A. Baskys

Asymmetric PID controller

The controller for plants that are characterized by the different dynamics during the rise and decay of the plant output parameter has been suggested and analyzed. The control algorithm used in the proposed controller is modification of the PID control method. The characteristic property of the algorithm is that parameters of the controller are changed when the sign of the error changes. This feature enables achieving good response of the analyzed control system in case of plants with the asymmetric dynamics. The results of the investigation of the concrete control system based on the proposed controller are presented. The investigation was performed using the electronic circuit simulation program Spice

SVPWM method with the averaged pulse length versus conventional modulation method

The efficiency of the AC induction motor used in the variable speed drive fed by the three-phase AC voltage formed using developed by authors Space Vector Pulse Width Modulation (SVPWM) method with the averaged pulse length has been investigated. The obtained results are compared with the results gained using a conventional SVPWM method. They show that the SVPWM method with the averaged pulse length provides higher motor efficiency as compared to the case when a conventional SVPWM method is employed.

Asymmetric PI Controller for Mechatronic Systems

An asymmetric PI (aPI) controller based on a control algorithm, which is the modification of the PI control method, has been suggested. The principal characteristic feature of the aPI controller is that different values of proportional and integral constants are used at positive and at negative errors. Contrary to the classical PI controller, the proposed controller allows us to improve the positive disturbance rejection of control systems without sacrificing the unit step response dynamics. Results of the investigation of the concrete control systems based on the aPI controller are also presented. Using the dynamic system simulation program Simulink performed the investigation.

The model of the p-n junction depletion region v-i characteristic considering the dependence of concentration of majority carriers on voltage

The equation of the p-n junction depletion region v-i characteristic considering the dependence of concentration of majority carriers on voltage is proposed and examined. The analysis of equation leads to the new conclusions about the behaviour of the junction, which in the general case contradict the propositions presented in a good many of books dedicated to semiconductor devices

Selection Methodology of Energy Consumption Model Based on Data Envelopment Analysis

Abstract The energy efficiency monitoring methods in industry are based on statistical modeling of energy consumption. In the present paper, the widely used method of energy efficiency monitoring “Monitoring and Targeting systems” has been considered, highlighting one of the most important issues — selection of the proper mathematical model of energy consumption. The paper gives a list of different models that can be applied in the corresponding systems. The numbers of criteria that estimate certain characteristics of the mathematical model are represented. The traditional criteria of model adequacy and the “additional” criteria, which allow estimating the model characteristics more precisely, are proposed for choosing the mathematical model of energy consumption in “Monitoring and Targeting systems”. In order to provide the comparison of different models by several criteria simultaneously, an approach based on Data Envelopment Analysis is proposed. Such approach allows providing a more accurate and reliable energy efficiency monitoring.

Application of sequential analysis of Wald for energy efficiency monitoring

The issue of energy efficiency monitoring in industry has been analyzed. The methodology of widely used statistical method of energy efficiency monitoring “Monitoring and Targeting systems” investigated in the paper. The critical disadvantages of Monitoring and Targeting systems were highlighted. In order to eliminate the disadvantages of Monitoring and Targeting systems authors propose apply probabilistic-statistical approaches, in particular the sequential analysis of Wald.

Calculation of electrical energy balances of production systems based on probabilistic-statistical approach

The paper analyzes well-known methods of calculation of electrical energy balances on enterprises. The drawbacks of these methods under conditions of fuzzy and incomplete initial information are shown. In order to obtain more reliable electrical energy balances under such conditions a new probabilistic-statistical approach is proposed. The method uses a hierarchical principle of obtaining electrical energy balances with two levels: electrical energy balances by types of products and electrical energy balances by technological equipment, which are involved in production processes of each type of products. Advisability of application regression analysis for calculation electrical energy balances on the first level is considered. The methods proposed for calculation electrical energy balances on the second level include expert survey, simulation, probabilistic-statistical methods and optimization techniques.

Asymmetric Integral Controller

The control of plants with the asymmetric dynamics is analyzed. The characteristic feature of these plants is that the dynamics of the plant output parameter during the rise and decay is different. The controller for plants with the asymmetric dynamics has been suggested and analyzed. The control algorithm used in the proposed controller is modification of the integral control method. The characteristic property of the algorithm is that the value of integral constant of the controller is changed when the sign of the error changes. This feature enables achieving improved transient performance of the analyzed control system as compared to the case when the classical integral controller is used. The noteworthy advantage of the proposed controller is higher electromagnetic disturbance compatibility as compared to the asymmetric controllers that include proportional and derivative terms. The results of the investigation of the concrete control system based on the proposed controller are presented and analyzed. The investigation was performed using the electronic circuit simulation program Spice.

Investigation of microinverter based on the two-switch DC-DC flyback converter topology

The investigation results of the grid connected photovoltaic single stage microinverter with a new topology are presented. The microinverter is based on the couple of two-switch DC-DC flyback converters and has simple design. The investigation results show that the analyzed microinverter is characterized by the high efficiency and low total harmonic distortion of output voltage.

Application of Local Outlier Factor Algorithm to Detect Anomalies in Computer Network

Gap between the new attack appearance and signature creation for this attack may be critical. During this time, many computer systems may be affected and valuable resources may be lost. Even after signature creation, many computer systems still stay vulnerable because of bad security practice, i.e. patches and updates are not installed as needed. Therefore, anomaly intrusion detection system (IDS) that is capable to detect new unknown attacks is valuable security tool. This paper analyses the use of Local Outlier Factor (LOF) to detect anomalies in the computer network. The application of the LOF algorithm for the detection of anomalies when only normal network data are used for the model training has been demonstrated. Experimental results of different threshold values influence on the anomaly detection accuracy using NSL-KDD dataset is presented. DOI: http://dx.doi.org/10.5755/j01.eie.24.3.20972