scholarly journals Analysis of Fault-Tolerant Operation Capabilities of an Isolated Bidirectional Current-Source DC–DC Converter

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3203
Author(s):  
Andrei Blinov ◽  
Roman Kosenko ◽  
Andrii Chub ◽  
Volodymyr Ivakhno

Reliable and predictable operation of power electronics is of increasing importance due to continuously growing penetration of such systems in industrial applications. This article focuses on the fault-tolerant operation of the bidirectional secondary-modulated current-source DC–DC converter. The study analyzes possible topology reconfigurations in case an open- or short-circuit condition occurs in one of the semiconductor devices. In addition, multi-mode operation based on topology-morphing is evaluated to extend the operating range of the case study topology. The influence of post-failure modes on the functionality and performance is analyzed with a 300 W converter prototype. It is demonstrated that failure of one transistor in the current-source side can be mitigated without dramatic loss in the efficiency at maximum power, while preserving bidirectional operation capability.

2020 ◽  
Vol 11 (2) ◽  
pp. 37 ◽  
Author(s):  
Daouda Mande ◽  
João Pedro Trovão ◽  
Minh Cao Ta

Power electronics play a fundamental role for electric transportation, renewable energy conversion and many other industrial applications. They have the ability to help achieve high efficiency and performance in power systems. However, traditional inverters such as voltage source and current source inverters present some limitations. Consequently, many research efforts have been focused on developing new power electronics converters suitable for many applications. Compared with the conventional two-stage inverter, Z-source inverter (ZSI) is a single-stage converter with lower design cost and high efficiency. It is a power electronics circuit of which the function is to convert DC input voltage to a symmetrical AC output voltage of desired magnitude and frequency. Recently, ZSIs have been widely used as a replacement for conventional two-stage inverters in the distributed generation systems. Several modifications have been carried out on ZSI to improve its performance and efficiency. This paper reviews the-state-of-art impedance source inverter main topologies and points out their applications for multisource electric vehicles. A concise review of main existing topologies is presented. The basic structural differences, advantages and limitations of each topology are illustrated. From this state-of-the-art review of impedance source inverters, the embedded quasi-Z-source inverter presents one of the promising architectures which can be used in multisource electric vehicles, with better performance and reliability. The utilization of this new topology will open the door to several development axes, with great impact on electric vehicles (EVs).


2021 ◽  
Author(s):  
Juan Carlos Iglesias-Rojas

<div>Isolated multilevel inverters are widely used in renewable energy systems and industrial applications. Isolated IGBT topologies exploit the usage of low-frequency transformers that improve robustness and reliability. However, critical failure mechanisms should be considered at the design stage to ensure proper performance. This paper describes these critical failure mechanisms, such as short circuit, cross-conduction, IGBT high inductive load avalanche, IGBT second turn-on, VS-undershoot, transformer inrush current, IGBT thermal runaway, and cable switching interference. Furthermore, this paper comprises design techniques to prevent these failures. The previous failure mechanisms come from the inverter's power stage, except switching interference from control signal cables and directly affecting the control device functionality. This work also proposes a circuit topology based on FPGA resources to reduce switching interference from control signal cables. It behaves like a fault tolerant digital input that effectively filters bouncing events shorter than 2μs. Measurements report satisfactory experimental results upon constructing a 45kVA ac-side-isolated 13-level inverter.</div>


Author(s):  
Jingyi Liu ◽  
Yugang Zhang ◽  
Bifeng Song

This paper establishes a competing failure analysis model for complex mechanical system under component failure and performance failure considering degradation. Traditionally, mechanical system is composed by a number of components. Meanwhile, mechanical system has the ability to accomplish its specific performance. Therefore, mechanism may fail because of two kinds of failure modes, the component failure due to degradation (such as component wear) and the performance failure (system couldn't complete performance). The two failure modes compete with each other because as soon as one mode occurs the system just fails. The component will degrade with time as system operates as well as the system performance. In this paper, Brownian motion (BM) with nonlinear drift is used to model the degradation of components based on which component failure is analyzed. The function of performance measurement is built by surrogate and performance failure is analyzed by it at different working circulation. Farlie–Gumbel–Morgenstern (FGM) copula is introduced to describe the dependence. The system reliability is analyzed by FGM copula as well as competing failure probability for each failure mode. Finally, a numerical example and an engineering case study are used to illustrate the proposed model.


Author(s):  
M O T Cole ◽  
P S Keogh ◽  
C R Burrows

Magnetic bearings now exist in a variety of industrial applications. However, there are still concerns over the control integrity of rotor/magnetic bearing systems and the ability of control systems to cope with possible faults that can occur during operation. Unless control systems can be developed that have the ability to maintain safe operation when the system is in a degraded or faulty state, then many, otherwise viable, magnetic bearing applications will remain unfulfilled. In this paper, a method is proposed for the design of a fault-tolerant control system that can detect and identify both incipient and sudden faults as and when they occur. A multivariable H∞ controller is reconfigured on occurrence of a fault so that stability and performance is maintained. A neural network is trained to identify faults associated with the system position transducer measurements so that the output from the neural network can be used as the decision tool for reconfiguring control. In this way, satisfactory control of the system can be maintained during failure of a control input. The method requires no knowledge of the system dynamics or system disturbances, and the network can be trained on-line. The validity of this method is demonstrated experimentally for various modes of sensor failure.


2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Kittipong Saetia ◽  
Sarah Lukens ◽  
Erik Pijcke ◽  
Xiaohui Hu

A standardized taxonomy enables asset-intensive industrial organizations to systematically measure and track efficiency and performance of assets at different levels in an asset hierarchy. Having a well-structured taxonomy also allows companies to take advantage of emerging data-driven technologies such as PHM through enabling straightforward mapping of assets to analytical content specific to equipment commonalities, e.g., failure modes. However, the complexity and use of equipment taxonomy and coding structures in maintenance management systems vary widely for different organizations. This paper describes a data-driven approach for identifying equipment taxonomy from equipment records in maintenance management systems. The approach combines machine learning-based and rule-based methods into a hybrid man-in-the-loop workflow, which enables rapid and consistent mapping of equipment into a standard taxonomy. A case study is presented to demonstrate the performance and challenges of the proposed approach on equipment taxonomy classification.


2021 ◽  
Author(s):  
Juan Carlos Iglesias-Rojas

<div>Isolated multilevel inverters are widely used in renewable energy systems and industrial applications. Isolated IGBT topologies exploit the usage of low-frequency transformers that improve robustness and reliability. However, critical failure mechanisms should be considered at the design stage to ensure proper performance. This paper describes these critical failure mechanisms, such as short circuit, cross-conduction, IGBT high inductive load avalanche, IGBT second turn-on, VS-undershoot, transformer inrush current, IGBT thermal runaway, and cable switching interference. Furthermore, this paper comprises design techniques to prevent these failures. The previous failure mechanisms come from the inverter's power stage, except switching interference from control signal cables and directly affecting the control device functionality. This work also proposes a circuit topology based on FPGA resources to reduce switching interference from control signal cables. It behaves like a fault tolerant digital input that effectively filters bouncing events shorter than 2μs. Measurements report satisfactory experimental results upon constructing a 45kVA ac-side-isolated 13-level inverter.</div>


2015 ◽  
Vol 3 (2) ◽  
pp. 55
Author(s):  
Norol Hamiza Zamzuri ◽  
Khairil Wahidin Awang ◽  
Yuhanis Abdul Aziz ◽  
Zaiton Samdin

The growth of the event sector is underpinned by the demand of organizing a business event.  Thus, it leads to an increase in economic and social impact. However, the problems from the growth of this sector potentially results from the use of several event materials, transportation and infrastructure development.  Organizing a green event is seen as one of the strategies to reduce the environmental impact.  Therefore, the aim of this paper is to explore the issues involved throughout the process of greening an event by applying Mair and Jago Model.  Semi-structured interviews were conducted with event managers from six Malaysia business event companies that encourage green practices during their event.  Findings suggest that impact, initiative, support and performance motivates event organizers in organizing a green event.  It has also been found that knowledge, resources and behaviour are the barriers faced by event organizers throughout the process of organizing a green event.  Based on the findings it appears that two important factors have emerged from the data collection and analysis that showed a deviation from the Mair and Jago Model, namely “impact” for the motivation element and “support” for the barrier element.  The main limitation of this study was the scope of the study; as it only focuses on business events.  However, as the main purpose of this study is to explore the issues of organizing a green event, it has been found that there are other issues need to be explored in other contexts and geographical area.  Apart from this, as this is a case study, it can only replicate according to the circumstances of this case study. However, this study can be generalized in terms of the theory that has emerged from it.  It is suggested that further research should explore more issues in other contexts and geographical areas. 


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