def test_parallel_connected_mj_cells(self):
"""
Connected two triple-junction cells in parallel
:return:
"""
sq1_cell = SQCell(eg=1.87, cell_T=300, plug_in_term=rev_breakdown_diode)
sq2_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_breakdown_diode)
sq3_cell = SQCell(eg=1.0, cell_T=300, plug_in_term=rev_breakdown_diode)
tj_cell = MJCell([sq1_cell, sq2_cell, sq3_cell])
tj_cell.set_input_spectrum(load_astm(("AM1.5d")))
tj_cell_1 = copy.deepcopy(tj_cell)
tj_cell_2 = copy.deepcopy(tj_cell)
iv_funcs = [tj_cell_1.get_j_from_v, tj_cell_2.get_j_from_v]
parallel_v, parallel_i = solve_parallel_connected_ivs(iv_funcs, vmin=-2, vmax=3.5, vnum=30)
volt = np.linspace(-2, 3.5, num=30)
curr = tj_cell_1.get_j_from_v(volt)
plt.plot(volt, curr, '.-', label="single string")
plt.plot(parallel_v, parallel_i, '.-', label="strings connected in parallel")
plt.ylim([-600, 0])
plt.show()
def test_mj_j_from_v(self):
"""
Test MJCell.get_j_from_v()
:return:
"""
sq1_cell = SQCell(eg=1.87, cell_T=300, plug_in_term=rev_diode)
sq2_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq3_cell = SQCell(eg=1.0, cell_T=300, plug_in_term=rev_diode)
tj_cell = MJCell([sq1_cell, sq2_cell, sq3_cell])
tj_cell.set_input_spectrum(load_astm(("AM1.5d")))
solved_mj_v, solved_mj_i = tj_cell.get_iv()
volt = np.linspace(2.5, 5, num=300)
solved_current = tj_cell.get_j_from_v(volt, max_iter=3)
interped_i = np.interp(volt, solved_mj_v, solved_mj_i)
print(solved_current - interped_i)
plt.plot(volt, interped_i, '.-')
plt.plot(solved_mj_v, solved_mj_i, '.-')
plt.plot(volt, solved_current, '.-', label='get_j_from_v', alpha=0.3)
plt.ylim([-200, 0])
plt.legend()
plt.show()
def test_series_connected_mj_cells(self):
"""
Test three series-connected triple-junction cells.
We break them down into nine series-connected subcells and perform ```solve_series_connected_ivs()```
:return:
"""
sq1_cell = SQCell(eg=1.87, cell_T=300, plug_in_term=rev_diode)
sq2_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq3_cell = SQCell(eg=1.0, cell_T=300, plug_in_term=rev_diode)
tj_cell = MJCell([sq1_cell, sq2_cell, sq3_cell])
tj_cell.set_input_spectrum(load_astm(("AM1.5d")))
# Set up the MJCell() first. The purpose is only for calculating the transmitted spectrum
# and the photocurrent of each subcell. We don't use the MJCell.get_j_from_v() to solve the I-V
connected_cells = []
number_of_mjcell = 3
multi = np.array([0, 0.25, 0.5])
for i in range(number_of_mjcell):
# Need copy.deepcopy to also copy the subcells
c_tj_cell = copy.deepcopy(tj_cell)
# multi = np.random.random() * 0.5
c_tj_cell.set_input_spectrum(load_astm("AM1.5d") * (1 + multi[i]))
connected_cells.append(c_tj_cell)
# Extract each subcell, make them into series-connected cells
# Connect all the subcells in series
iv_funcs = []
for mj_cells in connected_cells:
for subcell in mj_cells.subcell:
iv_funcs.append(subcell.get_j_from_v)
reverse_plot = True
if reverse_plot:
rev_fac = -1
else:
rev_fac =1
from pypvcell.fom import isc
for idx, cell in enumerate(connected_cells):
v, i = cell.get_iv()
print(isc(v, i * rev_fac))
plt.plot(v, i * rev_fac, label="MJ cell {}".format(idx + 1))
iv_pair = solve_series_connected_ivs(iv_funcs, vmin=-1, vmax=3.5, vnum=300)
plt.plot(iv_pair[0], iv_pair[1] * rev_fac, '.-', label="Connected I-V")
plt.ylim(sorted([-300 * rev_fac, 0]))
plt.xlim([-10, 12])
plt.xlabel("voltage (V)")
plt.ylabel("current (A/m^2)")
plt.legend()
plt.savefig("./tests_output/Mjx3_demo.png", dpi=300)
plt.show()
def test_two_connected_mj_cells(self):
"""
Test three series-connected triple-junction cells.
We use MJCells.get_j_from_v() as the iv_func of the bracket-based root-finding solver.
Warning: this is slow.
:return:
"""
sq1_cell = SQCell(eg=1.87, cell_T=300, plug_in_term=rev_diode)
sq2_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq3_cell = SQCell(eg=1.0, cell_T=300, plug_in_term=rev_diode)
tj_cell = MJCell([sq1_cell, sq2_cell, sq3_cell])
tj_cell.set_input_spectrum(load_astm(("AM1.5d")))
tj_cell_1 = copy.deepcopy(tj_cell)
tj_cell_2 = copy.deepcopy(tj_cell)
iv_funcs = [tj_cell_1.get_j_from_v, tj_cell_2.get_j_from_v]
# solved_v,solved_i=solve_series_connected_ivs(iv_funcs, vmin=-2, vmax=3, vnum=10)
volt_range = np.linspace(-1, 4, num=25)
curr_range = tj_cell_1.get_j_from_v(volt_range)
from scipy.optimize import brentq
solved_v, solved_i = solve_v_from_j_by_bracket_root_finding(iv_funcs[0], curr_range, -5, 5, brentq)
plt.plot(solved_v, solved_i, '.-')
plt.ylim([-300, 0])
plt.show()
def test_mjcell(self):
sq_ingap = SQCell(eg=1.9, cell_T=293)
sq_gaas = SQCell(eg=1.42, cell_T=293)
dj_cell = MJCell([sq_ingap, sq_gaas])
dj_cell.set_input_spectrum(self.input_ill)
print("2J eta:%s" % dj_cell.get_eta())
def test_3jcell(self):
sq_ingap = SQCell(eg=1.9, cell_T=293)
sq_gaas = SQCell(eg=1.42, cell_T=293)
sq_ge = SQCell(eg=0.67, cell_T=293)
tj_cell = MJCell([sq_ingap, sq_gaas, sq_ge])
tj_cell.set_input_spectrum(self.input_ill)
print("3J eta: %s" % tj_cell.get_eta())
def test_mj_cell_iv(self):
"""
Test solving multi-junction cells, by breaking it down into series-connected subcells.
:return:
"""
sq1_cell = SQCell(eg=1.87, cell_T=300, plug_in_term=rev_breakdown_diode)
sq2_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_breakdown_diode)
sq3_cell = SQCell(eg=1.0, cell_T=300, plug_in_term=rev_breakdown_diode)
tj_cell = MJCell([sq1_cell, sq2_cell, sq3_cell])
tj_cell.set_input_spectrum(load_astm(("AM1.5d")))
solved_mj_v, solved_mj_i = tj_cell.get_iv()
# plot the I-V of sq1,sq2 and sq3
volt = np.linspace(-3, 3, num=300)
plt.plot(volt, sq1_cell.get_j_from_v(volt), label="top cell")
plt.plot(volt, sq2_cell.get_j_from_v(volt), label="middle cell")
plt.plot(volt, sq3_cell.get_j_from_v(volt), label="bottom cell")
plt.plot(solved_mj_v, solved_mj_i, '.-', label="MJ cell")
plt.ylim([-200, 0])
plt.xlim([-5, 6])
plt.xlabel("voltage (V)")
plt.ylabel("currnet (A/m^2)")
plt.legend()
plt.show()
def test_parallel_connected_mj_cells_2(self):
"""
Try connecting two strings of cells. All are Eg=1.42 SQCell.
Each string has five cells. One string has a cell has only 0.5 sun.
:return:
"""
normal_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
normal_cell.set_input_spectrum(load_astm("AM1.5d"))
low_current_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
low_current_cell.set_input_spectrum(load_astm("AM1.5d") * 0.5)
# A trick is used here to configure MJCell. The MJCell is not illuminated.
# But each of the subcell is illuminated individually.
tj_cell_1 = MJCell([copy.deepcopy(normal_cell) for i in range(4)] + [copy.deepcopy(low_current_cell)])
tj_cell_2 = MJCell([copy.deepcopy(normal_cell) for i in range(5)])
iv_funcs = [tj_cell_1.get_j_from_v, tj_cell_2.get_j_from_v]
parallel_v, parallel_i = solve_parallel_connected_ivs(iv_funcs, vmin=-2, vmax=6, vnum=30)
volt = np.linspace(-2, 6, num=30)
curr_1 = tj_cell_1.get_j_from_v(volt)
curr_2 = tj_cell_2.get_j_from_v(volt)
plt.plot(volt, curr_1, '.-', label="string 1")
plt.plot(volt, curr_2, '.-', label="string 2")
plt.plot(parallel_v, parallel_i, '.-', label="parallel-connected string")
plt.ylim([-600, 0])
plt.legend()
plt.show()
def test_dbcell(self):
gaas_qe = gen_step_qe(1.42, 1)
gaas_db = DBCell(qe=gaas_qe, rad_eta=1, T=300)
gaas_db.set_input_spectrum(load_astm("AM1.5g"))
gaas_db_eta = gaas_db.get_eta()
sq_gaas = SQCell(eg=1.42, cell_T=300)
sq_gaas.set_input_spectrum(load_astm("AM1.5g"))
sq_gaas_eta = sq_gaas.get_eta()
self.assertTrue(np.isclose(gaas_db_eta, sq_gaas_eta, rtol=5e-3))
def test_sqcell_transmission(self):
sq_cell = SQCell(eg=1.42, cell_T=293, n_c=1, n_s=1)
sq_cell.set_input_spectrum(input_spectrum=self.input_ill)
sp = sq_cell.get_transmit_spectrum()
sp_arr = sp.get_spectrum(to_x_unit='eV')
for i in range(sp_arr.shape[1]):
if sp_arr[0, i] > 1.42:
self.assertEqual(sp_arr[1, i], 0)
if False:
plt.plot(sp_arr[0, :], sp_arr[1, :])
plt.show()
def with_reverse_diode(plot_arrow=False):
sq1_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq1_cell.set_input_spectrum(load_astm("AM1.5d") * 0.5)
sq2_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq2_cell.set_input_spectrum(load_astm("AM1.5d"))
sq3_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq3_cell.set_input_spectrum(load_astm("AM1.5d") * 1.1)
iv_funcs = [
sq1_cell.get_j_from_v, sq2_cell.get_j_from_v, sq3_cell.get_j_from_v
]
volt = np.linspace(-3, 2, num=300)
arrow_dx = volt + 1.0
arrow_dy = np.zeros_like(volt)
plt.plot(volt, sq1_cell.get_j_from_v(volt), '.-', label="cell 1")
prev_current = None
if plot_arrow:
for v in volt:
current = sq1_cell.get_j_from_v(v)
if (prev_current is None) or (np.isclose(
current, prev_current, rtol=5e-2) == False):
plt.arrow(v,
sq1_cell.get_j_from_v(v),
2.0 - v,
0,
color='C0',
linestyle='--')
prev_current = current
plt.plot(volt, sq2_cell.get_j_from_v(volt), '.-', label="cell 2")
prev_current = None
if plot_arrow:
for v in volt:
current = sq2_cell.get_j_from_v(v)
if (prev_current is None) or (np.isclose(
current, prev_current, rtol=5e-2) == False):
plt.arrow(v,
sq2_cell.get_j_from_v(v),
2.0 - v,
0,
color='C1',
linestyle='--')
prev_current = v
plt.plot(volt, sq3_cell.get_j_from_v(volt), '.-', label="cell 3")
prev_current = None
if plot_arrow:
for v in volt:
current = sq3_cell.get_j_from_v(v)
if (prev_current is None) or (np.isclose(
current, prev_current, rtol=5e-2) == False):
plt.arrow(v,
sq3_cell.get_j_from_v(v),
2.0 - v,
0,
color='C2',
linestyle='--')
prev_current = v
plt.ylim([-350, 0])
plt.xlim([-1.5, 4])
plt.xlabel("voltage (V)")
plt.ylabel("current (A/m^2)")
plt.legend()
plt.savefig("./figs/with_rev_diode_iv.png", dpi=600)
plt.savefig("./figs/with_rev_diode_iv.pdf")
plt.show()
plt.close()
plt.figure()
solved_iv, subcell_ivs = solve_series_connected_ivs(iv_funcs,
-2,
3,
100,
return_subcell_iv=True,
add_epsilon=0.0)
# plot sub cell I-Vs
for subcell_id in range(3):
plt.plot(subcell_ivs[subcell_id, 0, :],
subcell_ivs[subcell_id, 1, :],
'.-',
label="cell {}".format(subcell_id + 1))
# plot summed up the voltages
plt.plot(solved_iv[0], solved_iv[1], '.-', label="connected cell")
plt.ylim([-350, 0])
plt.xlim([-3, 4])
plt.xlabel("voltage (V)")
plt.ylabel("current (A/m^2)")
plt.legend()
plt.savefig("./figs/with_rev_diode_iv_solved.png", dpi=600)
plt.savefig("./figs/with_rev_diode_iv_solved.pdf")
plt.show()
def no_reverse_diode():
sq1_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=None)
sq1_cell.set_input_spectrum(load_astm("AM1.5d") * 0.5)
sq2_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=None)
sq2_cell.set_input_spectrum(load_astm("AM1.5d"))
sq3_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=None)
sq3_cell.set_input_spectrum(load_astm("AM1.5d") * 1.1)
iv_funcs = [
sq1_cell.get_j_from_v, sq2_cell.get_j_from_v, sq3_cell.get_j_from_v
]
volt = np.linspace(-1, 2, num=300)
plt.plot(volt, sq1_cell.get_j_from_v(volt), '.-', label="cell 1")
plt.plot(volt, sq2_cell.get_j_from_v(volt), '.-', label="cell 2")
plt.plot(volt, sq3_cell.get_j_from_v(volt), '.-', label="cell 3")
plt.ylim([-350, 0])
plt.xlim([-1.5, 4])
plt.xlabel("voltage (V)")
plt.ylabel("current (A/m^2)")
plt.legend()
plt.savefig("./figs/no_rev_diode_iv.png", dpi=300)
plt.savefig("./figs/no_rev_diode_iv.pdf")
plt.show()
plt.close()
plt.figure()
current_to_solve = sq1_cell.get_j_from_v(volt)
current_to_solve = np.unique(current_to_solve)
# plt.plot(volt, sq1_cell.get_j_from_v(volt),'.-',label="cell 1")
sum_v = np.zeros_like(current_to_solve)
for idx, iv_func in enumerate(iv_funcs[0:]):
v, i = solve_v_from_j_by_bracket_root_finding(iv_func,
current_to_solve, -3, 5,
bisect)
sum_v += v
plt.plot(v, i, '.-', label="solved cell {}".format(idx + 1))
# plot summed up the voltages
plt.plot(sum_v, current_to_solve, '.-', label="connected cell")
plt.ylim([-350, 0])
plt.xlim([-1.5, 4])
plt.xlabel("voltage (V)")
plt.ylabel("current (A/m^2)")
plt.legend()
plt.savefig("./figs/no_rev_diode_iv_solved.png", dpi=300)
plt.savefig("./figs/no_rev_diode_iv_solved.pdf")
plt.show()
from pypvcell.solarcell import SQCell
import numpy as np
import matplotlib.pyplot as plt
import scipy.constants as sc
from pypvcell.illumination import load_astm
def rev_diode(voltage):
rev_j01 = 4.46e-19
rev_bd_v = 20
return -rev_j01 * np.exp(sc.e * (-voltage - rev_bd_v) / (sc.k * 300) - 1)
sq1_cell = SQCell(eg=1.3, cell_T=300, plug_in_term=rev_diode)
sq1_cell.set_input_spectrum(load_astm("AM1.5d"))
test_v = np.linspace(-21, 1.5, num=100)
test_j = sq1_cell.get_j_from_v(test_v)
print(test_j)
# model reverse breakdown
print(sq1_cell.j01)
plt.plot(test_v, test_j)
plt.show()
plt.close()
def test_solving_five_cells(self):
"""
Test five series-connected, non-uniform illuminated, Eg=1.42 solar cells
:return:
"""
sq1_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq1_cell.set_input_spectrum(load_astm("AM1.5d") * 0.5)
sq2_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq2_cell.set_input_spectrum(load_astm("AM1.5d"))
sq3_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq3_cell.set_input_spectrum(load_astm("AM1.5d"))
sq4_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq4_cell.set_input_spectrum(load_astm("AM1.5d") * 1.5)
sq5_cell = SQCell(eg=1.42, cell_T=300, plug_in_term=rev_diode)
sq5_cell.set_input_spectrum(load_astm("AM1.5d") * 0.75)
iv_funcs = [sq1_cell.get_j_from_v, sq2_cell.get_j_from_v, sq3_cell.get_j_from_v, sq4_cell.get_j_from_v,
sq5_cell.get_j_from_v]
iv_pair = solve_series_connected_ivs(iv_funcs=iv_funcs, vmin=-3, vmax=3, vnum=300)
volt = np.linspace(-3, 3, num=300)
plt.plot(volt, sq1_cell.get_j_from_v(volt))
plt.plot(volt, sq2_cell.get_j_from_v(volt))
plt.plot(volt, sq4_cell.get_j_from_v(volt))
plt.plot(volt, sq5_cell.get_j_from_v(volt))
plt.plot(iv_pair[0, :], iv_pair[1, :], '.-')
plt.ylim([-500, 0])
plt.xlim([-5, 6])
plt.xlabel("voltage (V)")
plt.ylabel("currnet (A/m^2)")
plt.show()