Analiza elektromagnetnih in mehanskih lastnosti sinhronskega motorja s trajnim magnetom

Rupnik, Urban (author), Miljavec, Damijan (mentor)

V pričujočem delu je predstavljena problematika elektromehanskih sil v sinhronskem motorju s trajnimi magneti BG19. Omenjene sile so vir vibracij in posledičnega zvočnega pritiska. Za izračun sil je potrebno analizirati elektromagnetne razmere v motorju in nato rezultate te analize uporabiti v mehanskem časovnem odzivu motorja. Z meritvijo pospeškov mehanskega odziva motorja smo nakazali tudi ostale probleme, ki se zaradi magnetnih in mehanskih razmer pojavijo v motorju, in kakšne so njihove posledice. Izračun poteka gostote magnetnega pretoka v zračni reži temelji na že obstoječem analitičnem izračunu. Rezultate smo uporabili za izračun elektromagnetnega navora na gredi, te pa smo nato uporabili pri analizi mehanskega odziva in magnetnih sil. Zapisali smo osnovne enačbe za torzijsko nihanje in jih izračunali s programom Matlab. V programu Ansys, ki temelji na metodi končnih elementov, smo zgradili model motorja BG19. Z njim smo validirali analitične rezultate, dobljene na podlagi osnovnih enačb torzijskega nihanja. Za ovrednotenje učinkovitosti modela, smo opravili elektromehanske meritve na motorju iz proizvodnje. Prvi rezultat magistrskega dela prikazuje dobro ujemanje časovnega mehanskega odziva rotorja z analitičnim izračunom z uporabo metode Maxwellovega napetostnega tenzorja in numeričnega izračuna s programom Ansys, ki temelji na metodi končnih elementov. Drugi, ključnejši, pa je ujemanje analitičnega izračuna frekvenc pospeškov na statorju z eksperimentalnimi meritvami, opravljenimi s pospeškomerom. Naloga je prvi korak k sklapljanju elektromagnetnih in mehanskih stanj v motorju. Implementira se jo lahko kot nadgradnja programov za izračun gostote magnetnega pretoka v zračni reži motorja za namen predvidevanja odziva rotorja z bremenom v delovni točki. Algoritmi in programska koda, ki je bila razvita v tej nalogi z dodatnimi optimizacijskimi algoritmi, se lahko uporabi za načrtovanje elektromotorja ne samo z vidika najboljšega izkoristka in elektromagnetnih stanj, ampak tudi z vidika vibriranja motorja in nato hrupa.

• Language: Slovenian
• Keywords: sinhronski motor s trajnimi magneti, sklopljena analiza, elektromagnetna analiza, mehanska analiza, elektromagnetni navor, mehanski odziv, vibracije, Ansys
• Work type: Master's thesis/paper
• Organization: FE - Faculty of Electrical Engineering
• Year: 2017
• PID: 20.500.12556/RUL-95795
• Publication date in RUL: 21.09.2017

Secondary language

• Language: English
• Title: Analysis of electromagnetic and mechanical properties of a permanent magnet motor

Abstract

The thesis addresses problems of electromechanics forces in synchronous motor with permanent magnets (type BG19). This forces are source of vibration and air pressure oscillation. To define forces we need to analyze electromagnetic conditions in the motor. This analysis is the base to define mechanical transient response of motor. With experimental measurements on motor response we indicated also some further problems of magnetic and mechanical conditions appearing in the motor, and their consequences. Calculations of magnetic field density in the air gap preformed in this master thesis are based on previously developed analytical. Results of these calculations are used to define electromagnetic torque on the shaft, magnetic forces, and also mechanical response analysis. Differential equations for torsional oscillation are then numerically solved using Matlab software package. Validation of analytical results for torsional oscillations was done on a model of BG19 motor using Ansys software, which is based on finite element method. Evaluation of the developed numerical model was made with electromechanical experiments performed on a motor from serial production. The results of the master thesis showed a good agreement between the result of transient mechanical response of rotor with analytical calculation on Maxwell stress tensor method and numerical calculations with program Ansys based on finite element method. In addition, a good agreement was obtained also between analytical calculation and experimental measurements of stator acceleration frequency spectrum. The work done in this master thesis is the first step toward efficient coupling of electromagnetic and mechanical phenomena describing the behavior of electrical machines. The important applicability of this approach is that it can be implemented as an upgrade for existing software programs used for calculation of magnetic field density within the motor air gap. This can be of great importance for prediction of mechanical motor response operating in a given working point. The algorithms and the program code developed in this master thesis upgraded with optimization methods and previously described software programs can be used as an efficient tool for the electrical machine designing with optimum electromagnetic and mechanical properties. This means the design of the machine with high efficiency and reduced vibration and noise.

• Keywords: synchronous motor with permanent magnet, coupled analysis, electromagnet analysis, mechanical analysis, electromagnetic torque, mechanical response, vibrations, Ansys