The electric motor was once the driving force of the industrial revolution, and it remains highly relevant today as the muscle behind technological evolution. Available in many different types for a huge variety of purposes, motor drives affect many aspects of our lives whether we recognize it or not.
Used to control the speed of machinery, adjustable speed motor drives have many industrial applications including assembly lines. Typically designed with several pre-set speed ranges that can be chosen, they are available in four basic types:
Variable speed drives typically allow for more control over their exact speed than adjustable speed drives as they are not limited to pre-set ranges. These drives are used in many electro-mechanical systems from small appliances to mine mill drives in order to control motor speed and torque. In fact, up to 25% of the world's electricity is used by motors of this type employed in many industrial applications!
The three main types of variable torque and power systems include: variable torque, commonly used in centrifugal fans, pumps, and blower systems; constant torque, generally seen in conveyor and positive displacement pump applications; and constant power which is most often utilized in the form of power tools and traction applications.
Soft starters are used on AC electrical motors in order to reduce stress and damage to both mechanical and electrical systems in startup.
During startup, the inrush currents can reach levels up to 7 times higher than the standard running current while startup torque can reach levels almost 3 times higher than average. This can cause sudden stress to the system, reducing service life and causing dips in power. By utilizing soft start drives, this stress can be negated, effectively increasing the life of your equipment.