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 twenty years. In this paper, Field Oriented Control (FOC) is applied to
cascaded voltage regulation and servo control using a 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.
[1]
Austin Hughes,et al.
Electric Motors and Drives: Fundamentals, Types and Applications
,
1990
.
[2]
Taylor T. Johnson,et al.
Turbo-alternator stalling protection using available-power estimate
,
2011,
2011 IEEE Power and Energy Conference at Illinois.
[3]
James F. Whidborne,et al.
Attitude control system for directional drilling bottom hole assemblies
,
2012
.
[4]
Weiping Li,et al.
Applied Nonlinear Control
,
1991
.
[5]
Dong-Choon Lee,et al.
DC-bus voltage control of three-phase AC/DC PWM converters using feedback linearization
,
2000
.
[6]
Stefan Östlund,et al.
Integrated energy transducer for hybrid electric vehicles
,
1997
.
[7]
Peter Vas,et al.
Sensorless vector and direct torque control
,
1998
.