PSpice Application Notes

APPLICATION NOTE 5 N is the phase number (1, 2, 3 in this example) P is the number of motor phases Keeping in mind that the sine terms of the equations are the same, and adding the other four electrical properties of the motor windings, you come up with the following model for the motor: * The motor with both ends of each coil available. * * Phase 3 coil ----------------+---+ * Phase 2 coil --------+---+ | | * Phase 1 coil +---+ | | | | * | | | | | | .subckt bldcmtr p1a p1b p2a p2b p3a p3b shaft_speed shaft_angle + params: + J= .30 ; moment of inertia of rotor (g*cm*sec*sec) + B= .36 ; Damping and eddy current losses * (linear torque with speed) (g*cm*sec/rad) + F= .72 ; Friction/drag losses (constant torque losses) * (g*cm) + D= 2.9 ; Magnetic detent torque (g*cm) + A= 2 ; Number of north poles on the rotor + P= 3 ; Number of phases (if you change this you need * to add more windings to the motor subckt.) + CL=3mh ; winding inductance (Henrys) + CR=6ohm ; winding resistance (Ohms) + CC=.001uf ; winding capacitance to ground (Farads) + CM=.5 ; adjacent winding mutual coupling factor + Cb=.12 ; Back EMF constant (Volt*sec/rev) + Ct=300 ; Torque constant (g*cm/amp) + twopi = {2 * 3.141596} * Model each winding. The inductor must be here so we can include * mutual inductance. The other effects are modeled in * motor_winding Lwinding1 p1a p1x {CL} R_snub_1 p1a p1x {1K*twopi*CL} * ; snubbing resistor to limit coil Q x1 p1x p1b shaft_speed shaft_angle motor_winding + params: N=1 A={A} P={P} CL={CL} CR={CR} CC={CC} + CM={CM} Cb={Cb} Ct={Ct} twopi={twopi} Lwinding2 p2a p2x {CL} R_snub_2 p2a p2x {1K*twopi*CL} * ; snubbing resistor to limit coil Q x2 p2x p2b shaft_speed shaft_angle motor_winding + params: N=2 A={A} P={P} CL={CL} CR={CR} CC={CC} + CM={CM} Cb={Cb} Ct={Ct} twopi={twopi} Lwinding3 p3a p3x {CL} R_snub_3 p3a p3x {1K*twopi*CL} * ; snubbing resistor to limit coil Q x3 p3x p3b shaft_speed shaft_angle motor_winding + params: N=3 A={A} P={P} CL={CL} CR={CR} CC={CC} + CM={CM} Cb={Cb} Ct={Ct} twopi={twopi} * Model the mutual inductance here. * (For three phase, all windings are adjacent to each other.) k1 Lwinding1 Lwinding2 {Cm}

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