Search results for "roller"
showing 10 items of 247 documents
Performances Comparison for a Rotating Shaft Suspended by 4-Axis Radial Active Magnetic Bearings via 𝜇 -Synthesis, Loop-Shaping Design, and Sub ( 𝐻…
2011
The control systems applied on active magnetic bearing are several. A perfect levitation is characterized by maintaining the operating point condition that is characterized by the center of stator coincident with the geometric center of shaft. The first controller implemented for this purpose is PID controller that is characterized by an algorithm that leads the amplifier to produce control current until the operating point condition is not reached, this is obtained by an integration operator. The effect of an integrator is essential but not necessary for a centered levitation for example in the robust control characterized by a dynamic model depended on plant of system so that it depends o…
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…
Application of the Morris method for screening the influential parameters of fuzzy controllers applied to wastewater treatment plants
2011
In this paper,we evaluate the application of a sensitivity analysis to help fine-tuning a fuzzy controller for a biological nitrogen and phosphorus removal (BNPR) plant. TheMorris Screeningmethod is proposed and evaluated as a prior step to obtain the parameter significance ranking. First, an iterative procedure has been performed in order to find out the proper repetition number of the elementary effects (r) of the method. The optimal repetition number found in this study (r = 60) is in direct contrast to previous applications of the Morris method, which usually use low repetition number, e.g. r = 10 ~ 20. Working with a non-proper repetition number (r) could lead to Type I error (identify…
SELF-TUNING FUZZY CONTROL OF A ROTARY DRYER
2002
Abstract Drying, especially rotary drying is without doubt one of the oldest and most common unit operations in industries. It is a very complex non-linear process including the movement of solids in addition to thermal drying. This means that both the modelling and control of a rotary dryer is difficult with conventional methods. The aim of this research was to improve dryer control by developing control systems based on self-tuning PID-type fuzzy logic controllers. The behaviour of the control systems has been tested with simulations based on the model of a pilot plant dryer located in the Control Engineering Laboratory at the University of Oulu. The control results have been compared ach…
Cascaded PD-PI controller for active power frequency control of two-area multi-units power system
2016
In interconnected multi-area power system; the real power generation within each area has to be managed through active power frequency control considering scheduled power exchange. In this work, two different controllers, namely cascaded PD-PI and conventional PID controller are considered for analyzing the dynamic response of the two area interconnected power system. Area-1 consists of two reheat type thermal generating power plant units and area-2 comprises of two non-reheat type thermal power plant units. The controller gains of PD-PI and PID controllers are efficiently tuned by ‘Teaching Learning based Optimization Technique’. In area-1, 1% step load disturbance is applied for analyzing…
A Low-cost, Real-time Monitoring System for PV Plants based on ATmega 328P-PU Microcontroller
2015
This paper presents a real-time monitoring system for PV power plants based on a microcontroller Atmega328P-PU. The proposed system, whose performances can be relatively close to those achieved with commercial monitoring systems, is simple, low-cost and open source technology-based. In addition, a user interface, capable to communicate through a wireless network by using a standard communication protocol IEEE 802.15.1, is here presented. From the experimental tests described and discussed in this paper it is demonstrated that the proposed monitoring system provides, with adequate accuracy, all the information about the operating status of the PV plant, even during fault conditions.
Obtaining dynamic Norton parameters of a solar panel from manufacturer data
2016
Photovoltaic arrays have been shown to possess significant influence on the dynamic performance of coupled source-converter-load system while its dynamic resistance is the most important parameter, contributing to the overall system dynamics. In this paper, a method of deriving the parameters of linearized photovoltaic equivalent circuit from manufacturer data is proposed. The approach allows predicting the range of dynamic Norton parameters for the expected irradiation and temperature operation conditions thus defining clear bounds required for robust design of the system controller.
Comparing different control strategies for indoor thermal comfort aimed at the evaluation of the energy cost of quality of building
2010
Abstract The rapid improvement in the standard of living requires more detailed and sophisticated methods of evaluating comfort conditions. But, maintaining thermal comfort conditions in confined environments may require complex regulation procedures and the proper management of heating, ventilating and air conditioning (HVAC) systems. In turn, the requirements for indoor thermal comfort do not necessarily coincide with those of energy saving purposes, which in the last years are becoming a crucial issue owing to the enactment of the European Energy Performance of Buildings Directive (EPBD). The aim of this work is to compare different indoor control thermal comfort strategies in view of th…
Type-2 fuzzy control of a fed-batch fermentation reactor
2010
Abstract The aim of the paper is to present the application of type-2 fuzzy logic controllers (T2FLCs) to the control of a fed-batch fermentation reactor in which the penicillin production is carried out. The performance of the control system using T2FLCs is compared by simulation with that of a control system using type-1 fuzzy logic controllers (T1FLCs). The non linear model used for the simulation study is an unstructured model characterized by the presence of non linearities, parameter uncertainty and measurement noise. Simulation results confirm the robustness of the T2FLC which shows a better performance than its type-1 counterpart particularly when uncertainties are present in the co…
Control of the Biodegradation of Mixed Wastes in a Continuous Bioreactor by a Type-2 Fuzzy Logic Controller
2009
Abstract Type-2 fuzzy logic control is proposed for nonlinear processes characterized by bifurcations. A control simulation study was conducted for a bioreactor with cell recycle containing phenol and glucose as carbon and energy sources in which a pure culture of Pseudomonas putida is carried out. The model developed by Ajbar [Ajbar, A. (2001). Stability analysis of the biodegradation of mixed wastes in a continuous bioreactor with cell recycle. Water Research, 35 (5), 1201–1208] was used for the simulations. The particular dynamics of the bioreactor, characterized by two saddle-node bifurcations, makes its control difficult, since it may become unstable also for small variations of some p…