This short article constitutes an introductory part the Special Section on Intelligent Fault Monitoring and Fault-Tolerant Control in Power Electronics, Drives and Renewable Energy Systems. In the current issue of the journal the first part of this Section is published. Accepted articles are focused mainly on the sensor-fault diagnosis methods for T-type inverter fed dual-three phase PMSM drives, partial demagnetization.faults of the Permanent Magnet Synchronous Generator (PMSG) and online open phase fault detection in the sensorless five phase induction motor drive implemented with an inverter output LC filter and third harmonic injection. Also neural networks (NN) application in the detection of stator and rotor electrical faults of induction motors have been proposed in one of the papers and the observer-based fault detection concept for unknown systems using input-output measurements was applied to BLDC motor drive with unknown parameters.