Energy Efficient Speed and Position Control of Electric Drives with Pmsm

progress on energy efficient speed control of electric drives has already been made. Model reference linear adaptive speed control of the drive with dc motor is exploited in [2] to drive output speed at any load to the maximum efficiency by controlling motor field current. A new energy saving control strategy for variable speed controlled parallel pumps based on sensorless flow rate estimation and pump operation analysis is described in [3]. Sheta et al developed minimum energy motion control systems respecting principles of optimal control theory for the drive with dc motor [4]. Similar approach was applied by Dodds et al, for the drives with PMSM [5]. Both control systems achieve A new speed and position controller respecting principles of near-energy optimal control for the drives with permanent magnet synchronous motor are developed as a contribution to the energy saving and environmental protection. Two various approaches to the energy saving controller design are analysed. The first approach is strictly based on energy optimal control theory and derives analytical solutions of the control problem. The second approach develops approximated solution for the drive position controller when the optimal speed trajectory is modified to correspond to the triangular and trapezoidal profile. This approach enables not only to compare energy demands of the individual control system design but also to exploit near-energy optimal controller for any controlled industrial drive.