Why is soft-start important and how is it implemented?

Soft-start limits inrush current during power-up, protecting components and avoiding input voltage sag. Implementation methods: ramping reference voltage (controller output increases gradually), limiting duty cycle (PWM duty cycle ramps from zero), series resistance/impedance (resistor bypassed after startup), and pre-charge circuits (charge DC bus capacitors through resistor before main contactor closes). Duration depends on application - milliseconds for small converters to seconds for large drives. Proper soft-start prevents nuisance tripping of input protection and reduces stress on components.