Stand-alone Power Supply System Research Articles

Novel control of PV-wind-battery powered standalone power supply system based LSTM based ANN

Integrated wind-photovoltaic (PV) based standalone electric power supply systems are widely used for various applications. A battery storage system is needed to provide continuous power supply to loads despite changes in loads, wind speed, and solar irradiance. Power quality is crucial in these hybrid systems, as the battery needs to charge from surplus power when generation exceeds the load and discharge to meet load demand. A bidirectional DC to DC converter is used to connect the battery to the network, and maximum power point tracking devices with proper algorithms are incorporated for optimal utilization of PV and wind turbines. Multiple PV systems and wind turbines are considered for proper power supply system ratings. Long short-term memory (LSTM) based artificial neural network (ANN) controllers are implemented for various control units in the hybrid standalone power system. The proposed control techniques improve power quality under various situations. Results are presented using MATLAB/Simulink to evaluate the performance of the proposed method.

Novel Control of PV-Battery Powered Standalone Power Supply System with Neuro-Fuzzy Controller

Photovoltaic (PV) powered standalone electrical power supply systems are becoming more precious networks nowadays worldwide. Many challenging tasks are existed in PV based standalone systems due to random changes in solar irradiances, load and it is absent during nighttime. Innovative controllers are necessary to uphold power quality in these systems. A battery pack is required in this standalone system since solar irradiance is unpredictable and in order to provide continuous stable power to electrical loads during no irradiance. Therefore, a battery bank is connected to a standalone unit via a DC to DC bidirectional circuit. The maximum power point tracking converter, in conjunction with the perturbed and observe algorithm, is employed to optimize the operation of the PV system and enhance the overall efficiency of the system. Neuro-Fuzzy controller based novel controller is designed for both inverter as well as bidirectional circuit to supply quality power to both single and three phase loads. Comprehensive findings have been showcased and accessed via hardware-in-loop testing on the OPAL-RT platform to optimize the suggested controller for a 1MW standalone system in various scenarios. Keywords PV, Neuro-Fuzzy, MPPT, HIL, Standalone System, Power Quality.

Facile fabrication of flexible and adhesive micro-supercapacitor tapes from conducting polymer solution for self-powered wearable sensing system

Flexible micro-supercapacitor (MSC) with in-plane electrodes has attracted significant attention as microscale energy storage device. Especially, flexible MSCs with adhesion properties are of great interest for wearable electronics. Here, we demonstrate a facile and cost-effective mask-assisted drop-casting method to fabricate adhesive MSC on medical tape using dimethyl sulfoxide (DMSO) doped poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) aqueous solution. The fabricated MSC with poly (vinyl alcohol)/H3PO4 gel electrolyte exhibits an areal specific capacitance of 10.96 mF cm−2 at a current density of 0.1 mA cm−2 with excellent mechanical flexibility. The MSC can be attached on various substrates due to the stickiness of the medical tape. For practical application, the MSC can be coupled with a solar cell to achieve a stand-alone power supply system for a flex senor in monitoring finger movements. Therefore, we believe that the mask-assisted drop-casting method paves a new way to develop flexible and adhesive MSCs for self-powered integrated wearable electronics.

OPTIMIZATION OF OPERATIONAL CONTROL OF AUTONOMOUS PHOTO-DIESEL POWER SUPPLY SYSTEM WITH DC BUS

Link for citation: Lukutin B.V., Muravyev D.I. Optimization of operational control of autonomous photo-diesel power supply system with DC bus. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2022, vol. 333, no. 4, рр. 224-235. In Rus.
 The relevance. An increase in the contribution of renewable energy sources to the generation of the autonomous hybrid energy industry is important in order to reduce the environmental impact of diesel generator plants and decrease operating costs in the production of electrical energy in smart microgrids with distributed generation, including so-called «green» generation. This issue has the highest relevance for cell towers of mobile communication, rotational residential camps, meteorological stations and other remote consumers, the rated capacity of which is tens to hundreds of kW. Objective: the development of computer models for optimizing the management of the operational staff and modes of an autonomous photo-diesel power supply system with a DC bus, so as to make it possible to minimize the operating time of a diesel generator plant by increasing the contribution of the photovoltaic plant at optimal technical and economic indicators. The use of a DC bus for the electricity integration from distributed energy sources is considered promising in reducing the number of hours of inefficient operation of a diesel generator plant, which will make it possible to save diesel fuel and extend the life expectancy of the diesel generator. Novelty. This work expands the known options for modeling and optimizing the modes of a standalone hybrid DC power plant in terms of using an objective function with appropriate restrictions, adapting models of power equipment for the intended purposes of modeling, presenting the structure of a feasibility study based on commercially available characteristics of the elements of the power supply system. Methods. The study entails the development of computer models of the intelligent control architecture of a standalone hybrid power plant including a photovoltaic plant, a diesel generator plant, an electric energy storage system, a remote consumer, as well as auxiliary converter devices. Modeling of control processes is implemented in the Stateflow library, as well as by using the language syntax of the Matlab high-level package, the capabilities of which are acceptable for the intended purposes. Results. The analysis of the results shows that DC PV-diesel power supply systems can be cost-effective in all scenarios that include different types of batteries while for systems without power storage, DC distribution is often not cost-effective. The results will be of interest to specialists developing or operating standalone power supply systems and organizations planning to upgrade existing diesel power plants.

Shape and Measurement Monitoring of Inrush Current Characteristics of a Battery-Capacitive Energy Storage Device with Two-Channel Digital Oscilloscope

The main reason of voltage instability in stand-alone power supply systems is the electric drive motors inrush current, which are usually higher than their nominal value. The most reasonable way to solve this problem is using capacitive energy storage. The purpose of research is shape and measurement monitoring of battery-capacitive energy storage device inrush current characteristics. Parameters comparative analysis for lithium-ion battery (LIB) part and capacitive part of the energy storage device was holding with the twochannel digital oscilloscope.Measuring testing bench included parallel connected LIB part and capacitive part of the storage device and connected to the power source. The LIB part of the storage device is made on the basis of the ATOM 10 multifunctional motor drive device of the new generation, which contains 15 V lithium-ion battery and 9.4 A·h capacity. The capacitive part of the storage device is the INSPECTOR Booster supercapacitor with an 80 F electrostatic capacitance and 15.5 V voltage. A 12 V AC/DC step-down converter was used as a power source. An electric air automobile compressor M-14001 was used as a current drain. The testing bench measuring part consisted of a two-channel digital oscilloscope and two standard measuring shunts with 15000 μOm resistance serial attached to LIB part and capacitive part of the storage device. Shape and measurement monitoring of inrush current characteristics of LIB part and capacitive part of the energy storage device was held synchronously using a two-channel digital oscilloscope with recording data to FAT32 file system USB flash drive. Obtained data was transferred to a personal computer and analyzed.The measurement results showed that 82.3 % of the energy losses compensation of the motor start is taken over by the capacitive part of the energy storage device, what makes longer LIB’s life. By adjusting the oscilloscope sweep trace index you can analyze more detailed time response shape and its duration. The values of the inrush current amplitudes were calculated in proportion to the voltage drop on the shunts and their resistances.The developed method for monitoring shape and measurement inrush current characteristics can be used in various technical applications: smart stand-alone photovoltaic system, uninterruptible power supply devices, electric drive control systems, etc.

Solar Hydrogen System Configuration Using Genetic Algorithms

For standalone power supply systems based on solar hydrogen technology to work efficiently, the photovoltaic generator and electrolyser stack have to be con?gured so that they produce the needed amount of hydrogen in order for the fuel cell to produce sufficient power to operate the load. This paper discusses how genetic algorithms were applied to optimise the design of the photovoltaic generator and electrolyser combination by searching for the best con?guration in terms of number parallel and series PV modules, number of electrolyser cells, and cell surface area. First, a mathematical simulation model based on the current-voltage PV characteristics and the polarisation characteristics of the electrolyser was developed. The models parameters were obtained by ?tting the mathematical models to experimental data. A genetic algorithm code was then developed. The code is based on the PV and electrolyser models as an evaluation measure for the ?tness of the solutions generated. Results are presented con?rming the effectiveness of using the genetic algorithm technique for solar hydrogen system con?guration.

Energy demand side management in stand-alone power supply system with renewable energy sources

The article presents the demand side management for electricity consumption in the conditions of autonomous power supply systems with several sources of generation–traditional and renewable energy sources. The paper gives a classification of household electrical appliances in accordance with this, even devices with a high priority, which are often referred to as non-shiftable load, can participate in the program. An algorithm for the interaction of the demand side management control system and the user is proposed. It is shown that with the participation in the demand management program even some types of equipment can achieve a significant economic effect, increase the service life of the equipment and reduce the negative impact on the environment.

Research and development of a PV converter-based stand-alone power supply system for technical security equipment power supply

The purpose of the work is to develop a methodology for designing a stand-alone power supply system based on photovoltaic (PV) converters for technical security equipment power supply. The object of the study is a PV converter - based stand-alone power supply system. Energy storage units, which are widely used in the designing of power supply systems for power supply of technical security equipment are presented. A methodology for designing a power supply system is used, which takes into account the integral effect of solar insolation, ambient temperature in the range from - 40°C to +50°C, temperature of a PV module and a storage battery; PV module capacity; requirements for independent operation of technical security equipment; electrical characteristics of the solar charge controller (rated open-circuit voltage and rated charge current). To calculate the total solar insolation arriving at the surface of a photovoltaic module, the Kastrov model is used for calculating direct solar radiation; the Berlage model is used for calculating the scattered solar energy and the Berland model is used for calculating insolation in cloudy conditions. The studies of lithium-titanate storage batteries have been carried out in the climate chamber and a corresponding mathematical model has been developed for the temperature-dependent capacity of the battery. To determine solar insolation falling on the tilted surface of the PV module the software has been developed in the C# programming language. The designed PV module-based power supply system provides an independent uninterrupted continuous power supply of equipment under constant consumption of no more than 115.2 Wh per day by technical security equipment. The results of the work can be used in the development of a stand-alone power supply system for power supply of technical security equipment, security and control.

Application of highly efficient hydrogen generation and storage systems for autonomous energy supply

Purpose. Development of scientific and engineering solutions to improve the reliability of power supply of stand-alone systems and mitigate the environmental burden by using hydrogen technologies for energy storage. Methodology. The calculation method provides a set of optimal technical solutions for determining the effective operating modes of a stand-alone power supply system for supplying hydrogen to a fuel cell based on the electric load schedules of a particular consumer by using a computational experiment. Findings. Based on the study, a technological scheme of a stand-alone power supply system based on fuel cells was developed, and an approach to the creation of a metal hydride system for accumulating and supplying hydrogen to fuel cells was substantiated. A calculation algorithm was developed that allows calculating the annual energy balance of a specific consumer and selecting the necessary equipment to implement the scheme based on the annual heat and electric load schedule. Originality. An alternative scheme of guaranteed electric power and heat supply for a stand-alone house without using imported fuel is proposed. The advantage of such a scheme is that it is closed because hydrogen is produced on site to power the fuel cell, while the metal hydride hydrogen storage system is capable of performing hydrogen absorption and its release due to the hot and cold water resources available in the system. Practical value. The technology for converting the energy of primary sources by creating a wind-driven energy technological complex using an electrolysis plant and a metal hydride hydrogen storage system will solve the problem of smoothing the irregular electric power supply from renewable sources.

NiCo Metal-Organic Framework and Porous Carbon Interlayer-Based Supercapacitors Integrated with a Solar Cell for a Stand-Alone Power Supply System.

Nickel cobalt-metal-organic framework (NiCo-MOF), with a semihollow spherical morphology composed of rhombic dodecahedron nanostructures, was synthesized using a scalable and facile wet chemical route. Such a structure endowed the material with open pores, which enabled rapid ion ingress and egress, and the high effective surface area of the MOF allowed the uptake and release of a large number of electrolyte ions during charge-discharge. By combining this NiCo-MOF cathode with a highly porous carbon (PC) anode (derived from the naturally grown and abundantly available bio-waste, namely, palm kernel shells), the resulting PC//NiCo-MOF supercapacitor using an aqueous potassium hydroxide (KOH) electrolyte delivered a capacitance of 134 F g-1, energy and power densities of 24 Wh kg-1 and 0.8 kW kg-1 at 1 A g-1, respectively, over an operational voltage window of 1.6 V. By employing thin interlayers of PC coated over a Whatman filter paper (PC@FP), the modified supercapacitor configuration of PC/PC@FP//PC@FP/NiCo-MOF delivered greatly enhanced performance. This cell delivered a capacitance of 520 F g-1 and an energy density of 92 Wh kg-1, improved by nearly 4-fold, compared to the analogous supercapacitor without the interlayers (at the same power and current densities and voltage window), thus evidencing the role of the cost-effective, electrically conducting porous carbon interlayers in amplifying the supercapacitor's energy storage capabilities. Further, illumination of white light-emitting diodes (LEDs) using a three-series configuration and the photocharging of this supercapacitor with a solution-processed solar cell are also demonstrated. The latter confirms its ability to function as a stand-alone power supply system for electronic/computing devices, which can even operate under medium lighting conditions.

ПЕРСПЕКТИВЫ ДЕЦЕНТРАЛИЗОВАННЫХ СИСТЕМ ЭЛЕКТРОСНАБЖЕНИЯ ПОСТОЯННОГО ТОКА С РАСПРЕДЕЛЁННОЙ СОЛНЕЧНОЙ ГЕНЕРАЦИЕЙ

Актуальность исследования обусловлена необходимостью расширения вариантов автономных систем электроснабжения, в частности, фотоэлектрических, в рамках постановления правительства, связанного с ратификацией Россией Парижского соглашения по климату от 23.09.19. Системы электроснабжения постоянного тока с участием возобновляемых энергоисточников для децентрализованных потребителей могут стать предпочтительной альтернативой переменному токуприусловиисоответствия большинству обязательств Парижского соглашения по климату, а также требованиямповышения энергетической безопасности. Цель: повышение качества электрической энергии в распределительных сетях 0,4 кВ, декарбонизация окружающей среды от углеводородных энергоносителей, повышение энергетической безопасности автономной системы электроснабжения путём увеличения вкладав энергетический баланс возобновляемого энергоресурса, а также снижение стоимости вырабатываемойэлектрической энергии путём перехода с переменного на постоянный ток. Методы. Ввиду сложности натурного исследования электроэнергетических систем с генерацией различной физической природы в качестве инструментов исследования были определенны: математическоемоделирование споследующей компьютерной реализацией в программныхкомплексах высокого уровня.Наиболее полно условиям моделирования отвечает MatLab, в частности, его приложение блочного моделированияSimulink и библиотека блоков SimPowerSystems. Результаты. Разработан программный инструмент, позволяющий осуществлять имитационное моделирование режимов работы фото-дизельных систем электроснабжения, включая генерацию с учётом текущего электропотребления и инсоляции с целью определения рациональных технико-экономических параметров гибридных генерирующих систем; выявлены критерии целесообразности и эффективности построения фото-дизельных электрических систем на постоянном токе для электроснабжения удаленных потребителей.

Adaptive Reference Trajectory for Power Quality Enhancement in Three-Phase Four-Wire Standalone Power Supply Systems With Nonlinear and Unbalanced Loads

This article presents an advanced control strategy for power quality enhancement in standalone power supply systems (PSSs) with grid forming four-leg voltage source inverters (FL-VSIs). Indeed, an online adaptive reference generator (ARG) with a gray wolf optimizer (GWO) is proposed to sustain the control performances of a feedback linearization control (FLC) strategy and improve its robustness against load-side disturbances and system parameters’ uncertainties. The key purpose of the proposed GWO-based ARG is to compensate for load and phase disturbances through smooth reference adjustments, in order to improve the voltage waveforms’ quality and symmetry and conform to the existing power quality standards and metrics. The design methodology of the proposed control approach is thoroughly detailed, and its effectiveness is asserted through simulation and experimental tests, demonstrating its superiority in maintaining the voltage waveforms within the required standard limitations even under unbalanced and nonlinear loading conditions.

Development of Stand-Alone Green Hybrid System for Rural Areas

Despite the tremendous efforts exhibited by various utilities around the world during the past few years, there are still exceedingly many remote regions unreached by the electrical grid. For those regions, the enormous available potential of renewable energy resources is believed to be useful for the development of a stand-alone power supply system. This paper presents the modeling of a stand-alone hybrid system for the remote area of Ethiopia. A comparison of the economic performance of various scenarios of a stand-alone photovoltaic (PV)-wind hybrid system, with battery storage and diesel as a backup for electrifying remote rural areas, is presented. Therefore, a practical example, Kutur village of Awlio kebele of the Axum district, Ethiopia (which is 30 km away from the closest national grid) is considered for this research. Two electric load scenarios are estimated by considering the set of incandescent and efficient lamps for lighting for the 120 existing households. The above-mentioned solar radiation and wind speed are then used as an input to simulate the hybrid set-up for the high and low load estimation using HOMER software. The simulation result shows that the net present costs (NPC) corresponding to the high and low load scenarios is $262,470 and $180,731, respectively. Besides, an essential load forecasting is performed to see the effect of the increase in electric demand of the community on the required investment to install a stand-alone hybrid set-up. The NPC after load forecasting is found to be more than three folds of the NPC required for the reference year. In both cases, the simulation results indicate that using a stand-alone PV-wind hybrid system with battery storage and a diesel generator as a backup for electrifying Kutur village is cost-effective and comparable against the cost required for electrifying the village by extending the grid.

Planning of off-grid power supply systems in remote areas using multi-criteria decision analysis

Providing electricity access in remote and rural areas across the world has always been economically and technically challenging. Prioritising energy sources to electrify a remote community is the most complicated step. A combination of multiple resources is always preferable as no single alternative is absolute. The incorporation of economic, technical and environmental aspects in the strategic decision-making makes the process complicated for standalone off-grid power supply system planning. This study proposes a novel method using an Analytical Hierarchy Approach-based multi-criteria decision analysis along with system optimisation to obtain universal priority criteria and the best system configuration among a few alternatives. The novelty of the approach lies in the structured deliberation and the analysis to formulate a planning approach for the off-grid power supply system using a combination of experts’ assessment and system optimisation study. The method is applied to a remote Australian community. The analysis result identifies the most preferred standalone off-grid power supply system options for a remote rural area, which in this Australian case, is the Diesel-PV-Battery system.

Assessment of Stand-Alone Hydrokinetic Power Supply System with Battery Energy Storage for Rural Electrification

Assessment of Stand-Alone Hydrokinetic Power Supply System with Battery Energy Storage for Rural Electrification

An energy flow simulation tool for incorporating short-term PV forecasting in a diesel-PV-battery off-grid power supply system

One of the primary technical challenges of integrating high levels of PV generation into standalone off-grid power supply systems is their variable power output characteristics. In dealing with this issue, the integration of reliable PV forecasting techniques and preferably energy storage, are highly effective. Applying a short-term PV forecasting method, together with a compensatory controllable resource, can help in the management of system operation. This study incorporates the development of an energy flow modelling tool that has been used to analyse the benefits of 1-min ahead PV forecasting and battery storage for different system configurations. Based on the five days of 1-min ahead forecasting results analysed, it is found that PV forecasting enables the prosumer to install more than double the PV capacity, compared to the allowed installed PV capacity when no forecasting is employed. This additional PV capacity saves around 24–25% (on average) of diesel fuel per day for the diesel-PV-battery configuration. The outcomes evidently indicate that incorporating 1-min ahead PV forecasting enables a significant increase of PV hosting capacity of the system, without compromising the reliability of the system.

Hybrid Stand-alone Power Supply Systems for the Arctic Polar Stations

Hybrid power supply systems based on the renewable energy sources, electrochemical rechargeable batteries, and fuel cells are considered. Such systems provide stable power supply and offer some advantages both over the traditional hydrocarbon-fueled diesel generators and over the radioisotope thermoelectric generators. The innovative technology of group connection to the Russian Satellite Communications Company resources is considered as a tool for the remote control of operation modes of various power generation sources under changing environmental parameters and payload. It is proposed to use such hybrid power systems to provide power supply for autonomous observation stations in the Russian Arctic.

Modeling of an intelligent battery controller for standalone solar-wind hybrid distributed generation system

In this paper, a different approach of standalone hybrid distributed generation has been shown. Due to the intermittent nature of the renewable energy resources, the reliability of the power system is decreased using single renewable energy source based electricity supply system. To overcome the problem the size of the storage system exceptionally large which increases the overall cost of the system and drastically reduces the flexibility. To resolve the problem a standalone hybrid power supply system is designed by integrating the solar and wind energy to generate electricity. The hybrid system increases the generation capacity without increasing the storage unit and maintains reliable electricity to the consumer. The proposed system has been modelled using Matlab/Simulink and verify under variable sources and load condition without compromising with the power quality issue.

Energy Management of Stand-Alone Hydrokinetic Power Supply System with Battery Energy Storage for Rural Electrification

In this paper, optimal energy management for a stand-alone hydrokinetic power supply system with a battery storage system isproposed to sufficiently explore hydrokinetic energy for customers at the demand side. The management of power flow aims tooptimal energy supply subject to a number of constraints, such as power balance, hydrokinetic power output, and battery capacity. The hydrokinetic turbine is connected with permanent magnet synchronous generator (PMSG), power electronic devicesand battery bank. The battery bank is used to store the surplus of energy when the load demand is low and discharges again thestored energy to the load when hydrokinetic power is not sufficient to supply the load. The proposed system can meet the load for every hour of the days without interruption. The average daily load requirement and available hydrokinetic power are calculated for three seasons. In this research, the average daily load requirement of the summer season is chosen because it is the highest in energy consumption from three seasons. The simulation results show that the management of the system is satisfied between available hydrokinetic power and load demand

Stand-alone power supply system with DC photo-diesel source

An object of research is a diesel power supply system of the decentralized village of Tokma, Irkutsk Region, Russia. The objective is to increase the contribution of the PV part of a photo-diesel electrical system operating in parallel with a diesel power plant to a stand-alone distribution network of DC compared to parallel PV and diesel stations operating on AC; quality improvement and voltage stabilization in the electrical network; cost reduction of generated electricity. Optimization of the characteristics of a stand-alone power supply system at a DC is a difficult task, due to the impossibility of conducting tests in a real electric power system, and the use of physical modeling because of its extreme complexity. Given this fact, the task is to design software and hardware tools for optimizing the parameters of a DC photo-diesel power system. The developed models use MS Excel, MatLab/Simulink software packages, as well as weather data bases. A software tool has been developed that allows for simulation modeling of operating modes of photo-diesel power supply systems, generation, consumption and insolation level of a decentralized consumer, as well as determining rational technical and economic parameters; criteria of expediency and efficiency of constructing photo-diesel electric systems with DC have been identified. As a result, the level of voltage drop is reduced compared to the AC power supply system, the cost of 1 kWh of electrical energy is lower than in the AC power supply system, and the negative environmental impact is reduced.