Procjena varijabli stanja vektorski upravljanog asinkronog motora

scientific master's theses

• Title (english): State Variables Estimation in Vector Controlled Induction Machines
• Author: Dinko Vukadinović
• Mentor: Gorislav Erceg (mentor)
• Committee member: Drago Ban (član povjerenstva)
• Committee member: Gorislav Erceg (član povjerenstva)
• Committee member: Mate Smajo (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; Zagreb
• Defense date and country: 2002-10-29, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering; Power Engineering
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

U radu su analizirane strukture vektorskog upravljanja asinkronim motorom zasnovane na ulančenom toku statora i ulančenom toku rotora. Za ove upravljačke strukture napravljeni su odgovarajući simulacijski programi. Uzet je u obzir utjecaj pogreške procjene induktiviteta motora. Analiziran je utjecaj efekta zasićenja u željezu na statičke i dinamičke karakteristike asinkronog motora pri konstantnom ulančenom toku statora i konstantnom ulančenom toku rotora. Napravljena je usporedba struktura vektorskog upravljanja asinkronim motorom zasnovanih na magnetskom toku statora i magnetskom toku rotora. Simulirane su skokovite promjene reference elektromagnetskog momenta sa utjecajem pogreške u procjeni rasipnih induktiviteta i međuinduktiviteta i bez nje. Na laboratorijskom modelu motora u otvorenom regulacijskom krugu obavljena je procjena varijabli stanja, elektromagnetskog momenta i snage pomoću digitalno snimljenih napona i struja statora. Da bi taj postupak bio izvediv napravljen je programski algoritam u C jeziku za numeričku integraciju digitalno snimljenih napona i struja statora.Upotrebom programskog paketa MATLAB kreirani su odgovarajući digitalni filteri sa ciljem odstranjvanja šuma i parazitnih efekata. U radu se, također, nalazi i kratki pregled teorije digitalnih filtera i elemnti izbora digitalnih filtera. Postupak procjene varijabli stanja, također, je proveden pomoću odgovarajućih analognih sklopova. Matematički postupci sumiranja, integriranja i množenja izvedeni su upotrebom sklopova s operacijskim pojačalima i analognim množačima, a analogno filtriranje faznih napona statora asinkronog motora je obavljeno analognim filterom drugog reda. U ovom radu je pokazano da je analogni postupak procjene varijabli stanja asinkronog motora preporučljiv samo za stacionarne režime rada i za frekvencije osnovnog harmonika napona napajanja koje su manje od 10 Hz. Potreba za procjenjivanjem varijabli stanja pri nižim frekvencijama napona napajanja (kada utjecaj viših harmoničkih komponenti u naponu napajanja postaje značajan), digitalnim postupkom, može se riješiti na način da se komponente vaktora napona statora filtriraju analognim filterom, a zatim digitalno integriraju, zbrajaju, oduzimaju i množe. U šestom poglavlju je analizirana jedna od struktura vektorskog upravljanja asinkronim motorom bez mjernog člana brzine vrtnje. Predložena struktura vektorskog upravljanja se zasniva na teoriji adaptivne regulacije i teoriji observera uz istovremenu identifikaciju omskog otpora statora. Ova struktura vektorskog upravljanja se razlikuje od konvencionalne upravljačke strukture zasnovane na referentnom modelu s adaptivnim sustavom (MRAS) s obzirom na definiranje referentnog i adaptivnog sustava, te izbor brzine vrtnje koordinatnog sustava u kojem se opisuje matematički model. Kod konvencionalne regulacijske strukture zasnovane na referentnom modelu s adaptivnim sustavom se, uobičajeno, tzv. naponski model za procjenu magnetskog toka rotora koristi kao referentni model, a strujni kao adaptivni model. U ovom radu se naponski model promatrao kao adaptivni, a strujni kao referentni. U ovom radu je napravljen odgovarajući program za simulaciju zaleta i kočenja asinkronog motora sa istovremenom procjenom brzine vrtnje i identifikacijom omskog otpora statora.

Abstract (english)

This paper analyses the vector control system based on rotor magnetic flux and vector control system based on stator magnetic flux. Corresponding simulation programs for these control systems has been made. Impact of errors on inductance estimation of the induction motor has been taken into account. Impact of saturation effect in iron on induction motor static and dynamic characteristics with constant stator magnetic flux and rotor magnetic flux have analysed. Comparison of vector control systems based on rotor magnetic flux and stator magnetic flux has been made. Step changes of electromagnetic torque reference value with and without estimation error on leakage inductance and mutual inductance has been simulated. In laboratory model of induction motor in open loop estimation of state variable, electromagnetic torque and electrical power using sampled stator voltages and currents has been made. For this method numerical algorithm in C language has been made. Using program MATLAB corresponding digital filters has been created for noise and reactive effects elimination. There is, in this paper, a short oversee of digital filter theory and base for choice of digital filters. Also, algorithm of state variable estimation has been made using analog circuits. Mathematical proceedings (summarizing, integration and multiplication) has been made using circuits that incorporate amplifiers and analog multiplicators. Analog filtering of phase voltages of stator has been made using second order analog filter. In this paper have demonstrated that analog algorithm of state variable estimation is recommendable only for stationary states and for base harmonic frequencies in supply voltage that are less than 10 Hz. Estimation of state variable by lower frequencies (when impact of higher harmonic components in supply voltage become significant), using digital algorithm, one can to solve by filtering stator voltage components using analog filter, and thereupon that components add, subtract and multiplier. Into six chapter have analysed some with sensorless vector control of induction motor. The proposed system is based on a flux observer and the adaptive control theory with simultaneously stator resistance identification. The proposed scheme is simpler that the conventional MRAS scheme because the proposed system is constructed in the synchronous reference frame and current model is used as a reference model and voltage model is used as a adaptive model. Conventional MRAS scheme use current model as a adaptive model and voltage model as a reference model. In this paper has been made simulation program for start and break of induction motor with simultaneously stator resistance identification.

• Keywords: Asinkroni motor; vektorska regulacija; procjena; simulacija; varijable stanja; digitalni filter; analogni filter; observer; procjena brzine vrtnje rotora
• Keywords (english): Induction motor; vector control; estimation; simulation; state variables; digital filter; analog filter; observer; estimation of rotor velocity
• Language: croatian
• URN:NBN: urn:nbn:hr:168:969178
• Study programme: Title: Postgraduate master programme in electrical engineering; Study programme type: university; Study level: postgraduate; Academic / professional title: Magistar znanosti elektrotehnike (Magistar znanosti elektrotehnike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-04-30 07:19:44