Journal of Applied Dynamic Systems and Control
http://jadsc.aliabadiau.ac.ir/
Journal of Applied Dynamic Systems and Controlendaily1Thu, 31 Dec 2020 00:00:00 +0330Thu, 31 Dec 2020 00:00:00 +0330Constrained Controllability of Linear Discrete Time Systems: A sufficient condition based on Farkas' Lemma
http://jadsc.aliabadiau.ac.ir/article_679220.html
This paper provides sufficient conditions for controllability of discrete time linear systems with input saturation. Controllability is a central notion in linear system theory, optimal quadratic regulators as well as model predictive control algorithms. The more realistic notion of constrained controllability has given less attention probably due to mathematical complications. Most of the existing works on constrained controllability studies the properties of reachable sets. However, there are only a few works which investigate the problem of whether a state is reachable or not. In this paper, a set of sufficient conditions are firstly given for constrained controllability of time varying linear systems in discrete time formulation. The given conditions are obtained using the Farkas&rsquo; lemma for alternative inequalities. The obtained results improve existing literature by providing conditions for both null-controllability and controllability regardless of the system stability. A sufficient condition is then given for the special case of time invariant single input linear systems with diagonal Jordan canonical form. Numerical examples are given for clarification.Improving the Insulating Properties of Transformer Oil Using Nanomaterials with Regard to Thermal Aging
http://jadsc.aliabadiau.ac.ir/article_679266.html
Incorporation of nanoparticles into transformer oils improves their electrical and insulating properties. However, thermal aging may undesirably decrease the performance of nanomaterials in transformer oils. Herein, pure oil together with TiO2, ZnO, and CNTs incorporated oil (nanofluids) can underwent thermal aging by simulating this phenomenon at 110, 120, and 130 &deg; C for 30, 30, and 15 days (equivalent of 10, 30, and more than 40 years of normal oil operation, respectively). During the accelerated thermal aging process, the total acid number (TAN), breakdown voltage, and lightning impulse breakdown voltage of all samples were measured periodically. The TAN increased with increasing temperature and time, but never exceeded the allowable level of 1.2 mg KOH/g. As the oil ages, its corrosion rate increases, which is undesirable for the transformer. The results of the breakdown voltage test suggest that the TiO2 was the best candidate, such that the breakdown voltage increased with respect to the pure oil by 17, 27, and 48% at 110, 120, and 130 &deg;C, respectively. The outcome of the lightning breakdown test also indicated that TiO2 still performed better than the other samples. TiO2 was able to improve the lightning voltage at 110, 120, and 130 &deg;C by 33, 8, and 5%, respectively. Therefore, as it was observed, TiO2 has been able to perform the best performance in thermal aging.FTC of Three-phase Induction Motor Drives under Current Sensor Faults
http://jadsc.aliabadiau.ac.ir/article_679268.html
&nbsp;In this study, single-phase current sensor Fault-Tolerant Control (FTC) for Three-Phase Induction Motor (TPIM) drives using a flux observer is proposed. In the proposed FTC scheme, a 3rd difference operator executes the Fault Detection (FD) task and the reconstruction of the faulted current is achieved through a flux observer. The presented FTC system is able to switch TPIM drive systems from normal mode to the faulty mode suitably. The proposed method in this study can be utilized in many industries particularly in electric vehicles, medical devices, and aerospace where TPIM drive systems are needed to continue the desired operation even during fault situations. The effectiveness of the proposed FTC system is confirmed by experiments on a 0.75kW TPIM drive platform.Optimal Active Distribution Network Reconfiguration for Loss and Supply Cost Minimization Using Grey Wolf Algorithm
http://jadsc.aliabadiau.ac.ir/article_679371.html
In this paper, a novel reconfiguration approach for distribution network incorporating distributed generation is introduced aiming to minimize power losses and energy supply costs. Given the temporally variable consumption of residential, industrial and commercial loads and the time-variant energy prices, an hourly reconfiguration scheme for an entire daily cycle is proposed. Also considering the privately-owned nature of distributed sources, the energy supply is carried out within a competitive market. The optimization is based on grey wolf algorithm (GWO), implemented in MATLAB software on an IEEE 33-bus test network. The simulation is done for four scenarios with respective objective functions for the evaluations of the results thereof. By comparing the obtained results it is concluded the configuration of network will be the unique for each of objective function. Finally, the effects of switching at different hours of day are compared in terms of loss minimization and supply costs against single daily switching scheme.Optimal Location and Determination of Fault Current Limiters in the Presence of Distributed Generation Sources Using a Hybrid Genetic Algorithm
http://jadsc.aliabadiau.ac.ir/article_679372.html
Nowadays, the presence of distributed generation (DG) units in the distribution network is increasing due to their advantages. Due to the increasing need for electricity, the use of distributed generation sources in the power system is expanding rapidly. On the other hand, in order to respond to the growth of load demand, the network becomes wider and more interconnected. These factors increase the level of fault current in the power system. Sometimes this increase causes the fault current level to exceed the ability to disconnect the protective devices, which can cause serious damage to the equipment in the power system. Using fault current limiters (FCLs) in power system is very promising solution in suppressing short circuit current and leads use of protective equipment with low capacities in the network. In this paper, in order to solve the problem of increasing the fault current, first using sensitivity analysis, network candidate lines are selected to install the fault current limiter, which helps to reduce the time and search space to solve the problem. Simultaneously finding the optimal number, location and amount of impedance for the installation of a resistive superconductor limiter is solved using the multi-objective Non-dominated genetic algorithm with non-dominated sorting (NSGA-II). The method presented in a 20 kV ring sample network, simulated in PSCAD software, is evaluated in the presence of distributed generation sources and its efficiency is shown.Sport Result Prediction Using Classification Methods
http://jadsc.aliabadiau.ac.ir/article_679387.html
Traditional sport was based on the ability of the players and less science and knowledge was considered. However, sport has become a profession and an industry. Therefore, the use of technology and analysis on data in order to achieve goals is very important. Classification is one of technologies to classify new incoming samples. Furthermore, sports produce considerable information about each season, teams, matches and players. Classification on sport data helps managers and coaches in order to predict the match result, evaluate the player performance, predict the player injury, identify the sports talent and evaluate the match strategy. There are many algorithms to predict the basketball results, track the health of players and determine the strategy of the match against different opponents, which help coaches a lot. Further, preprocessing procedure makes better dataset. In this paper, we use classification methods on sport dataset using preprocessing procedure and without preprocessing. The results show an improvement was obtained results using preprocessing.