| Sažetak | Ovaj diplomski rad nastao je kao rezultat suradnje Tehničkog fakulteta i tvrtke Danieli
Automation S.p.A. na razvoju naprednih upravljačkih struktura za elektromotorne pogone. Težište
ovog diplomskog rada stavljeno je na razvoj sustava vektorskog upravljanja sinkronog stroja s
električnom uzbudom namijenjenog napajanju iz ciklopretvarača. Shodno tome, nakon uvodnih
razmatranja danih u prvom poglavlju, u drugom je poglavlju rada dan pregled teorije koordinatnih
sustava na temelju koje je nadalje izveden dvoosni (dq) model sinkronog stroja iz kojeg proizlazi
vektorski dijagram stroja. U trećem poglavlju ukratko je opisan način rada ciklopretvarača. Četvrto
poglavlje posvećeno je razvoju sustava vektorskog upravljanja sinkronim strojem. U sklopu tog
poglavlja opisan je princip vektorskog upravljanja sinkronim strojem koji se temelji na vektorskom
dijagramu stroja, pripadna struktura upravljanja, kao i metode za estimaciju magnetskog toka u
čijoj orijentaciji se vrši upravljanje. Budući je razvijena struktura vektorskog upravljanja
višepetljasta, opisan je proces određivanja optimalnih parametara regulatora. Ispravnost
razvijenog sustava vektorskog upravljanja ispitana je na simulacijskom modelu istog koji je opisan
u petom poglavlju, a pripadni rezultati prikazani su u šestom poglavlju. U sedmom poglavlju
opisan je izrađeni simulacijski model ciklopretvarača i pripadnog mu upravljanja. Rezultati
simulacije rada ciklopretvarača prikazani su u osmom poglavlju. Naposljetku, zaključna
razmatranja iznesena su u posljednjem, devetom poglavlju. |
| Sažetak (engleski) | Electrically excited or wound rotor synchronous machines are mainly associated with
power generation. However, electrically excited synchronous machines (hereinafter synchronous
machines) are being increasingly used in variable speed drives, especially in high-power drives
where their advantages over other machines come to the fore. Namely, the main advantages of
synchronous machines over induction, but also other types of machines, are certainly high
efficiency (up to 97% in large synchronous machines) and their reactive power control capability
with which they are able to significantly correct the power factor and thus reduce unwanted losses
and costs in industrial power systems with a multitude of inductive loads. At the same time, highperformance responses of a synchronous machine can be achieved by applying the so-called vector
control.
The basic principle of vector or field-oriented control is well known as it has already been
a subject of many landmark books. In short, vector control of AC machines, whose foundations
were laid in the early 1970s by Karl Hasse and Felix Blaschke, is based on representing the space
vector of the stator current in a rotating reference frame related to the space vector of one of the
magnetic fluxes in the machine. Such a representation of the stator current space vector allows its
decomposition into two components: a flux producing component and a torque producing
component. Therefore, by controlling these two stator current components, it is possible to achieve
a high-performance decoupled control of the machine's torque and flux, like in a case of a
compensated separately excited DC machine.
This master thesis was written as a result of cooperation between The Faculty of
Engineering and Danieli Automation S.p.A. on the development of advanced control structures for
electric drives. The aim of this master thesis was the development of a vector control structure for
an electrically excited synchronous machine originally intended to be fed from a cycloconverter.
Therefore, in Chapter Two of this master thesis, an overview of the reference frame theory is given,
based on which a two-reaction (dq) model of the synchronous machine is derived. Chapter Three
briefly describes the operating principles of a cycloconverter. Chapter Four is dedicated to the
development of a vector control structure for a synchronous machine. This chapter describes the
principle of vector control of a synchronous machine based on the machine's space vector diagram,
the associated control structure, as well as usual methods for estimating the flux used for
orientation. Since the developed control structure is a multiloop one, the process of determining the optimal parameters of the controllers is shown. The performance of the developed vector
control structure has been tested on a simulation model built in PLECS. The obtained simulation
results are presented in Chapter Six. In Chapter Seven, a simulation model of the three-phase
cycloconverter and its associated control is described. The results regarding the simulation of
cycloconverter operation are presented in Chapter Eight. Finally, concluding remarks are made in
the last, ninth chapter. |
