Search results for "Drivetrain"
showing 10 items of 22 documents
Identification of induction motor thermal model for improved drivetrain design
2016
Selection of components of electric drivetrains is not only based on evaluating their ability to perform according to mechanical specifications, but — what is equally important — on assessing their thermal protection limits. These are typically affected by electrical and thermal properties of motors and drives. Although rated parameters (such as power, torque, speed, etc.) are easily accessible in catalogs of equipment producers, more specific properties like mass / length of copper winding, heat dissipation factor, rotor / stator dimensions etc. are not available to customers. Therefore, effective selection of drivetrain components is limited due to the lack of sufficient data and the need…
Mitigation of Fatigue Damage and Vibration Severity of Electric Drivetrains by Systematic Selection of Motion Profiles
2016
The offshore drilling industry is among the most demanding markets for electrical equipment. Heave motion, irregular cyclic loads, harsh weather conditions, and vibrations are causing accelerated deterioration of drilling equipment. One of the most common solutions to these problems is to design actuation systems of such machinery overly conservative to gain additional safety, which results in too high initial investment and maintenance costs. To mitigate the fatigue damage and vibration severity of rotating elements of electric drivetrains operating offshore, this paper presents a comparative analysis of four popular input functions used in motion control of industrial systems. We evaluate…
Load Torque Estimation Method to Design Electric Drivetrains for Offshore Pipe Handling Equipment
2016
One of the main design objectives for electric drivetrains operating in offshore drilling equipment is to keep them as small, yet as effective, as possible, to minimize space they occupy on drill floor and maximize their performance. However, practical experience shows that typically choices made by design engineers are too conservative due to the lack of enough data characterizing load conditions. This results in too costly and too heavy selected components. Therefore, in the current paper we present a method to estimate required full-scale motor torque using a scaled down experimental setup and its computational model. A gripper arm of an offshore vertical pipe handling machine is selecte…
Feasibility study of electromechanical cylinder drivetrain for offshore mechatronic systems
2017
Currently, there is an increasing focus on the environmental impact and energy consumption of the oil and gas industry. In offshore drilling equipment, electric motors tend to replace traditionally used hydraulic motors, especially in rotational motion control applications. However, force densities available from linear hydraulic actuators are still typically higher than those of electric actuators. Therefore, usually the remaining source of hydraulic power is thereby the hydraulic cylinder. This paper presents a feasibility study on the implementation of an electromechanical cylinder drivetrain on an offshore vertical pipe handling machine. The scope of this paper is to investigate the fea…
Influence of variability and uncertainty of wind and waves on fatigue damage of a floating wind turbine drivetrain
2021
Abstract This study investigates the effect of variability and uncertainty of wind and wave conditions on the short-term fatigue damage of a 10-MW floating wind turbine drivetrain. Global dynamic responses of a semi-submersible wind turbine are calculated by aero-hydro-servo-elastic simulations in various environmental conditions. Then, rotor and generator loads, as well as nacelle motions from the global analysis are provided to a drivetrain model to investigate its dynamics. One-hour fatigue damage of the drivetrain bearings is calculated based on the bearing loads and speeds, and the effect of uncertainties related to wind and waves is assessed. The results indicate that the variations o…
Integrated dimensional and drive-train design optimization of a light-weight anthropomorphic arm
2012
An approach to minimize the mass of robotic manipulators is developed by integrated dimensional and drive-train optimization. The method addresses the influences of dimensions and characteristics of drive-trains in the design optimization. Constraints are formulated on the basis of kinematic performance and dynamic requirements, whereas the main objective is to minimize the total mass. Case studies are included to demonstrate the application of the optimization method in the design of assistive robots.
EKF-based estimation and control of electric drivetrain in offshore pipe racking machine
2016
A typical challenge for electric drivetrains is to reduce the number of sensors required for control action or system monitoring. This is particularly important for electric motors operating in offshore conditions, since they work in hostile environment which often damages data acquisition systems. Therefore, this paper deals with verification and validation of the extended Kalman filter (EKF) for sensorless indirect field-oriented control (IFOC) of an induction motor operating in offshore conditions. The EKF is employed to identify the speed of the induction motor based on the measured stator currents and voltages. The estimated speed is used in the motor speed control mode instead of a ph…
Integrated Design Optimization of a 5-DOF Assistive Light-weight Anthropomorphic Arm
2011
An integrated dimensional and drive train optimization method was developed for light-weight robotic arm design. The method deals with the determination of optimal link lengths and the optimal selection of motors and gearboxes from commercially available components. Constraints are formulated on the basis of kinematic performance and dynamic requirements, whereas the main objective is to minimize the weight. The design of a human-like arm, which is 10 kg in weight with a load capacity of 5 kg, is described. An integrated dimensional and drive train optimizationmethod was developed for light-weight robotic armdesign. The method deals with the determination of optimallink lengths and the opti…
Torque peak reduction and overload monitoring of induction motors in offshore drilling operations
2015
Current drivetrain design procedures for electric actuation systems operating in offshore conditions typically consider two major requirements: to provide sufficient steady-state and maximum motor torques. As a result of this, no information regarding the transient state (e.g. during motor acceleration) is utilized when selecting drivetrain components. This leads to potentially dangerous situations when motors undergo saturation in these regions due to too high dynamic loads. A common reason for this (apart from lack of information about transient state when designing a drivetrain) is applying trapezoidal reference motion profiles that cause discontinuities in system acceleration and infini…
Linear parameter‐varying modelling and control of an offshore wind turbine with constrained information
2014
This study deals with linear parameter-varying modelling and output-feedback H ∞ control design for an offshore wind turbine. The controller is designed with consideration that not all the information in the feedback loop will be used. This constraint is incorporated into the design procedure. Constrained information means that a special zero-non-zero pattern is forced upon the gain matrix. The constrained controller is obtained based on parameter-dependent Lyapunov functions and formulated in terms of linear-matrix inequalities. Since the functions are dependent on the wind speed and accurate wind speed measurements are rarely available in practice, an extended Kalman filter is used to est…