def calculate(self, dt):
self.Bemf = self.Ke * self.I[0] * self.Omega
# Calculate current change in field coil
if isnan(self.Vin[0]):
self.I[0] = 0
else:
dIf = (self.Vin[0] - self.I[0] * self.Rf) / self.Lf
self.I[0] += dIf * dt
# And in armature
if isnan(self.Vin[1]):
self.I[1] = 0
else:
#dIa = (self.Va - self.Bemf - self.Ia*self.Ra) / self.La
#self.Ia += dIa * dt
self.I[1] = (self.Vin[1] - self.Bemf) / self.Ra
self.T = self.Ke * self.I[0] * self.I[
1] # Losses not taken into account -> mechanical power = electrical power
# Calculate mechanical side
Motor.calculate_mechanical(self, dt)
#self.power = self.T * self.Omega
return
def calculate(self, dt):
self.Bemf = self.Ke * self.Omega
# Calculate current change
if isnan(self.Vin):
self.I = 0
else:
dI = (self.Vin - self.Bemf - self.I * self.R) / self.L
self.I += dI * dt
self.T = self.Ke * self.I # Losses not taken into account -> mechanical power = electrical power
#self.P = self.Bemf * self.I
# Calculate mechanical side
Motor.calculate_mechanical(self, dt)
return
def calculate(self, dt):
alpha = 2.0 * 3.14159 / 3.0 # Coil interval in radians
# Todo: calculate inductance variation due to salient poles, e.g.
#La = self.Ld + self.Lq + (self.Lq - self.Ld) * cos(2*self.angle*self.polepairs + 3.14159/3.0)
# todo: what are the phase angle offsets..?
self.Vcommon = 0.0
nact = 0.0
for n in range(3):
# Calculate common mode voltage
if not isnan(self.Vin[n]):
nact += 1.0
self.Vcommon += self.Vin[n]
if nact != 0.0:
self.Vcommon /= nact
# Calculate effect of phases
self.B = [0.0, 0.0, 0.0]
dI = [0.0, 0.0, 0.0]
self.T = 0.0
#ang = self.P * self.Theta + pi/6.0 # First coil position (electrical) TODO: Was like this
ang = self.P * self.Theta
for n in range(3):
# Calculate magnetic flux at coil positions
self.B[n] = self.Ke * sin(ang) # TODO: This was original...
#self.B[n] = self.Ke * cos(ang)
ang -= alpha # Next coil position (electrical)
# Calculate back-emf at coil
self.Bemf[n] = self.P * self.Omega * self.B[n]
# If phase voltage is nan, then the phase is floating ->
# force phase current to zero
if isnan(self.Vin[n]):
# Decrease other coil from which the current is flowing
for k in range(3):
if k != n and self.I[n] * self.I[k] < 0.0:
self.I[k] += self.I[n]
self.I[n] = 0
else:
self.Vin[n] = self.Vin[n] - self.Vcommon
dI[n] = (self.Vin[n] - self.Bemf[n] -
self.R * self.I[n]) / self.Ld
self.I[n] += dI[n] * dt
# TODO: Force phase current sum to zero?
isum = 0.0
for n in range(3):
isum += self.I[n]
if isum != 0.0:
for n in range(3):
if not isnan(self.Vin[n]):
self.I[n] -= isum
break
# Add torque generated by each phase together
for n in range(3):
self.T += self.I[n] * self.B[n]
# Calculate final torque
self.T *= self.P
# And calculate mechanical side
Motor.calculate_mechanical(self, dt)
# Handle HALL sensor outputs depending on rotor electrical angle
# Accordign to https://e2e.ti.com/blogs_/b/motordrivecontrol/archive/2013/11/08/generate-your-own-commutation-table-trapezoidal-control-3-phase-bldc-motors-using-hall-sensors
# TODO: Check if pi/6 offset is correct!
ang = (self.P * self.Theta - pi / 6) % (2.0 * pi)
if ang < pi:
self.hall[0] = 1
else:
self.hall[0] = 0
if ang >= (2.0 * pi / 3.0) and ang < (5.0 * pi / 3.0):
self.hall[1] = 1
else:
self.hall[1] = 0
if ang < (pi / 3.0) or ang >= (4.0 * pi / 3.0):
self.hall[2] = 1
else:
self.hall[2] = 0
return