A soft starter is an integrated motor control device that combines soft start, soft stop, light-load energy saving, and various protection functions. It not only achieves a smooth and shock-free motor start throughout the process but also adjusts parameters during the start-up, such as current limiting value and start-up time, based on the characteristics of the motor load.

Soft start technology is an emerging technique for controlling and starting motors, which has garnered widespread attention from modern society and is actively applied in industrial production activities. This technology allows for a smooth motor start, effectively reduces voltage, and can compensate for and vary the motor's frequency, thereby minimizing the adverse effects of motor startup on the power grid and related equipment, protecting various associated devices.

A soft starter is a motor control device that integrates soft starting, soft stopping, light load energy saving, and various protection functions. It is known as Soft Starter internationally. Its main components are the three-phase reverse-parallel thyristors connected in series between the power supply and the controlled motor, along with their electronic control circuit. By using different methods to control the conduction angle of the three-phase reverse-parallel thyristors, the input voltage of the controlled motor can be adjusted to meet different requirements, thereby achieving various functions. Soft starters and variable frequency inverters are two different types of products. Variable frequency inverters are used where speed control is needed; their output changes both voltage and frequency. A soft starter, on the other hand, is essentially a voltage regulator, used during motor startup, where it only changes the voltage without altering the frequency. While variable frequency inverters have all the functions of a soft starter, they are significantly more expensive and complex in structure.