Power Supply Source Research Articles

Design and Implementation of Solar Powered Automatic Irrigation System

This research is geared towards employing modern technology to enhance agricultural productivity through local and mechanized farming systems. The research work involves the construction of a device that controls water flow in an irrigation system most especially, in areas where there is acute shortage of water supply or insufficient rainfall which may be due to climate change resulting or causing draught and other environmental conditions. It is a device that is solar powered, as an alternative source of power supply to the entire irrigation system. The solar power supply consist of two modules or panels, a battery and charge regulator whose function is to control the battery charge and as well supply power to the load (motor) at various weather and soil moisture conditions. The device was tested and it was (is) able to minimize electrical power consumption, with a flow rate of water averaging at 20 liters per minute, due to the pump size and capacity. The humidity of the soil is detected by the soil moisture sensor which determines the voltage levels at which the water pump switches on/off. Also, there is an ultraviolet light sensor that enables the controller to switch off the pump during the period of higher intensity of sunlight, owing to the fact that most crop plants are irritated by water when the sun is very hot. The water pump is a D. C submersible type. An algorithm was designed for the smooth operation of the entire system.

Facility Readiness for Childhood Routine Immunization Services in Primary Healthcare Centres in Benin City, Edo State, Nigeria

Background and objective of study: immunization remains an essential strategy for reducing mortalities and morbidities due to vaccine preventable diseases. Immunization service delivery is dependent on planning of immunization sessions, and Supervision of the immunization process as this is very important in order to achieve immunization coverage target.Materials and Methods: A descriptive cross sectional study was utilised. This was done using an observational check list guide which was developed by the researcher and utilised for assessment of facility readiness for routine immunization service delivery. It was used to assess the facilities, amenities and logistics utilised in the immunization services process and also the functionality of the amenities. It was utilised in 35 Primary health care centres in the 3 Local Government Areas.Results: Thirty two (91.4%) had sufficient staff offering immunization and 22 (62.9%) had sufficient seats for clients. All the facilities had supervisory visits by the government. Thirty three (94.3%) had health talks before immunization and 25 (71.4%) had an alternate functional source of power supply readily availableConclusion: Only 3 of the PHCs were ready for routine immunization service delivery while 32 were partially ready for immunization

To the issue of complex increasing energy efficiency of electric receivers of oil and gas fields

When designing oil and gas industry facilities and petrochemical facilities, the issue of the organization of their power supply system does not lose its relevance. At the stage of the feasibility study, the options based on the use of renewable energy sources, as well as energy storage systems are not often considered due to the high cost of solutions. The absence of standard solutions for the use of renewable energy sources and energy storage systems, the incompleteness of the regulatory framework force designers to refuse to consider them when designing power supply systems. This article analyzes the theoretical aspects and practical examples of the use of additional non-traditional sources of power supply, contributing to the improvement of energy efficiency of power supply systems as a whole.

The use of light filters in the photovoltaic solar power station to improve economic efficiency

The agriculture and forestry sector require a solution to the problem of energy supply to autonomous consumers. The use of renewable energy sources is relevant worldwide in accordance with environmental requirements. The paper considers the project of a photovoltaic solar power station using light filters to reduce the number of solar panels to provide the required power. The Krasnoyarsk State Agrarian University has developed an experimental setup for studying the characteristics of solar panels using light filters. The aim of the study is to develop a technology for the use of light filters in photovoltaic solar power station and to optimize their operation modes in order to increase the economic efficiency of using autonomous sources for power supply to agricultural consumers. The objectives of the study are the selection and analysis of light filter materials to increase the generated power, substantiate the application of the photovoltaic solar power station for autonomous objects of agriculture and forestry and prove the economic efficiency of the proposed installation. The paper presents the results of a study of the characteristics of solar modules using filters, the main economic indicators are calculated, the economic efficiency of the use of filters is proved. The use of photovoltaic solar power station will ensure a reduction in the cost of electricity generation by 7% compared to existing plants.

Математическое обеспечение автоматических систем выравнивания мощностей модульных источников питания

An algorithm for controlling the modules of a power supply source of vacuum electric furnaces intended for growing artificial monocrystals of leucosapphire according to the Kyropoulos method is considered. Since the modules from which a source with the required capacity is assembled by connecting them in parallel are not exactly identical with one another, and so are the current conducting buses used to interconnect them, a situation may occur in which some of the modules are underloaded, while others are overloaded. Therefore, in addition to stabilizing the total power produced by the source, the automatic control system must minimize the power difference among the modules. An algorithm ensuring balanced operation of the modules is developed, which is based on modeling the processes in an electrical system consisting of power supply modules and current supply buses that take into account their parameters — resistance, inductance, and mutual inductance. The algorithm has been implemented in the MatLab environment. The algorithm testing results have shown that the power difference among the power supply modules is decreased by more than a factor of two.

Резонансный электромагнитный вибровозбудитель колебаний с обратной связью

A number of modern technological processes can be significantly intensified due to the use of vibrations with a wide range of oscillation frequencies and amplitudes. In many cases, electromagnetic vibration exciters (EMVE) can serve as the most effective vibration source. Direct conversion of electric energy into mechanical vibration energy opens the possibility for developing devices controlled by electrical methods. However, the oscillatory processes in the circuits containing electromagnetic exciters have been studied to an insufficient extent as applied to vibration engineering. This is connected with the complexity of the effects caused by the nonlinearity of vibration exciter electromagnets and power source on the vibration processes, i.e., a nonlinear dependence of the vibration amplitude and phase on the system parameters and a nonlinear dependence of inductance from the armature displacement. The results from theoretical and experimental studies of oscillating electromechanical systems (EMC) built on the basis of an EMVE with feedback, and the development of methods for analyzing resonant EMVE circuits with a view to obtain the optimal characteristics in low-frequency oscillation modes (LFO) demonstrate the possibilities of economically efficient consumption of electric energy and the performance of the EMVEs used in different industry branches. With the introduction of feedback proportional to the control frequency and the output voltage amplitudes of the EMVE power supply source, it becomes possible to automatically adjust the vibration frequency to the resonance frequency of the elastically suspended EMVE load-carrying member for maintaining constancy of vibration velocity amplitudes and, hence, the system performance. To achieve a stable resonance operation mode of the electromagnetic vibration exciter, the voltage proportional in phase between the inverter output voltage and the load-carrying member motion speed are analyzed. The study results have shown that, owing to the feedback effect that adjusts the driving frequency in phase toward tuning to resonance, a rational EMVE operation mode can be secured.

Энергосберегающая методика изучения физической модели высоковольтного инвертора на основе электронно-лучевого клапана

The schemes of inverters applied in static reactive power compensators (SRPC) are as a rule developed with the use of power semiconductor devices (PSD); however, attempts to develop industry-grade prototypes of high-voltage inverters on the basis of serially produced vacuum-tube devices (VTD) are also made. High-voltage electron beam valves (EBV), which feature—owing to beam recovery at the anode — the minimum possible voltage drop across the anode-cathode section in the conductive state among the VTDs and a high steepness of the impulse front and trailing edges in comparison with PSDs, seem to be promising for such applications. An EBV was simulated in the EWB circuit engineering computer program environment to determine the minimum permissible load resistance at which the EBV has the maximum electrical efficiency up to 0.99. To determine whether it is advisable to construct such inverters, it is necessary to conduct not only theoretical, but also experimental investigations on physical models using dedicated test benches. A high-voltage energy-saving bench for testing EBVs operating within the SRPC circuit in an inverter mode has been developed. The bench takes power supply from the 3x380 V, 50 Hz network. The bench comprises a three-phase high-voltage transformer, using which the power supply voltage can be increased to a 40 kV level. This voltage is rectified according to the Larionov bridge scheme, and, owing to an artificial midpoint, the 0 to +20 kV and 0 to -20 kV voltages with the maximum current up to 1 A are obtained. The voltage amplitude can be smoothly varied using a three-phase electromechanical regulator installed in the high-voltage transformer primary winding. A 50 Hz sine-wave voltage is produced in the inverter mode by means of pulse-width modulation (PWM) with a clock frequency smoothly variable in the 1...3 kHz range and is applied to a water equivalent of load. To increase the bench power level during the test and achieve energy saving, a gating logic device (GLD) was introduced, which allows the EBV control system to operate in an intermittent PWM generation mode. The GLD produces pulses using which three cycles of a 50 Hz sine-wave voltage (with the total duration equal to 60 ms) repeating at approximately 1.2 s intervals are generated. The use of the GLD producing packs of control pulses makes it possible to study the EBV operation modes on the bench at a short-term power of up to 200 kW in pulse-periodic mode, which is significantly (by 10.20 times) higher than the average power of the bench constant-voltage network power supply source. The GLD output voltage waveforms and the load voltage and current front and trailing edge waveforms are given.

Обоснование параметров преобразователя постоянного тока для источника автономного электроснабжения

As the Smart Grid concept has become a part of the electric power industry development, DC/DC conver­ters have turned into a matter of increased interest. This is due to their effective coordination in the DC-bus system operating different types of power sources, including renewable ones and energy storage devices (batteries, supercapacitor modules), and various loads. The article analyzes switch mode power supply DC/DC converters for autonomous power supply systems. The application of the SEPIC (Single Ended Primary Inductance Converter) type converter is substantiated. The techniques of determining the parameters of the converter are presented. The active phase at the duty cycle operation has been demonstrated, and justified in accordance with the theoretical behavior in response to an input voltage change above and below the desired output value. A simulation of the converter's operation in the buck and boost modes in order to stabilize the output voltage at a set level has been performed in the MATLAB / Simulink package. The obtained simulation results show the effectiveness of the suggested solution for an autonomous power supply source.

Система автоматической синхронной подачи резервного питания в системах электроснабжения с двигательной нагрузкой

We developed an automatic system of synchronous connection of a backup power supply source in power systems with synchronous and asynchronous motors in case of power loss from the main source. Here, we propose performing continuous monitoring of the instantaneous voltage values of the main and backup power sources and determining the angle between them. The time to send the command to turn the backup power switch on is determined on the basis of the results of approximating the dependence of the angle between the voltages of the main and backup power sources on time. The proposed algorithm can be used in microprocessor fast-acting automatic transfer switch devices to ensure acceptable levels of currents of stators and electromagnetic moments of electric motors in self-starting modes and to maintain a complex continuous technolo­gical process at industrial enterprises. The effectiveness of the developed automatic system of synchronous connection of a backup power supply source has been confirmed using mathematical modeling methods and laboratory tests at an experimental stand.

Design of automatic measurement system for pre-tightening parameters of multi-axis wrist force pressure sensor

Aiming at the shortcomings of low efficiency and poor accuracy of the existing pressure sensor pre-tightening parameter measurement system, an automatic multi-axis wrist force sensor pre-tightening parameter measurement system is designed. The multi-axis wrist force sensor module is used to collect real-time tension signal from the loaded hand wheel. After amplification, the signal is transmitted to the multi-channel gating module through RS485 communication module to realize the tested sensing. After fast switching and constant current source power supply control function, the data collector collects the pull signal obtained by multi-axis wrist force pressure sensor and transmits it to the upper computer of the system designed by LabVIEW through RS485 bus. The upper computer controls and collects the pressure sensor according to the pull signal feedback from the data collector, and the pre-tightening displacement of multi-axis wrist force sensor is determined by parameters such as axial displacement and friction resistance moment. The experimental results show that the designed system can fully measure the pre-tightening parameters of the sensor, and the starting moment measurement error is only 0.102%. The system can meet the requirements of batch measurement and calibration of multi-axis wrist force sensor with accuracy of 1%-0.1%.

Инновационные принципы электроснабжения нетяговых потребителей железнодорожного транспорта

The issues of fundamental changes of electric power-supply of non-traction devices, such as, line-section devices and systems of railway transport are addressed in the article. It is clearly shown that the possibility of electric power-supply of such consumers without using the common high-voltage line-section power-supply lines of alternative voltage of 6 or 10 kV and respective power-supply substations can be implemented in practice. The essence of the proposed is that the electric power-supply source is not a high-voltage power-supply line, but a device which converts potential mechanical energy of a train, moving along a line section between signal points of railway automatic block system, into electrical one. Putting the described power-supply devices into operation provides technical as well as economic advantages over currently and widely used power-supply systems. The conversion of energy is carried out by changing magnetic resistance of a magnetic circuit, which includes railway car wheel-set in motion and direct neodymium magnet. Change in magnetic resistance due to the law of electromagnetic induction results in alternate voltage in the inductance coil, which is used as the electric power-supply source for non-traction line-section power consumers, including but not limited to, signal point of railway automatic block system. In case there is no wheel-set on the converter, electric power-supply for the power consumer is delivered by the electric energy accumulated in an ionistor (supercapacitor).

ДЖЕРЕЛА ЖИВЛЕННЯ АВТОНОМНОГО ЕЛЕКТРОТРАНСПОРТУ ТА ЕФЕКТИВНІСТЬ ЇХ ЗАСТОСУВАННЯ

ДЖЕРЕЛА ЖИВЛЕННЯ АВТОНОМНОГО ЕЛЕКТРОТРАНСПОРТУ ТА ЕФЕКТИВНІСТЬ ЇХ ЗАСТОСУВАННЯ

INTERNET OF THINGS (IOT) APPLICATIONS USING THE LORAWAN PROTOCOL FOR MONITORING IRRIGATED LAND

The article analyzes available information on the application of the Internet of Things (IoT) for agriculture. It is pointed out that for large areas remote from cities and power supply sources for fields and farms, the construction of traditional communication channels is expensive enough, and classical mobile technologies for solving business problems are only partially suitable. Therefore, the article analyzes the practical approaches to using the Internet of Things (IoT) to monitor irrigated lands. The possibility of connecting soil moisture, temperature, pressure, direction and speed wind sensors based on LoRaWAN protocol to Internet gateways (base stations) without payment for cellular communication, additional power supply, deployment of complex Wi-Fi networks in the field was studied. Practical results on the characteristics of the sensors in the field, setting up a guaranteed LoRaWAN base station (gateway) connection, technical characteristics and causes of possible equipment malfunction were obtained. That is, the purpose of the study was to develop a budget solution for practical research and use of the Internet of Things (IoT) using the LoRaWAN protocol to monitor weather and soil moisture on irrigated lands. Among the main results of the study are the following. Equipment features and the specifics of sensors allocation and their terrain settings based on LoRaWAN protocol were studied, in particular: technical characteristics (operating frequencies, material, length, connection types and antenna placement height, radio signal transmission range and quality); use of different power sources (different types of batteries and solar panels surfaces); features of field operation (possible interference with radio signal propagation, dependence on the effect of pests, temperature fluctuations); encryption when exchanging data. A budget solution for monitoring meteorological indicators, soil moisture on irrigated lands was developed. A wireless monitoring network based on the LoRaWAN protocol was deployed in the irrigated fields of the SE ES of Askaniye of Kakhovsky District State in the Kherson region, consisting of 1 base station and 5 terminal units up to 2 km away. It was found that LoRa technology enables to control the channel expansion coefficient by determining the data transmitted over a period of time. It is determined that for the successful operation of wireless systems, an important issue is the proper radio planning and designing solutions for specific customer tasks. When deploying wireless networks, basic requirements for the reliability of the base stations and terminal units were identified and investigated. The developed budget solution for practical research and application of the Internet of Things (IoT) using the LoRaWAN protocol was compared with the Pessl Instruments GmbH and Davis Instruments Co brand developments to monitor weather, soil moisture on irrigated lands were. Among the most important findings are the development of a budget solution for monitoring meteorological indicators, soil moisture on irrigated lands consisting of 1 base station (gateway) of and 5 terminal units (monitoring stations). The coverage area of the base station with a base antenna for LoRaWAN was 0.6 km, with augmented and refined antenna - 2 km. Sensor data is advisable to transmit in 30-40 bytes per a send, with an expansion factor of SF = 12 without loss of quality. The best signal quality was ensured in the line of sight from the base station to the monitoring station.

The safety improvement of VVER-1000 NPP against SBO accident using portable air-cooled diesel generator

The Fukushima accident demonstrated that the safety design of nuclear power plants should be assessed by installing additional backup sources of electrical power and cooling to cope with extreme natural events. It is supposed that both off-site and on-site AC power supply sources are lost during the station blackout accident (SBO). The probabilistic safety analysis (PSA) of VVER-1000/V-446 nuclear reactor shows that the core damage frequency (CDF) due to SBO is a dominant contributor to the total CDF of NPP. In this study, the installation of portable air-cooled diesel generator (PDG) is proposed to prevent severe core damage and maintain the safety functions during SBO accident in NPP. The scenarios to remove the residual heat of the core through primary and secondary cooling systems by deploying PDG are determined. The list of loads and sequence connection of safety systems are specified for each scenario. The capacity, type, and characteristics of PDG are determined based on the identified electrical loads and weather condition of the NPP site. The conceptual plans for connections of PDG into the electrical distribution of NPP to feed safety systems are represented as well. The suggested scenarios are justified by thermal balance method and assessment of reported thermal-hydraulic calculation of NPP. The PSA analysis is performed by SAPHIRE code as a reliability and risk assessment software to investigate safety improvement of NPP against SBO accident with considering PDG. The results show that the CDF due to SBO is reduced from 3.61E−06 (1/year) to 9.897E−009 (1/year).

Distributed day‐ahead scheduling of community energy management system group considering uncertain market prices using stochastic optimization

Because of the deregulation of electric power, electricity supply has changed from an exclusive supply by general electric utilities in each region to a competitive supply by various electric utilities. Furthermore, the wholesale electric power exchange (EPX) has been established, and it is becoming possible to procure and sell electricity through the market. Because the prices in the EPX are uncertain, a planning method considering the uncertainty is needed. A community energy management system (CEMS) stands between energy consumers in the community and energy suppliers. A CEMS purchases energy from external power supply sources and operates the equipment to provide ancillary service to consumers. In this paper, we consider the day‐ahead scheduling problem of a CEMS group using stochastic optimization. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

A Portable and Wireless Multi-Channel Acquisition System for Physiological Signal Measurements.

We propose a portable and wireless acquisition system to help consumers or users register important physiological signals. The acquisition system mainly consists of a portable device, a graphic user interface (GUI), and an application program for displaying the signals on a notebook (NB) computer or a smart device. Essential characteristics of the portable device include eight measuring channels, a powerful microcontroller unit, a lithium battery, Bluetooth 3.0 data transmission, and a built-in 2 GB flash memory. In addition, the signals that are measured can be displayed on a tablet, a smart phone, or a notebook computer concurrently. Additionally, the proposed system provides extra power supply sources of ±3 V for the usage of external circuits. On the other hand, consumers or users can design their own sensing circuits and combine them with this system to carry out ubiquitous physiological studies. Four major advantages in the proposed system are the capability of combining it with a NB computer or a smart phone to display the signals being measured in real time, the superior mobility due to its own independent power system, flash memory, and good expandability. Briefly, this acquisition system offers consumers or users a convenient and portable studying tool to measure dynamic vital signals of interest in psychological and physiological research fields.

Tritium Power Supply Sources Based on AlGaAs/GaAs Heterostructures

The results of the development of a radioisotope power supply source based on a semiconductor (AlxGa1 –xAs/GaAs) β-radiation energy converter and tritium as a radiation source are presented. The efficiency of this converter with a tritium saturated titanium disk, a green luminescent tritium lamp, or tritium gas as a radioisotope radiation source is compared. For a converter based on the Al0.35Ga0.65As/GaAs heterostructure in a capsule with tritium, efficiency η = 5.9% at a maximum specific output electrical power of 0.56 μW/cm2. Due to their long service life, such stand-alone and compact power supply sources can be used in space and subsea technologies, implantable cardiac pacemakers, biosensors, and portable equipment of high reliability.

Kinerja dari Prototipe Robot Visual Pengumpul Sampah Perairan dengan Remote Control menggunakan Telemetri

The making of prototype robot waste water collection aims to know the performance itself. The prototype of the Aquatic Waste Collection Robot is designed to float and clean trash in remote controlled waters. The main control drives a series of DC brushless motors to drive while the MG995 servo motor drives a rudder or defender. The device is also equipped with a camera as a medium to see the condition of the robot directly or in real time which will be displayed on the monitor screen. The camera and screen are connected to a telemetry circuit consisting of a transmitter and receiver with a frequency of 5.8 GHz, and a Li-Po battery as a source of robot power supply. The results of prototype testing of water garbage collection robots have been carried out in Embung Langensari Yogyakarta with a depth of 2-3 meters and an area of 5890 m2, the robot can go with a maximum speed of 0.3 m / s with or without the garbage load. Garbage nets used with a capacity of 20 liters. Robots can maneuver to turn right or left with a rudder. In the garbage collection process, this robot can collect relatively small waste

Increasing the efficiency of using renewable energy sources for energy supply of autonomous highland objects

Ways of increasing the efficiency of using renewable energy sources in the autonomous power supply of highland facilities are considered. Descriptions of autonomous multifunctional energy complexes that simultaneously use converters of various types: sunlight, wind and water flows into electrical energy, patented in NCIMM (STU) are given. The prospects of using renewable energy sources for autonomous power supply of highland facilities are substantiated.

Predictive Control on Power Source Selection in Hybrid Vehicle System

Technology advances day by day. It improves like revolutions. As in TeleCom, the mode of communications advances from electrical lines to optical lines to increase the speed of data transmission and now it is wireless. This pattern holds true for the revolution in automotive industry. It is the part of “Fourth Industrial Revolution” targeting connectivity, electrificatio n and update in customer needs. This revolution is in-need of more energy compared to the conventional requirement. Progress in battery technologies are providing us an option towards the electrification of the automobiles. The advancing safety features has demand in power which roots towards electrification. As pulses, the initial effort has taken in improving the utilizatio n of Energy Storage Systems for Electric or Hybrid Vehicles. Drives used in Electric Vehicles (EV) are configured to act as generator during braking, thus charging the Energy Storage System (ESS). This ESS offers efficiency in storing re-generative braking energy, vehicle acceleration and battery safety. Appropriate switching algorithm (ANFIS) is required to control the power supply source during power demand, which based on the past learnings that target to improve the efficiency of control mechanism to maintain the quality of Battery and Super Capacitor in Hybrid Energy Storage System (HESS).