Title :
A simple speed sensorless control for variable frequency induction motor drives
Author :
Jeftenic, B.I. ; Bebic, M.Z. ; Mitrovic, N.N.
Author_Institution :
Fac. of Electr. Eng., Belgrade Univ., Serbia
fDate :
9/1/1999 12:00:00 AM
Abstract :
This paper presents a method for speed control of an AC drive with variable frequency PWM inverter without a speed sensor. The proposed control algorithm is based on speed compensation as a function of the load torque. The load torque estimate is obtained with a single current sensor in the DC link of the inverter. Most of the problems that are the consequence of cross-coupling and numerous nonlinearities in the system, are solved with the use of pre-formed look-up table, that gives the stator frequency as a function of the reference speed and the load. The control system is implemented using digital techniques, and the steady state error is less than half of the stator frequency resolution. Theoretical analyses and experimental verification supports the validity of the proposed control concept, and its usefulness to practical application
Keywords :
DC-AC power convertors; PWM invertors; compensation; control system analysis computing; control system synthesis; digital control; electric machine analysis computing; induction motor drives; load (electric); machine testing; machine theory; machine vector control; parameter estimation; velocity control; control algorithm; control design; control performance; control simulation; digital control techniques; load; load torque estimation; re-formed look-up table; reference speed; speed sensorless control scheme; stator frequency; stator frequency resolution; steady state error; variable frequency PWM inverter; variable frequency induction motor drives; Control systems; Error correction; Frequency; Pulse width modulation inverters; Sensorless control; Stators; Steady-state; Table lookup; Torque control; Velocity control;
Journal_Title :
Energy Conversion, IEEE Transactions on
