Transistor Open-circuit Fault Research Articles

The Fault Detection, Localization, and Tolerant Operation of Modular Multilevel Converters with an Insulated Gate Bipolar Transistor (IGBT) Open Circuit Fault

Reliability is one of the critical issues for a modular multilevel converter (MMC) since it consists of a large number of series-connected power electronics submodules (SMs). In this paper, a complete control strategy including fault detection, localization, and tolerant operation is proposed for the MMC under an insulated gate bipolar transistor (IGBT) open circuit fault. According to the output characteristics of the SM with the open-circuit fault of IGBT, a fault detection method based on the circulating current and output current observation is used. In order to further precisely locate the position of the faulty SM, a fault localization method based on the SM capacitor voltage observation is developed. After the faulty SM is isolated, the continuous operation of the converter is ensured by adopting the fault-tolerant strategy based on the use of redundant modules. To verify the proposed fault detection, fault localization, and fault-tolerant operation strategies, a 900 kVA MMC system under the conditions of an IGBT open circuit is developed in the Matlab/Simulink platform. The capabilities of rapid detection, precise positioning, and fault-tolerant operation of the investigated detection and control algorithms are also demonstrated.

A Fast-Acting Diagnostic Algorithm of Insulated Gate Bipolar Transistor Open Circuit Faults for Power Inverters in Electric Vehicles

To improve the diagnostic detection speed in electric vehicles, a novel diagnostic algorithm of insulated gate bipolar transistor (IGBT) open circuit faults for power inverters is proposed in this paper. The average of the difference between the actual three-phase current and referential three-phase current values over one electrical period is used as the diagnostic variable. The normalization method based on the amplitude of the d-q axis referential current is applied to the diagnostic variables to improve the response speed of diagnosis, and to avoid the noise and the delay caused by signal acquisition. In the parameter discretization process, the variable parameter moving average method (VPMAM) is adopted to solve the variation of the average value over a period with the speed of the motor; hence, the diagnostic reliability of the system is improved. This algorithm is robust, independent of load variations, and has a high resistivity against false alarms. Since only the three-phase current of the motor is utilized for calculations in the time domain, a fast diagnostic detection speed can be achieved, which is significantly essential for real-time control in electric vehicles. The effectiveness of the proposed algorithm is verified by both simulation and experimental results.

Phase current reconstruction strategy for switched reluctance machines with fault‐tolerant capability

This study presents a novel phase current reconstruction strategy for switched reluctance machines (SRMs) using two cross-winding current sensors. The phase currents are reconstructed by solving the linear equations associated with two adjacent phase currents in the different turn-on regions. The effect of current sensor offset and power transistor fault on the proposed reconstruction method is analysed. On the basis of the current difference at the rising edge of each drive signal, an offset sensor identification method is presented and two online compensation schemes are adopted. For power transistor short-circuit fault, the logic-judgment-based and freewheeling-time-based diagnostic methods are investigated and a virtual current sensor is introduced to ensure the effectiveness of the reconstruction process. The proposed phase current reconstruction strategy is free from power transistor open-circuit fault. In addition, the current reconstruction method is easily extended to SRMs with higher number of phases without additional current sensors. Simulations and experiments validate the effectiveness and flexibility of the proposed reconstruction strategy.

Detection of single and multiple IGBTs open-circuit faults in a field-oriented controlled induction motor drive

Abstract In this paper a transistor open-circuit fault diagnosis method in a rotor field oriented controlled induction motor drive, fed by a two-level voltage inverter has been proposed. The diagnostic procedure ensures detection and localization of single or multiple power switch failures in time shorter than one period of a stator current fundamental harmonic, without regard to a drive operation point. A new simple scheme of the diagnostic system is proposed. In order to validate the proposed transistor fault diagnostic method, a detailed simulation as well as experimental tests of the field-oriented control drive system were carried out and some of them are shown in this paper.

Analysis of Transistor Open Fault Diagnosis for Shunt Active Power Filters

<p>In this paper a transistor open-circuit fault diagnosis problem in two-level voltage inverter controlled shunt active power filter drives was discussed. Taking into consideration requirements of the contemporary monitoring drive systems original transistor fault diagnostic technique were proposed. Presented results were obtained by designed in PSIM software simulation model.</p>

Current kernel density estimation based transistor open‐circuit fault diagnosis in two‐level three phase rectifier

Two-level three phase rectifiers are widely used in industrial applications due to their superior performance. Their reliability has attracted lots of attention in recent decades. Transistor is one of the most fragile component because they suffer from voltage surge and thermic cycling. A fault diagnosis method based on current kernel density estimation for transistor open-circuit faults is proposed. The proposed method needs no extra sensors and it includes three steps: current kernel density estimation, Euclidean distance, fault detection and isolation. Experimental results show the proposed diagnosis method is highly efficient in single open-circuit fault and multiple open-circuit fault on the same leg.

Open-circuit fault detection and diagnosis in pulse-width modulation voltage source inverters based on novel pole voltage approach

In this paper, fault detection and an isolation technique for an insulated-gate bipolar transistor open-circuit fault in a voltage source inverter are presented. This technique consists of analysing the pole voltage and providing the detection and the location of simple, simultaneous and multiple faults. Open-circuit faults can be detected by sensing the pole voltage of each leg and comparing it with the theoretical one. To improve the calculation speed and reliability of this technique and to avoid false diagnosis alarms, the fault detection and isolation scheme is based on a novel model of pole voltage taking into account the time delays due to the turn-on and turn-off process of the power switches. This method reduces the detection time and is applied for open-loop or closed-loop faults in a transient or steady state.

Real-Time IGBT Open-Circuit Fault Diagnosis in Three-Level Neutral-Point-Clamped Voltage-Source Rectifiers Based on Instant Voltage Error

This paper presents a real-time diagnostic algorithm for insulated-gate bipolar transistor open-circuit faults in three-level neutral-point-clamped rectifiers. This algorithm is based on the instant voltage error in the converter and requires only signals already available to the control system, avoiding the use of additional hardware. The algorithm is independent from the load and from the used control strategy and provides very fast detection and identification of the fault, with diagnostic times as low as two sample periods (in favorable conditions). Experimental results are presented for the operation of the rectifier with two distinct control and modulation strategies and in different conditions. Results show the algorithm's speed, effectiveness, and robustness.

Comparison of Two Methods Basing on Artificial Neural Network and SVM in Fault Diagnosis

two diagnosis methods based on a neural network classifier and SVM are proposed for a pulse width modulation voltage source inverter. They are used to detect and identify the transistor open-circuit fault. BP neural network (BPNN) is capable of recognition. However, it has shortcomings obviously. These are just advantages of SVM, which has ability of global search. As an alternative to ANN, SVM can offer higher detection efficiency and reliability. Index Terms -neural network;SVM; fault diagnosis

Fault Detection of 3-Phase VSI using Wavelet-Fuzzy Algorithm

The good knowledge and information about the fault mode behaviour of the PWM voltage source inverter is important to improve system design, protection and fault tolerant control. This paper develops a real-time condition-monitoring algorithm for 3-phase Pulse Width Modulation (PWM) inverter in fuzzy speed controlled induction machine. It is designed to detect and identify the transistor open-circuit fault and an intermittent misfiring fault, which commonly occurs in the inverter drive system. The condition monitoring mechanism is based on Discrete Wavelet Transform (DWT) and Fuzzy Logic (FL). In this method, the stator currents are used as an input to the system. No direct access to the induction motor is required. The developed system has been rigorously assessed theoretically and experimentally, and it has been shown that the system is robust and reliable.

Wavelet-fuzzy-based algorithm for condition monitoring of voltage source inverter

A real-time condition monitoring algorithm for a three-phase pulse width modulation inverter in a fuzzy controlled induction machine is developed. It is designed to detect and identify the transistor open-circuit fault and intermittent misfiring fault, which commonly occurs in the drive system. The condition monitoring mechanism is based on discrete wavelet transform and fuzzy logic. The developed system has been rigorously assessed theoretically and experimentally, and it has been shown that the system is robust and reliable.