The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
For high-power converters with low pulse ratios (e.g. 80 Hz load frequency with 600Hz carrier frequency for a 27 MVA Variable Frequency Drive), the current control loop design has been a challenge due to the large signal delay and potentially higher-order plant (LCL filter between the converter and machines). The stability issue and cross-coupling effect is a problem in such application. In this paper,...
This paper presents an improved phase lead repetitive compensator (RC) for a linear actuator (LA) system. The linear phase lead compensation provided by the proposed compensator structure compensates the phase lag of the feedback system caused by payload variations and nonlinear friction present in the LA system. Unlike conventional phase lead RC structures which use a pure linear phase advance compensator...
In this paper describe the small signal stability of the load-frequency control with hydro-turbine. The effects of parameter variation on the dynamic behavior of the power system have been investigated. Application of compensation in response water turbine with eigenvalues analysis and behavior dynamic simulation of the power system is shown. Also, using transfer function, PID controller for load-frequency...
A novel approach to robust controller design with input hard constraints is presented. The proposed design procedure contains robust stability condition based on the M-delta structure and it is used for system with additive uncertainty. The obtained results, illustrated on example, show the applicability of the designed robust controller and its ability to cope with model uncertainties.
In recent years, the research and studies on fractional order (FO) modeling of dynamic systems and controllers are quite advancing. To improve the stability and dynamic response of automatic voltage regulator (AVR) system, we presented fractional Order PID (FOPID) controller by employing Genetic Algorithm (GA) and Ant Colony Optimization (ACO) techniques. We designed a masked fractional order PID...
This paper presents the application of H-infinity controller for speed control of variable speed wind turbine system. For constant Wind speed and blade pitch angle aerodynamic torque coming from wind is constant, with the increase in demanded electrical torque the rotor speed decrease. Preferred function of the wind turbine is to keep the turbine speed close to rated speed and also the output power...
This paper describes a fundamental limitation of the implicit anti-aliasing filter in continuous-time feedback compensated sigma-delta modulators and a method to overcome it. This anti-aliasing filter can be used to relax an additionally required pre filtering stage. If a strong alias rejection is required, commonly used continuous-time feedback compensated sigma-delta modulators would need some pre-filtering...
Fractional-order models have been found to provide a more realistic and compact representation to real world and man-made systems. On the other side, fractional-order controllers have proved their efficacy over the conventional integer-order controllers by providing more flexibility in the design as well as by guaranteeing a more robust closed-loop configuration. In this paper, Bode's ideal loop transfer...
In this paper we designed a Fractional order controller for level control system. Based on experimental model of the process, the different tuning rules have been computed and compared in order to minimize the integral square error with a constraint on the maximum sensitivity. To assess the controller performance with achieved performance, we tested the robustness of the system for process model stability...
In this paper, μ-synthesis is used to design a robust voltage controller for the cascaded boost dc-dc converter in continues conduction mode. The open loop is analyzed using a nominal frequency transfer function. The state space averaging technique and a structured uncertainty modeling approach are used to develop the controller model. The D-K iteration method is used to design a robustly performing...
This study describes and demonstrates the model-following control using a robust gain matrix based on the normalized plant. The normalized plant is constructed by inserting the matrices for normalizing into the original plant, rendering it independent of the plant parameters. The robust gain matrix also adopts a switching function determined by the linear quadratic regulator (LQR) method. The robust...
This paper describes and shows an H∞ controller design based on the Butterworth filter conversion. The proposed method refers to the conception of a normalized plant. By converting the control target to a Butterworth filter, it is not necessary to redesign the controller depending on the control target. Simulation and experimental results show the proposed method to be robust against an external disturbance...
A framework based on the gap metric and integral quadratic constraints (IQCs) is developed for analysing robust synchronisation of heterogenous linear time-invariant networks. Both the agents and the communication channels are allowed to be dynamic and unstable. Structural properties of the uncertainty are described by IQCs and exploited in synchronisation analysis as a means to reduce conservatism...
This paper studies the H2/H∞ approach to control the Internet traffic. We are interested in using the H2 formulation to improve transient performances in addition to maintaining the robust performance offered by the formerly used H∞ formulation. In this controller, the closed-loop dynamics are monitored and controlled by the sensitivity functions along with their associated weight functions. The LMI...
It is shown that for the case of minimum phase stable plants there exists, among the set of stabilizers controllers, a solution, simultaneously decoupling the outputs and at-tenuating the perturbations of the system. At the same time, the dynamics is assigned to stable positions. The at-tenuation is given by an approximation of the controllers rejecting the perturbations, which are singulars. These...
Worst case average performance analysis is considered in this paper. The disturbance in the system is assumed to belong to a “class of inputs signals”. A class of signals is here defined to be a set of families of signals, where each family satisfies an average spectral constraint. Exact characterizations in terms of integral quadratic constraints (IQC) are given for a class of white signals and a...
In this paper a PI decentralized constant-volume controller for open-channels is designed by minimizing the H2 norm of a suitable transfer function matrix. Since the fundamental property which must be retained for all possible perturbations of the plant is stability of the feedback system, we have studied whether the proposed feedback design is robust in the face of output-multiplicative perturbations...
This paper analyzes the performance and robustness of some of the structures of dead-time compensators that have been proposed in literature. The analysis is made using the two most typical models of processes with delay that are found in the process industry. All the structures are compared to a simple two degree of freedom Smith predictor. The comparative analysis shows that for the cases studied...
An approach is presented to design a robust PI-controller from bounded noise measurement data of a first order process with and without time delay. This controller guarantees a known robust performance. It is shown that in the case without time delay, the conservatism of the robust approach can be reduced by consciously choosing the nominal plant. The theory is illustrated to a first-order process...
In this paper we present an efficient algorithm to compute exact value set contours of affine uncertain transfer functions. This algorithm is based on a generalization of line-sweep algorithms developed for computational geometric applications and preserves the geometric parametrization of value set contours.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.