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。
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.
软驱动器是和变频器完全不同的两个电力电子设备，主要区别如下：
The soft driver is the two power electronic equipment which is completely different from the frequency converter. The main difference is as follows:
1、软起动器不是调速设备，只是软起动器设备，用于替代原来的星三角启动等应用，主要使用在电机不需要调速的场合（电机要么全速运行、要么停止）；变频器可以任意改变电机的速度，调速范围很宽。
1, the soft starter is not just speed control equipment, soft starter equipment, used to replace the original star delta starting applications, mainly used in the motor without speed occasions (or motor running at full speed or stop); inverter can arbitrarily change the motor speed, speed range is very wide.
2、两者使用的功率器件和主回路拓扑完全不一样，前者使用只使用可控硅，输出电压幅值可变，但频率不变；后者则使用了二极管、IGBT等功率器件，输出电压幅值和频率成比例变化。从启动效果看，变频器要永远好于软起动器。
2, the power devices used in the two are completely different from the main circuit topology. The former uses only thyristor, and the output voltage amplitude is variable, but the frequency is constant. The latter uses diode and IGBT power devices, and the output voltage amplitude and frequency vary proportionally. From the start effect, the frequency converter should always be better than the soft starter.
