--The relationship between the two-individual current control and the vector space decomposition (VSD) control for a dual three-phase permanent magnet synchronous machine (PMSM) is investigated in this paper. It is found that the VSD control is more flexible on controlling the fundamental current in sub-plane and the fifth, seventh current harmonics in z 1 z 2 sub-plane with different PI gains, while the two-individual current control is comparable to the VSD control in having the same PI gains in the and z 1 z 2 subplanes. It is also found that the two-individual current control may have potential instability issues due to the mutual coupling between the two sets of three-phase windings. If the mutual coupling between the two sets is weak to some extent, then the two-individual current control could have the same dynamic performance as the VSD control without the stability issues. Experiments are conducted on a prototype dual three-phase PMSM to validate the theoretical analysis.Index Terms--double d-q synchronous frame current control, double-star motor, dual three-phase, instability, two-individual current control, VSD control.

© 2017. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. Reproduced in accordance with the publisher's self-archiving policy.eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request.Abstract --A method for enhancing torque capability of a dual 3-phase permanent magnet synchronous machine (PMSM) based on conventional dual 3-phase drive system by injecting the fifth and seventh current harmonics without any hardware re-configuration is proposed in this paper. Compared with the third current harmonic injection which is commonly used to enhance torque capability of dual three-phase machine, the two isolated neutral points of each set of single 3-phase windings do not need to be re-connected to the middle point of dc-link capacitors or an additional power switching bridge to provide flowing path for zerosequence current. Further, no additional current sensors are required to obtain the feedback of zero-sequence current to regulate it effectively. For a prototype dual 3-phase PMSM, the average torque increases approximately by 9% at the cost of 0.56% increase in the 12th harmonic torque ripple. The effectiveness of the torque capability enhancement is confirmed by experiments.

--The relationship between the two-individual current control and the vector space decomposition (VSD) control for a dual three-phase permanent magnet synchronous machine (PMSM) is investigated in this paper. It is found that the VSD control is more flexible on controlling the fundamental current in sub-plane and the fifth, seventh current harmonics in z 1 z 2 sub-plane with different PI gains, while the two-individual current control is comparable to the VSD control in having the same PI gains in the and z 1 z 2 subplanes. It is also found that the two-individual current control may have potential instability issues due to the mutual coupling between the two sets of three-phase windings. If the mutual coupling between the two sets is weak to some extent, then the two-individual current control could have the same dynamic performance as the VSD control without the stability issues. Experiments are conducted on a prototype dual three-phase PMSM to validate the theoretical analysis.Index Terms--double d-q synchronous frame current control, double-star motor, dual three-phase, instability, two-individual current control, VSD control.

No abstract

Sumsurooah, Sharmila and Odavic, Milijana and Bozhko, Serhiy (2017) A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription.For more information, please contact eprints@nottingham.ac.uk µ approach to robust stability domains in the space of parametric uncertainties for a power system with ideal CPL Sharmila Sumsurooah, Milijana Odavic, Member, IEEE, and Serhiy Bozhko, Member, IEEE Abstract-Power electronic systems are prone to instability. The problem, generally attributed to the constant power load (CPL) behaviour of their power electronic controlled loads, can become more acute when the systems are subject to parametric uncertainties. The structured singular value (SSV) based µ method has proven to be a reliable approach for assessing the stability robustness of such uncertain systems. Despite its numerous benefits, the µ method is not often applied to electrical power systems (EPS) with multiple uncertainties. This may be due to the mathematical complexity underlying the µ theory. This work aims to make the µ approach more application-friendly by providing clearer insights into the meaning and usefulness of the robust stability measure µ for EPS with multiple parametric uncertainties. This is achieved by presenting a methodology for translating µ analysis results from the frequency domain to the more perceivable uncertain parameters domain. The method directly demonstrates dependences of system stability on uncertain system parameters. Further, it clearly identifies robust stability domains as subsets of the much wider stability domains. The work is based on a representative EPS connected to an ideal CPL. µ analysis predictions are evaluated and validated against analytical results for the example CPL system.

Αβστραχτ -Ιν τηισ παπερ, τηε ζερο σεθυενχε χιρχυλατινγ χυρρεντ ιν οπεν ωινδινγ (ΟW) περmανεντ mαγνετ σψνχηρονουσ mαχηινε (ΟW−ΠΜΣΜ) δριϖεσ ωιτη χοmmον DΧ βυσ ισ σψστεmατιχαλλψ αναλψσεδ φορ τηε φιρστ τιmε. Ιτ ισ ρεϖεαλεδ τηατ τηε ζερο σεθυενχε χιρχυλατινγ χυρρεντ ισ αφφεχτεδ βψ ζερο σεθυενχε βαχκ ελεχτροmοτιϖε φορχε (ΕΜΦ), χροσσ χουπλινγ ϖολταγεσ ιν ζερο σεθυενχε, φροm τηε mαχηινε σιδε, πυλσε ωιδτη mοδυλατιον (ΠWΜ) ινδυχεδ ζερο σεθυενχε ϖολταγε ανδ ινϖερτερ νονλινεαριτψ, φροm τηε ινϖερτερ σιδε. Παρτιχυλαρλψ, τηε ινφλυενχεσ φροm τηε χροσσ χουπλινγ ϖολταγεσ ιν ζερο σεθυενχε ανδ παρασιτιχ εφφεχτ οφ ινϖερτερ νονλινεαριτψ αρε ινϖεστιγατεδ φορ τηε φιρστ τιmε ιν τηισ παπερ. Τηεν τηε σψντηετιχ mοδελ οφ τηε εθυιϖαλεντ ζερο σεθυενχε χιρχυιτ ισ προποσεδ ασ ωελλ. Εαχη χαυσε ισ στυδιεδ ινδεπενδεντλψ ϖια αναλψτιχαλ mοδελλινγ, φινιτε ελεmεντ αναλψσισ ανδ εξπεριmεντσ. Μεανωηιλε, το ταχκλε τηισ ισσυε, τηε ρελεϖαντ συππρεσσιον στρατεγψ υσινγ φρεθυενχψ αδαπτιϖε προπορτιοναλ ρεσοναντ χοντρολλερ ισ πρεσεντεδ ανδ τεστεδ ον τηε 3κW ΟW−ΠΜΣΜ πλατφορm.Κεψωορδσ-Χιρχυλατινγ χυρρεντ, ινϖερτερ νονλινεαριτψ, οπεν ωινδινγ, ΠΜΣΜ, ζερο σεθυενχε.

No abstract

Abstract-Stability studies are a crucial part of the design of power electronic systems, especially for safety critical applications. Standard methods can guarantee stability under nominal conditions but do not take into account the multiple uncertainties that are inherent in the physical system or in the system model. These uncertainties, if unaccounted for, may lead to highly optimistic or even erroneous stability margins. The structured singular value-based µ method justifiably takes into account all possible uncertainties in the system. However, the application of the µ method to power electronic systems with multiple uncertainties is not widely discussed in the literature. This work presents practical approaches to applying the µ method in the robust stability analysis of such uncertain systems. Further, it reveals the significant impact of various types of parametric uncertainties on the reliability of stability assessments of power electronic systems. This is achieved by examining the robust stability margin of the dc/dc buck converter system, when it is subject to variations in system load, line resistance, operating temperature and uncertainties in the system model. The µ predictions are supported by time domain simulation and experimental results.Index Terms-Robust stability analysis, dc/dc buck power electronic converter, Linear fractional transformation, Structured singular value, µ analysis.