Short Switch Faults Research Articles

Model Predictive Direct Torque With Fault Tolerance Control for a Permanent Magnet Synchronous Generator Based on Vienna Rectifier

This paper presents the fault tolerance of model predictive direct torque control for a permanent magnet synchronous generator under a faulty Vienna rectifier. The fault applied includes open-switch and short-switch fault in a particular active switching device of the Vienna rectifier. The measured input current is used in the proposed fault diagnosis approach to detect the switch fault’s position without any additional hardware being implemented. Whenever a switching fault occurs at any phase of the Vienna rectifier, the available switching vectors for prediction control are reduced from five to four. The feasibility and effectiveness of the proposed fault tolerance model predictive direct torque control under a faulty Vienna rectifier are demonstrated and investigated through MATLAB/Simulink. The results show that it is feasible for the proposed method to be operated under a short-switch fault with slightly higher total harmonics distortion of the input current but out of control under an open-switch fault.

Diagnosis and Tolerance of Common Electrical Faults in T-Type Three-Level Inverters Fed Dual Three-Phase PMSM Drives

In this paper, diagnosis and tolerant control schemes have been studied for common electrical faults in T-type three-level inverter fed dual-three phase permanent magnet synchronous motor (PMSM) drives for safety-critical applications. Based on vector space decomposition and double three-phase space vector modulation, diagnostic and tolerant control methods have been developed comprehensively for open-phase faults, open-switch faults, and short-switch faults in T-type three-level inverter fed dual-three-phase PMSM drives, in such way that misdiagnosis of different faults sharing similar faulty features can be avoided. In particular, a two-step diagnostic scheme is proposed in order to simplify the diagnostic process. The first step is to identify the faulty phase and fault category by analyzing current trajectories on harmonic subspace, and the second step is to determine the specific fault type in a small fault-searching area obtained from the first step. In the aspect of fault-tolerant control, a novel current compensation method is proposed for open-phase fault without changing the machine model, space vector diagram, and control framework. Open-switch faults and short-switch faults are tolerated by making full use of the remaining vectors after faults. The validity of the proposed fault diagnosis and tolerance schemes has been verified by experiments.

Short switch fault diagnosis method for power converter using a model‐based approach in switched reluctance motor drives

Switched reluctance motor (SRM) is a competitive solution for aircraft and automotive applications due to its fault-tolerant capabilities and robust configuration. Power converter is a key component in SRM drives, but it prone to faults. In this study, a new and fast diagnosis method for short-circuit fault of the SRM converter is proposed based on the mixed logical dynamic (MLD) model and residual generation. Effects of short-circuit fault on SRM drives are analysed in detail. The MLD model of an asymmetrical half-bridge converter of SRM drives is presented to evaluate the currents of the power converter. The short-circuit faulty switch is identified by analysing the system residual, achieved by comparing the outputs of the MLD model and the sensor measurements. In contrast to other methods, the presented method requires no additional hardware but only measured phase currents and command signals, which are available in the control system. Simulation results confirm the effectiveness of the proposed diagnosis method. It is shown that such diagnosis method can identify the faulty switch of the power converter in a few milliseconds, which is important to avoid catastrophic consequences. It is fast, reliable and easy for industrial applications due the low-computational requirement.

Extended Kalman Filter for Sensorless Fault Tolerant Control of PMSM with Stator Resistance Estimation

<p><span>This paper aims to provide a high performance sensorless control based on an Extended Kalman Filter (EKF) applied to fault-tolerant PMSM drive system with stator-resistance estimation. It proposes a fast method of fault switches detection in the power converters. The considered drive is composed of three phases PMSM and a four leg three phase’s inverter when the fourth is the redundant leg. After a short-switch fault occurrence, the redundant leg replaces the faulty leg. The simulation results verify that the proposed control method and the fault tolerant inverter ensure the high reliability and continuously operation of the sensorless vector control PMSM system under inverter fault.</span></p>