Open AccessModelling and control of the roll‐stabilised control unit of a rotary steerable system directional drilling tool
Author(s) -
Alturbeh Hamid,
Whidborne James F.,
Luk Patrick,
Bayliss Martin
Publication year - 2019
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2018.8211
Subject(s) - servo drive , servo , drill string , control theory (sociology) , servo control , electrohydraulic servo valve , voltage , engineering , mandrel , control system , rotary encoder , control engineering , computer science , drill , mechanical engineering , encoder , control (management) , electrical engineering , artificial intelligence , operating system
A directional drilling tool control unit whose design is based on servo control of a rotary valve using the roll‐stabilised instrumented system approach has been successfully used in oil fields for over 20 years. Here, field‐oriented control (FOC) is applied to cascaded voltage regulation and servo control using an open‐loop plant model of the roll‐stabilised control unit. The servo control is applied to the rotary valve so that drilling mud is ported in a geostationary direction despite the rotation of the drill string and the bottom hole assembly of the rotary steerable system. Voltage regulation is applied in order to provide a DC voltage bus for the servo control of the valve. A torquer or alternator, which is a type of permanent magnet synchronous machine, is the core of the roll stabilised control unit. So, a mathematical model of the torquer is derived. An FOC scheme is proposed for servo control and to provide a DC regulated voltage using the torquers. The algorithm is tested in MATLAB/Simulink.