PARAMETERS MONITORING ORGANIZATION OF THE SOLAR PANELS EXPERIMENTAL STAND

Актуальность разработки обусловлена необходимостью создания устройства для сбора и обработки информации с экспериментального стенда солнечных панелей. Назначением стенда является получение достоверных данных для верификации моделей оценки показателей гелиопотенциала, использующихся при обосновании эффективности применения солнечных электростанций на территории восточных регионов России. Дано описание основного и вспомогательного оборудования экспериментального стенда. Солнечные панели стенда разноориентированы для определения наиболее эффективного угля наклона и обоснования необходимости применения следящей за солнцем системы. Для снятия и записи мгновенной мощности солнечных панелей разработано устройство на основе микроконтроллера Arduino. Для мониторинга показаний силы тока используется шунтовый амперметр, подключаемый в разрыв цепи питания. Приведена схема счётчика тока и описана его работа. Приведены первичные результаты собранных данных. Намечены основные этапы дальнейшей обработки данных. The relevance of the presented development is due to the need to create a device to read and process information from an experimental array of solar panels. The purpose of the array is to obtain reliable data for the verification of models for estimating photovoltaic power potential indicators used in justifying the feasibility of the adoption of solar power plants in the eastern regions of Russia. We present a description of the main and auxiliary equipment of the experimental array. The array's solar panels are arranged in different ways so as to determine the most efficient tilt angle and justify the need to use a sun tracking system. The proprietary device based on the Arduino microcontroller was designed to read and write the value of instantaneous power of solar panels. To monitor the readings of the amperage, a shunt ammeter is used, which is connected to the gap of the power circuit. The study provides a diagram of the current meter and describe its operation. We outlined the main stages of subsequent data processing.

The Evaluation of Electric Power by Separate Analysis of Fourier Transform Components

This paper presents a substantiation of an approach for the evaluation of components of apparent power and intended to simplify the computational procedures which usually should be implemented in order to process the preliminary sampled waveform of instantaneous power. The results of carried out studies have shown that both active and reactive power can be calculated by the analysis of calculated components of sine and cosine Fourier transforms. This paper also presents the discussion of restrictions, which should be imposed on the duration of the analyzed signal and on frequencies of the auxiliary trigonometric functions, which are applied in order to calculate components of Fourier transform which are used for the evaluation of active and reactive power. The compliance with these restrictions allows us to eliminate the undesirable bias of active and reactive power estimation caused by the refusal from the decomposition of the analyzed waveform of the instantaneous power by applying the complete system of orthogonal trigonometric functions, as the evaluation of components of the apparent power is attained based on separate analysis of sine and cosine Fourier transforms calculated for the analyzed signal. The results of carried out simulations illustrate the frequency dependencies of sine Fourier transform calculated for the case of compliance with the restrictions, which allow to attain the highest accuracy of estimation and for the case when the duration of analyzed signal does not fit these restrictions.

Minimization of power and energy consumption of mechatronic drives in robotics and technological equipment

The maximum instantaneous power consumption of robot drives determines the requirements for the energy supply system and the dimensions of the machine. For numerous machines, there are no technological restrictions on the types of applied motion laws and their numerical characteristics i.e. maximum speeds and accelerations. The type of the motion law and especially its parameters are traditionally determined according to the preferences of the design engineer without any justification, though some-times restrictions on maximum accelerations or speeds are considered. The restrictions on maximum accelerations are related to ensuring the strength and accuracy of the drive, and the restrictions on maximum speeds are related to the safety of personnel in the workplace. The motor power is selected according to the maximum value of the instantaneous power and thermal load, which depends on the duration of switching on. The article analyzes the ways of minimizing of this maximum (peak) of instantaneous power inside the cycle for different laws and different loads. The main parameter by which the maximum (peak) power is minimized for all types of laws is the acceleration and braking times. On the example of the most common motion laws, the dependence of instantaneous power and energy consumption on accelerating time and braking time for various types of loads are studied. In this article, the dependence of instantaneous power and energy consumption on accelerating time and braking time for various types of loads are studied on the example of the most common motion laws. The research results are intended to create a design technique for drives of modern equipment.

Optimal Predictive Control Method of PWM Rectifiers Based on Artificial Intelligence

Direct power control (DPC) of pulse width modulation (PWM) is often used to control the instantaneous power of rectifiers. The instantaneous power contains both grid voltage and current information, and its value is not affected by coordinate transformation. It is constant in steady state and reflects the DC control characteristics. However, the switching frequency of traditional DPC is not fixed, the DC voltage has static error, and the system fluctuates greatly. In this work, we introduce the concept of stator flux of the AC motor into the PWM rectifier. Combined with the space vector PWM (SVPWM) technology, we use the virtual flux estimation method to obtain the instantaneous power value, which saves the grid voltage sensor, eliminates the static difference of DC voltage. Furthermore, considering that the neural proportion integral differential (PID) control depends heavily on the initial weight coefficient of the network, we use chaos particle swarm optimization (CPSO) algorithm, which combines the basic PSO algorithm and chaos theory to optimize the initial weight coefficient of neural PID control. In the experiment, the results prove that the performance of the controller can be effectively improved.

APPLICATION OF CYCLOSTATIONARY PROPERTIES OF PERIODIC SIGNALS FOR POWER ANALYSIS IN ELECTRIC CIRCUITS

Предложен циклостационарный подход к анализу мощности электрических цепей, возбуждаемых источниками периодических токов и напряжений. Получены теоретические выражения для характеристик мгновенной мощности на основе взаимной спектральной ковариационной функции и показана их связь со средней и полной мощностью. Проведен анализ гармонического распределения мощности в линейной цепи при периодическом воздействии. На примере численного расчета резонансной цепи продемонстрированы этапы циклостационарного анализа и получены основные характеристики мощности. The paper proposes a cyclostationary approach to the power analysis for electric circuits excited by sources of periodic currentsorvoltages.Theformalexpressions forcharacteristics of instantaneous power are obtained on the basis of cross spectral covariance function and their relation to the average and apparent power is established. The analysis of the harmonic distribution of the power in a linear circuit under periodic excitation is carried out. The main stages of the method are illustrated with a numerical simulation example.

Cyclostationary Approach to the Analysis of the Power in Electric Circuits under Periodic Excitations

This paper proposes a cyclostationary based approach to power analysis carried out for electric circuits under arbitrary periodic excitation. Instantaneous power is considered to be a particular case of the two-dimensional cross correlation function (CCF) of the voltage across, and current through, an element in the electric circuit. The cyclostationary notation is used for deriving the frequency domain counterpart of CCF—voltage–current cross spectrum correlation function (CSCF). Not only does the latter exhibit the complete representation of voltage–current interaction in the element, but it can be systematically exploited for evaluating all commonly used power measures, including instantaneous power, in the form of Fourier series expansion. Simulation examples, which are given for the parallel resonant circuit excited by the periodic currents expressed as a finite sum of sinusoids and periodic train of pulses with distorted edges, numerically illustrate the components of voltage–current CSCF and the characteristics derived from it. In addition, the generalization of Tellegen’s theorem, suggested in the paper, leads to the immediate formulation of the power conservation law for each CSCF component separately.

Reducing the Power Consumption of the Electrodynamic Suspension Levitation System by Changing the Span of the Horizontal Magnet in the Halbach Array

In high-speed magnetic railways, it is necessary to create the forces that lift the train. This effect is achieved by using active (EMS) or passive (EDS) magnetic systems. In a passive system, suspension systems with permanent magnets arranged in a Halbach array can be used. In this paper, an original Halbach array with various alternately arranged horizontally and vertically magnetized magnets is proposed. Correctly selected geometry allows us to obtain higher values of levitation forces and lower braking forces in relation to a system with identical horizontally and vertically magnetized elements. The effect of such a shape of the magnetic arrangement is the reduction of instantaneous power consumption while traveling due to the occurrence of lower braking forces. In order to perform a comparative analysis of the various geometries of the Halbach array, a simulation model was developed in the ANSYS Maxwell program. The performed calculations made it possible to determine the optimal dimensions of horizontally and vertically magnetized elements. The results of calculations of instantaneous power savings for various cruising speeds are also included.