جستجوی مقالات مرتبط با کلیدواژه "کنترل کننده" در نشریات گروه "برق"

In this paper, an applicable control-relevant nonlinearity assessment method is proposed for nonlinear dynamic systems. In this method, nonlinear system is decomposed to a bank of linear systems using gap metric, a smart tool for measuring the distance between two linear systems. Then, the ability of each local linear model is investigated to stabilize all linear models. A criterion is proposed to measure the nonlinearity of nonlinear system based on gap metric and maximum stability margin values which bounded between 0 and 1. Unlike most of the current nonlinearity measurement, the proposed method could be used for both integrating and unstable nonlinear systems. Besides, the presented method supplies to distinguish that a single linear controller is adequate to control the nonlinear system or it is necessary to employ the multi-model based controllers design methods. Therefore, the redundancy problem could be avoided by employing the proposed method. A nonlinear Continues Stirred Reactor Tank (CSTR) process is studied that the results confirm the capability of presented nonlinearity assessment method..

A microgrid has two operating modes, parallel to the grid and islanded operation modes. In the parallel operation mode, the scattered productions inside the microgrid can be powered synchronously with the production network or they can be turned off, and in the islanded operation mode, the scattered productions supply the loads inside the microgrid. The purpose of this article is to improve the power quality and transient response of a microgrid including DG sources using power electronics in islanded and grid-connected modes. For this purpose, a control method using a mode feedback controller is used to control the switching of interface converters for compensating unbalanced and non-linear loads. In this controller, a 2nd-degree linear regulator is used to produce a suitable profit margin and it will deal with optimal load allocation between scattered production sources. The proposed compensator, while providing the real power required by the network, is capable of load balancing, harmonic compensation, and reactive power control. Also, the feeding of local loads can be divided by any desired ratio between the network and DG.

Nowadays, solar arrays and wind energy are considered as many renewable energy sources. These sources can deliver their energy to the grid or directly to the consumer. In power electronics, multi-input converters are commonly used to convert the energy of renewable energy sources into the power required by the grid. In this article, a high-gain non-insulated three-port converter based on a quadratic boost converter has been proposed. This converter includes two power supplies with controllable currents. This improves the performance of the converter and reduces the ripple current of the input sources. In addition, the proposed converter has two operating modes and can work with one or two voltage sources. To design a high-gain multi-input converter, first the structure and performance of the proposed converter are thoroughly analyzed and evaluated Then, using MATLAB software, the stability of the proposed converter is checked and the output voltage and input currents are controlled independently using the decoupling network method. Then the main equations are calculated theoretically and its performance in different duty cycles is investigated. Finally, the simulation results for different modes show the correct operation of the converter and controller.

The use of the input low-pass filter causes instability in DC-DC converters. These instabilities occur because of the interaction between the filter and the converter. In this paper, a control method based on Lyapunov is proposed. This control method uses the exact system model without linearization. All state variables are controlled using an instantaneous model. A new state variable is defined to reduce the static output voltage error. No condition is necessary to implement the control strategy. The simulation and experimental results are presented to validate the proposed control method.

Unlike classical cryptography, where security is based on computational complexity, quantum cryptography has unconditional security, which is based on physical constraints. So far, the semi-quantum version of many of the problems of secure quantum communication protocols has been proposed. In this study, we examined semi-quantum protocols that allow users to access a secret message directly without distributing the key. An important factor used to analyze the performance of secure quantum direct communication protocols is efficiency. In this study, the proposed semi-quantum secure communication protocol against various quantum attacks has been investigated. In the proposed scheme for decoding the confidential message by the receiver, a sequence of single photons is required, which is first generated by the controller. The proposed protocol has a yield of 50%, which is higher than the previous protocol, which has a yield of 66.6%.

Static Synchronous Compensator (STATCOM) is a FACTS device whose structure is based on a voltage source converter and is installed in parallel to control the voltage of the transmission line in the power system. In this paper, a flat adaptive control system for STATCOM output voltage control is simulated. By linearizing the nonlinear dynamics and changing the system state variables, the controller designs the rules of control input stability, and an adaptive rule is obtained for designing the controller coefficients with the least system error. In the simulation results, the adaptive controller is compared with the traditional PI controller.

One of the most important concepts in constant target tracking of different equipment Which have inertical bodies viewed from a moving platforms is their picture stabilization. In this paper a new method for cinematic equations resolving is presented in which the angular errors are obtained to correct body movement and to optimize the constant tracking.which uses specific view.fur ther more of using identification system In determining of dynamic model of meters for designing the controller and dead zone reduction are applied such that the steady state error is minimized and the rise time is reduced and the wine sliding is decreased. Practical results at the gyroscope (experimental type) show good performance of the system.