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AC Motor Control System


AC Motor Control System Diagram

Digital Power & Motion's AC Motor Control System is a network of Embedded Variable Frequency Drives connected to a main Sequencer, actually a custom Programmable Logic Controller, to orchestrate their motion.  At each VFD, one or more Magnetic Encoders work to track the position of an alternating pole magnetic strip.  Also at each VFD are switches that provide digital inputs to the system.  The drives act intelligently to position the mechanical device connected to the motor based on feedback from the encoders and switch inputs.  The sequencer acts to instruct various drives what to do using high level commands as well as a window into the system operation.  The maximum network length is a function of the communication speed, but up to 5000' is possible.

For example, the digital inputs at the Sequencer may indicate that the system should move Motor #1 to position X1 and Motor #99 to position X99.  The Sequencer will then send high level commands to Drive #1 and Drive #99 telling them where they should move to.  Based on this instruction, the drives first verify that it is safe to move based on their local inputs, and then move the motor loads to the commanded positions using local feedback from the Magnetic Encoders.

Alternatively, an even higher level controller can provide commands to the Sequencer to instruct the system how to behave via a SCADA CAN port.  Or, an Embedded VFD can act alone to control a motor without any supervisory controller or sequencer.  The system is very flexible!

Please find more details on each components web page.  Please contact us soon to discuss how this system, or components of it could work for you!  Also, we'd be happy to discuss how an entirely custom system would work for your application!