Study on Small PV Intelligent Power Supply System

This article deals with the sensor-less control of a DC Motor via a SEPIC Converter-Full Bridge combination powered through solar panels. We simultaneously regulate, both, the output voltage of the SEPIC-converter to a value larger than the solar panel output voltage, and the shaft angular velocity, in any of the turning senses, so that it tracks a pre-specified constant reference. The main result of our proposed control scheme is an efficient linear controller obtained via Lyapunov. This controller is based on measurements of the converter currents and voltages, and the DC motor armature current. The control law is derived using an exact stabilization error dynamics model, from which a static linear passive feedback control law is derived. All values of the constant references are parameterized in terms of the equilibrium point of the multivariable system: the SEPIC converter desired output voltage, the solar panel output voltage at its Maximun Power Point (MPP), and the DC motor desired constant angular velocity. The switched control realization of the designed average continuous feedback control law is accomplished by means of a, discrete-valued, Pulse Width Modulation (PWM). Experimental results are presented demonstrating the viability of our proposal.

This paper proposes a microcontroller based single axis automatic solar panel tracking control method for keeping the solar panel approximately at right angle with the incident photon for the better performance and maximize the output power of the solar panel. The charge controller with the DC-DC boost converter is used along the automatic tracking system for further enhancing output power under variable insolation conditions and protecting the battery from being overcharged and over discharged condition. The Boost converter is used to overcome the lower output voltage of solar panel for not fulfilling the minimum charging voltage requirement of the battery thus more power extraction is possible from the solar panel to battery. The system includes a photovoltaic array, three LDRs sensor, a PWM controlled Boost converter, charge controller and sensor circuits. This paper discusses the low cost implementation of the whole system in the 8-bit microcontroller using the tools and techniques to generate optimized real time code in C for ATMega8 microcontroller which will demonstrate how maximization of power output is visible and efficient solution for increasing the efficiency of a solar system based on experimental results rather than on mathematical models.

This research paper is about implementing energy harvesting solutions to maximize the output voltage of solar panel and to harvest the waste energy from solar panel for low voltage application. As the range of applications for solar energy increases, the improved materials and methods used to harness this power source needs to be developed. Major influences on overall efficiency include solar cell efficiency, intensity of source radiation and storage technique. To circumvent this problem this technique is implemented by solar energy system independent on irradiance and temperature developed by using buck-boost converter. Fuzzy logic controller generate variable duty cycle depends on variable solar panel voltage. Generated duty cycle is applied to buck-boost converter on which output is depends which is used for low voltage application such as battery charging. The charge battery will be used for lightening the parking, staircase and quoridor etc.

Although fossil fuels are still readily available, their use is becoming less and less common. Solar energy produced by panels on the roof can be used as a source of power. Semiconductor-based solar panel technology can absorb photons from sunshine and transform them into ecologically beneficial electrical energy. Of course, a control device that regulates the electrical energy charging system is required when using solar cells as a power source to charge a battery. This device is typically referred to as a charge controller. The DC-DC converter of the buck type with a Ziegler Nichols-based Proportional Integral Differential (PID) control approach utilizing Arduino Uno is the control system utilized in this solar cell battery charging. The buck converter reduces and stabilizes the solar panel's output voltage following the requirements for charging the accumulator. For charging batteries, a set point voltage of 13.8 V is employed. By testing the converter with both static and dynamic loads, the research that has been done can produce results. The 35 Watt lamp static load test results with a fixed voltage source show that the set point voltage is 13 V and that it takes 28 s to attain a steady condition. When applied to dynamic loading using a battery charge of 12 V/7.5 Ah with a 20 WP solar panel source during hot, partly cloudy weather, the charging efficiency is 68 percent. A steady state of about 28 s may be claimed to be a satisfactory control system response.

To solve the wide range of the output voltage, difficult storage and not unified interface of solar cell, a novel solar charging system was proposed. The system consists of the solar panel, the voltage regulator circuit, the battery charge management circuit, the lithium battery, the booster circuit and the USB output circuit. The voltage regulator circuit can convert the output voltage of solar panel into 5V. By means of the charge management circuit, the energy is stored in the lithium battery, and it can be provided to the load via the booster circuit and USB interface, which can achieve the goal of the conversion, storage and utilization from solar to electrical energy. Under the condition of effective illumination between 10:00 and 16:00, the solar charging system was tested for 7 days. Experimental results show that the output voltage always maintained at 5V during the test. The output voltage of lithium battery reaches to 4.2V after four hours, and the output voltage of USB port always stabilizes at about 5V.

The authors describes an integrated power station which supplies both uninterrupted DC power and AC power at a regulated voltage by UPS (uninterruptible power supply) or line conditioner, depending on which is more appropriate for the site requirements. The station is contained in a single mechanical structure, a standard 19 in. rack. The station is very versatile from both the power and the installation points of view, and is very suitable for power supply to telecommunications and computer equipment in areas with restricted space. The installation, use, and maintenance of the system are discussed, and its technical characteristics are presented. >

The article presents solar modules of various types and designs, in the development and study of which the author took part. Along with planar photovoltaic solar modules with an extended term of nominal power, high-voltage matrix solar modules with an extended term of nominal power and electrical efficiency up to 28% are considered. Such modules are made with the help of encapsulation technology with a polysiloxane compound, which improves the performance of solar modules and increases their service life. For autonomous power supply of mobile and compact electrical devices in the field, folding and sectional solar modules are proposed, which, when parallel-sequential switching, allow to gain the necessary power. For architectural solutions, solar roofing panels are presented, which along with electrogeneration make it possible to generate heat energy, and the base can be made of recycled plastic, which has a positive effect on the environment. To reduce the number of solar cells used, a concentrating solar roofing panel has been proposed, which allows the use of thermal energy. For the cogeneration of electric energy and thermal energy, a concentrator solar photovoltaic thermal module with a paraboloid type concentrator is also proposed. Each type of solar modules is used in a stationary heat and electric power supply and mobile power generation.

Our daily life is supported by powerful information networks which are composed of computers and communication equipments. If they do not work correctly or completely, our daily life would be surely confused. Under some circumstances safety could not be kept. Uninterruptible Power Supply (UPS) systems are commonly equipped to supply stable power to the critical loads, for example, large computer center telephone and telecomnication center, aviation control system and so on. Several kinds of UPS systems are now used in many important fields as the above mentioned. But they almost do not have been evaluated numerically based on system reliability.This paper evaluates MTBF of parallel redundant UPS systems, and reports MTBF of 2 sets of parallel redundant UPS system is lower than that of 3 sets of parallel redundant UPS system under some circumstances. Continuous power supply reliability of the UPS system with bypass and uninterruptible transfer switch is much higher than any other UPS system without bypass circuit and uninterruptible transfer switch. And then the last some highly reliable parallel operation technology are shown.

<p>Livingston Island is one of the eleven islands of the South Shetland Archipelago which is separated from the Antarctic Peninsula by Bransfield Strait and from South America by the Drake Passage. In 1988 in the eastern part of the Island, the Bulgarian Antarctic Base “St. Kliment Ohridski” (BAB) was established. The Base works during the austral summers and accommodates scientists from different branches of the science. The first Bulgarian Polar Seismic Station LIVV was set in operation in 2014 as a seasonal station operating during the regular Antarctic expeditions. In 2019, the station was rebuilt on a new site one kilometer far from BAB. The seismological equipment was installed on a bedrock outcrop at the base of a hill. The equipment consists of broadband seismometer Guralp CMG40T with 30 s to 50 Hz flat velocity response and one short period 4.5 Hz Geophone. Thermo-insulation covers are mounted over the both sensors to ensure stable environment. The digitizer Reftek DAS-130/6 and the solar panel controller are installed close to the sensors in a thermo insulated box. The station is powered by a battery and solar panel. A GPS receiver ensures time synchronization. At the end of the XXVIII Bulgarian Antarctic expedition in March of 2020, the seismic station LIVV was set as permanent year-round operational Antarctic station. Using the recorded state of the health information and the registered seismic data, we analyzed the performance of the station LIVV. For the two years of permanent deployment, the seismic equipment works stable. The battery has retained its working capacity despite low temperatures and high humidity. There are interruptions in the recording when the sunlight is not high enough to charge the battery above 12V. After restoring the power supply, the equipment immediately is switched on in the normal registration mode. The temperature inside of the thermal box hasn’t dropped below 6⁰ C and the electronic components have worked in an optimal environment. The cycle operational mode of the GPS receiver is suitable set to ensure high accuracy time. The analysis of the recorded seismic data shows that the mode value of the ambient seismic noise, for longer periods greater than 1s, is 10-20dB below High Noise Model and for the shorter periods below 1 s it falls to -140dB. The noise level suggests good recording capabilities of the station especially in the short periods. This is proven by the large number of recorded earthquakes and events in the ice cover of the Livingston Island during the two years exploitation period. The analysis of the performance of the seismic station LIVV shows that the station is built on a stable foundation (bedrock), and the provided thermal insulation creates an optimal mode of operation of the seismic equipment. With an uninterruptible power supply, the seismic station will operate reliably and without interruption throughout the year, and the quality of the recorded data will be high enough to analyze the seismicity in the region and the behavior of the ice sheet of the Island.</p>

A Data Center can consist of a large group of networked servers and associated power distribution, networking, and cooling equipment. All these applications consume enormous amounts of energy which result in a significant increase in energy inefficiency problems. One of the causes of Data Center energy inefficiency power distribution is from the uninterruptible power supply (UPS). The UPS system is an alternate or backup source of power linking between mains power supply and end critical loads in order to provide back-up power and protection for the sensitive load. This study attempts to answer the question of how can future UPS topology and technology improve the efficiency of Data Center. In order to analyze the impact of different UPS technologies and their operating efficiencies, a model for a medium size Data Centre is developed, and load schedules and worked schematics were created to analyze and test the components of each of the UPS system topologies.

Since the auxiliary three-phase oil pump motor of ship machine set needs uninterrupted power supply(UPS), the oil pump motor needs to be switched to UPS equipment for power supply in case of power loss of the generator. In order to realize the smooth transition of the oil pump motor when switching to UPS, the three-phase voltage output by the inverter in UPS needs to be in the same frequency and phase as the generator voltage. In this paper, the basic working principle of UPS is introduced, the advantages and disadvantages of two phase-locked loops for tracking phase are analyzed, and a phase-locked loop(PLL) based on second-order generalized integrator is selected to be used in inverter. Finally, the feasibility of this method is verified by experiments.

This paper is concerned with the control of a line interactive Uninterruptable Power Supply (UPS) system in a Microgrid. In grid connected mode, power can be imported from the grid to charge the battery or it can be injected into the grid to boost the power supplied by the Microgrid. In island mode, the UPS supplies local critical load in parallel with other sources. Power flow is controlled using the frequency and voltage drooping technique to ensure seamless transfer between grid connected and parallel islanding modes of operation. When the power is imported from the grid, an outer voltage controller that regulates the DC link voltage sets the power demand for an inner power flow controller. The outer voltage loop is designed with the aid of small signal analysis which has been used to model the dynamics of the inner power flow controller. Due to the limited DC link capacitance, the drooping coefficients are chosen carefully to limit transient circulating active power from the grid to the UPS module or from one UPS module to another. The traditional way of measuring active and reactive power which is based on using a low pass filter is replaced by a real time integration method which is shown to improve the response of the controller. A virtual impedance is utilized in grid-connected mode to improve output current THD. Experimental results of two 60kW line interactive UPS modules are provided to validate the design.

An alternative to inverters with add-on charging circuits or standby uninterruptible power supply (UPS) hardware, the bimode UPS, is discussed. The bimode UPS uses common circuitry and power components for DC-to-AC inversion and battery charging. It also provides an automatic and nearly instantaneous AC power transfer function when the engine-generator is started or stopped. The components of the renewable hybrid energy system are described to provide a background for understanding the bimode evaluation. Operating characteristics and requirements of each part of the system are provided. A short description of standby UPS is given, and a comparison of the two systems is made to establish their similarities; the similarities show how the UPS may be used in hybrid systems. Evolution of the UPS to the bimode UPS allows simplification of the hybrid system if the bimode UPS proves its compatibility with loads, batteries, and engine generator. The renewable conversion device operates independently of the UPS. The incorporation of the bimode UPS is discussed, and the Abacus bimode UPS is evaluated.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

In the article, based on the concept of increasing the reliability of the formed image of the complex of technical means for ensuring the operation of an unsolicited measuring station of the network of stations of the ground control complex, a solution is proposed for choosing the general scheme of an uninterruptible power supply as part of a complex of technical means of unsolicited measuring systems. The uninterrupted power supply system is designed to automatically provide a set of technical means for ensuring the operation of a non-demand measuring station with a guaranteed and uninterrupted power supply in accordance with the indicators of reliability, autonomy and quality of electricity specified in the terms of reference. A procedure for selecting the constituent elements of an uninterruptible power supply is proposed, the main stages and composition of the protection means for the power supply network are considered. A block diagram of protection over the power supply network is presented. It is noted that structurally, the uninterruptible power supply should be able to be placed both in a stationary room and in a block container.

Nowadays the use of Uninterruptible Power Supply (UPS) is common because UPS is able to provide a backup electrical power when the main source is disconnected or interrupted. With the use of a UPS, the supply of electrical power to the system will not be interrupted. When the UPS operates, the voltage go through dual conversion process, from AC to DC by the rectifier and from DC to AC by the inverter. The DC voltage in the UPS is used to supply the battery charger and the AC voltage is used to supply the load system. The switching process of the inverter can produce disturbances at high frequency. In this study, a 1 KVA UPS is connected to a capacitive load 3.6 µF, 7.2 µF, 14.4 µF and 28.8 µF which generate the highest disturbances voltage of 309.53 mV at a frequency of 9.8 kHz at a load of 28.8 μF and the lowest of 1.33 mV at a frequency of 110.6 kHz at a load of 3.6 μF. The disturbances voltage occur at three dominant frequencies of 19-24 kHz, 35-44 kHz and 105- 114 kHz and increases as the increase of capacitive load level.