The motor coil is an inductive load, so the current in the coil will have a certain delay relative to the load voltage on the coil.

李二峰

The motor coil is an inductive load, so the current in the coil will have a certain delay relative to the load voltage on the coil. [Copy link]

Lead Angle is often used in brushless DC motor (BLDC - BrushLess DC) control. Because the motor coil is an inductive load, the current in the coil will have a certain delay relative to the load voltage on the coil, which will affect the efficiency of the motor and generate noise. Can anyone explain the LA lead angle?

bigbat

The lead angle means exactly what it says, which is the angle that is opened earlier than the normal angle. Just like the description above, if the voltage supply is started at a normal angle, then since the current lags behind the voltage, the current is the factor that generates the magnetic field, that is, the field strength and the current are in phase (this is my understanding, I don't know if it is right or wrong). The presence of voltage does not necessarily generate a magnetic field, and the magnetic field strength is proportional to the rate of change of voltage.

eew_1PrAA0

The commutation point is defined as the lead angle/conduction angle 0 degree point. This point is located how many degrees to the right (behind) of the midpoint of the phase voltage. The Lead Angle/conduction angle, as the name implies, is how many degrees ahead of the lead angle 0 degree to the left (forward).