Projektiranje vanjskog sustava prigušenja torzijskih vibracija bušaćeg vretena za istosmjerni serijski motor reguliran po brzini vrtnje

undergraduate thesis

• Title (english): Design of an external drill-string drive torsional vibration damping system for a speed-controlled series-excitation direct current motor
• Author: Filip Plavac
• Mentor: Danijel Pavković (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2018-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Živimo u svijetu u kojem proizvodnja energije na račun eksploatacije fosilnih goriva još uvijek nema dovoljno isplativu niti obećavajuću alternativu. Oko fosilnih goriva sagrađena je enormna industrija o kojoj nije potrebno puno govoriti, te se poput ostalih grana industrije odlikuje obiljem inženjerskih izazova. Jedan od takvih izazova je modernizacija zrelih bušaćih garnitura novim upravljačkim algoritmima koji svojim niskim troškovima i jednostavnošću primjene prevladavaju nad hardverskim rješenjima. Pametna strategija upravljanja značajno produljuje životni vijek takvih postrojenja, a ujedno rezultira i manjom potrošnjom energije u odnosu na slučaj pod-optimalnog upravljanja. Štetne pojave koje se ovakvom strategijom nastoje spriječiti su: „stick-slip“ efekt koji nastaje uslijed prirode fenomena trenja, takozvani „back-spinning“ efekt, te pojava torzijskih vibracija unutar bušaćih cijevi, na primjer uslijed nagle promjene reference brzine vrtnje. U ovom radu opisan je elektromotorni pogon naftnog bušaćeg vretena, te je prikazan i detaljno objašnjen dizajn sustava regulacije struje i brzine vrtnje istosmjernog serijskog motora. Određeni su parametri regulatora za slučaj pogona s „krutom“ vezom. Na kraju je predstavljen vanjski sustav za prigušenje torzijskih vibracija temeljen na estimaciji momenta bušaćeg vretena i korekciji reference brzine vrtnje. Sustav je spojen na istosmjerni serijski motor tvrtke General Electric GE752 AUT reguliran po brzini vrtnje, čije su karakteristike također dane u radu. Navedeni sustav ispitan je za različite dubine bušenja, te različita podešenja.

Abstract (english)

We live in a world in which energy production based on fossil fuel exploitation still neither has a sufficinetly efficient nor a promising alternative. An enormous industry has been built around fossil fuels, which requires no further introduction, and is abundant with engineering challenges as other branches of industry. One of those challenges is retrofitting of mature drilling rigs with new control algorithms characterized by low capital costs and ease-of-use, which prevail over expensive hardware-based solutions. Life span of such plants can be significantly extended using a well-thought control strategy, which in turn results in mitigated energy consumption, as opposed to the case of sub-optimal control. This control strategy is used to prevent undesirable phenomena such as: stick-slip motion, which appears due to the nature of the friction phenomenon, back-spinning effect and poorly-damped drill-pipe torsional vibrations due to the sudden changes of motor speed reference. An electrical top-drive is described in this paper, followed by the design of current and speed control systems of a series-excitation DC motor being depicted herein. Controller parameters for the case of „stiff“ coupling have been calculated. Finally, a torque estimation and speed reference correction based external torsional vibration damping system is presented herein. The system is coupled with a speed controlled series-excitation DC motor from the General Electric GE752 AUT series, whose characteristics are also given in this work. The aformentioned system has been tested for different drilling depths, as well as for different tunning of the control system.

• Keywords: modernizacija; bušaćih garnitura; životni vijek; istosmjerni serijski motor; torzijskih vibracija; prigušenje
• Keywords (english): retrofitting; drilling rigs; life span; series-excitation DC motor; torsional vibrations; damping
• Language: croatian
• URN:NBN: urn:nbn:hr:235:569332
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2020-10-01
• Created on: 2019-05-22 22:49:14