Adaptive control schemes for improving dynamic performance of efficiency-optimized induction motor drives.

Area of Science:

• Electrical Engineering
• Control Systems
• Power Electronics

Background:

• Model Based Control (MBC) is an energy-optimal strategy for vector-controlled Induction Motors (IMs).
• While MBC conserves energy, especially at part-load, it introduces torque and speed ripples during load transitions, degrading drive dynamic performance.

Purpose of the Study:

• To investigate and propose methods for improving the dynamic performance of three-phase IMs operating with MBC.
• To analyze the impact of load transitions on MBC performance and evaluate proposed enhancements.

Main Methods:

• Three control schemes were proposed: MBC with a low-pass filter, torque-producing current injection, and a Variable Structure Speed Controller (VSSC).
• Dynamic performance was tested on a 1-hp, three-phase squirrel-cage IM using a mine-hoist load profile.
• Comparisons were made against conventional field-oriented control and MBC without enhancements.

Main Results:

• All three proposed schemes significantly improved motor dynamics, reducing overshoot and undershoot in torque and DC link power during load transitions.
• The enhancements maintained or improved energy savings characteristic of MBC.
• The effectiveness of the proposed schemes was validated under parametric variations.

Conclusions:

• The proposed control schemes effectively mitigate the dynamic performance issues associated with MBC in Induction Motors.
• These methods offer a viable solution for achieving both energy efficiency and improved dynamic response in IM drives.
• The study demonstrates a significant enhancement in motor drive performance through advanced control strategies.