Smart Fault-Tolerant Control System Based on Chaos Theory and Extension Theory for Locating Faults in a Three-Level T-Type Inverter

Abstract

This study proposes a smart fault-tolerant control system based on the theory of Lorenz chaotic system and extension theory for locating faults and executing tolerant control in a three-level T-type inverter. First, the system constantly monitors the fault states of the 12 power transistor switches of the three-level T-type inverter; if a power transistor fails, the corresponding output phase voltage waveform is converted by a Lorenz chaotic system. Chaos eye coordinates are then extracted from a scatter diagram of chaotic dynamic states and considered as fault characteristics. The system then executes fault diagnosis based on extension theory. The fault characteristic value is used as the input signal for correlation analysis; thus, the faulty power transistor can be located and the fault diagnosis can be achieved for the inverter. The fault-tolerant control system can maintain the three-phase balanced output of the three-level T-type inverter, thereby improving the reliability of the motor drive system. The feasibility of the proposed smart fault-tolerant control system was assessed by conducting simulations in this study, and the results verified its feasibility. Accordingly, after the occurrence of the fault in power switches, the balanced three-phase output line voltage remained unchanged, and the quality of the output voltage was not reduced by using the integration of the proposed fault diagnosis system and fault-tolerant control system for a three-level T-type Inverter.

Three-Level T-Type Inverter Fault Diagnosis and Tolerant Control Using Single-Phase Line Voltage

“…The measurement results reveal that the proposed diagnosis method can correctly diagnose fault types despite noise interference. Compared with current three-level T-type inverter fault diagnosis systems [26], the proposed fault diagnosis system only requires extracting single-phase line voltage data for analysis, which reduces system operation times. In addition to references from the literature, the proposed fault diagnosis system covers normal operation and fault occurrences in…”

“…However, because these inverters require a large number of power transistors, fault detection for these transistors is difficult. To increase equipment reliability and maintain the continual operation of the inverter's power transistor components during the occurrence of a fault, scholars around the globe have improved upon the fault detection mechanisms [6]- [15] and fault-tolerant control functions [16]- [19], [19]- [26] of multilevel inverters.…”

“…The author of this study has investigated fault diagnosis and tolerant control in three-level T-type inverters [26]. However, this previous study was limited by difficulties from the complex computation and fault diagnosis processes.…”

Improving Deep Echo State Network with Neuronal Similarity-based Iterative Pruning Merging Algorithm

“…The Lorenz time series prediction [26] is another benchmark problem for ESN. The Lorenz dynamic system is described by the following equations:…”

The Diagnostic Method for Open-Circuit Faults in Inverters Based on Extended State Observer

“…At present, the diagnostic methods of IGBT open-circuit fault are classified into the current-based method, the voltagebased method, and the intelligent algorithm methods. e intelligent inverter fault diagnosis methods are mainly the neural network method [3][4][5], the fuzzy logic method [6], spectrum analysis method [7], and so on. Due to these intelligent fault diagnosis methods which rely on experience and the fact that they are subjective, they are less used in inverter fault diagnosis.…”