1,303 research outputs found
Optimal Fault-Tolerant Control of Six-Phase Induction Motor Drives with Parallel Converters
Multiphase drives and parallel converters have
been recently proposed in low-voltage high-power
applications. The fault-tolerant capability provided by
multiphase drives is then extended with parallel converters,
increasing their suitability for safety-critical and renewable
uses. This advantageous feature, compared to standard threephase
drives, has been analyzed in the event of open-phase
faults. However, when using parallel converters, a converter
fault does not necessarily imply an open-phase condition, but
usually just a limited phase current capability. This work
analyzes the fault-tolerant capability of six-phase drives with
parallel converter supply. Different scenarios considering up
to three faults for single and two neutral configurations are
examined, optimizing off-line the post-fault currents and
modifying accordingly the control strategies. Experimental
results confirm the smooth transition from pre- to post-fault
situations and the enhanced post-fault torque capability.Ministerio de Ciencia e Innovación ENE2014- 52536-C2-1-R DPI2013-44278-RJunta de Andalucía P11-TEP-755
Impact of post-fault flux adaptation on six-phase induction motor drives with parallel converters
The redundancy of multiphase drives
provides an inherent fault-tolerant capability that is
appreciated in applications with a complicated
corrective maintenance or safety-critical requirements.
Fault restrictions however force the system to be
reconfigured to operate in a smooth and efficient
manner. Previous works have been focused on the
optimization of current waveforms to generate an
undisturbed operation but still maintaining the pre-fault
rated flux settings. This work shows that efficient
controllers can improve the post-fault performance in
six-phase induction machines supplied by parallel-
connected converters if offline optimization is used to
obtain a variable reference flux. Theoretical and
experimental results confirm that the proposed flux
adaptation method provides higher torque/power
capability, lower degree of imbalance in the current
sharing between windings and efficiency improvementMinisterio de Ciencia e Innovación ENE2014-52536-C2-1-R DPI2013- 44278-RJunta de Andalucía P11-TEP-755
Multiphase induction motor drives - a technology status review
The area of multiphase variable-speed motor drives in general and multiphase induction motor drives in particular has experienced a substantial growth since the beginning of this century. Research has been conducted worldwide and numerous interesting developments have been reported in the literature. An attempt is made to provide a detailed overview of the current state-of-the-art in this area. The elaborated aspects include advantages of multiphase induction machines, modelling of multiphase induction machines, basic vector control and direct torque control schemes and PWM control of multiphase voltage source inverters. The authors also provide a detailed survey of the control strategies for five-phase and asymmetrical six-phase induction motor drives, as well as an overview of the approaches to the design of fault tolerant strategies for post-fault drive operation, and a discussion of multiphase multi-motor drives with single inverter supply. Experimental results, collected from various multiphase induction motor drive laboratory rigs, are also included to facilitate the understanding of the drive operatio
Fault-tolerant Operation of Six-phase Energy Conversion Systems with Parallel Machine-side Converters
The fault tolerance provided by multiphase machines
is one of the most attractive features for industry applications
where a high degree of reliability is required. Aiming to take advantage of such postfault operating capability, some newly designed
full-power energy conversion systems are selecting machines with
more than three phases. Although the use of parallel converters
is usual in high-power three-phase electrical drives, the fault tolerance of multiphase machines has been mainly considered with
single supply from a multiphase converter. This study addresses
the fault-tolerant capability of six-phase energy conversion systems supplied with parallel converters, deriving the current references and control strategy that need to be utilized to maximize
torque/power production. Experimental results show that it is possible to increase the postfault rating of the system if some degree
of imbalance in the current sharing between the two sets of threephase windings is permitted.Ministerio de Ciencia e Innovación ENE2014-52536-C2–1-R DPI2013-44278-RJunta de Andalucía P11-TEP-755
Fault-tolerant efficient control of six-phase induction generators in wind energy conversion systems with series-parallel machine-side converters
This work discusses the implementation of an efficient fault-tolerant control m a multiphase wind energy conversion system. The conversion system consists of an asymmetrical six-phase induction generator supplied by four voltage source converters (VSCs) m a hybrid series/parallel configuration. Post-fault operation must preserve the current ratings of the system and should also maximize the generated power by means of a proper flux adjustment. Both requirements are achieved m this work using a non-linear optimization analysis and some modifications m the control scheme. Simulation results confirm the optimal and safe performance of the wind energy system under study
Fault-Tolerant Operation of Six-Phase Energy Conversion Systems With Parallel Machine-Side Converters
The fault tolerance provided by multiphase machines is one of the most attractive features for industry applications where a high degree of reliability is required. Aiming to take advantage of such postfault operating capability, some newly designed full-power energy conversion systems are selecting machines with more than three phases. Although the use of parallel converters is usual in high-power three-phase electrical drives, the fault tolerance of multiphase machines has been mainly considered with single supply from a multiphase converter. This study addresses the fault-tolerant capability of six-phase energy conversion systems supplied with parallel converters, deriving the current references and control strategy that need to be utilized to maximize torque/power production. Experimental results show that it is possible to increase the postfault rating of the system if some degree of imbalance in the current sharing between the two sets of threephase windings is permitted
Multiphase Machines and Drives-Revisited
Although the concept of a multiphase drive system dates back to the middle of the 20th century, the initial pace of development was rather slow, as witnessed by the first two surveys of the area published in the beginning of this century. However, considerably new developments have resulted in the last decade of the 20th century and the beginning of this century, leading to an authoritative survey of the asymmetrical six-phase drive control and subsequently of the review of the complete area. This also initiated the organization and subsequent publication of the first IEEE Transactions on Industrial Electronics "Special Section on Multiphase Machines and Drives" in May 2008, which commenced with another survey paper, and that contained 12 original research papers. Since the publication of this Special Section in May 2008, the level of interest and pace of developments in the area have further accelerated and substantial new knowledge has been generatedwith an ever-increasing number of published research papers and reported new industrial applications. Such a trend has been emphasized in a recent paper. It therefore seemed appropriate to revisit the area and organize this Special Section as a sequel to the first one. The call for the Special Section papers resulted in 51 submissions, almost twice as many as the total back in 2008, thus confirming a substantial growth of the area. Indeed, the amount of new knowledge acquired since the publication of the first Special Section in 2008 has meant that it was not possible to provide a complete and thorough survey of the field in a single review paper
Multilevel Converters: An Enabling Technology for High-Power Applications
| Multilevel converters are considered today as the
state-of-the-art power-conversion systems for high-power and
power-quality demanding applications. This paper presents a
tutorial on this technology, covering the operating principle and
the different power circuit topologies, modulation methods,
technical issues and industry applications. Special attention is
given to established technology already found in industry with
more in-depth and self-contained information, while recent
advances and state-of-the-art contributions are addressed with
useful references. This paper serves as an introduction to the
subject for the not-familiarized reader, as well as an update or
reference for academics and practicing engineers working in
the field of industrial and power electronics.Ministerio de Ciencia y Tecnología DPI2001-3089Ministerio de Eduación y Ciencia d TEC2006-0386
Predictive current control in electrical drives: an illustrated review with case examples using a five-phase induction motor drive with distributed windings
The industrial application of electric machines in variable-speed drives has grown in the last decades thanks to the
development of microprocessors and power converters. Although three-phase machines constitute the most common case, the
interest of the research community has been recently focused on machines with more than three phases, known as multiphase
machines. The principal reason lies in the exploitation of their advantages like reliability, better current distribution among phases
or lower current harmonic production in the power converter than conventional three-phase ones, to name a few. Nevertheless,
multiphase drives applications require the development of complex controllers to regulate the torque (or speed) and flux of the
machine. In this regard, predictive current controllers have recently appeared as a viable alternative due to an easy formulation
and a high flexibility to incorporate different control objectives. It is found however that these controllers face some peculiarities
and limitations in their use that require attention. This work attempts to tackle the predictive current control technique as a viable
alternative for the regulation of multiphase drives, paying special attention to the development of the control technique and the
discussion of the benefits and limitations. Case examples with experimental results in a symmetrical five-phase induction machine
with distributed windings in motoring mode of operation are used to this end
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