2-2-4. Wire Connection of Brushless DC Motor
Next, an explanation of the coil connection method used in brushless DC motors.
Two connection methods are used for brushless DC motors.
One method is to connect the coils in a loop as we compared it with the rotor winding of DC motors in Fig. 2.27. This method is called a Δ (delta) connection.
The other method is to connect three coils, U, V, and W, in a block.
This method is called a Y connection or a star connection. The bundled portion of the coils in a star connection is called a neutral point or a common point.
Current to each coil in a star connection can be controlled, but the switch is turned ON and OFF a little differently.
Fig. 2.28 shows a star connection. It shows the switching method for applying the same current as that for the delta connection in Fig. 2.27 <1>.
The connection type to be employed depends on the operating voltage and how the motor is to be used. However, a star connection is generally used unless special motors are used.