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The necessary conditions for the diagnosability of control systems with a complex structure are given. It is shown that the topological conditions for detectability and localization of the fault signal do not depend on the class of operators of the dynamic model of the control system and are checked by using path search algorithms in directed graphs.
The problem of dependability assessment can be solved analytically just under predefined conditions. If they do not hold, alternative approaches must apply. Widely, they rely on the Monte Carlo simulation, suffering by the high computational complexity. Some rest on further instruments such as probabilistic timed automata that have been shown to be efficient to solve problems in various areas. However,...
A real – time fire and explosion detection system is presented in this paper. The data being used was acquired by a Wireless Sensor Network, residing in a room. Noise is first rejected from the acquired samples, using an appropriate filter. Next, a model of the stochastic process is computed in real time using a robust – adaptive method. It will be used to predict the temperature's future evolution...
This paper focuses on the assessment of power systems dynamic stability, considering the example of the Blackout that occurred in Tunisia in 2014. The fault that caused the blackout is a short circuit that occurred on 31 August 2014. This work is a simulation of this fault using PSS/E Program with an assessment of the dynamic stability of the Tunisian power system. The work also addresses the importance...
WSNs are often besieged with issues related to interference when transmissions of two or more closely located sensor nodes interfere with each other. This forces the data aggregating nodes to receive distorted, faulty or interference ridden signals, which severely affects the fidelity of data being aggregated. If such faults are not arrested at the source, interference laden transmissions or Interference-Faults...
The modern power electric network is subject to insure more and more complicated functions; the main functions are transfer of energy and information. The faults in wiring cables constitute one of worst problems of power electric network. In practice, the combination of Time Domain Reflectometry (TDR) and wavelet transform is generally used to detect and localize the faults in electric network. Classically,...
This paper presents a modeling of a surface permanent magnet synchronous motor in healthy and faulty cases and a control approach aiming at reducing the torque ripple which appears in faulty case. The fault considered in this work is a stator inter-turn short circuit. The model proposed in this paper is based on the dynamic equations of the motor. Simulation results show the possibility to reduce...
Direct solar radiation is important in a solar trough plant because it is the perturbation that affects most the operation. Generally, it is measured locally. Production losses or dangerous situations may occur when controlling a plant with wrong measurements. A possible solution is to have several pyrheliometers though two problems arise: cost and sensor fusion (complexity). The aim of this paper...
In this paper we proposed a new approach for detection of faults in linear analog VLSI circuits. Our approach is very simple and efficient which is based on Signal Flow Graph. This approach is also used to calculate the tolerance of the component which is very important parameter of any VLSI circuit. In this paper we describe the whole method for testing of linear analog VLSI circuits and this approach...
Fault Detection and Isolation (FDI) is important in many industries to provide safe operation of a process. To determine the kind, size, location and time of fault, many Fault detection and Identification (FDI) Techniques are proposed. The Characteristic of FDI techniques include robustness, fast detection and isolation of faults. In this paper a comparison of fault diagnosis system based on Artificial...
In this paper we proposed a new approach for detection of faults in linear analog VLSI circuits. Our approach is very simple and efficient which is based on Signal Flow Graph. This approach is also used to calculate the tolerance of the component which is very important parameter of any VLSI circuit. In this paper we describe the whole method for testing of linear analog VLSI circuits and this approach...
The variation in wind speed causes the variation in the real/reactive power transfer of Squirrel Cage Induction Generators (SCIGs) based wind energy system (WES) connected to the grid resulting in fluctuations in the grid voltage and frequency. The SCIG based wind energy systems have to rely upon the mechanical pitch angle control of their wind turbines to smoothen out power fluctuations. This paper,...
Fault detection and diagnosis (FDD) are important engineering tasks that could effectively improve safety and reliability of technical processes by reducing the number of shutdowns that are necessary for traditional maintenance routines. Many techniques have been proposed in the area of FDD and the use of observers in fault detection is well established. This paper presents an improvement for Luenberger...
Stator winding faults are one of most frequent PMSM motor damages resulting from the degradation of the inter-turn, inter-phase and main isolation of the motor winding. So this paper presents a dynamic model for PMSM with inter-turn fault. The faulty model is used for studying the machine behavior and extracting the fault signatures.
Identifying fault prone modules at the very early stage of software development life cycle is very much necessary. This helps software developers to concentrate more on quality assurance, use the man power in proper perspective and mainly reduce the fault removal cost to be in-cured for the software system being developed. In literature, it is found that numerous authors have come up with cost based...
This paper investigates the performance of a wound rotor induction motor (WRIM) under rotor inter-turn short circuit fault using magnetic equivalent circuit (MEC) and finite elements method (FEM). Impacts of the fault on the signals of the motor including rotor current, stator current, and developed torque of the motor are addressed. Current of short circuit turns signal is considered here. This MEC-based...
The harmonic distortions of motor currents can be mitigated by the application of the double-delta sourced winding (DDSW), which implements multi-level operation with two-level converters. In practice, dual winding induction machine (DWIM) has been considered for this application due to its inherent compatibility to DDSW. The modeling of DWIM is discussed for the vector control, and a decoupling control...
In this paper we propose an estimator of solar radiation and a heuristic radiation selector to design a solar radiation Fault Tolerant Model Predictive Control strategy for solar trough plants. The complete design of the control system proposed has been simulated using the model of ACUREX solar trough plant at the Plataforma Solar de Almería (PSA) using a Gain Scheduling Generalized Predictive Control(GS-GPC)...
This paper presents real-time simulation results of a 512-level modular multilevel converter (MMC). Using off-the-shelf computers and FPGA boards, the converter, including the 6 valves, 6 arm inductors and the transformer, is simulated with a time-step of 450 ns. Such a small time-step is required to ensure high accuracy when applying gating signals but also when observing fault conditions. Simulation...
Because of the advantage of gear, gearbox was used widely. But its fault also brought many losses of the production and society. It was necessary to research and analysis on the dynamical behavior of the gear system. One kind of gear fault was numerically simulated so that the influence of gear fault to change of vibration state was studied theoretically, and the symptom generated by faults was found...
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