一、软启动器是一种集软启动、软停车、轻载节能和多功能保护于一体的电机控制装备。实现在整个启动过程中无冲击而平滑的启动电机，而且可根据电动机负载的特性来调节启动过程中的各种参数，如限流值、启动时间等。
First, soft starter is a kind of motor control equipment which integrates soft start, soft parking, light load energy saving and multi-function protection. It realizes no impact and smooth starting motor in the whole start-up process, and can adjust various parameters in start-up process according to the characteristics of motor load, such as current limit and start time.
二、变频器（Variable-frequency Drive，VFD）是应用变频技术与微电子技尸通过改变电机工作电源频率方式来控制交流电动机的电力控制设备。
Two, Variable-frequency Drive (VFD) is the power control equipment that controls the AC motor by changing frequency technology and microelectronic technology corpse by changing the frequency of the motor power supply.
三、变频器和软启动的区别
Three, the difference between the frequency converter and the soft start
1、频率方面：
1. Frequency:
软启动器的输出频率固定为电源频率，频率不可调；变频器是输出频率可调。
The output frequency of the soft starter is fixed to the frequency of the power supply and the frequency is not adjustable; the frequency converter is adjustable in the output frequency.
2、电压方面：
2. Voltage:
软启动器通过控制可控硅（或其他电力电子元件）导通角来控制输出电压，其输出电压由0V慢慢升到额定电压；变频器的电压是可调的。
The soft starter controls output voltage by controlling the conduction angle of thyristor (or other power electronic components), and its output voltage slowly rises from 0V to rated voltage. The voltage of frequency converter is adjustable.
3、电机速度方面：
3. Motor speed:
软启动器不可调节电机速度；变频器可以调节电机在任何速度运行。
The soft starter can not adjust the speed of the motor; the frequency converter can adjust the motor to run at any speed.
