Motor Soft starter is a novel motor control device which integrates motor soft starting, soft parking and multiple protection functions. It is called Soft Starter abroad.

Its main structure is three-phase reverse parallel thyristor and its electronic control circuit connected in series between the power supply and the controlled motor. Using different methods to control the conduction angle of three-phase anti-parallel thyristor to make the input of the controlled motor Voltage varies according to different requirements, and different functions can be realized.

Motor Soft starter and frequency converter are two completely different products. Frequency converter is used where speed regulation is needed. Its output not only changes the voltage but also the frequency. Soft starter is actually a voltage regulator. When used for motor starting, the output only changes the voltage and does not change the frequency. Inverter has all the functions of soft starter, but its price is much more expensive than soft starter, and its structure is much more complex.

Motor soft starter is a soft starter connected in series with the power supply and the controlled motor to control the conduction angle of its internal thyristor, so that the input voltage of the motor rises gradually from zero to the preset function relationship until the end of the start, giving the motor full voltage, that is, soft start. In the soft start process, the starting torque of the motor increases gradually, and the speed increases gradually.