- Issue Time
（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 .
Advantages: small starting current and small starting torque，
Disadvantages: can only be used for delta connected motors.
Advantages: small starting current, wide application range and simple operation，
Disadvantages: high cost, complex internal structure.