Following to be considered
Servos are available as a solution in the form of a set that consists of motor,matched gear box with position feed back sensor like encoder along with controller module.All the components are tightly coupled and designed to work as a system
In contrast, VSD (Variable Speed Drive) is available as product.
Servos are available upto 5KW - Maximum
VSD are available at various Kw ratings at different voltage ratings like LV & MV
Servos are used for precise positioning and CNC machines
VSDs are used in pumps,blowers,materials handling cranes,HVAC.......
VSD - Variable Speed Drive
is based on different technologies like Eddy current, Variable Voltage and Variable Frequency.