Mitsubishi Electric is celebrating what it says is an industry first after launching its new EM-A series of salient-pole motors that provide high-quality speed and position control without encoders.
Offering a competitively priced alternative to servo motors, the EM-A series is designed for use in various applications that require positioning and/or accurate speed control. Smaller than most induction motors by one or two frame sizes, the range meets efficiency class IE5, reducing energy losses by almost 50% versus equivalent IE2 motors with a smaller overall footprint.
The EM-A range is compatible with Mitsubishi Electric's FR-A800 and FR-E800 inverters and can carry out point-to-point position control and or accurate speed control without the need for motor mounted encoders. As a result, the EM-A is more compact and requires less wiring while still delivering a positioning accuracy of 200p/rev and command resolution of 4096p/rev.
Each unit's sensor-less vector control avoids significant speed variation during load changes, with a servo lock function that generates holding torque when the motor stops to prevent movement via external force. With a speed variation rate of +/-0.05% and a speed control range of 1:1300, the control provides users with precise speed and positioning control comparable to servo motors up to 7.5kW.
All major communication protocols can also be used by switching parameters by equipping the motor with a variable frequency drive. The EM-A series is available 0.1kW up to 7.5kW, and unlike induction motors can operate at low speed without the need of a force fan vent fan.