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EN
Nowadays the simulation is inseparable part of researcher's work. Its computation time may significantly exceed the experiment time. On the other hand, multi-core processors are common in personal computers. These processors can be used to reduce computation time by using parallel computing on multiple cores. The most popular software applied to simulate behavior of the plant is MATLAB/Simulink. A single simulation of Simulink model cannot be computed by multiple cores, but there are many engineering problems, that require a multiple simulation of the same model with different parameters. In these problems, the parallel computing can be employed to decrease the overall simulation time. In this paper the parallel computing is used to speed-up the auto-tuning process of state feedback speed controller for PMSM drive. In order to obtain the optimal coefficients of the controller, an Artificial Bee Colony optimization algorithm is employed.
EN
In this paper, we are concerned with drive-response synchronization for a class of fuzzy cellular neural networks with time varying delays. Based on the exponential dichotomy of linear differential equations, the Banach fixed point theorem and the differential inequality technique, we obtain the existence of almost periodic solutions of this class of networks. Then, we design a state feedback and an impulsive controller, and construct a suitable Lyapunov function to study the problem of global exponential almost periodic synchronization for the drive-response systems considered. At the end of the paper, we provide an example to verify the effectiveness of the theoretical results.
EN
This paper presents state feedback control with a linear-quadratic regulator of a doubly fed induction generator. Resonant terms are added to the plant model in order to provide disturbance rejection and reference tracking. A new approach to controlling a parameter varying linear model of the induction machine is presented, allowing to apply a linear-quadratic regulator to the doubly fed induction generator. The control scheme described herein is suitable for the doubly fed induction generator operating under unbalanced stator voltage conditions, because the controller with resonant terms is built in the stationary αβ coordinate system. In it, the positive and negative symmetrical sequences have equal frequencies. The paper highlights specific problems associated with state feedback control of the doubly fed induction generator, i.e. the process of generator connection to an unbalanced grid. In contrast with classical voltage-oriented cascade control methods, in state feedback control of a stand-alone doubly fed induction generator there is no separate rotor current controller. This may cause over-current problem during DFIG synchronization with the grid which has been solved in this paper. Voltage synchronization and grid operation of the generator were tested in a laboratory rig with a 7.5 kW wound-rotor induction machine.
EN
The modification of the stability and positivity of standard and descriptor linear electrical circuits by state feedbacks is investigated. It is shown that: 1) There is a class of nonpositive and unstable R, L, e circuits that can be stabilized and modified to positive ones by state feedback; 2) There is a class of nonpositive and stable R, L, e circuits that can be modified by state feedback to positive ones without loss of stability. The modification of stability and positivity of linear descriptor electrical circuits is addressed. Considerations are illustrated by examples of linear electrical circuits.
PL
W pracy rozpatrzono problem modyfikacji stabilności i dodatniości standardowych i deskryptorowych liniowych obwodów elektrycznych poprzez sprzężenie zwrotne od wektora stanu. Pokazano, że: 1) Istnieje klasa niedodatnich i niestabilnych obwodów typu R, L, e, które mogą zostać ustabilizowane i zmodyfikowane do obwodów dodatnich; 2) Istnieje klasa niedodatnich i stabilnych obwodów typu R, L, e, które mogą zostać zmodyfikowane do obwodów dodatnich bez utraty stabilności. Rozpatrywany problem uogólniono dla klasy układów deskryptorowych. Rozważania zilustrowano przykładami obwodów elektrycznych.
EN
The positivity and linearization of a class of nonlinear continuous-time system by nonlinear state feedbacks are addressed. Necessary and sufficient conditions for the positivity of the class of nonlinear systems are established. A method for linearization of nonlinear systems by nonlinear state feedbacks is presented. It is shown that by a suitable choice of the state feedback it is possible to obtain an asymptotically stable and controllable linear system, and if the closed-loop system is positive then it is unstable.
EN
In this paper, an electromagnetic levitation system was used with a synchronous motor to navigate the control rod of a small-type research reactor. The result from this prototype magnetic levitation system was in agreement with simulation results. The control system was programmed in MATLAB through open-loop system, closed-loop with state feedback and closed-loop with state feedback integral tracking. The final control system showed the highest performance with a low positioning error. Our results showed that the developed control system has the potential to be used as a reliable actuator in nuclear reactors to satisfy higher performance and safety.
EN
The pressurizer water level control system in nuclear power plant with pressurized water reactor (PWR) is responsible for coolant mass balance. The main control goal is to stabilize the water level at a reference value and to suppress the effect of time-varying disturbances (e.g. coolant leakage in primary circuit pipeline system). In the process of PWR power plant operation incorrect water level may disturb pressure control or may cause damage to electric heaters which could threaten plant security and stability. In modern reactors standard PID controllers are used to control water level in a pressurizer. This paper describes the performance of state feedback integral controller (SFIC) with reduced-order Luenberger state observer designed for water level control in a pressurizer and compares it to the standard PID controller. All steps from modeling of a pressurizer through control design to implementation and simulation testing in Matlab/Simulink environment are detailed in the paper.
EN
The robust H∞ state feedback control problem for both continuous- and discrete-time singular systems with polytopic-type uncertainties is revisited via a parameter-dependent approach. Attention is focused on the design of a parameter-dependent state feedback controller, such that the closed-loop system is admissible with prescribed H∞ noise attenuation level for all parameter uncertainties. Without using decomposition technique to the singular model, sufficient condition for the existence of an H∞ state feedback controller is expressed in terms of strict linear matrix inequalities (LMIs). In case that the LMI conditions are feasible, a suitable state feedback control law is explicitly given. The proposed approach is expected to be less conservative compared with previous results. Numerical examples are also provided to show the effectiveness of the approach.
PL
Analizowany jest odporny system sterowania ze sprzężeniem zwrotnym H∞ dla przypadku systemu dyskretnego i ciągłego i z niepewnościami typu polytopic. Do analizy wykorzystuje się metod. zależności parametrycznych. Sterownik opisany jest liniową macierzą nierowności LMI. (Odporne sterowanie ze sprzężeniem zwrotnym H∞ - metoda zależności parametrycznych)
EN
In this paper, stabilizing problems in control design are addressed for linear discrete-time systems, reflecting equality constraints tying together some state variables. Based on an enhanced representation of the bounded real lemma for discrete-time systems, the existence of a state feedback control for such conditioned stabilization is proven, and an LMI-based design procedure is provided. The control law gain computation method used circumvents generally an ill-conditioned singular design task. The principle, when compared with previously published results, indicates that the proposed method outper forms the existing approaches, guarantees feasibility, and improves the steady-state accuracy of the control. Furthermore, better performance is achieved with essentially reduced design effort. The approach is illustrated on simulation examples, where the validity of the proposed method is demonstrated using one state equality constraint.
EN
The paper presents a discrete-time LTV controller for the rejection of harmonic disturbances with time-verying based on a state-augmented observer-based state-feedback controller with a time-verying internal model and a scheduled state-feed back gain. The control design method is based on quadratic stability for LPV systems. The design is carried out in discrete time and the controller can easily be implemented on real-time hardware.
PL
W pracy przedstawiono dyskretny regulator LTV do eliminacji składowych harmonicznych zakłóceń. Wprowadzony regulator bazuje na sprzężeniu od zmiennych stanu z zależnym od czasu wewnętrznym modelem. Konstrukcja regulatora wykorzystuje własności stabilności układów LPV. Regulator został opisany równaniami dyskretnymi i może być łatwo zaimplementowany w układach czasu rzeczywistego.
11
Content available Pairwise control principle in large-scale systems
EN
The purpose of the paper is present an algorithm of partially decentralized control design for one type of large-scale linear dynamical system. The pairwise autonomous principle is preferred where design conditions are derived in the bounded real lemma form, and global system stability is reproven to formulate potential application principle in fault tolerant control. The validity of the proposed method is demonstrated by the numerical example.
12
Content available remote Voltage/current control mode for combined three-phase inverter
EN
For parallel inverters system, controlling the output voltage in normal operation constantly is named the voltage control mode (VCM), and controlling the output current constantly in abnormal operation conditions (such as short circuit) is named the current control mode (CCM). The combined three-phase inverter topology is presented, the equivalent inverter topology with a LCL filter is obtained and mathematical models are built in VCM and CCM. A hybrid control strategy is proposed. The PID control and the repetitive control are used in VCM to obtain the fast dynamic responses and low harmonic distortions. On the other hand, the state feedback control is used in CCM. Pole assignment has been employed in designing parameter of the PID controller and state feedback, and the repetitive control design process is given. Experimental results validate the proposed control using two 400KVA parallel inverters.
PL
Dla równoległego systemu przekształtników zazwyczaj stosuje się system kontroli napięcia VCM i system kontroli prądu CCM (w warunkach specjalnych - np. zwarcia). Zaprezentowano topologie przekształtnika trójfazowego. Odpowiednia topologia przekształtnika z filtrem LCL została przedstawiona. Zaproponowano hybrydową strategię sterowania. System PID sterowania użyty w VCM zapewnia szybką odpowiedź dynamiczną i małe zniekształcenia. W układzie CCM użyto stałego sprzężenia zwrotnego. Sprawdzono położenie biegunów. Wyniki eksperymentu z dwoma 400kVA równoległymi przekształtnikami potwierdziły założenia.
EN
The notion of a common canonical form for a sequence of square matrices is introduced. Necessary and sufficient conditions for the existence of a similarity transformation reducing the sequence of matrices to the common canonical form are established. It is shown that (i) using a suitable state vector linear transformation it is possible to decompose a linear 2D system into two linear 2D subsystems such that the dynamics of the second subsystem are independent of those of the first one, (ii) the reduced 2D system is positive if and only if the linear transformation matrix is monomial. Necessary and sufficient conditions are established for the existence of a gain matrix such that the matrices of the closed-loop system can be reduced to the common canonical form.
EN
The LMI based method for the control with the state estimate, subject to the input variable constraints in the state feedback control of the linear MIMO systems, is presented in the paper. For this problem are obtained the state feedback as well as the estimator gain matrices that capture the required stability by solving the linear matrix inequalities formulated in the sense of the unified algebraic approach. The method is particularly effective when the input variable constraints and the system output are of interest.
EN
Design conditions for existence of observer-based memory-less feedback control for stabilization of discrete-time systems with equality constraints given on the state variables are presented in the paper. These conditions are associated with eigenstructure assignment based on the singular value decomposition principle. The validity of the proposed method is demonstrated by a numerical example with the equality constraint tying together all state variables.
EN
In this paper, the problem of exponential stability for the standard form of the state control, realized in a networked control system structure, is studied. To deal with the problem of stability analysis of the event-time-driven modes in the networked control systems the delayed-dependent exponential stability conditions are reformulated and proven. Based on the delay-time dependent Lyapunov-Krasovskii functional, exponential stability criteria are derived. These criteria are expressed as a set of linear matrix inequalities and their structure can be modified to use the bilinear inequality techniques.
EN
In the paper, simplified models of signals are introduced. The set of signals belonging to the class considered is divided into abstract subsets. Every subset of signals has a representative signal of a very simple form. These representative signals are next used as simplified models of signals and they can be applied to very complicated considerations in systems theory and control theory. For example, they are applied to designing high precision, state feedback control systems. In consequence, such systems approximate (for large gain in feedback loop) the inverse operation to the plant P considered. For solving this problem, the sum of differences of state variables of system and state of control signal are taken into consideration. Based on the simplified models of signals the linear combination of the state variables of system and state of control signal (not only sum of difference) can be used. This is important if the gain in the feedback tends to infinity. A scheme of such systems is presented in the paper.
18
EN
This paper presents a design approach to a state controller for permanent magnet synchronous motor (PMSM) servo-drives. Firstly, the well known non-linear mathematical model of PMSM is evaluated to a linear decoupled form by introducing new variables. An internal input model was used to achieve zero steady state error for ramp input as well as disturbance rejection. The proposed control method was implemented in a microcomputer system (TMS320F2812-DSP) and tested in a setup system.
PL
Przedstawiono sposób projektowania regulatora stanu dla serwonapędu z silnikiem synchronicznym o magnesach trwałych. Zastosowano wewnętrzny model liniowo narastającego sygnału referencyjnego w celu wyeliminowania błędu pozycji w stanie ustalonym oraz wyeliminowania wpływu zakłóceń . Zaproponowaną metodę sterowania zaimplementowano w procesorze sygnałowym (TMS320F2812-DSP) i zweryfikowano na stanowisku laboratoryjnym.
EN
The paper considers a set of linear discrete-time systems with uncertain parameters. A method of synthesis of robust control which simultaneously stabilizes all the systems from this set is proposed. This method consists of two steps. First, a set of stochastic comparison systems with multiplicative noises is constructed such that if the stochastic system from this set is mean square stable then the corresponding system with uncertain parameters from the original set is robustly stable. Second, the simultaneous stabilization problem for the comparison system is solved. To find a gain matrix of the simultaneously stabilizing controller in the case of state feedback an LMI based algorithm is given and in the case of static output feedback a new method and convergent iteration algorithm are obtained.
20
Content available remote Hybrid stabilization of discrete-time LTI systems with two quantized signals
EN
We consider stabilizing a discrete-time LTI (linear time-invariant) system via state feedback where both the quantized state and control input signals are involved. The system under consideration is stabilizable and stabilizing state feedback has been designed without considering quantization, but the system’s stability is not guaranteed due to the quantization effect. For this reason, we propose a hybrid quantized state feedback strategy asymptotically stabilizing the system, where the values of the quantizer parameters are updated at discrete time instants. We also extend the result to the case of static output feedback.
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