Classification of Single Current Sensor Failures in Fault-Tolerant Induction Motor Drive Using Neural Network Approach

Abstract

In the modern induction motor (IM) drive system, the fault-tolerant control (FTC) solution is becoming more and more popular. This approach significantly increases the security of the system. To choose the best control strategy, fault detection (FD) and fault classification (FC) methods are required. Current sensors (CS) are one of the measuring devices that can be damaged, which in the case of the drive system with IM precludes the correct operation of vector control structures. Due to the need to ensure current feedback and the operation of flux estimators, it is necessary to immediately compensate for the detected damage and classify its type. In the case of the IM drives, there are individual suggestions regarding methods of classifying the type of CS damage during drive operation. This article proposes the use of the classical multilayer perceptron (MLP) neural network to implement the CS neural fault classifier. The online work of this classifier was coordinated with the active FTC structure, which contained an algorithm for the detection and compensation of failure of one of the two CSs used in the rotor field-oriented control (DRFOC) structure. This article describes this structure and the method of designing the neural fault classifier (NN-FC). The operation of the NN-FC was verified by simulation tests of the drive system with an integrated FTC strategy. These tests showed the high efficiency of the developed fault classifier operating in the post-fault mode after compensating the previously detected CS fault and ensuring uninterrupted operation of the drive system.

Review of Fault Detection and Diagnosis Techniques for AC Motor Drives

“…Sensor-fault detection is critical in fault-tolerant drives and the continuation of healthy operation [98][99][100]. Unexpected sensor measurements confuse the controller as well as existing FDD schemes, indicating a system fault whereas it is a sensor fault.…”

“…In the literature, combined sensor-failure detection schemes with PE faults are reported for motor drive systems [81,86,91,92], as well as standalone detection schemes [98][99][100][101][102][103]. Estimators take previous estimations as a reference to detect anomalies.…”

“…Any discrepancy between estimated values and measured values can be detected and, instead of measured, estimated values are used for fault-tolerant operation. NN-based sensor fault-detection schemes are also proposed in [100,103] and an extreme learning machine is used in [102] for the detection and classification of the type of faults. But, similar to PE faults, due to the lack of available data and the presence of simpler alternatives, ML literature is not as rich in sensor fault detection area.…”

Analysis of the Stator Current Prediction Capabilities in Induction Motor Drive Using the LSTM Network

“…However, there is a lack of fault classification methods based on NNs that use current prediction. For example, a previous work (Skowron et al, 2022) indeed uses an NN for classification, but as mentioned, the developed method does not use current prediction values. Therefore, the main reason for the research presented in this article was to explore the possibility of predicting stator currents in the IM drive using LSTM networks, including selected CS fault types such as gain change, offset, and saturation.…”

Experimental Validation of Current Sensors Fault Detection and Tolerant Control Strategy for Three-Phase Permanent Magnet Synchronous Motor Drives

“…Unfortunately, sensors are highly susceptible to failures and can experience various issues that hinder their proper functioning. These failures may include open circuits, disconnections, gain changes, DC-offset, signal noise, or complete sensor breakdown [3,4]. Such failures can disrupt the accurate measurement and feedback of critical information in a PMSM adjustable speed drive, potentially leading to degraded performance, safety concerns, and the need for appropriate Fault Detection, Isolation, and Reconfiguration (FDIR) mechanisms to ensure the reliable operation of the drive system.…”