What Are The Advantages Of Motor Soft Starters?

   https://www.kaichuanpower.com/soft-starte/

The motor soft starter is a new type of starting equipment designed and produced by using power electronics technology, microprocessing technology and modern control theory, which has the international advanced level. The motor soft starter can effectively limit the starting current of the AC asynchronous motor when starting, and can be widely used in the load of fans, pumps, conveyors and compressors, and is an ideal replacement product for traditional star/triangle conversion, auto-coupling step-down, magnetron step-down and other step-down equipment.

Below, what are the advantages of the motor soft starter in use?

1. Cause grid voltage fluctuations, affect the operation of other equipment in the same power grid, when the AC motor starts directly at full voltage, the starting current will reach 4~7 times of the rated current, when the capacity of the motor is relatively large, the starting current will cause a sharp drop in the grid voltage, affecting the normal operation of other equipment in the same power grid. When the soft start cabinet is used for the motor, the starting current is generally 2~3 times of the rated current, and the grid voltage fluctuation rate is generally within 10%, which has little impact on other equipment.

2. The impact on the power grid The impact on the power grid is mainly manifested in two aspects:

(1) The impact of the large current directly started by the super-large motor on the power grid is almost similar to the impact of the three-phase short circuit on the power grid, which often causes power oscillation and makes the power grid lose stability.

(2) The starting current contains a large number of high-order harmonics, which will cause high-frequency resonance with the parameters of the power grid circuit, resulting in faults such as malfunction of relay protection and failure of automatic control. The starting current of the soft start cabinet for the motor is greatly reduced when starting, and the above effects can be completely eliminated.

3. Damage the motor insulation and reduce the life of the motor

(1) The Joule heating generated by the high current repeatedly acts on the outer insulation of the wire, which accelerates the aging of the insulation and reduces the service life.

(2) The mechanical force generated by the high current causes the wires to rub against each other, reducing the insulation life.

(3) The jitter phenomenon of the contact when the high-voltage switch is closed will produce an operating overvoltage on the stator winding of the motor, sometimes reaching more than 5 times of the applied voltage, and such a high overvoltage will cause great damage to the motor insulation.