Electrical Grid Supply Research Articles

MPPT algorithm based on metaheuristic techniques (PSO & GA) dedicated to improve wind energy water pumping system performance

This paper presents a comparative study between four techniques recently used to improve the wind energy conversion system (WECS) to water pumping systems. The WECS is a renewable energy source which has developed rapidly in recent years. The use of the WECS in the water pumping field is a free solution (economically) compared to the use of the electricity grid supply. The control of WECS, equipped with a permanent magnet synchronous generator, has the objective of carefully maximising power generation. A comparative study between the proposed Fuzzy Logic Control, optimised using a genetic algorithm and particle swarm optimisation algorithm, and the conventional Perturb and Observe MPPT method using Matlab/Simulink, is presented. The performance of the proposed system has been verified against the generated output voltage, current and power waveforms, intermediate circuit voltage waveform, and generator speed. The presented results demonstrate the effectiveness of the control strategy applied in this work.

A Comparative Life Cycle Assessment of Hydrogen Production & Storage with Renewable Energy Source and Grid Electricity Source

The role of electricity is becoming significant in our advancing world. Currently, Ireland’s energy mix heavily relies on carbon-polluting fossil fuels, posing an environmental challenge. As per the Paris Agreement 2015, Ireland is ambitiously targeting to meet net zero carbon dioxide (CO2) emissions by 2050 and a 51% reduction by 2030. The country is shifting towards renewable energy sources to generate power to achieve this target. With abundant wind energy available, Ireland can meet its goal. However, due to the intermittent availability of wind energy, an energy backup for power generation is necessary. The use of curtailed or dedicated wind for producing hydrogen gas through electrolysis, and storing it in underground salt caverns is one approach to the problem. Northern Ireland has a rich source of Permian salt deposits offering a better place to store hydrogen which can be withdrawn for electricity generation, or used as fuel in transportation sectors. The Life Cycle Assessment (LCA) of the hydrogen systems can scrutinise the environmental impact of carbon emissions. This study analyses routes to reduce the environmental impact by evaluating polluting hotspots during the construction and operation phase of the system. This paper compares the impacts of the LCA on a hydrogen system which consists of a wind energy source for hydrogen production through electrolysis, transportation in pipelines and compression before storing it in salt caverns. A comparative analysis is carried out with the LCA of the hydrogen system with an electrical grid supply source. The results show that the impacts contributed by a renewable source are less than the electricity from the grid for the island of Ireland.

ОЦЕНКА ВЕРОЯТНОСТИ НЕСАНКЦИОНИРОВАННОЙ ПОДАЧИ НАПРЯЖЕНИЯ В СЕЛЬСКИХ ЭЛЕКТРИЧЕСКИХ СЕТЯХ 0,4-10 КВ

One of the causes of electrical injuries in rural power grids of 0.4-10 kilovolts is the unauthorized power supply, which is caused by various causes: the fall of a wire from one power line to another (disconnected), incorrect connection of an electric generator in a private household, etc. At the same time, the occurrence of a power supply in the 0.4 kilovolt grid due to reverse transformation at the 10/0.4 kilovolt transformer substation leads to the appearance of a voltage in the 10 kilovolt grid and poses a danger of electric shock both in 0.4 and 10 kilovolt grid. However, it is not possible to identify the number of cases of unauthorized power supply based on statistics or other data due to the fact that this information is not recorded until the accident occurs. Therefore, the definition of cases of unauthorized voltage supply is actual. (Research Purpose) The research purpose is estimating the probability of unauthorized power supply in electrical grids of 0.4-10 kilovolts. (Materials and methods) Methods of expert survey and processing of its results were applied. 74 experts serving rural power grids of 0.4-10 kilovolts were interviewed, who were asked questions about actual cases of unauthorized power supply and the expectation of meeting with such cases. Based on the results of the survey, the specific probabilities of the unauthorized power supply per kilometer of the line were determined (Results and discussion) The actual number of cases of unauthorized power supply recorded by experts has been determined, which amounted to 91 cases over five years, and the specific value is 0.011 cases per kilometer of lines per year. The assessment was carried out taking into account the total length of the grid serviced by experts - 1704 kilometers. The specific value of the probability of unauthorized power supply was determined according to experts (0.0056 cases per kilometer of lines per year). (Conclusions) The number of cases of unauthorized power supply predicted by experts is lower than the actual one, which confirms the need for additional training of personnel of power grid organizations on this issue.

The optimized integration of temperature-controlled transports into distributed sector-integrated energy systems

A model for the electric integration of temperature-controlled transports into decentralized, sector-integrated energy systems of logistics facilities is presented herein. A method for modeling an energy systems interaction with the energy components of a refrigerated trailer (reefer) is also introduced. Furthermore, the optimized integration of all sectors was demonstrated using the open energy modeling framework (oemof). For this purpose, the electricity, heat and transport sectors of a typical logistics company’s premises are considered in the context of a case study, spanning the period of one year. Energy costs, CO2 emissions, load peaks, and PV own-consumption are used to evaluate the gradual conversion of reefer preconditioning (pre-cooling and -heating) from diesel fuel into electrical grid supply. A linear solver optimizes the energy system in terms of costs and facilitates the optimized integration of reefers and the sector-integrated energy system, incorporating load peaks and CO2 emissions. The results of the study demonstrate the great potential of reducing costs and emissions through the electrical integration of different numbers of refrigerated trailers and furthermore show the challenges and implications of this for other sectors. Based on the results of the optimization, normalized preconditioning operations were created and divided by setpoint, such as for transferability and comparability. Substituting diesel with electricity for the preconditioning of refrigerated trailers reduces costs and CO2 emissions: 0.89 € and 1.56 kgCO2 can be saved per normalized electric preconditioning process compared to diesel preconditioning, depending on the setpoint it can be more or less. This positive effect can be enhanced by making optimal use of decentralized PV. The use of battery storage increases self-consumption and reduces load peaks at the grid connection point, thus enabling the optimized integration of preconditioned temperature-controlled transports into sector-integrated energy systems. With optimized use of the battery storage and PV self-consumption, the savings compared to diesel can be increased to 1.12 € and 2.11 kgCO2 per normalized preconditioning process.

Evaluating the impact of refrigerated transport trucks in China on climate change from the life cycle perspective

With global increases in population and economic growth, refrigerated transport trucks play a critical role in human life, food quality and security, and environmental issues. However, little research has been done on the greenhouse gas (GHG) emissions arising from refrigerated trucks that are rapidly increasing in developing countries, such as China. As such, projecting GHG emissions associated with refrigerated trucks and exploring effective measures to mitigate its global warming impact is necessary to reach climate goals. This study presents a carbon footprint novel model for evaluating refrigerated trucks by considering the lifecycle impacts of their refrigeration systems (refrigerators and refrigerants), insulated truck bodies, and truck chassis, including these elements' production, transportation, installation, use and repair, and recycling phases. We then quantitatively evaluate refrigerated trucks' overall carbon footprint based on data from seven typical regions in China. Our results show that the carbon footprint is remarkably high in the use phase, accounting for approximately 96% of an refrigerated truck's total GHG emissions. The hotspots in the refrigerated truck lifecycle have been identified as fuel consumption and the temperature difference between the outside and inside of the insulated truck body during the use phase. Moreover, we prioritize four low-carbon management strategies to mitigate the refrigerated truck sector's climate change impact, including energy efficiency improvement, clean electricity grid supply, environmentally friendly refrigerants, and alternative refrigeration technologies.

Analysis of the influence of the parameters of the power supply network on the operating modes of the electric drives of the stands of the hot rolling mill 1700 of ArcelorMittal Temirtau JSC

The finishing group of stands of the 1700 SRS-1 continuous mill of ArcelorMittal Temirtau JSC is characterized by high rolling speeds and high productivity. The use of DC motors as power sources for the main drives of the stands of high-power thyristor converter units significantly affects the nature of the operating modes of the power supply system and the quality of electricity on the buses of the SRS-1 substation. Experiments were performed to study the electricity grid supply substation in which the basic indexes of quality of electric energy and the built waveform voltage SAG during rolling. Voltage dips are observed throughout the rolling process and reach 10% of the rated network voltage. Due to the complexity of removing individual parameters of electric drives and conducting experiments on a real mill, an adequate model of the electric drive of the stand of the finishing group of the 1700 SRS-1 mill was developed and built.

Life cycle assessment of organic photovoltaic charger use in Europe: the role of product use intensity and irradiation

Solar chargers for mobile phones are the first integration of organic photovoltaic (OPV) technology into commercial products. Although environmental impacts of OPVs have been studied extensively, the performance of chargers have been narrowly examined in reference to intensity of their use and use geographies. To explore these aspects, we study the environmental impacts of OPV chargers considering the charger as a substitute for a local electricity grid supply for charging a mobile phone. A consequential life-cycle assessment (LCA) was carried out to evaluate the environmental performance of the OPV charger in six European countries representative of different electricity grids and solar irradiation contexts. Particular effort is made to explore the implications of use intensity of the charger and determine a frequency at which charger is competitive. The results suggest that using an OPV charger has the potential to be environmentally friendly only in countries with high fossil-fuel share in their electricity supplies. The OPV charger is environmentally beneficial in Greece and Spain across most of the evaluated impact categories if used 100–120 times per year, which is practical given the high solar insulation in the two countries. Charging a phone with OPV in Germany or the Netherlands is environmentally-friendly only under conditions of intensive use of the device, or for selective impact categories. In the category of climate change, charging with OPV would represent an improvement in Greece and Germany. In two countries a phone-charging supported by OPV generates 2.5 kg of CO2-equivalents per year in comparison to 2.9–3 kg CO2-equivalents charging from the grid. Phone-charging supported by OPV in Norway and France is more impactful than using the grid for the majority of impact categories, including the category of climate change. The study contributes a novel methodology for looking at photovoltaic technology and helps inform users and policymakers who should consider the local context before an adoption of environmental technologies.

Comparison of individual and microgrid approaches for a distributed multi energy system with different renewable shares in the grid electricity supply

The transition to 100% renewable energy systems is an important factor in the transition to sustainable energy systems. A top-down approach is often used to study the design of such energy systems on a country or continental scale. Results of these studies are useful for developing energy roadmaps but they lack the details about how distributed multi energy systems should be designed and operated at local level. An optimisation model of distributed multi energy systems is applied in order to investigate how urban districts should be optimally designed in the (near) future when the goals of energy roadmaps are achieved. The impact of individual and microgrid approaches on distributed multi energy systems is analysed on an urban district level for scenarios with different levels of renewable energy in the electricity grid supply.

Decarbonizing the electricity grid: The impact on urban energy systems, distribution grids and district heating potential

Many energy policies set a goal of decreasing the carbon emissions of the energy sector by up to 100%, including the electricity grid. This is a long term and gradual process. Energy systems in cities will likely be the starting point for greenhouse gas emissions mitigation since they account for 80% of global carbon emissions. This paper analyses the impact on urban districts of decarbonizing the electric grid supply. A multi-objective optimization model has been developed that combines the optimal design and operation of distributed energy systems, the design of district heating (DH), electricity grid constraints based on linearized alternating current (AC) power flow and grid upgrade options. A number of scenarios were defined corresponding to different levels of renewable energy share in the electricity grid. For each scenario, we analyse the changes to the design and operation of the urban energy system, the impact on the district heating potential, and the impact on the operation of the distribution grid as well as the grid upgrade potential.The results showed that the renewable share of the grid has a large impact on the optimal solutions obtained. When the renewable share is below 55%, a lot of photovoltaic (PV) electricity has to be used to offset the carbon emissions from the grid. Conversely, when the renewable share is above 70%, the use of PV decreases and heating systems become electrified by producing heat with heat pumps (HP). District heating is used regardless of the renewable share in the grid, but as carbon emissions limits are tightened the potential of DH decreases. Only when the renewable share in the electricity grid is 100% it is possible to have a carbon-neutral district. In the carbon optimal solutions of each scenario there is no need for DH, but the grid has to be upgraded to enable electrification of the heating system.

An ensemble-in-time forecast of solar irradiance

The increment of solar energy production requires an accurate estimation of surface solar irradiance. A forecast of surface solar irradiance allows estimate the energy production, and therefore minimizes the fluctuations in the electric grid supply. In this work, hourly solar irradiance is estimated by means of the Weather Research Forecast meteorological model (WRF) in operational mode along 1-year. Different WRF outputs were combined to obtain an ensemble-in-time forecast, with four members. This solar irradiance forecast is validated against ground measurements at three locations in the northwest (NW) of Galicia (NW of the Iberian Peninsula) along one year.

PENGARUH BEBAN TEKAN TERHADAP KEMAMPUAN EKSTRAKSI MASSA CAIR SLURRY OLEH “ALAT PEMISAH FASES-URINE SAPI” YANG DIOPERASIKAN SECARA MANUAL

Cow manure can be used as a source of energy and as a solid or liquid fertilizer. An adult cow can produce fases (solid manure) to 23 kg/day and urine (liquid manure) 9 kg/day. Three or four cow is capable to fullfill the dayly needs of cooking fuel for one rural household. Cow manure slurry can also be convert as fertilizer, that is liquid fertilizer which is derived from urine and solid fertilizer originating from the solids. Solid and liquid from cow manure is usually mixed, therefore to make the liquid and solid fertilizer, the liquid and solid masses need to be separated first. Recent separators of fases and urine are are electrical energy driven, so that those kind of device could not be used in the rural areas where the electric grid supply were not available. So that a model of a faces-urine separator of cow manure slurry is utilize which was constructed for manual pressing force. Moreover, through this research It have had created a manual fases-urine separator which only requires one operator. The separator consists of main parts including; lever press, chamber press, fases-urine separation mechanism, the mechanism of loading-unloading, and ajustment mechanism for pressing pressure. This design is capable of performing the separation in a wide range of pressing force and it only requires one operator. Results Show That the model is capable to separate liquid from the slurry as much as 13.9% at a pressing force of 14 kg the which is applied for 18 seconds.

Optimum hybrid photovoltaic-based solution for remote telecommunication stations

The vast growth of the mobile telecommunication (T/C) sector during the recent years has led to the extension of the respective networks even to the most remote areas. Many of these areas, however, often lack electricity grid supply and as a result installation of energy autonomous T/C stations, usually based on diesel-oil electricity generation, is essential. On the other hand, technological developments and considerable procurement cost reduction of photovoltaics (PVs) encourage also the use of PV stand-alone configurations, as an alternative energy solution for the operation of these remote T/C stations. Instead of using PV-battery configurations alone, contribution of a diesel engine in terms of moderate fuel consumption may downsize the system and improve its economic performance. In this context, an optimum sizing methodology currently developed is used to determine the dimensions of such an autonomous hybrid system, based on the criterion of minimum initial cost. The developed methodology is accordingly applied to a representative Greek area of high solar potential under different scenarios of fuel consumption and panels’ tilt angle. From the results obtained, the proposed hybrid power station appears to be one of the most attractive energy solutions for the support of remote T/C stations, providing increased levels of reliability and presenting low maintenance needs.

Increasing of the quality of energy from stochastic fluctuating sources using dynamic power conditioning

The stochastic fluctuating offer of wind energy limits the capacity of supply in electrical grids for technical and economical reasons. To increase the supply, a concept of dynamic conditioning with the objective of increasing the quality of supply was developed. The concept envisages supporting and managing the electrical grid, respectively by compensating of active and reactive power with static converters ('Electronic Synchronous Machine') and short term storage. Through the four-quadrant operation of the converters, short term fluctuation of the energy sources and changes of the load can be absorbed or smoothed directly on location. By using dynamic storage systems an intermediate storage of the stochastically offered primary energy is achieved. This low order energy can thereby be converted into high order recallable energy, which can even be used to satisfy peak demands. The local compensation of the fluctuation of the energy supply on the one hand and the changes of the demand on the other hand, allows a more steady energy demand from the nation-wide electrical grid.