Sensor and sensorless fault tolerant control for induction motors using a wavelet index.

Area of Science:

• Electrical Engineering
• Control Systems
• Power Electronics

Background:

• Fault-tolerant control (FTC) systems are essential for the reliable operation of industrial motor drives.
• Induction motor drives are widely used but susceptible to various faults, necessitating robust control strategies.
• Existing FTC systems may lack flexibility or efficient fault detection mechanisms.

Purpose of the Study:

• To propose a novel FTC system for induction motor drives capable of handling multiple fault types.
• To enhance system reliability and operational safety through intelligent switching between different control strategies.
• To develop an efficient fault detection method and a speed estimation technique for sensorless control.

Main Methods:

• Implementation of a switching mechanism to transition between sensor vector control, sensorless vector control, closed-loop V/f, and open-loop V/f control.
• Fault detection using a wavelet index for identifying speed sensor failures, winding open circuits, shorts, and voltage faults.
• Introduction of a Boosted Model Reference Adaptive System (BMRAS) for reduced-tuning-time speed estimation in sensorless vector control.

Main Results:

• The proposed FTC system demonstrated fast and effective fault detection capabilities through simulations and experiments.
• Smooth transitions between control methods were achieved, maintaining the effectiveness of the FTC system.
• The system showed flexibility by rapidly reverting to the primary controller when the motor returned to a healthy state.

Conclusions:

• The developed FTC system provides a robust and adaptable solution for ensuring the safe and continuous operation of induction motor drives.
• The combination of multiple control strategies and advanced fault detection enhances system resilience against various electrical and sensor faults.
• The novel BMRAS improves the performance of sensorless control, contributing to the overall effectiveness of the fault-tolerant system.