Proactive fault-tolerant IGBT-based power converters for mission critical applications in MW range

Author(s):  
Victor N. Ferreira ◽  
Braz J. Cadoso Filho ◽  
Anderson V. Rocha
2018 ◽  
Vol 8 (3) ◽  
pp. 20-31 ◽  
Author(s):  
Sam Goundar ◽  
Akashdeep Bhardwaj

With mission critical web applications and resources being hosted on cloud environments, and cloud services growing fast, the need for having greater level of service assurance regarding fault tolerance for availability and reliability has increased. The high priority now is ensuring a fault tolerant environment that can keep the systems up and running. To minimize the impact of downtime or accessibility failure due to systems, network devices or hardware, the expectations are that such failures need to be anticipated and handled proactively in fast, intelligent way. This article discusses the fault tolerance system for cloud computing environments, analyzes whether this is effective for Cloud environments.


Role of Configurable Distributed Checkout and Launch System (CDCLS) is pivotal in carrying out quick health checks and launching of Aerospace Flight Vehicles. Configurable Distributed Architecture provides flexibility for connecting nodes and scaling Distributed System. Different configurations can be derived from the Master Configuration. Since, Ultra high reliability and infallible performance of the CDCLS is of paramount importance, Safety criticality and Mission criticality analysis needs to be carried out for determination of mission critical parameters. These critical parameters need to be addressed by required fault tolerant architecture, which can be implemented in Hardware and Software for achieving system reliability objective (Say, 0.99).


2019 ◽  
Vol 63 (3) ◽  
pp. 227-234
Author(s):  
Mongi Moujahed ◽  
Bilel Touaiti ◽  
Hechmi Ben Azza ◽  
Mohamed Jemli ◽  
Mohamed Boussak

This paper exhibits a sensor-less speed control method based MRAS observer applied to a fault-tolerant PMSM drive system. So, this paper proposes a rapid method of fault switch detection in the power converters aiming to make sure the continuity of service even though the fault presence of an opening phase. In fact, the MRAS observer is used to replace the mechanical sensor and a redundant inverter leg is equally employed to replace the faulty leg. The proposed fast fault diagnosis method has the features of simple algorithm, independence of the transient states and being simply integrated without any additional sensors.


Author(s):  
Wenbing Zhao

The use of good random numbers is crucial to the security of many mission-critical systems. However, when such systems are replicated for Byzantine fault tolerance, a serious issue arises, i.e., how do we preserve the integrity of the systems while ensuring strong replica consistency? Despite the fact that there exists a large body of work on how to render replicas deterministic under the benign fault model, the solutions regarding the random number control are often overly simplistic without regard to the security requirement, and hence, they are not suitable for practical Byzantine fault tolerance. In this chapter, we present a novel integrity-preserving replica coordination algorithm for Byzantine fault tolerant systems. The central idea behind our CD-BFT algorithm is that all random numbers to be used by the replicas are collectively determined, based on the contributions made by a quorum of replicas, at least f+1 of which are not faulty.


2020 ◽  
Vol 174 (3-4) ◽  
pp. 229-258
Author(s):  
Qian Matteo Chen ◽  
Alberto Finzi ◽  
Toni Mancini ◽  
Igor Melatti ◽  
Enrico Tronci

In critical infrastructures like airports, much care has to be devoted in protecting radio communication networks from external electromagnetic interference. Protection of such mission-critical radio communication networks is usually tackled by exploiting radiogoniometers: at least three suitably deployed radiogoniometers, and a gateway gathering information from them, permit to monitor and localise sources of electromagnetic emissions that are not supposed to be present in the monitored area. Typically, radiogoniometers are connected to the gateway through relay nodes. As a result, some degree of fault-tolerance for the network of relay nodes is essential in order to offer a reliable monitoring. On the other hand, deployment of relay nodes is typically quite expensive. As a result, we have two conflicting requirements: minimise costs while guaranteeing a given fault-tolerance. In this paper, we address the problem of computing a deployment for relay nodes that minimises the overall cost while at the same time guaranteeing proper working of the network even when some of the relay nodes (up to a given maximum number) become faulty (fault-tolerance). We show that, by means of a computation-intensive pre-processing on a HPC infrastructure, the above optimisation problem can be encoded as a 0/1 Linear Program, becoming suitable to be approached with standard Artificial Intelligence reasoners like MILP, PB-SAT, and SMT/OMT solvers. Our problem formulation enables us to present experimental results comparing the performance of these three solving technologies on a real case study of a relay node network deployment in areas of the Leonardo da Vinci Airport in Rome, Italy.


Author(s):  
Sam Goundar ◽  
Akashdeep Bhardwaj

With mission critical web applications and resources being hosted on cloud environments, and cloud services growing fast, the need for having greater level of service assurance regarding fault tolerance for availability and reliability has increased. The high priority now is ensuring a fault tolerant environment that can keep the systems up and running. To minimize the impact of downtime or accessibility failure due to systems, network devices or hardware, the expectations are that such failures need to be anticipated and handled proactively in fast, intelligent way. This article discusses the fault tolerance system for cloud computing environments, analyzes whether this is effective for Cloud environments.


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