class Switch:
""" Ideal switch class. Contains functions to initiliaze
the switch according to name tag, unique cell position,
update system matrix on each iteration. """
def __init__(self, switch_index, switch_pos, switch_tag):
""" Constructor to initialize value.
Also, takes in the identifiers -
index (serial number), cell position and tag. """
self.type="Switch"
self.number=switch_index
self.pos=switch_pos
self.tag=switch_tag
self.has_voltage="yes"
self.switch_level=120.0
self.current=0.0
self.voltage=0.0
self.polrty=[-1, -1]
self.resistor_on=0.01
self.status="off"
self.control_tag=["Control"]
self.control_values=[0.0]
def display(self):
print "Switch is ",
print self.tag,
print " located at ",
print self.pos,
print " with negative polarity towards %s" %(csv_element(self.polrty))
return
def ask_values(self, x_list, ckt_mat, sys_branch):
""" Writes the values needed to the spreadsheet."""
switch_params=["Switch"]
switch_params.append(self.tag)
switch_params.append(self.pos)
switch_params.append("Voltage level (V) = %f" %self.switch_level)
if self.polrty==[-1, -1]:
# Looking for a default value of polarity
# in the neighbouring cells
self.switch_elem=csv_tuple(self.pos)
if self.switch_elem[0]>0:
if ckt_mat[self.switch_elem[0]-1][self.switch_elem[1]]:
self.polrty=[self.switch_elem[0]-1, self.switch_elem[1]]
if self.switch_elem[1]>0:
if ckt_mat[self.switch_elem[0]][self.switch_elem[1]-1]:
self.polrty=[self.switch_elem[0], self.switch_elem[1]-1]
if self.switch_elem[0]<len(ckt_mat)-1:
if ckt_mat[self.switch_elem[0]+1][self.switch_elem[1]]:
self.polrty=[self.switch_elem[0]+1, self.switch_elem[1]]
if self.switch_elem[1]<len(ckt_mat)-1:
if ckt_mat[self.switch_elem[0]][self.switch_elem[1]+1]:
self.polrty=[self.switch_elem[0], self.switch_elem[1]+1]
else:
for c1 in range(len(sys_branch)):
if csv_tuple(self.pos) in sys_branch[c1]:
if not self.polrty in sys_branch[c1]:
print
print "!"*50
print "ERROR!!! Switch polarity should be in the same branch as the switch. Check switch at %s" %self.pos
print "!"*50
print
switch_params.append("Negative polarity towards (cell) = %s" %csv_element(self.polrty))
switch_params.append("Name of control signal = %s" %self.control_tag[0])
print switch_params
x_list.append(switch_params)
return
def get_values(self, x_list, ckt_mat):
""" Takes the parameter from the spreadsheet."""
self.switch_level=float(x_list[0].split("=")[1])
# Choosing 1 micro Amp as the leakage current that
# is drawn by the switch in off state.
self.resistor_off=self.switch_level/1.0e-6
self.resistor=self.resistor_off
switch_polrty=x_list[1].split("=")[1]
# Convert the human readable form of cell
# to [row, column] form
while switch_polrty[0]==" ":
switch_polrty=switch_polrty[1:]
self.polrty=csv_tuple(switch_polrty)
if not ckt_mat[self.polrty[0]][self.polrty[1]]:
print "Polarity incorrect. Branch does not exist at %s" %csv_element(self.polrty)
self.control_tag[0]=x_list[2].split("=")[1]
while self.control_tag[0][0]==" ":
self.control_tag[0]=self.control_tag[0][1:]
return
def transfer_to_sys(self, sys_loops, mat_e, mat_a, mat_b, mat_u, source_list):
""" The matrix A in E.dx/dt=Ax+Bu will be updated by the
resistor value of the switch."""
for c1 in range(len(sys_loops)):
for c2 in range(c1, len(sys_loops)):
# Updating the elements depending
# on the sense of the loops (aiding or opposing)
for c3 in range(len(sys_loops[c1][c2])):
# Check if current source position is there in the loop.
if csv_tuple(self.pos) in sys_loops[c1][c2][c3]:
# Add current source series resistor
# if branch is in forward direction
if sys_loops[c1][c2][c3][-1]=="forward":
mat_a.data[c1][c2]+=self.resistor
else:
# Else subtract if branch is in reverse direction
mat_a.data[c1][c2]-=self.resistor
# Because the matrices are symmetric
mat_a.data[c2][c1]=mat_a.data[c1][c2]
# If the positive polarity appears before the voltage position
# it means as per KVL, we are moving from +ve to -ve
# and so the voltage will be taken negative
if sys_loops[c1][c1][c2].index(self.polrty)>sys_loops[c1][c1][c2].index(csv_tuple(self.pos)):
if sys_loops[c1][c1][c2][-1]=="forward":
mat_b.data[c1][source_list.index(self.pos)]=-1.0
else:
mat_b.data[c1][source_list.index(self.pos)]=1.0
else:
if sys_loops[c1][c1][c2][-1]=="forward":
mat_b.data[c1][source_list.index(self.pos)]=1.0
else:
mat_b.data[c1][source_list.index(self.pos)]=-1.0
return
def transfer_to_branch(self, sys_branch, source_list):
""" Update the resistor info of the switch
to the branch list """
if csv_tuple(self.pos) in sys_branch:
sys_branch[-1][0][0]+=self.resistor
# For the switch forward voltage drop.
if csv_tuple(self.pos) in sys_branch:
if sys_branch.index(self.polrty)>sys_branch.index(csv_tuple(self.pos)):
sys_branch[-1][1][source_list.index(self.pos)]=-1.0
else:
sys_branch[-1][1][source_list.index(self.pos)]=1.0
return
def generate_val(self, source_lst, sys_loops, mat_e, mat_a, mat_b, mat_u, t, dt):
""" The switch forward drop voltage is updated
in the matrix u in E.dx/dt=Ax+Bu ."""
if self.status=="on":
mat_u.data[source_lst.index(self.pos)][0]=0.7
else:
mat_u.data[source_lst.index(self.pos)][0]=0.0
return
def update_val(self, sys_loops, lbyr_ratio, mat_e, mat_a, mat_b, state_vec, mat_u, sys_branches, sys_events):
""" This function calculates the actual current in the
switch branch. With this, the branch voltage is found
with respect to the existing switch resistance. The switch
voltage is then used to decide the turn on condition. """
# Local variable to calculate the branch
# current from all loops that contain
# the current source branch.
act_current=0.0
for c1 in range(len(sys_loops)):
for c2 in range(len(sys_loops[c1][c1])):
if csv_tuple(self.pos) in sys_loops[c1][c1][c2]:
# If switch negative polarity is after the switch
# position, the current is positive.
if sys_loops[c1][c1][c2].index(self.polrty)>sys_loops[c1][c1][c2].index(csv_tuple(self.pos)):
# Then check is the loop is aiding or opposing
# the main loop.
if sys_loops[c1][c1][c2][-1]=="forward":
act_current+=state_vec.data[c1][0]
else:
act_current-=state_vec.data[c1][0]
else:
if sys_loops[c1][c1][c2][-1]=="forward":
act_current-=state_vec.data[c1][0]
else:
act_current+=state_vec.data[c1][0]
self.current=act_current
self.voltage=self.current*self.resistor
# Identifying the position of the switch branch
# to generate events.
for c1 in range(len(sys_branches)):
if csv_tuple(self.pos) in sys_branches[c1]:
branch_pos=c1
# Switch will turn on when it is forward biased
# and it is gated on.
if self.control_values[0]>=1.0 and self.voltage>1.0:
if self.status=="off":
sys_events[branch_pos]="yes"
self.status="on"
# Switch will turn off when gated off or
# when current becomes negative.
if self.control_values[0]==0.0 or self.current<0.0:
if self.status=="on":
sys_events[branch_pos]="yes"
self.status="off"
if self.status=="off":
self.resistor=self.resistor_off
else:
self.resistor=self.resistor_on
return