VSDs are significantly large and costly when compared to soft starters.
Fremont, CA: Starting an electric motor or any electrical device requires the most energy. As speed up from zero to the required speed consumes a lot of power, a large starting current is required when accelerating an AC motor to full speed using a high voltage connection.
In addition, the uncontrolled torque from an AC motor could shock the connected equipment and cause potential damage. Therefore, using a soft starter or a varying speed drive (VSD)/ variable frequency drive (VFD) counts on what output is desirable, safe, and cost-efficient.
Soft start drives are utilized to limit the current inrush associated with the start-up cycle of an electric motor. By adding solid-state series impedance, soft start drives lower the initial voltage into an engine. There are a lot of applications for soft starters:
1. Desired torque control and sped ramping when stopping or starting. High opening currents to start large motors must be restricted to avoid supply network issues or penalty charges.
2. Gradual and controlled start-up is needed to avoid torque spikes and tension in mechanical systems like conveyors, gears, belt-driven systems, and coupling.
3. Soft starters evade hammering and pressure surges in piping systems.
Benefits to soft starters are that they are more economical when only the initial condition when speed and torque control is reviewed. But when considering the space occupied, they generally occupy less space than VSDs.
An unstable speed drive is an electric motor control device that controls the speed and protects an AC induction motor, decreases the power consumption during start-up, and gives complete control of engine speed during all the stages of a motor.
The more accurate the rule, the less stress and strain it has on the system, offering longevity to the devices because of less wear and tear. It is applied when custom control is considerable. The benefits of VSDs are that they give fully adjustable speed for pumps, fans, and conveyors. In addition, it has dynamic control with advanced overload protection; it can relay outputs and perform self-diagnostics and communications.
VSDs are significantly large and costly when compared to soft starters. Therefore, not every manufacturer can invest in VSDs, but a soft starter is a good start in energy efficiency.
