Motorola M68HC08 Reference Manual page 33

3.2.4.4 Effect of Mutual Phase Capacitance
DRM028 — Rev 0
MOTOROLA
Freescale Semiconductor, Inc.
Figure 3-8. Detail of Mutual Inductance Effect
The negative effect of mutual inductance is not the only one to disturb
the back-EMF sensing. So far, the mutual capacitance of the motor
phase windings was neglected in the motor model, since it affects
neither the phase currents nor the generated torque. Usually the mutual
capacitance is very small. Its influence is only significant during PWM
switching, when the system experiences very high du/dt.
The effect of the mutual capacitance can be studied using the model
shown in Figure 3-9.
BLDC Motor Control
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BLDC Motor Control
Brushless DC Motor Control Theory
Designer Reference Manual
33