What are the ways and characteristics of motor starting?

What are the ways and characteristics of motor starting?


(1)D-Direct On Line:
Advantages: less starting equipment, simple starting mode, low cost, 
Disadvantages: the starting current is large, affecting the service life of the motor and unfavora to the stable operation of the power grid .
(2)YD-Star-Delta:
Advantages: small starting current and small starting torque,
Disadvantages: can only be used for delta connected motors.
(3)VFD:
Advantages: small starting current, wide application range and simple operation,
Disadvantages: high cost, complex internal structure.