Estimatori magnetskog toka rotora kaveznog asinkronog stroja

master's thesis

• Title (english): Rotor magnetic flux estimators of cage induction machine
• Author: Gabrijel Guberović
• Mentor: Zlatko Maljković (mentor)
• Committee member: Zlatko Maljković (predsjednik povjerenstva)
• Committee member: Damir Žarko (član povjerenstva)
• Committee member: Martina Kutija (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2016-07-07, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering

Abstract

U ovom radu opisana je struktura vektorskog upravljanja s naglaskom na estimatorima magnetskog toka rotora. Opisani su αβ koordinatni sustav (koordinatni sustav statora) i dq koordinatni sustav (koordinatni sustav magnetskog toka rotora). Izveden je matematički model kaveznog asinkronog motora u αβ koordiatnom sustavu. Objašnjena je važnost koordinatnog sustava magnetskog toka rotora za operacije s rotirajucim vektorima te je izveden model kaveznog motora u dq koordinatnom sustavu. Iz modela stroja u αβ sustavu izveden je model stroja s varijablama stanja u αβ koordinatnom sustavu. Detaljno je izloženo načelo rada naponskog modela estimatora toka rotora (eng. Voltage model) te je objašnjeno načelo estimacije kuta i amplitude toka rotora u strujnom modelu estimatora toka (eng. Current model). Dani su parameti kaveznog asinkronog motora koji su korišteni u ovom radu te je regulacijski sustav parametriran prema tim vrijednostima. Korištenjem metode tehnickog optimuma podešeni su parametri PI regulatora d i q komponente struje statora. Pokazano je da je parametre regulatora brzine vrtnje moguce podesiti metodom simetričnog optimuma te je postupak podešavanja detaljno izložen. Opisana je praktična metoda određivanja parametara regulatora. Obrazložen je utjecaj rasprezanja regulacijskog kruga za d i q komponente struje statora te su opisane različite metode za kompenzaciju nepoželjnih utjecaja koji se pojavljuju zbog rasprezanja. Provedene su simulacije u kojima je motor u praznom hodu, u kojima je opterećen s 50% nazivnog tereta te u kojima se ispituje osjetljivost regulacijskog kruga na promjenu parametara motora. U poglavlju 5.1 se uspoređuju odzivi strujnog i naponskog modela estimatora toka u stacionarnom stanju. S oba modela provedena je simulacija praznog hoda te simulacija u kojoj je motor opterecen s 50% nazivnog tereta. U poglavlju 5.2 se ispituje osjetljivost naponskog i strujnog modela na promjenu dvaju parametara motora - otpora statora Rri međuinduktiviteta Lm. Uspoređuju se odzivi uz tvorničku vrijednost parametra, uz 50% tvorničke vrijednosti te uz 150% tvorničke vrijednosti. Rezultati svih simulacija su detaljno analizirani i uspoređeni s teorijskim očekivanjima.

Abstract (english)

This paper describes the structure of the vector control with an emphasis on rotor magnetic flux estimators. αβ coordinate system (coordinate system of stator) and the dq coordinate system (coordinate system of the rotor flux) are described. Mathematical model of squirrel cage induction motor in αβ koordiatnom system is derived. The importance of the coordinate system of the rotor flux for operations with rotating vectors is explained, and a mathematical model of squirrel cage induction motor in dq koordiatnom system is derived. From the model in αβ system a machine model with state variables in αβ coordinate system is designed. The principle of operation for voltage model of the rotor flux estimator is set forth in detail, and the principle for rotor flux angle and amplitude estimation in current model is explained. Parameters of the squirrel cage induction motor that was used in this study are given, and the control system is configured according to these values. Using the technical optimum method the parameters of PI controllers of the stator current are set. It is shown that the parameters of the speed controller can be adjusted using the symmetric optimum method and the process of optimization is set forth in detail. The practical method of determining the parameters of the regulator is described. The impact of the decoupling of the regulationlation circuits of d and q component of the stator current is explained, and various methods for compensation of undesirable impacts that occur due to decoupling are described. Simulations were performed in which the engine is idling, in which it is burdened with 50% of the rated load, and in which the sensitivity of the control loop to the change in value of the engine parameters is tested. In section 5.1. responses of current and voltage models of flux estimators in steady state are compared. With both models, a simulation of idling and a simulation in which the engine is burdened with 50% of the rated load are conducted. Section 5.2 examines the sensitivity of the current and voltage models to the change in the value of two engine parameters - stator resistance Rr and mutual inductance Lm. Responses with parameter value equal to the factory value, with 50% of the factory value, and with 150% of the factory value were compared. The results of simulations are analyzed in detail and compared with expectations based on the theoretical model.

• Keywords: asinkroni stroj; vektorsko upralvjanje; estimacija toka; naponski model; strujni model
• Keywords (english): induction machine; vector control; flux estimation; voltage model; current model
• Language: croatian
• URN:NBN: urn:nbn:hr:168:123822
• Study programme: Title: Electrical Engineering and Information Technology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije (magistar/magistra inženjer/inženjerka elektrotehnike i informacijske tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2018-02-06 09:05:00