Search results for "Control engineering"
showing 10 items of 435 documents
Automated Kick Control Procedure for an Influx in Managed Pressure Drilling Operations
2016
Within drilling of oil and gas wells, the Managed Pressure Drilling (MPD) method with active control of wellbore pressure during drilling has partly evolved from conventional well control procedures. However, for MPD operations the instrumentation is typically more extensive compared to conventional drilling. Despite this, any influx of formation fluids (commonly known as a kick) during MPD operations is typically handled by conventional well control methods, at least if the kick is estimated to be larger than a threshold value. Conventional well control procedures rely on manual control of the blow out preventer, pumps, and choke valves and do not capitalize on the benefits from the instru…
LPV Predictive Control of the Stall and Surge for Jet Engine 1
2001
Abstract Predictive control of constrained LPV systems is applied to the model of the stall and surge control for jet engine compressors. The objective of the used technique is to optimize nominal performance while guaranteeing robust stability and constraint satisfaction. This is achieved by exploiting invariant sets and a receding horizon optimization procedure which provides on-line a non-linear correction to a gain-scheduled linear feedback designed off-line. A comparison with a contractive gain-scheduling control technique is also shown.
A Robust Predictive Current Control for Three-Phase Grid-Connected Inverters
2009
This paper presents a new predictive control algorithm for grid-connected current-controlled inverters. The control combines a two-sample deadbeat control law with a Luenberger observer to estimate the future value of the grid currents. The resulting control offers robustness against the computational delay inherent in the digital implementation and considerably enhances the gain and phase margins of the previous predictive controls while maintaining the high-speed response typical of the deadbeat controllers.
Hidden oscillations in stabilization system of flexible launcher with saturating actuators
2013
Abstract In the paper the attitude stabilization system of the unstable flexible launcher with saturating input is considered. It is demonstrated that due to actuator saturation the system performance can significantly degrade. The analytical-numerical method is applied to demonstrate possibility of hidden oscillations and localize their attractor.
On the Impact of Plant Model and Controller Sophistication on Performance of Disturbance Attenuation and System Robustness
2006
In the paper the problem of disturbance attenuation performance in single-loop control system is investigated. Modified MV control strategy with bounded control variance is used as benchmark for both LQG and classically and optimally tuned PID-type controllers. Certain time and frequency domain functions are then examined to further assess the control performance in terms of robustness. It has been shown that as long as the system to be controlled is delay-free, and there is no extreme demand on performance, simple lag-delay system model along with optimally tuned PID control algorithm provides control quality similar to that of LQG controlled original system assuming the same bound on cont…
Energy efficient operation in smart grids: optimal management of shiftable loads and storage systems
2012
In this paper, the authors analyze the impact of the participation of customers to the sustainable implementation of energy rational strategies in microgrids. The management of shiftable loads is compared to the control of real and reactive storage systems in smart grids. An optimization algorithm is used as analysis tool to assess the impact of such control variables in different conditions. The results clearly indicate that if shiftable loads are of suitable size, they have a more promising as tools to both reduce losses and to flatten the peak load through the HV/MV bus. Many tests have been carried out on a real experimental MV system in the area of Rome Italy.
Application of distributed expert systems to the advanced control of smart houses
2003
Abstract A distributed expert system has been proposed for the smart house control. Its configuration is mainly based on the use of distributed nodes connected by means of a CAN network. This kind of systems allow the implementation of highly flexible control systems capable of adapting themselves to different situations. The expert system used is based on Rule Nets (RN), which are a formalism that seeks to express an automatism in a similar way to as would make it a human being: "IF antecedents THEN consequents". But at the same time Rule nets are a tool for the design, analysis and implementation of rule based systems (RBS), and consist on a mathematic-logical structure which analytically…
Modeling and Parameter Identification of Deflections in Planetary Stage of Wind Turbine Gearbox
2012
The main focus of this paper is the experimental and numerical investigation of a 750[kW] wind turbine gearbox. A detailed model of the gearbox with main shaft has been created using MSC.Adams. Special focus has been put on modeling the planet carrier (PLC) in the gearbox. For this purpose experimental data from a drive train test set up has been analyzed using parameter identification to quantify misalignments. Based on the measurements a combination of main shaft misalignment and planet carrier deflection has been identified. A purely numerical model has been developed and it shows good accordance with the experimental data.
Advanced Control Structure for Energy Management in Ground Coupled Heat Pump HVAC System
2008
Abstract Over the last 15 years, computerized controls have become more and more common in our homes. The smart home looks at expanding the use of the computers into the difference parts of the home, creating a network that can be easily and conveniently controlled. The use of computer controls removes the need to actually flick a switch and allows elements of the home to respond automatically to the people living in it. Successful control and heating ventilating and air-conditioning (HVAC) systems is a primary concern in building project: in order to achieve the required comfort and energy efficiency goals, a lot of variables must be coordinated and kept at particular pre-designed operatio…
Multi-objective strategies for management and design of distributed electric storage systems in a Mediterranean island
2013
The paper proposes an analytical study about the design and operation of distributed Electrical Storage Systems(ESS) in an active distribution network supplying a Mediterranean island, according to different criteria. The approach is based on the application of a multi-objective optimization algorithm (NSGA-II) that outputs a set of optimized schedules of the ESS in different configurations when operated according to different criteria (minimum energy losses in the grid, total generation cost, greenhouse gas emissions, limiting the fluctuations of the generation from fossil fuel plants). Moreover the variability of the voltage profile has been investigated also by a comparison with a refere…