Abstrait

Digital Control of Permanent Magnet Synchronous Motor

Jayasri R. Nair

The principle of vector control of electrical drives is based on the control of both the magnitude and the phase of each phase current and voltage. For as long as this type of control considers the three phase system as three independent systems, the control will remain analog and thus present several drawbacks. With high computational power silicon devices, it has been possible to realize precise digital vector control algorithms. The most common is the Field Orientated Control, which demonstrates the capability of performing direct torque control of handling system limitations and of achieving higher power conversion efficiency. The new families of DSPs enable cost-effective design of intelligent controllers for brushless motors which can fulfill enhanced operations, consisting of fewer system components, lower system cost and increased performances. This algorithm maintains efficiency over a wide range of speeds for a 24V, 4000 rpm Permanent Magnet Synchronous Motor and takes into consideration torque changes with transient phases by controlling the flux directly from the rotor coordinates.