SW-Spec-25051.csv'],
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]
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]
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create_database('jepl-cable.db',cable_database)
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create_database('jepl-cable.db',cable_database)
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@ -47,4 +47,4 @@ def panels_per_string(Vmax,Voc,beta=-0.5,temp = 25,STCtemp = 25):
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panels_per_string_max = Vmax // Vocadj
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panels_per_string_max = Vmax // Vocadj
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return panels_per_string_max
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return int(panels_per_string_max)
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