Title Regulacija bezležajnog motora s izraženom nelinearnom ovisnošću razvijene magnetske sile o strujama : doktorska disertacija
Title (english) Control structure for bearingless electrical drive with nonlinear dependency between developed magnetic force and currents : doctoral thesis
Author Nikola Turk
Mentor Neven Bulić (mentor)
Committee member Dubravko Franković (predsjednik povjerenstva)
Committee member Rene Prenc (član povjerenstva)
Committee member Damir Sumina (član povjerenstva)
Granter University of Rijeka Faculty of Engineering Rijeka
Defense date and country 2021-02-12, Croatia
Scientific / art field, discipline and subdiscipline TECHNICAL SCIENCES Electrical Engineering
Universal decimal classification (UDC ) 62 - Engineering. Technology in general
Abstract Bezležajni motori spadaju u specijalnu vrstu električnih strojeva koji umjesto
mehaničke koriste magnetsku suspenziju rotora. Korištenje magnetske suspenzije rotora
eliminira potrebu za korištenjem mehaničkih ležajeva, te omogućuje rad motora u kojem
rotor nema nikakav fizički kontakt sa statorom. Stoga bezležajni motori imaju prednosti kao
što su dugi životni vijek, niski troškovi održavanja, ne postoji potreba za korištenjem maziva,
nema potrebe za brtvljenjem i omogućuju hermetičku razdvojenost statora i rotora. Navedene
prednosti čine bezležajne motore veoma pogodnim za aplikacije u kojima se zahtijeva visoka
čistoća.
Upotreba magnetske suspenzije (magnetske levitacije) podrazumijeva održavanje
rotora u centralnom položaju korištenjem isključivo magnetskih sila, što predstavlja jednu
od glavnih problematika kojom se bavi područje bezležajnih motora. Problem magnetske
suspenzije rotora rješava se odgovarajućim dizajnom i konstrukcijom motora, što, između
ostaloga, podrazumijeva upotrebu većeg broja senzora, višefazni izvor napajanja i digitalni
sustav upravljanja.
Pojednostavljenje konstrukcije bezležajnog motora postignuto je uvođenjem
bezležajnog motora s rotorom u obliku diska. Korištenje rotora u obliku diska omogućuje
pasivnu stabilizaciju rotora u tri stupnja slobode njegova gibanja. Stabilizacija rotora u
preostala dva stupnja slobode gibanja postiže se aktivnom stabilizacijom (upravljanjem
strujama). Aktivna stabilizacija ostvaruje se regulacijom.
Uslijed postojanja potrebe za aktivnom stabilizacijom rotora, može se zaključiti da je
regulacijska struktura neophodna za rad bezležajnog motora. Većina suvremenih bezležajnih
motora posjeduje linearnu ovisnost razvijenih sila o strujama motora, te su posljedično i
regulacijske strukture bezležajnih motora temeljene na pretpostavci linearne ovisnosti
razvijene sile o strujama.
Međutim, kod određenih vrsta bezležajnih motora, posebice kod bezležajnih motora
s reluktantnim rotorom, nije moguće zanemariti nelinearnu ovisnost razvijenih sila o
strujama. Ovaj rad se bavi izradom regulacijske strukture bezležajnog motora u slučaju kada
pretpostavka linearne ovisnosti razvijene sile o strujama nije ispunjena. U radu su opisani svi
važni koraci od kojih se sastojalo provedeno istraživanje, što uključuje izrade modela, razvoj
nove regulacijske strukture, njeno pojednostavljenje u svrhu implementacije, implementacija
razvijene regulacijske strukture na digitalni sustav upravljanja bezležajnog motora i
eksperimentalne provjere razvijene regulacijske strukture.
Abstract (english) Bearingless motors belong to a special type of electric machines that use a magnetic
suspension instead of a mechanical one for holding rotor in the air gap avoiding physical
contact between rotor and stator. The use of a rotor magnetic suspension eliminates the needs
of mechanical bearings usage and allows the motor operation in which the rotor has no
physical connection with the stator over the classical bearing system. Therefore, bearingless
motors have advantages over classical motors such as long service life, low maintenance
costs, no usage of lubricants, no need for sealing and allow hermetic separation of stator and
rotor. These advantages make bearingless motors very suitable for applications where high
cleanliness is required.
The use of magnetic suspension (magnetic levitation) involves keeping the rotor in a
central position using only magnetic forces, which is one of the main issues in a bearingless
motors operations. The problem of the magnetic suspension of the rotor is solved by the
appropriate design and construction of the motor, which, among other things, implies the use
of a large number of sensors, a multi-phase power supply and a specially designed digital
control system.
Simplification of the construction of the bearingless motor was achieved by the
introduction of the bearingless motor with a disk-shaped rotor. The usage of a disk-shaped
rotor allows passive stabilization of the rotor movement in three degrees of freedom. Rotor
stabilization in the remaining two degrees of freedom is achieved by active stabilization
(current control). Active stabilization is done by motor current regulation with appropriate
control structure necessary for proper operation of the bearingless motor.
Most of the modern bearingless motors have a linear dependence between the
developed forces in the motor and motor currents. This leads to the fact that the bearingless
motor control structures are based on the assumption of a linear relationship between
developed forces on the rotor and the motor currents.
However, in certain types of bearingless motors, especially in the case of bearingless
motors with pronounced reluctancy on the rotor side, the nonlinear dependence of the
developed forces and the motor currents cannot be neglected. Focus in this thesis is on the development of the novel nonlinear bearingless motor control structure for the case when
there is no linear dependence between the developed force on the rotor and the motor
currents. In this work all steps of the research are presented. This includes: bearingless motor
simulation model development, development and testing of a new control structure based on
nonlinear bearingless motor model, model reduction techniques for implementation,
implementation of the newly developed nonlinear control structure in the bearingless motor
digital control system and experimental verification of the developed nonlinear control
structure on laboratory prototype.
Keywords
bezležajni motor
digitalni sustav upravljanja
nelinearno upravljanje
Keywords (english)
bearingless motor
digital control system
nonlinear control
Language croatian
URN:NBN urn:nbn:hr:190:093714
Promotion 2021
Study programme Title: Postgraduate university doctoral study in the area of Engineering sciences, in the field of Electrical engineering; specializations in: Electrical Engineering Course: Electrical Engineering Study programme type: university Study level: postgraduate Academic / professional title: doktor/doktorica znanosti, područje tehničkih znanosti (doktor/doktorica znanosti, područje tehničkih znanosti)
Type of resource Text
Extent XII, 161 str. ; 30 cm
File origin Born digital
Access conditions Open access
Terms of use
Created on 2021-04-07 13:09:47