Permanent magnet servo motors provide energy efficient solution

While the motor is often the focus of any assessment to identify potential energy savings, it is often a combination of different measures that will yield the most positive results. In its continuing drive to help customers achieve goals of productivity and profitability, Stober Drives already provides products and components that are suited to energy optimisation.

According to the company key to a highly efficient drive operation is looking at the whole system, which should not be over specified for the task in hand and should also use intelligent components.

Stober asynchronous motors are often operated with a frequency inverter, further increasing efficiency, however drives with a constant operating speed do not need an inverter if speed and torque can be defined using a gear unit. The MSG modular geared motor system features a close range of gear set increments to provide precise performance and achieve energy savings.

In the power range up to 10kW, Stober also urges customers to consider the use of permanent magnet servo motors, which, asserts the company, achieve higher energy efficiency than comparable asynchronous motors and also have reduced maintenance requirements.

While the purchase cost of a permanent magnet servo motor can be approximately 60% higher than a comparable asynchronous motor, the initial expenditure can be paid back in energy cost savings after just a year according to Stober.

For example, on a machine with four axes and a total power rating of 10kW, permanent servo motors can save around 7000kWh of electricity per year in a two-shift operation, equating to a CO₂ saving of 4.5t.

Furthermore, the different version of the ED and EK servo motors offer additional potential for an energy optimised application. ED motors used for dynamic applications have comparatively low power consumption due to their low mass moment of inertia.