def test_triplex_secondary():
"""
Test against 1/0 AA triplex secondary cable from example 11.3 on page 463
of 'Distribution System Modeling and Analysis' by William H.Kersting,
4th edition.
"""
conductor = {
'resistance': (0.97 * (ohms / miles)).to('ohm / meters').magnitude,
'gmr': (0.0111 * feet).to('meters').magnitude,
'wire_positions': (0, 1),
}
insulation_thickness = 0.08 # inches
phase_conductor = {
**conductor,
'outside_radius':
((0.368 / 2 + insulation_thickness) * inches).to('meters').magnitude,
}
neutral_conductor = {
**conductor,
'outside_radius': (0.368 / 2 * inches).to('meters').magnitude,
}
multi_line_model = MultiLineModel({
'S1': phase_conductor,
'S2': phase_conductor,
'N': neutral_conductor
})
carsons_model = MultiConductorCarsonsEquations(multi_line_model)
assert_array_almost_equal(
calculate_impedance(carsons_model),
array([[1.5304 + 1j * 0.6132, 0.5574 + 1j * 0.4461],
[0.5574 + 1j * 0.4461, 1.5304 + 1j * 0.6132]]) *
OHM_PER_MILE_TO_OHM_PER_METER,
decimal=4)
def test_triplex_phased_cable():
"""
Test against 3/0 triplex NS75 aluminum conductor cable.
"""
phases = 'ABC'
insulation_thickness = 0.00137 # meters
phase_conductor = {
'resistance': (0.611 * (ohms / miles)).to('ohm / meters').magnitude,
'gmr': (0.014 * feet).to('meters').magnitude,
'wire_positions': (0, 5),
'outside_radius':
((0.464 / 2 * inches).to('meters').magnitude + insulation_thickness),
}
multi_line_model = MultiLineModel({ph: phase_conductor for ph in phases})
carsons_model = MultiConductorCarsonsEquations(multi_line_model)
assert_array_almost_equal(calculate_impedance(carsons_model),
array([[
4.389e-4 + 1j * 9.200e-4,
5.922e-5 + 1j * 8.277e-4,
5.922e-5 + 1j * 8.277e-4
],
[
5.922e-5 + 1j * 8.277e-4,
4.389e-4 + 1j * 9.200e-4,
5.922e-5 + 1j * 8.277e-4
],
[
5.922e-5 + 1j * 8.277e-4,
5.922e-5 + 1j * 8.277e-4,
4.389e-4 + 1j * 9.200e-4
]]),
decimal=4)
def test_multi_conductor_cable_with_neutral(phases, resistance, gmr,
wire_position, core_radius,
insulation_thickness,
expected_result):
conductor = {
'resistance':
(resistance * (ohms / miles)).to('ohm / meters').magnitude,
'gmr': (gmr * feet).to('meters').magnitude,
'wire_positions': wire_position,
}
phase_conductor = {
**conductor,
'outside_radius':
((core_radius * inches).to('meters').magnitude + insulation_thickness),
}
neutral_conductor = {
**conductor,
'outside_radius': (core_radius * inches).to('meters').magnitude,
}
line_model_dict = {ph: phase_conductor for ph in phases}
line_model_dict.update({'N': neutral_conductor})
multi_line_model = MultiLineModel(line_model_dict)
carsons_model = MultiConductorCarsonsEquations(multi_line_model)
assert_array_almost_equal(calculate_impedance(carsons_model),
expected_result,
decimal=4)
def test_2ph_concentric_neutral_cable():
"""
Validation test against OpenDSS example found in documentation
http://svn.code.sf.net/p/electricdss/code/trunk/Distrib/Doc/
'TechNote CableModelling.pdf' - Practical Example: Concentric Neutral Cable
"""
model = ConcentricNeutralCarsonsEquations(
ConcentricLineModel({
"A": {
'resistance':
(0.0776 * (ohms / kft)).to('ohm / meters').magnitude,
'gmr': (0.205 * inches).to('meters').magnitude,
'wire_positions': (0, 0)
},
"B": {
'resistance':
(0.0776 * (ohms / kft)).to('ohm / meters').magnitude,
'gmr': (0.205 * inches).to('meters').magnitude,
'wire_positions': ((6 * inches).to('meters').magnitude, 0)
},
"NA": {
'neutral_strand_gmr':
(0.02496 * inches).to('meters').magnitude,
'neutral_strand_resistance':
(2.55 * (ohms / kft)).to('ohm / meters').magnitude,
'neutral_strand_diameter':
(0.064 * inches).to('meters').magnitude,
'diameter_over_neutral':
(1.29 * inches).to('meters').magnitude,
'neutral_strand_count':
13,
},
"NB": {
'neutral_strand_gmr':
(0.02496 * inches).to('meters').magnitude,
'neutral_strand_resistance':
(2.55 * (ohms / kft)).to('ohm / meters').magnitude,
'neutral_strand_diameter':
(0.064 * inches).to('meters').magnitude,
'diameter_over_neutral':
(1.29 * inches).to('meters').magnitude,
'neutral_strand_count':
13,
},
}))
assert_array_almost_equal(
calculate_impedance(model),
array([
[0.867953 + 1j * 0.442045, 0.389392 + 1j * 0.0511399, 0 + 1j * 0],
[0.389392 + 1j * 0.0511399, 0.867953 + 1j * 0.442045, 0 + 1j * 0],
[0 + 1j * 0, 0 + 1j * 0, 0 + 1j * 0],
]) * OHM_PER_MILE_TO_OHM_PER_METER,
decimal=4)
def test_concentric_neutral_cable_IEEE37():
"""
Validation test against IEEE37 network underground cable configuration 723.
"""
model = ConcentricNeutralCarsonsEquations(
ConcentricLineModel({
"A": {
'resistance':
(0.7690 * (ohms / miles)).to('ohm / meters').magnitude,
'gmr': (0.0125 * feet).to('meters').magnitude,
'wire_positions': (0, 0)
},
"B": {
'resistance':
(0.7690 * (ohms / miles)).to('ohm / meters').magnitude,
'gmr': (0.0125 * feet).to('meters').magnitude,
'wire_positions': ((6 * inches).to('meters').magnitude, 0)
},
"C": {
'resistance':
(0.7690 * (ohms / miles)).to('ohm / meters').magnitude,
'gmr': (0.0125 * feet).to('meters').magnitude,
'wire_positions': ((12 * inches).to('meters').magnitude, 0)
},
"NA": {
'neutral_strand_gmr': (0.00208 * feet).to('meters').magnitude,
'neutral_strand_resistance':
(14.87 * ohms / miles).to('ohm / meters').magnitude,
'neutral_strand_diameter':
(0.0641 * inches).to('meters').magnitude,
'diameter_over_neutral':
(1.10 * inches).to('meters').magnitude,
'neutral_strand_count':
7,
},
"NB": {
'neutral_strand_gmr': (0.00208 * feet).to('meters').magnitude,
'neutral_strand_resistance':
(14.87 * ohms / miles).to('ohm / meters').magnitude,
'neutral_strand_diameter':
(0.0641 * inches).to('meters').magnitude,
'diameter_over_neutral':
(1.10 * inches).to('meters').magnitude,
'neutral_strand_count':
7,
},
"NC": {
'neutral_strand_gmr': (0.00208 * feet).to('meters').magnitude,
'neutral_strand_resistance':
(14.87 * ohms / miles).to('ohm / meters').magnitude,
'neutral_strand_diameter':
(0.0641 * inches).to('meters').magnitude,
'diameter_over_neutral':
(1.10 * inches).to('meters').magnitude,
'neutral_strand_count':
7,
},
}))
assert_array_almost_equal(
calculate_impedance(model),
array([
[1.2936 + 1j * 0.6713, 0.4871 + 1j * 0.2111, 0.4585 + 1j * 0.1521],
[0.4871 + 1j * 0.2111, 1.3022 + 1j * 0.6326, 0.4871 + 1j * 0.2111],
[0.4585 + 1j * 0.1521, 0.4871 + 1j * 0.2111, 1.2936 + 1j * 0.6713],
]) * OHM_PER_MILE_TO_OHM_PER_METER,
decimal=4)
def test_concentric_neutral_cable():
"""
Validation test against example in Kersting's book.
"""
model = ConcentricNeutralCarsonsEquations(
ConcentricLineModel({
"A": {
'resistance':
(0.4100 * (ohms / miles)).to('ohm / meters').magnitude,
'gmr': (0.0171 * feet).to('meters').magnitude,
'wire_positions': (0, 0)
},
"B": {
'resistance':
(0.4100 * (ohms / miles)).to('ohm / meters').magnitude,
'gmr': (0.0171 * feet).to('meters').magnitude,
'wire_positions': ((6 * inches).to('meters').magnitude, 0)
},
"C": {
'resistance':
(0.4100 * (ohms / miles)).to('ohm / meters').magnitude,
'gmr': (0.0171 * feet).to('meters').magnitude,
'wire_positions': ((12 * inches).to('meters').magnitude, 0)
},
"NA": {
'neutral_strand_gmr': (0.00208 * feet).to('meters').magnitude,
'neutral_strand_resistance':
(14.87 * ohms / miles).to('ohm / meters').magnitude,
'neutral_strand_diameter':
(0.0641 * inches).to('meters').magnitude,
'diameter_over_neutral':
(1.29 * inches).to('meters').magnitude,
'neutral_strand_count':
13,
},
"NB": {
'neutral_strand_gmr': (0.00208 * feet).to('meters').magnitude,
'neutral_strand_resistance':
(14.87 * ohms / miles).to('ohm / meters').magnitude,
'neutral_strand_diameter':
(0.0641 * inches).to('meters').magnitude,
'diameter_over_neutral':
(1.29 * inches).to('meters').magnitude,
'neutral_strand_count':
13,
},
"NC": {
'neutral_strand_gmr': (0.00208 * feet).to('meters').magnitude,
'neutral_strand_resistance':
(14.87 * ohms / miles).to('ohm / meters').magnitude,
'neutral_strand_diameter':
(0.0641 * inches).to('meters').magnitude,
'diameter_over_neutral':
(1.29 * inches).to('meters').magnitude,
'neutral_strand_count':
13,
},
}))
assert_array_almost_equal(
calculate_impedance(model),
array([
[0.7981 + 1j * 0.4467, 0.3188 + 1j * 0.0334, 0.2848 + 1j * 0.0138],
[0.3188 + 1j * 0.0334, 0.7890 + 1j * 0.4048, 0.3188 + 1j * 0.0334],
[0.2848 + 1j * 0.0138, 0.3188 + 1j * 0.0334, 0.7981 + 1j * 0.4467],
]) * OHM_PER_MILE_TO_OHM_PER_METER,
decimal=4)