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Number of results: 13
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Abstract

During a blackout, after the post-disaster collapse of an electric power system (EPS), units of thermal power plants should switch-over to the house load operation mode (PPW). However, regarding the dynamics of a post-disaster blackout process, many units can be in forced outage Therefore, restart of these units from the start-up sources with a self-start capability is necessary. The Transmission Network Code in force imposes periodic tests and system tests for such sources. Any system test must be preceded and followed by simulation investigations in which the possibilities: (1) to bring voltage to the started-up power plant by a starting path and (2) to activate the highest-power auxiliaries (PW) of the unit being started-up are evaluated. In the paper, chosen results of simulative investigations of the transient phenomena in the starting path from the hydroelectric power plant of Włocławek (HPP Włocławek) to the thermal power plant of P˛atnów (TPP P˛atnów), related to the system test conducted in September 2017 have been presented.

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Authors and Affiliations

Ireneusz Grządzielski
Bartosz Olejnik
Mikołaj Zakrzewski
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Abstract

In this paper, selected aspects of the national technical level of electric energy supply security is shown. An analysis and assessment of the electric power infrastructure in area of generation, transmission and distribution in aspects of electric energy security is conducted. The profile of the generation sector and grid infrastructure in the area of transmission and distribution is shown. The present and future situation in a range of operation of electric power infrastructure in the area of generation, transmission and distribution in the frames of the National Electric Power System in the electric energy supply security context is determined. The level of national electric energy supply security in area of generation and grid infrastructure is assessed. Threats of electric energy supply security are described and the catalogue of essential actions for the assurance of electric energy supply security are proposed. In the area of electricity generation, at present there is no danger to the electricity supply security in normal load conditions, but there is a high probability that it will occur in the future (after 2025) when the forecasted increase in electricity demand takes place and the new stringent environment protection requirements (Directive IED, BAT conclusions, Winter Package) enter into force. The network infrastructure in area of transmission and distribution is admittedly adapted for presently occurred typical conditions of electric energy demand and the realization of internal tasks in normal conditions, but can create a potential threat for electric energy supply security. In the context of the forecasted increase of electric energy demand, inadequate power generation sources in the National Electric Power System and available through intersystem connections, their uneven location on the territory of Poland in the shortage of proper network transmission capacities, the necessity of improvement of the quality and electric energy supply reliability to final consumers and the intensive development of renewable energy sources, the present network infrastructure in area of transmission and distribution will be insufficient.

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Authors and Affiliations

Waldemar Dołęga
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Abstract

An electric power steering system (EPS) is a new type of steering system developed after a mechanical hydraulic power system (MHPS) and electric-hydraulic power steering system (EHPS). In order to coordinate and solve the portability and sensitivity of the steering system optimally, taking an induction power steering system as the research object, the control algorithm of induction motor control under the EPS is studied in this paper. In order to eliminate the feed-forward performance degradation caused by the change of feed-forward parameters, an on-line identification algorithm of feed-forward parameters is proposed. It can improve the control performance of online identification among three feed-forward parameters in the T-axle motor, it improves on the robustness of feed-forward control performance, at the same time it also gives simulation and test results. This method can improve the control performance of the three feed-forward parameter online identification of the T-axis motor and improve the robustness of feed-forward control performance. At the same time, simulation and test results are given. The simulation results show that the algorithm can significantly improve the response speed and control accuracy of EPS system control.

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Authors and Affiliations

Zhang Naibiao
Cai Tianfang
Han Xuezheng
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Abstract

Thermoelectric generators using the Seebeck effect to generate electricity are increasingly used in various areas of human activity, especially in cases where a cheap high-temperature heat source is available. Despite many advantages, TEG generators have one major disadvantage: very low efficiency of heat conversion into electrical power which strongly depends on the applied load resistance. There is a maximum of generated power between the short and the open circuit in which it is zero. That is why optimization of TEG modules is particularly important. In this paper a method of maximization of generated power in a single TEG module is presented for two cases. The first case concerns a problem with fixed heat flux flow into the hot side of the module whereas the second one concerns a problem with fixed heat transfer parameters in hot heat exchanger i.e. supply gas temperature and heat transfer coefficient. A number of optimization results performed for various values of these parameters are presented and discussed.
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Authors and Affiliations

Artur Poświata
1
Paweł Gierycz
1

  1. Warsaw University of Technology, Faculty of Chemical and Process Engineering, ul. Waryńskiego 1, 00-645 Warsaw, Poland
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Abstract

The relevance of this research work is due to the fact that farms and other farms are located at a considerable distance from sources of centralized power supply. Therefore, it is necessary to introduce autonomous generators as the main units that ensure the uninterrupted functioning of energy systems. The purpose of this research work is to analyze the features of the functioning of an autonomous constant voltage generator, as well as to determine the basic physical laws that are of fundamental importance in its operation. The basis of the methodological approach in this scientific study is a combination of methods of system analysis with an analytical study of the general principles of operation of such devices, which are of fundamental importance from the point of view of ensuring the proper level of operational reliability. The main results obtained in this research work should be considered the definition of equations for calculating the instantaneous values of the three-phase excitation current, as well as the peak value of the three-phase excitation current of an autonomous constant voltage generator. The results obtained in the course of this scientific research and the conclusions formulated on their basis are of fundamental importance for developers of modern technological systems, including autonomous constant voltage generators, as well as for employees of technological services of modern industrial enterprises, whose professional responsibility includes the practical operation of such devices to solve a complex of technical tasks facing these enterprises.
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Authors and Affiliations

Orken Ordatayev
1
ORCID: ORCID

  1. Kazakh National Agrarian Research University, Kazakhstan
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Abstract

Due to unfavorable factors, dangerous conditions occurred in the delivery of electric energy in Poland. This was the most serious incident of its kind since the 1980’s. Such a serious incident raised concern about the safety of the electric power system in the summer and led to the formulation of conclusions for the future. In this article, the author analyses the conditions, which caused that situation. Poland was experiencing a doubt in August 2015, which along with an extremely high maximum daily temperature created remarkably unfavorable conditions for power plants and decreased the capacity of overhead power lines. Such unfavorable metrological conditions occurred not only in Poland, but also in Central-Eastern and Western Europe. It is worth emphasizing that the safety of electric energy delivery was endangered only in Poland. The improper renovation and upkeep policies, as well as unplanned outages in power plants caused a significant decrease of available power in the National Electric Power System. Unscheduled flows between Germany and Poland ruled out the possibility of importing electric energy at such a critical time. The author presents the correlation between the maximum daily air temperature in the sweltering heat and an increase in the demand for electric energy. Overall, unfavorable conditions posed a threat in the delivery of electric energy in Poland. In this article, the author draws attention to the report from the Supreme Audit Office (Najwyższa Izba Kontroli – NIK) from 2014, which predicted such a dangerous situation. Unfortunately, that report remained unnoticed. The author formulated appropriate solutions in order to increase the safety of electric energy delivery in the summer and to prevent such occurrences in the future.

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Authors and Affiliations

Bartosz Sobik
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Abstract

The overriding objective of the National Electric Power System (KSE) is to ensure the security of electricity supply. In summer, the upward trend in the demand for electric energy is caused by, among others, the proliferation of air conditioners. Therefore, the upward trend in summer’s on-peak demand is expected to be maintained. Examples from 2015, 2016 or 2018 indicate that National Electric Power System needs a summer’s on-peak source that will be able to produce electricity regardless of the hydrological conditions. Photovoltaics is a source of energy that can cover the peak demand during sweltering heat. This article briefly characterizes the problem of increasing demand for electricity in summer and uses examples that have taken place in recent years. The main conclusion is the postulate for the extension of photovoltaic power in the National Electric Power System, the purpose of which will be the production of electricity during sweltering heat, covering the peak load in the system. This article presented both the advantages and disadvantages of such a solution. Unfavorable weather conditions (high air temperature, low water level, lack of wind) limit the production of electricity from wind farms or conventional power plants, and also increase transmission losses, which is why photovoltaics is a desirable source from the National Electric Power System’s point of view. The article refers to examples from the Czech Republic and Germany, where a significant installed capacity of photovoltaics enables the stable operation of the power system during sweltering heat. It was also pointed out that the role of photovoltaics in the National Electric Power System is growing, which is consistent with the assumptions of the Polish Energy Policy Project until 2040.

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Authors and Affiliations

Bartosz Sobik
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Abstract

Using loans is an effective solution for the investment and construction of energy works in general and power plants in particular, especially for developing countries. In economic and financial studies of the project investment preparation stage, the options of using capital and paying interest will be taken into account to minimize risks and increase the project’s ability to pay due debts. However, it is difficult to know which loan repayment option is the most beneficial for the project and when the risk is for the project in the context of debt repayment. The current economic and financial analysis of the project mainly focuses on determining the feasibility of the project through basic parameters, such as net present value (NPV), benefit – cost – ratio (B/C), internal rate of return (IRR), profitability index (PI) and payback period (PP). These parameters do not indicate the most difficult time to pay off the project’s loans. This paper analyzes two options for repayment of long-term loans in Vietnam using the case study of Son La hydropower plant to clarify the above difficult times and recommend a suitable repayment plan for the power project. The analytical method is used to actualize the cash flow of capital and interest during the construction and operation of the works. In Option 1, the debt is paid annually for interest and capital with a constant amount of money during the repayment period. In Option 2, the original dept without interest is paid with a constant amount of money during the repayment period, the interest (due to the remaining original capital) must be paid in the year when the interest is incurred. The study results show that the amount of the annual payment in option 1 is smaller than in Option 2 in the first four years (of ten years of debt repayment). Thus, capital and interest payment in Option 2 may be more detrimental than Option 1 in the first three years of debt repayment, and the amount of money from debt repayment is greater than the profit obtained from power generation. Thus, depending on the profit in the first years when the power plant comes into operation, the investor needs to decide on a reasonable way to repay the loan so that the project can self-finance.
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Authors and Affiliations

Le Tat Tu
1
ORCID: ORCID
Vu Minh Phap
1
ORCID: ORCID
Nguyen Thi Thu Huong
1
ORCID: ORCID

  1. Institute of Energy Science, Vietnam Academy of Science and Technology, Viet Nam
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Abstract

Vacuum conditions in foundry installations are generated using electric-driven vacuum pumps. The purpose of the experiment is to evaluate the performance of a vacuum-assisted system for compaction of moulding sand basing on registered plots of selected electric power parameters of the power-supplying system of the pumps. Model testing done on an experimental vacuum system installation, power-supplied from a system incorporating the recorders of instantaneous current and voltage values. Following the numerical procedure, the experimental data are analysed to yield mathematical relationships between the variations of the generated vacuum pressure levels and variations of selected electric power parameters. Registered and computed values of selected parameters: instantaneous and RMS voltage and current values, active, reactive and apparent power levels and power coefficient allow for diagnosing the adequacy and reliability of the system operation. According to the authors, the applied monitoring of the power parameters of a vacuum-assisted installation may become an effective and easy practical method of evaluating the performance of such installations, used also in foundry plants.

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Authors and Affiliations

M. Brzeziński
E. Ziółkowski
R. Wrona
K. Smyksy
P. Zyzak
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Abstract

In this article the main problems related with the proper choice of the design and operation parameters of vacuum installation in vacuum moulding system have been discussed. In such system a vacuum are generated using electric-driven vacuum pumps. The aim of the experiment is to evaluate the performance of a vacuum system basing on registered plots of selected electric power parameters of the power-supplying system of the pumps with parallel measurements instantaneous values of pressure in selected points of model stand. The measurements system for power-supply unit has incorporated the recorders of instantaneous current and voltage values. Following the suitable numerical procedure, the experimental data are analysed to yield mathematical relationships between the variations of the generated vacuum pressure levels and variations of selected electric power parameters. According to the authors, the applied measurements system of the parameters of a vacuum-assisted installation may become an effective and easy practical method of evaluating the performance of such installations, used also in industry.

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Authors and Affiliations

K. Smyksy
E. Ziółkowski
M. Brzeziński
R. Wrona
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Abstract

This article presents an analysis of the sustainable development of generation sources in the Polish National Electric Power System (NEPS). First, the criteria for this development were formulated. The paper also discusses the current status of generation sources, operating in power plants and combined heat and power (CHP) plants of NEPS. Furthermore, it includes a prediction of power balance in NEPS, determining; predicted electricity gross use, predicted demand for peak capacity during the winter peak, predicted demand for peak capacity during the summer peak and required new capacity of centrally dispatched generation units (CDGUs) in 2025, 2030, 2035 and 2040 that would ensure NEPS operational security. Twenty prospective technologies of electricity generation and combined electricity and heat production were analyzed. These were divided into three groups: system power plants, high- and medium-capacity combined heat and power (CHP) plants, as well as small-capacity power plants and CHP plants (dispersed sources). The unit costs of electricity generation discounted for 2021 were calculated for the analyzed technologies, taking the costs of CO2 emission allowances into account. These costs include: capital costs, fuel costs, maintenance costs, operation costs and environmental costs (CO2 emission allowances). This proceeds to a proposal of a program of the sustainable development of generation sources in NEPS, which includes the desired capacity structure of power plants and CHP plants, and the optimal structure of electricity production in 2030 and 2040. The results of calculations and analyses are presented in tables and figure.
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Bibliography

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BP 2021. BP Statistical Review of World Energy, Edition 2021. [Online] https://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy.html [Accssed: 2021-09-17].
Directive 2005/89. Directive 2005/89/UE of the European Parliament and Council of 18 January 2006 on concerning measures to safeguarded security of electricity supply and infrastructure investment. Official Journal of the European Union, 2006, L 33/1 – L33/22.
Directive 2012/27. Directive 2012/27/UE of the European Parliament and Council of 25 October 2012 on energy efficiency. Official Journal of the European Union, 2012, L315/1 – L315/56.
KPEiK 2019. National Energy and Climate Plan 2021–2030 (Krajowy plan na rzecz energii i klimatu na lata 2021–2030). Ministerstwo Aktywów Państwowych, 2019 (in Polish).
MP 2020. Polish Nuclear Power Programme (Program polskiej energetyki jądrowej). Monitor Polski 2020, poz. 946 (in Polish).
PSE 2016. Forecast of Peak Capacity Demand Coverage in 2016–2035 (Prognoza pokrycia zapotrzebowania szczytowego na moc w latach 2016–2035). Polskie Sieci Elektroenergetyczne SA. [Online] https://www.pse.pl/-/prognoza-pokrycia-zapotrzebowania-szczytowego-na-moc-w-latach-2016-2035 [Accessed: 2021-08-10] (in Polish).
PSE 2020. Development Plan of Present and Future Electricity Satisfaction Demand Coverage in 2021–2035 (Plan rozwoju w zakresie zaspokojenia obecnego i przyszłego zapotrzebowania na energię elektryczną na lata 2021–2030). Polskie Sieci Elektroenergetyczne SA. [Online] https://www.pse.pl/ documents/20182/21595261/Dokument_glowny_PRSP_2021-2030_20200528.pdf [Accessed: 2021-08-10] (in Polish).
PEP2040 2021. Energy Policy of Poland until 2040 (Polityka energetyczna Polski do 2040 roku). MP 2021, poz. 128 (in Polish). Statistics 2019. Statistics of Polish Heat Industry 2018 (Statystyka Ciepłownictwa Polskiego 2018). Warszawa: Agencja Rynku Energii SA (in Polish).
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URE 2020. Information about Investment Plans in New Generation Capacity in 2020–2034 (Informacja na temat planów inwestycyjnych w nowe moce wytwórcze w latach 2020–2034). Urząd Regulacji Energetyki. [Online] https://www.ure.gov.pl>download>Raport-Plany inwestycyjne w nowe moce wytwórcze latach 2020-2034 [Accessed: 2021-08-10] (in Polish).
Zaporowski, B. 2016. Sustainable development of the electricity generation sources (Zrównoważony rozwój źródeł energii elektrycznej). Polityka Energetyczna – Energy Policy Journal 19(3), pp. 35–48 (in Polish).
Zaporowski, B. 2019. Energy and economic effectiveness of prospective generation technologies for Polish electric power industry (Efektywność energetyczna i ekonomiczna perspektywicznych dla polskiej elektroenergetyki technologii wytwórczych). Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej 63, część 2, pp. 87–90 (in Polish).
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Authors and Affiliations

Bolesław Zaporowski
1
ORCID: ORCID

  1. Institute of Electric Power Engineering of Poznań University of Technology, Poznań, Poland
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Abstract

A country’s “energy mix” typically evokes varying opinions among different groups within society. It also changes over time, at a pace that most energy consumers fail to appreciate. It is shifting even in Poland – certainly not a leader in the energy transition.
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Authors and Affiliations

Jan Kozłowski
1

  1. Institute of Environmental Sciences, Jagiellonian University in Kraków, Poland
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Abstract

One of the most critical systems of any satellite is the Electrical Power System (EPS) and without any available energy, the satellite would simply stop to function. Therefore, the presented research within this paper investigates the areas relating to the satellite EPS with the main focus towards the CubeSat platform. In this paper, an appropriate EPS architecture with the suitable control policy for CubeSat missions is proposed. The suggested control strategy combines two methods, the Maximum Power Point Tracking (MPPT) and the Battery Charge Regulation (BCR), in one power converter circuit, in order to extract the maximum power of the Photovoltaic (PV) system and regulate the battery voltage from overcharging. This proposed combined control technique is using a Fuzzy Logic Control (FLC) strategy serving two main purposes, the MPPT and BCR. Without an additional battery charger circuit and without switching technique between the two controllers, there are no switching losses and the efficiency of the charging characteristic can be increased by selecting this proposed combined FLC. By testing a space-based PV model with the proposed EPS architecture, some simulation results are compared to demonstrate the superiority of the proposed control strategy over the conventional strategies such as Perturb and Observe (P&O) and FLC with a Proportional Integral Derivative (PID) controller.

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Authors and Affiliations

Abderrahmane Seddjar
Kamel Djamel Eddine Kerrouche
Lina Wang

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