Hybrid sliding PID controller for  torsional vibrations mitigation in rotary drilling systems

Direct torque control (DTC) of induction motor is prominent to offer instant torque and flux control with a simple control structure. However, this scheme suffers from two major drawbacks namely high torque ripple and variable switching frequency of the inverter, especially during low-speed operation. During the low-speed condition, the positive torque slope is very steep and torque overshoot occurs frequently resulting in the torque ripple become of great significance. This paper proposes a new and effective technique to reduce the torque ripple by integrating the alternate switching technique to the inverter switching status to limit the torque slope surge. By varying the frequency and duty cycle of the alternate switching, the rate of surge can be controlled resulting in the chances of overshoots, and selection of reverse voltage vector can be avoided. The feasibility of the proposed technique has been validated using MATLAB/Simulink software and through experimental results. The results show the proposed alternate switching technique minimizes over 40% reduction in the torque ripple while maintaining the simple structure of DTC.

show abstract

“…By substituting (10) and ( 11) into discrete form of ( 9), torque slopes during increment and decrement can be expressed as:…”

Section: Operation Of Torque Using Alternate Switching Techniquementioning

confidence: 99%

Torque ripple minimization in direct torque control at low-speed operation using alternate switching technique

Aihsan

Jidin

Alias

et al. 2022

IJPEDS

View full text Add to dashboard Cite

show abstract

“…The drilling system has been driven In this scenario, the controller performance's improvement in suppressing the high frequency stick-slip vibrations has been investigated. The drilling system has been driven with a deactivated controller at the beginning and with Wob = 180 kN and a voltage of 300 V. These inputs cause the generation of the stick-slip phenomenon in the drill-string [9]. At t = 10 s, the controller has been activated, as shown in Figures 31 and 32a,b.…”

Section: Scenario 7: Voltage Step Reference Trackingmentioning

confidence: 99%

“…However, it necessitates a direct measurement of the drill bit velocity [7], which is not possible if the measurement while drilling (MWD) tool is not logged. From an academic point of view, several papers have been published about different control strategies for stick-slip vibrations mitigation in the drill-string [8,9], most of which have used a two degrees of freedom model of the rotary drilling system in the controller design [10][11][12][13][14]. This model has proven to be simple, practical, and sufficient, but only if the supposition given by [15], which indicates that stick-slip occurs at low frequencies, is verified.…”

Section: Introductionmentioning

confidence: 99%

Observer-Based H∞ Controller Design for High Frequency Stick-Slip Vibrations Mitigation in Drill-String of Rotary Drilling Systems

et al. 2022

Self Cite

View full text Add to dashboard Cite

The drilling process is among the most crucial steps in exploration and production activities in the petroleum industry. It consists of using mechanical mechanisms to crush rocks by the drill bit to pass through the different geological layers. The drill-string continuously transforms the rotational movement from the top drive motor to the drill bit through the drill pipes. Due to the strong interactions with the rocks, aggressive vibrations can arise in the drill-string in its three dimensions, and consequently, this may create three types of synchronous vibrations: axial, lateral, and torsional. The severe status of the latter is known as the stick-slip phenomenon, and is the most common in rotary drilling systems. Based on field observations, it has been inferred that the high frequency stick-slip vibrations may lead to drill-string fatigues and even to premature rupture. In the best case, it reduces the drilling efficiency by decreasing the rate of penetration, due to which the drilling operations become proportionally expensive. The main novelties of this research work are the design of an H∞ observer-based controller to mitigate the high frequency stick-slip vibrations, and the quantitative analysis of the vibrations’ severity for ten degrees of freedom model. The observer is designed to estimate the non-measurable rotational velocity of the drill bit due to the severity of the vibrations, while the controller is dedicated to suppressing the vibrations by using the top drive inputs. Thus, many scenarios have been considered to test and analyze the observer performance and the controller robustness. Furthermore, a comparison with the LQG observer-based controller has been conducted, where H∞ has demonstrated better efficiency in suppressing the stick-slip vibrations under unstructured perturbations.

show abstract

“…Other conventional controllers such PI and PID type have been successfully implemented over the years that are robust to variable and uncertain drilling parameters [7]. In some of the recent literature, a hybrid sliding mode controller [8] was designed to improve the drilling performance under high frequency tortional vibration conditions. In [9] a super-twisting controller was proposed to suppress stick-slip vibration and maintain the angular velocity of the drill string at the desired value, despite the operating conditions.The basis of all the above-mentioned control systems is to develop elaborate drill sting models that include dynamic non-linear forces and external excitations.…”

Section: Introductionmentioning

confidence: 99%

Experimental Comparison of PID Based RPM Control for Long Horizontal vs. Vertical Drillstring

Sharma¹,

Srivastava²,

Teodoriu³

et al. 2021

Preprint

View full text Add to dashboard Cite

Drilling vibrations has been identified as a key performance limiter that prevents successful energy transfer from the surface to the bit. The resultant irregular bit rotation speed causes drilling challenges like poor hole quality and reduction in rate of penetration to name a few. Amongst other vibration suppression techniques, active control of vibrations is widely used and recommended. Active control system utilizes a closed loop feedback control to continuously adapt to downhole vibrations detected at the surface. The system requires regular tuning and upgrades which is done experimentally before field deployment. The paper presents a PID based experimental tuning of horizontal and vertical strings for irregular RPM. In doing so, the paper highlights the need of having horizontal experimental setups for state-of-the-art PID tuning for downhole RPM. The settling time of irregular RPM for horizontal setup is found to be lower than the vertical configuration due to multiple contact points and increased friction coefficient.

show abstract

Hybrid sliding PID controller for torsional vibrations mitigation in rotary drilling systems

Cited by 12 publications

References 25 publications

Torque ripple minimization in direct torque control at low-speed operation using alternate switching technique

Torque ripple minimization in direct torque control at low-speed operation using alternate switching technique

Observer-Based H∞ Controller Design for High Frequency Stick-Slip Vibrations Mitigation in Drill-String of Rotary Drilling Systems

Experimental Comparison of PID Based RPM Control for Long Horizontal vs. Vertical Drillstring

Contact Info

Product

Resources

About