Validation of photovoltaics powered UPQC using ANFIS controller in a standard microgrid test environment

The power quality improvement becomes one of the important tasks while using microgrid as main power supply. Because the microgrid is combination of renewable energy resources. The renewable energy resources are intermittent in power supply and at the peak loading condition it has to supply the required power. So, the power quality problems may increase in that time. Out of all power quality issues the voltage drop and harmonic distortion is considered as the most serious one. In recent years unified power quality conditioner (UPQC) is emerged as most promising device which compensates both utility as well as customer side power quality disturbances in effective way. The compensating potentiality used in the UPQC is limited by the use of DC link voltage regulation and the conventional proportional integral (PI) controller. In this paper the compensating potentiality of the UPQC device is controlled by an adaptive neuro fuzzy inference system (ANFIS) control and it is powered from the available photovoltaics (PV) power generation. The effect of adding an intelligent UPQC is tested in the standard IEEE-14bus environment. MATLAB 2017b is used here for testing and plotting the simulation results.

MHD instability at the cathode spot as the origin of the vortex formation in high-intensity plasma arcs

Magnetohydrodynamic instability in a high-intensity arc, similar to typical arcs in DC electric arc furnaces, is simulated using an induction based model under 2D axisymmetric conditions. Time-averaged results show a good agreement with steady-state calculated results expected for a stable arc. The transient results declare that z-pinch close to the cathode, occurring due to the high electrical current density, is responsible for arc instability in this region. The unstable behavior of the arc can be evaluated in a periodic procedure. Moreover, correlations between the fluctuations in total voltage drop curve and the arc shape are investigated: when the arc is in form of column (or bell) the total voltage drop is on a minimum peak; if there is an irregular expansion of the arc in form of arms, the total voltage drop shows a maximum peak.

Mixed H2/H∞ Optimal Voltage Control Design for Smart Transformer Low-Voltage Inverter

The smart transformer has been widely applied for the integration of renewables and loads. For the smart transformer application, the voltage control of low-voltage inverter is important for feeding the load. In this paper, a multi-objective optimization control design approach which comprehensively considers all aspects of indexes, such as linear quadratic (LQ) index, H∞ norm, and closed-loop poles placement, is proposed based on the linear matrix inequality (LMI) solution. The proposed approach is able to alleviate the weight of the designer from the tedious design process of the multiple resonant controllers and the selection of the weighting matrix for the LQ control. Besides that, some excellent performances such as fast recovering time, low total harmonic distortion (THD) and high robustness are achieved by the proposed approach. The THD are 0.5% and 1.7% for linear and non-linear loads, respectively. The voltage drop for linear load step is reduced to 10 V. The proposed approach is applied to a 5 kVA three-phase inverter to yield an optimal control law. Results from the simulation and experiment presented herein will illustrate and validate the proposed approach.

Determination of Parameters of Electronic Devices by the Method of Passive Radio-Sensor Technical Diagnostics

Introduction. Technical diagnostics (TD) as a nascent discipline is rapidly developing in the field of both software and hardware. Modern TD methods, such as vibrometry, thermal control, JTAG testing and optical control, either exhibit high inertia, consume processor time, require suspension of the electronic device, or demand a galvanic contact with the study object, which is often unacceptable. These disadvantages can be eliminated by passive radio-sensor TD. To date, little information has been published on the parameters of electronic devices provided by this method.Aim. Determination of the parameters of electronic devices, the assessment of which can be provided by passive radio-sensor TD.Materials and methods. Signal radio profiles were obtained experimentally using metrological equipment and software-numerical methods for modeling radio wave processes. The parameters of the signal radio profile were calculated by a mathematical method for solving differential equations.Results. The main principles and results of radio-sensor TD, as well as the simplest toolkit, are shown. An equation is obtained for the signal radio profile emitted by the electronic unit of the device, as well as an expression for its free components. An approach for assessing the TD correctness based on the number of free components of the received signal radio profile and the reference is described. The possibility of obtaining information about temperature, voltage drop, speed of emitting nodes, as well as the state of its components and modes of operation of p–njunctions is demonstrated. It is shown that this information is carried by the parameters of the basic equation for the signal radio profile.Conclusion. The derived basic equation allows a non-contact, remote passive radio-sensor TD to be conducted by correlation analysis of the received signal, providing a detailed examination of malfunctions in each electronic unit. The described TD method based on the presented parameters is promising for assessing the technical state of electronic devices.

Increasing quality of the wireless module for monitoring and supervision of sound series of the expanded purpose

The sound series are considered as an addition to visual and thermal imaging information flows when using computerized monitoring systems (CS). A minimum complete structure of spaced microphones for collecting data on sound rows, which is suitable for calibrating, isolating and transmitting data on sound anomalies (SA), is proposed. Duplication of the data transmission channel by wire and Wi-Fi module for recording and determining the type and coordinates of the SA is provided. An experimental receiving module has been assembled, which includes microphones, amplifiers and signals matching boards for digital and analog forms, an ARDUINO UNO WIFI REV2 controller with an integrated Wi-Fi module. It is presented that its addition with a personal computer and a smartphone with the Android operating system forms a CS for remote wireless control of the course of the experimental analysis of sound series. It has been confirmed experimentally that its structure is minimally complete. An algorithm was developed and a software package was written in C/C++ languages. It is shown that the number of microphones is selected from the conditions of the problem from 1 to 5, but their number is limited to five digital inputs of the ARDUINO UNO WIFI REV2 board. A wave representation of the law of temporal changes in intensity and the integral norm of SA is applied. The possibilities of calibrating all data of sound series in analog and digital form are demonstrated. The article presents the suitability of testing the algorithms for determining the phases of echograms from time series data, containing SAs of different origins and recorded by three different microphones. The effect of connecting a Wi-Fi module on reducing the voltage drop by 0.5–1 V is shown. The necessity of an additional registration condition for all microphones is demonstrated. The software interfaces for the calibration of the receiving module and the operation of the mobile application have been developed.

Assessment of Voltage Imbalance Improvement and Power Loss Reduction in Residential Distribution Systems in Taiwan

In this study, the non-dominated sorting genetic algorithm II (NSGA-II) is used to optimize the annual phase arrangement of distribution transformers connected to primary feeders to improve three-phase imbalance and reduce power loss. Based on the data of advanced metering infrastructure (AMI), a quasi-real-time ZIP load model and typical sample distribution systems in Taiwan are constructed. The equivalent circuit models and solution algorithms for typical distribution systems in Taiwan are built using the commercial software package MATLAB. A series of simulations, analyses, comparisons, and explorations is executed. Finally, the quantitative evaluation results for improving the voltage imbalance and reducing the power loss are summarized. For the series of studies, the percentage reductions in (1) total power imbalance TSI, (2) total line loss TLL, (3) average voltage drop AVD, (4) total voltage imbalance factors for zero/negative sequences Td0/Td2, and (5) neutral current of the main transformer ILCO are up to 45.48%, 4.06%, 16.61%, 63.99%, 21.33%, and 88.01%, respectively. The results obtained in this study can be applied for energy saving and can aid the authorities to implement sustainable development policies in Taiwan.

Influence of Process Parameter on Carbon Nanotube Field Effect Transistor Using Response Surface Methodology

Carbon nanotube field-effect transistor (CNTFET) is a good option to replace silicon for low power consumption application. Recent research shows that CN-FET thermal and electrical properties alter with length, diameter, and gate parameters. Optimization of CNTFET design parameters helps control some of the factors. Double gate and cylindrical gate layouts are introduced to overcome these facts. Carbon nanotubes have an intercapacitance between them that increases as their diameter increases. Total capacitance and inductance of CNTFETs increase with nanotube count. In order to reduce the voltage drop between semiconducting and metallic terminals, the diameter and pitch must be raised. This study employs response surface methodology and ANOVA technique that were used to optimize CNTFET process parameters. Thickness, voltage, delay, and power were all considered. The most affecting parameter was investigated.