Started a file for PMSM and driver system simulation

analysis/Simulation/MotorSim.py

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+# this file is for the simulation of a 3-phase synchronous motor
+
+import numpy as np
+import scipy as sp
+
+def sign(num):
+    if num > 0:
+        return 1
+    elif num < 0:
+        return -1
+    else:
+        return 0
+
+# example params for d5065 motor
+# phase_R = 0.039 Ohms
+# phase_L = 0.0000157 H
+# pole_pairs = 7
+# KV = 270
+
+class motor_pmsm_electrical:
+    # class for simulating PMSM electrical dynamics in dq reference frame
+    # R, L input are phase-neutral, not phase-phase
+    def __init__(self, R, L_q, L_d, KV, pole_pairs):
+        # KV is published KV
+        kt = 8.27/KV
+        self.lambda_m = 2*kt/(3*pole_pairs) #speed constant in Vs/rad (electrical rad)
+        self.L_q = L_q
+        self.L_d = L_d
+        self.R = R
+        self.pole_pairs = pole_pairs
+
+        self.V_q = 0
+        self.V_d = 0
+        self.w_e = 0
+
+    def diff_eqs(self, t, y, V_d, V_q, w):
+        # this is for solving with solve_ivp or similar
+        # t is time, y is vector of state: [I_d, I_q], V_d and V_q are input voltages in dq ref frame, w is electrical freq
+        I_d = y[0]
+        I_q = y[1]
+
+        # set these equal to the inputs for plotting
+        self.V_d = V_d
+        self.V_q = V_q
+        self.w_e = w
+
+        I_d_dot = V_d / self.L_d - self.R / self.L_d * I_d + w * self.L_q / self.L_d * I_q
+        I_q_dot = V_q / self.L_q - self.R / self.L_q * I_q - w * self.L_d / self.L_q * I_d - w * self.lambda_m / self.L_q
+
+        return np.array([I_d_dot, I_q_dot])
+
+# example params for D5065 motor
+# J = 1e-4
+# b_coulomb = 0.001
+# b_viscous = 0.001
+
+class motor_pmsm_mechanical:
+    def __init__(self, J, b_coulomb, b_viscous):
+        # J is moment of inertia
+        # b_coulomb is coulomb friction coefficient
+        # b_viscous is viscous friction coefficient
+        self.J = J
+        self.b_c = b_coulomb
+        self.b_v = b_viscous
+
+    def diff_eqs(self, t, y, torque):
+        theta = y[0]
+        theta_dot = y[1]
+
+        theta_ddot = (1/self.J) * (torque - self.b_v * theta_dot - self.b_c * sign(theta_dot))
+
+        return np.array([theta_dot, theta_ddot])
+
+class motor_pmsm_combined:
+    def __init__(self, J, b_coulomb, b_viscous, R, L_q, L_d, KV, pole_pairs):
+        # J is moment of inertia
+        # b_coulomb is coulomb friction coefficient
+        # b_viscous is viscous friction coefficient
+        self.J = J
+        self.b_c = b_coulomb
+        self.b_v = b_viscous
+
+        kt = 8.27/KV
+        self.lambda_m = 2*kt/(3*pole_pairs) #speed constant in Vs/rad (electrical rad)
+        self.L_q = L_q
+        self.L_d = L_d
+        self.R = R
+        self.pole_pairs = pole_pairs
+
+    def diff_eqs(self, t, y, V_d, V_q):
+        # inputs are V_d, V_q
+        # state is y, y = [theta, theta_dot, I_d, I_q]
+
+        theta = y[0]
+        theta_dot = y[1]
+        I_d = y[2]
+        I_q = y[3]
+
+        torque = 3*self.pole_pairs/2 * (self.lambda_m * I_q + (self.L_d - self.L_q)*I_d*I_q)
+
+        # theta_dot = theta_dot, no ode here
+        theta_ddot = (1/self.J) * (torque - self.b_v * theta_dot - self.b_c * sign(theta_dot))
+        I_d_dot = V_d / self.L_d - self.R / self.L_d * I_d + theta_dot * self.L_q / self.L_d * I_q
+        I_q_dot = V_q / self.L_q - self.R / self.L_q * I_q - theta_dot * self.L_d / self.L_q * I_d - theta_dot * self.lambda_m / self.L_q
+
+        return np.array([theta_dot, theta_ddot, I_d_dot, I_q_dot])
+
+def inverter(vbus, timings, current):
+    # this function should take the relevant inputs and output voltages in dq reference frame.
+    pass