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(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_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_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_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()