Which are the differences between frequency converter and soft starter in application field?

Frequency inverter and soft starter are two different types of devices used to control the starting and running of motors, but there are obvious differences in their working principles, applications and functions.

The frequency inverter  is a power control device that mainly uses frequency conversion technology and microelectronics technology to control the speed and other performance of the AC motor by changing the power supply frequency when the motor is working. In addition, the frequency converter also has some protection functions, such as overcurrent, overvoltage, overload protection, etc. With the improvement of industrial automation, frequency converters have been widely used.

The soft starter is a motor control device that integrates motor soft start, soft stop, light load energy saving and multiple protection functions. Its main components are three-phase reverse parallel thyristor and its electronic control circuit connected in series between the power supply and the controlled motor. The soft start of the motor is essentially the motor starting slowly with a lower current, which can reduce the impact on the power grid and increase the service life of the equipment.

The difference in application areas：

Application areas of frequency inverter:

Precise speed control: Frequency inverter are widely used in applications that require precise speed control, such as fans, pumps, and conveying systems. By adjusting the input voltage and frequency, VFDs can achieve precise control of the motor speed to meet different process requirements.
Energy saving and optimization: Since frequency inverter can adjust the motor speed as needed, they are often used in applications that require energy saving and optimization of production processes.

Application areas of soft starters:

Reducing starting shock: Soft starters are mainly used to reduce mechanical shock and grid shock during startup, especially for high-power motors. They can gradually increase the voltage and limit the starting current, thereby extending the life of the equipment and reducing equipment maintenance costs.
Limiting starting current: In some applications, a high starting current may be generated when starting the motor. Soft starters can limit this current and reduce the impact on the grid.

Frequency  inverter are mostly used in places that require precise speed and load control, helping to control production lines and improve production efficiency; while soft starter are mainly used for motor and equipment protection, reducing starting current shock and mechanical pressure.