Added friction to the perturbation vector. Now the motor is not spinn…

…ing up to full bemf matching speed no matter what but actually reflects the decreased input power based on PWM duty cycle.
esden · Mar 27, 2012 · af1da6f · af1da6f
1 parent 93d7cf5
commit af1da6f
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Showing 3 changed files with 22 additions and 9 deletions.
diff --git a/control.py b/control.py
@@ -25,9 +25,9 @@
 
 import math
 
-PWM_freq = 200000
-PWM_cycle_time = (1./200000)
-PWM_duty = 1.
+PWM_freq = 16000
+PWM_cycle_time = (1./16000)
+PWM_duty = 0.6
 PWM_duty_time = PWM_cycle_time * PWM_duty
 
 debug = False

diff --git a/dyn_model.py b/dyn_model.py
@@ -53,7 +53,7 @@
     L = 0.00207                   # aka. Coil inductance in H
     M = -0.00069                  # aka. Mutual inductance in H
     R = 11.9                      # aka. Phase resistence in Ohm
-    VDC = 300.                    # aka. Supply voltage
+    VDC = 100.                    # aka. Supply voltage
     NbPoles = 4.                  #
     dvf = .0                      # aka. freewheeling diode forward voltage
 elif pset == 3: #modified psim
@@ -91,7 +91,8 @@
 
 # Components of the perturbation vector
 pv_torque  = 0
-pv_size = 1
+pv_friction = 1
+pv_size = 2
 
 # Components of the output vector
 ov_iu      = 0
@@ -372,8 +373,20 @@ def dyn_debug(X, t, U, W):
     # Electromagnetic torque
     etorque = (eu * X[sv_iu] + ev * X[sv_iv] + ew * X[sv_iw])/X[sv_omega]
 
+    # Mechanical torque
+    mtorque = ((etorque * (NbPoles / 2)) - (Damping * X[sv_omega]) - W[pv_torque])
+
+    if ((mtorque > 0) and (mtorque <= W[pv_friction])):
+        mtorque = 0
+    elif (mtorque >= W[pv_friction]):
+        mtorque = mtorque - W[pv_friction]
+    elif ((mtorque < 0) and (mtorque >= (-W[pv_friction]))):
+	mtorque = 0
+    elif (mtorque <= (-W[pv_friction])):
+	mtorque = mtorque + W[pv_friction]
+
     # Acceleration of the rotor
-    omega_dot = ((etorque * (NbPoles / 2)) - (Damping * X[sv_omega]) - W[pv_torque]) / Inertia
+    omega_dot = mtorque / Inertia
 
     V = voltages(X, U)
 

diff --git a/sim_1.py b/sim_1.py
@@ -73,16 +73,16 @@ def main():
 #    t_psim, Y_psim =  mio.read_csv('bldc_startup_psim_1us_resolution.csv')
 #    mp.plot_output(t_psim, Y_psim, '.')
 
-    freq_sim = 1e5                              # simulation frequency
+    freq_sim = 1e6                              # simulation frequency
     compress_factor = 3
-    time = pl.arange(0.0, 0.1, 1./freq_sim) # create time slice vector
+    time = pl.arange(0.0, 0.01, 1./freq_sim) # create time slice vector
     X = np.zeros((time.size, dm.sv_size))       # allocate state vector
     Xdebug = np.zeros((time.size, dm.dv_size))  # allocate debug data vector
     Y = np.zeros((time.size, dm.ov_size))       # allocate output vector
     U = np.zeros((time.size, dm.iv_size))       # allocate input vector
     X0 = [0, mu.rad_of_deg(0.1), 0, 0, 0]       #
     X[0,:] = X0
-    W = [0]
+    W = [0, 1]
     for i in range(1,time.size):
 
         if i==1: