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Tytuł:
The Determinants of Sub-Central Government’s Efficiency: The Case of Polish Districts
Autorzy:
Skica, Tomasz
Lazović-Pita, Lejla
Abdić, Ademir
Powiązania:
https://bibliotekanauki.pl/articles/36459696.pdf
Data publikacji:
2024
Wydawca:
Uniwersytet Warszawski. Instytut Ameryk i Europy. Centrum Europejskich Studiów Regionalnych i Lokalnych (EUROREG)
Tematy:
efficiency
public total and current expenditures
COVID-19
districts
Opis:
Academic research indicates that total or current expenditures have been most commonly used in sub-central or local government’s efficiency analysis as dependent variables, and a proxy for the cost of service provision. Our research applied in the case of Polish districts for 2019 and 2020 indicates two important results: firstly, regardless of whether total or current expenditures have been used, the determinants indicate the same direction of impact, and, secondly, the COVID-19 pandemic did not change the direction of the impact. The regression results confirm the positive direction that the administrative, educational, protection, and safety variables have on dependent variables.
Źródło:
Studia Regionalne i Lokalne; 2024, 95, 1; 7-20
1509-4995
Pojawia się w:
Studia Regionalne i Lokalne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wybrane kierunki badań z zakresu prawa konstytucyjnego na świecie – subiektywny przyczynek do dyskusji
Selected Directions of Research in the Field of Constitutional Law in the World – a Subjective Contribution to the Discussion
Autorzy:
Michalak, Anna
Powiązania:
https://bibliotekanauki.pl/articles/28762536.pdf
Data publikacji:
2024-02-29
Wydawca:
Wydawnictwo Adam Marszałek
Tematy:
prawa człowieka
prawo konstytucyjne
aktualne badania
kryzys konstytucyjny
badania komparatystyczne
human rights
constitutional law
comparative research
current research
Opis:
At present, there is a global discussion on desirable and necessary changes to the constitution, common and non-derogable democratic values, and the scope of the omnipotence of the authorities elected in free elections. Politicians, representatives of organizations representing civil society, experts and representatives of the world of science participate in this discussion. The Polish constitutional discourse after 2015 was dominated by the consequences of ruthless circumvention of the provisions of the constitution by politicians in power. Even in these circumstances, however, other issues that are currently being debated in international constitutional forums must not be lost sight of. It seems that at least some of them may prove useful in the discussion on restoring constitutional standards.
W chwili obecnej globalnie toczy się dyskusja na temat pożądanych i koniecznych zmian w konstytucji, wspólnych i niederogowalnych wartości demokratycznych, zakresu omnipotencji władz wyłonionych w drodze wolnych wyborów. W dyskusji tej uczestniczą politycy, przedstawiciele organizacji reprezentujących społeczeństwo obywatelskie, eksperci i przedstawiciele świata nauki. Polski dyskurs konstytucyjny po 2015 r. zdominowały konsekwencje bezpardonowego obchodzenia przez polityków sprawujących rządy postanowień ustawy zasadniczej. Jak się wydaje w Polsce dopiero zmiany polityczne, tj. zmiana partii politycznej odpowiedzialnej za kształtowanie polityki wewnętrznej i zewnętrznej państwa otworzy możliwość powrotu do funkcjonowania państwa w sposób zgodny z uznanymi standardami konstytucyjnymi i demokratycznymi, co wymagać będzie wdrożenia procedur naprawczych. Nawet w tych okolicznościach nie można jednak tracić z pola widzenia innych zagadnień, które obecnie stanowią przedmiot debaty na międzynarodowych forach konstytucjonalistów. Jak się wydaje – przynajmniej niektóre z nich – mogą okazać się przydatne w dyskusji nad przywracaniem standardów konstytucyjnych.
Źródło:
Przegląd Prawa Konstytucyjnego; 2024, 1(77); 137-149
2082-1212
Pojawia się w:
Przegląd Prawa Konstytucyjnego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A fuzzy logic approach to shunt active power filter and hybrid active power filter
Autorzy:
Sahoo, Nirjharini
Panda, Gayadhar
Subudhi, B. D.
Powiązania:
https://bibliotekanauki.pl/articles/41189662.pdf
Data publikacji:
2023
Wydawca:
Politechnika Warszawska, Instytut Techniki Cieplnej
Tematy:
Index terms
shunt active power filter
hybrid active power filter
hysteresis current controller
total harmonic distortion (THD)
indirect current controller
filtr mocy czynnej
filtr hybrydowy
zniekształcenie harmoniczne
regulator prądu
Opis:
This paper describes a Fuzzy Logic approach to Shunt Active power filter (SAPF) versus Hybrid Active Power Filter (HAPF) using Simulink. Here hysteresis controlled PWM method is applied to the SAPF and HAPF as a current controller and Fuzzy logic controller as a inverter dc voltage controller. To reduce harmonics, Shunt Active Power Filters (SAPFs) are used with various control schemes, but Hybrid Active power filter is a power electronic device which has both the characteristics of passive power filters and active power filters, which helps in cancelation of the harmonics by producing compensating signal. The fuzzy-hysteresis controller is designed and its simulation results are presented for both the filter types, showing acceptable THD results for the word length used in the fixed-point computations involved in the switching sequence generation. The results of the above controller are compared with the Indirect current controller.
Źródło:
Journal of Power Technologies; 2023, 103, 4; 209-217
1425-1353
Pojawia się w:
Journal of Power Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model-free direct predictive grid-current control strategy for grid-connected converter with an inductance-capacitance-inductance filter
Autorzy:
Guo, Leilei
Zheng, Mingzhe
Yu, Changzhou
Xu, Haizhen
Li, Yanyan
Powiązania:
https://bibliotekanauki.pl/articles/2202543.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
grid-connected converter
GCC
model-free predictive current control
MFPCC
parameter mismatch
robustness
Opis:
The disadvantages of the conventional model predictive current control method for the grid-connected converter (GCC) with an inductance-capacitance-inductance (LCL) filter are a large amount of calculation and poor parameter robustness. Once parameters of the model are mismatched, the control accuracy of model predictive control (MPC) will be reduced, which will seriously affect the power quality of the GCC. The article intuitively analyzes the sensitivity of parameter mismatch on the current predictive control of the conventional LCL-filtered GCC. In order to solve these issues, a model-free predictive current control (MFPCC) method for the LCL-filtered GCC is proposed in this paper. The contribution of this work is that a novel current predictive robust controller for the LCL-filtered GCC is designed based on the principle of the ultra-local model of a single input single output system. The proposed control method does not require using any model parameters in the controller, which can effectively suppress the disturbances of the uncertain parameter variations. Compared with conventional MPC, the proposed MFPCC has smaller current total harmonic distortion (THD). When the filter parameters are mismatched, the control error of the proposed method is smaller. Finally, a comparative experimental study is carried out on the platform of Typhoon and PE-Expert4 to verify the superiority and effectiveness of the proposed MFPCC method for the LCL-filtered GCC.
Źródło:
Archives of Electrical Engineering; 2023, 72, 1; 23--42
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A New Approach on Improving The Operation of Over-Current Relays in 6kV Mining Grids of QuangNinh, VietNam
Autorzy:
Bun, Ho Viet
Thanh, Le Xuan
Powiązania:
https://bibliotekanauki.pl/articles/24200705.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
over-current relays
open-pitch mines
instantaneous time characteristic
false trip
Time Multiplayer Setting
Opis:
Over-current relays (OCR) are the most popular protecting devices utilized in 6kV mining grids of open-pitch mines, QuangNinh province, VietNam. Depending on time of operation of OCR, there are many operating mode catergorized as: Instantaneous OCR, Inverse time OCR, Inverse definite minimum time (IDMT) OCR, Very invese relays, Extremely Inverse relays. Nowaday, to give protection against: Phase faults, Earth faults, Winding faults (in transformer), most of mining companies using Over-current relays with instantaneous characteristic. This charactersitic has the following important features: i) Operates in a definite time when current exceed relay’s pick-up/setting up values, ii) Relay’s operation is mainly relied on current magnitude, iii) Operating time is constant, iv) There isn’t any intentional time delay, v) The operating currents are progressively increased for the other relays when moving towars the source. Apart from many advantages, there is a significant disavantage of the relays’s operation: when there are faults at the beginning of feeders, OCR with instantaneous characteristic usually has a big-time tripping. Moreover, sometimes there are false trip of OCR because of improper set-up. In this study, an offline method is proposed with simulation in ETAP software to overcome these issues. With Gurobi-Optimizer application, an algorithm for identifying Time Multiplayer Setting (TMS) will be employed to generate inversetime characteristic/inverse definite minimum time charactersitic for improving the performance of over-current relay with better discriminative tripping. The proposed method is simulated on ETAP with a 6kV sample skeleton distribution network (in QuangNinh province of VietNam). The demonstrating results are: the prevention of false trip of OCR and the operating time of OCR is reduced.
Źródło:
Inżynieria Mineralna; 2023, 2; 29--38
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new closed-form formula for calculating a weakly singular static potential integral with linear current source distribution on a triangle
Autorzy:
Grytsko, Anna
Słobodzian, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2204516.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
static vector potential integral
linear current source distribution
analytic integration
isoparametric transformation
integration over a triangular domain
weakly singular integral
statyczna wektorowa całka potencjalna
liniowy rozkład źródła prądu
integracja analityczna
słabo osobliwe całki
transformacja izoparametryczna
integracja w domenie trójkątnej
Opis:
The article presents a closed-form formula for solving a weakly singular surface integral with a linear current source distribution associated with the SIE-MoM formulation used for solving electromagnetic (EM) problems. The analytical formula was obtained by transforming the surface integral over a triangular domain into a double integral, and then directly determining formulas for the inner and outer integrals. The solution obtained is marked by high computational efficiency, high accuracy, and very simple implementation. The derived formula, in contrast to the currently available formulas, consists of quantities that have a clear and simple geometric interpretation, related to the geometry of the computational domain.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 1; art. no. e143645
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aggregating sea surface hydrodynamic forecasts from multi-models for European seas
Autorzy:
Frishfelds, V.
She, J.
Murawski, J.
Nielsen, J. W.
Powiązania:
https://bibliotekanauki.pl/articles/24201473.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
weather research and forecasting
search and rescue
operational ocean forecasting
European Satellite Systems
surface current
drifting sea surface temperature
European waters
Opis:
Maritime information services supporting European agencies such as the FRONTEX require European‐wide forecast solutions. Following a consistent approach, regional and global forecasts of the sea surface conditions from Copernicus Marine Service and national met‐ocean services are aggregated in space and time to provide a European‐wide forecast service on a common grid for the assistance of Search and Rescue operations. The best regional oceanographic model solutions are selected in regional seas with seamless transition to the global products covering the Atlantic Ocean. The regional forecast models cover the Black Sea, Mediterranean Sea, Baltic Sea, North Sea and combine the North Sea – Baltic Sea at the Danish straits. Two global models have been added to cover the entire model domain, including the regional models. The aggregated product is required to have an update frequency of 4 times a day and a forecasting range of 7 days, which most of the regional models do not provide. Therefore, smooth transition in time, from the shorter timerange, regional forecast models to the global model with longer forecast range are applied. The set of parameter required for Search and Rescue operations include sea surface temperature and currents, waves and winds. The current version of the aggregation method was developed for surface temperature and surface currents but it will be extended to waves in latter stages. The method relies on the calculation of aggregation weights for individual models. For sea surface temperature (SST), near real‐time satellite data at clear‐sky locations for the past days is used to determine the aggregation weights of individual forecast models. A more complicated method is to use a weighted multi‐model ensemble (MME) approach based on best forecast features of individual models and possibly including near real time observations. The developed method explores how satellite observations can be used to assess spatially varying, near real time weights of different forecasts. The results showed that, although a MME based on multiple forecasts only may improve the forecast, if the forecasts are unbiased, it is essential to use observations in the MME approach so that proper weights from different models can be calculated and forecast bias can be corrected. It is also noted that, in some months, e.g., June in Baltic Sea, even SST was assimilated, the forecast still show quite high error. There are also visible difference between different Copernicus Marine Environment Monitoring Service (CMEMS) satellite products, e.g. OSTIA and regional SST products, which can lead different forecast quality if different SST observation products are assimilated.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2023, 17, 3; 533--541
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An alternating current calibration method for Helmholtz coil constant based on orthogonal calculation principle
Autorzy:
Zhang, Kuankuan
Cao, Mingxing
He, Jian
Gong, Wenjie
Huang, Yunhua
Powiązania:
https://bibliotekanauki.pl/articles/27311758.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Helmholtz coils constant
alternating current method
induction voltage
orthogonal calculations
Opis:
The Helmholtz coil constant (ℎ) is a crucial standard in magnetic moment measurement devices for permanent magnet materials. To overcome the problem of low accuracy of the direct-current (DC) calibration method, this study used a constant sinusoidal current in the Helmholtz coil and measured the induced voltage of the detection coil with known coil turns and coil area. Subsequently, the ℎ was calculated. The noise signal deduction rate in the induction voltage of the detection coil was greater than 99%, its influence on the induction voltage is less than 0.005%, and the repeatability of the calibration results is 0.003% (1). The results reveal that the alternating current (AC) method and orthogonal calculation (OC) can accurately measure the valid values of the voltage signal under the influence of the spatial stray field during the calibration of ℎ.
Źródło:
Metrology and Measurement Systems; 2023, 30, 3; 549--561
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of time-averaged secondary flow cells in wide and narrow straight open channels with lateral bed deformation
Autorzy:
Chattopadhyay, T.
Kundu, S.
Powiązania:
https://bibliotekanauki.pl/articles/38695706.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
turbulent flow
secondary current
method of separation of variable
Reynolds shear stress
Opis:
The usual cellular pattern of the time averaged secondary flow circulation in the central section of wide open channels shows a distorted (laterally or vertically) structure due to the changes in bed configurations along lateral direction. The structures of these secondary circulations (under different bed configurations) are crucial for different types of hydraulic modeling. This study presents mathematical models of the time averaged secondary velocities (lateral and vertical components) for a turbulence-induced secondary current at the central section of a wide open-channel flow under different types of elevated and non-elevated bed conditions. Starting with the Reynolds Averaged Navier-Stokes equation and using the continuity equation, at first the governing equation of secondary flow velocity is obtained including the effects of the eddy viscosity and viscosity of the fluid. The model equations is solved using a separation of the variable technique imposing the bed perturbation condition. Full analytical solutions are achieved through mathematical analysis using suitable boundary conditions consistent with experimental observations. Initially the models are derived for a non-elevated bedforms comprised of alternating equal widths of smooth and rough bed strips. These models are modified further for bedforms with unequal widths of rough and smooth bed strips and elevated periodic bed structures. Four different types of elevated bed configurations are investigated and a general approach is suggested for other types of bed forms. All the proposed models are validated with existing experimental results to ensure the applicability and in each cases, improved results are observed. Obtained results show that the centre of circulation of the cellular structure occurs above the junction of the rough and smooth bed strips (consistent with experimental observations) and it gradually shifts towards the smooth strip, when the length of the rough bed strip is increased. The shifting as a function shows a non-linear pattern with the length of the rough bed strip. A least-square model is proposed to identify the circulation center as a function of the ratio of rough to smooth bed strips. It is also found that the vertically distorted secondary cells are generated when the bed slope strictly increase/decrease throughout the length of the one whole circulation. Finally, all the proposed models are compared with an existing model and an error analysis is done. Results of error analysis show that the present study can be more suitable as it yields improved results.
Źródło:
Archives of Mechanics; 2023, 75, 1-2; 169-211
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Armature MMF and electromagnetic performance analysis of dual three-phase 10-pole/24-slot permanent magnet synchronous machine
Autorzy:
Chen, Zhenfei
Xing, Ning
Ma, Hongzhong
Li, Zhixin
Li, Jiayu
Fan, Chenyang
Powiązania:
https://bibliotekanauki.pl/articles/2202550.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dual three-phase winding
fractional-slot
concentrated winding
permanent magnet synchronous machines (SCW-PMSMs)
MMF harmonic analysis
space harmonics
magnet eddy-current loss (ECL)
SVPWM voltage supply
Opis:
Fractional-slot concentrated-winding permanent magnet synchronous machines (FSCW-PMSMs) have a good prospect of application in the drive system of electric and hybrid electric vehicles. However, the armature magnetomotive force (MMF) of FSCWPMSM contains a large number of space harmonics, which induce large magnet eddycurrent loss (ECL). To solve this problem, a dual three-phase 10-pole and 24-slot winding layout is proposed.MMFharmonic analysis shows that the 1st, 7th and 17th space-harmonic winding factors of the proposed winding can be reduced by 100%, 87% and 87% respectively, compared with a dual three-phase 10-pole and 12-slot winding. Electromagnetic performances of the proposed machine under rated sinusoidal current supply and space vector pulse-width-modulated (SVPWM) voltage supply are investigated based on 2D finite-element analysis. It is shown that the proposed machine can meet the requirement of torque and efficiency in the full speed range. Especially, magnet ECL can be reduced greatly due to the reduction of the 7th and 17th space harmonics.
Źródło:
Archives of Electrical Engineering; 2023, 72, 1; 189--210
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automated Eddy Current System for Aircraft Structure Inspection
Autorzy:
Lysenko, Iuliia
Kuts, Yurii
Petryk, Valentyn
Malko, Volodymyr
Melnyk, Andrii
Powiązania:
https://bibliotekanauki.pl/articles/36833004.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
aviation material inspection
eddy current
signal characteristics
information parameters
scanning
Opis:
Aircraft part diagnostics are crucial during both production and maintenance, with eddy current nondestructive testing (ECNDT) being the method of choice due to its cost-effectiveness, informativeness, productivity, and reliability. ECNDT excels regardless of surface condition or coatings. It’s employed for diagnosing various aircraft components, necessitating diverse transducer types, excitation modes, and advanced signal processing. To improve ECNDT, this article explores integrating harmonic and impulse excitation modes in a single tool to enhance informativeness. Building upon a wireless eddy current system, the authors propose a comprehensive method for processing and displaying information suitable for object condition monitoring systems. The system includes automated transducer mode control and experimental data processing algorithms. The constant expansion of tested objects and new materials underscores the need to enhance the theoretical foundations of eddy current non-destructive testing, refine signal processing techniques, and identify informative signs. This demands the development of new automated ECNDT tools, and this article offers a promising avenue for improvement. The results include model and experimental tests of system components, showcasing the potential of this approach to enhance ECNDT effectiveness, automation, and informativeness in the realm of aircraft part diagnostics.
Źródło:
Transactions on Aerospace Research; 2023, 4 (273); 33-40
0509-6669
2545-2835
Pojawia się w:
Transactions on Aerospace Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Closed loop ĈUK topology based single phase high performance AC-DC converter
Autorzy:
Hossain, Ismail
Alam, Mohammad Jahangir
Powiązania:
https://bibliotekanauki.pl/articles/41188229.pdf
Data publikacji:
2023
Wydawca:
Politechnika Warszawska, Instytut Techniki Cieplnej
Tematy:
PWM
state space averaging technique
small signal model
Ĉuk topology
voltage loop and current loop
korekcja współczynnika mocy
model małosygnałowy
napięcie
Opis:
This paper focuses on the analysis of a power factor correction (PFC) converter using close loop Ĉuk topology. Regardless of the input line voltage and output load variations, input current drawn by the buck or buck-boost converter is always discontinuous. The Boost converter suffers from high voltage stresses across the power electronic devices. The input current in Ĉuk converter is comparable to boost converter’s input current. In this paper output voltage is controlled by inner current and outer voltage control loop along with power factor correction (PFC). It shows less input current THD (less than 5%), nearly unity power factor and better output voltage regulation of AC-DC converter under variable input voltage and output load. Small signal model analysis is presented for obtaining frequency response of the control loop. The MATLAB Simulink programming environment is used as a simulation tool.
Źródło:
Journal of Power Technologies; 2023, 103, 3; 138-145
1425-1353
Pojawia się w:
Journal of Power Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computation of electromagnetic forces in the windings of amorphous core transformers
Autorzy:
Thanh, Bao Doan
Tung, Doan Duc
Le, Tuan-Ho
Powiązania:
https://bibliotekanauki.pl/articles/24202732.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
amorphous transformer
electromagnetic force
leakage flux
magnetic vector potential formulation
short-circuit current
Opis:
Electromagnetic forces generated by the short circuit current and leakage flux in low- and high-voltage windings of distribution transformers as well as amorphous core transformers will cause the translation, destruction, and explosion of the windings. Thus, the investigation of these forces plays a significant role for researchers and manufacturers. Many authors have recently used the finite element method to analyze electromagnetic forces. In this paper, an analytic model is first developed for magnetic vector potential formulations to compute the electromagnetic forces (i.e., axial and radial forces) acting on the low- and high-voltage windings of an amorphous core transformer. The finite element technique is then presented to validate the results obtained from the analytical model. The developed model is applied to an actual problem.
Źródło:
Archives of Electrical Engineering; 2023, 72, 2; 521--539
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Current economic situation in the Republic of Poland
Obecna sytuacja ekonomiczna w Polsce
Autorzy:
Kawęcki, Norbert
Powiązania:
https://bibliotekanauki.pl/articles/23050809.pdf
Data publikacji:
2023-03-20
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
makroekonomia
Rzeczpospolita Polska
obecna sytuacja ekonomiczna
macroeconomy
Republic of Poland
current economic situation
Opis:
The priorities for next years are structural reforms (OECD, 2021): • education and skills: promote participation in lifelong learning; • labor market: increase the labor force participation rate of older workers and women; • environmental policy: reduce air pollution levels and carbon emissions; • healthcare: improve efficiency in health and long-term care; • competition and regulation: ease business regulations and improve bankruptcy proceedings. Recommendation for business policy for coming years in Poland should take following aspects under consideration: ensuring the coherence of fiscal and monetary policies (the so-called policy mix) and restoring credibility each of these policies, stabilization of public finances, strengthening free market approach in the economy, launching KPO, stimulating investments, including energy transformation, the independence of banks from politics. It has been shown the following threats for Polish economy: inflation, energy price rise, conflict between Russia and Ukraine, COVID-19, lower consumption, rising unemployment. To protect and to help Polish economy should take under consideration many different aspects in wide understanding areas in fiscal and macroeconomic policy. Cooperation of all institutions with government should be considered to pick up the best options to protect the Polish economy.
Priorytetami na najbliższe lata są reformy strukturalne (OECD, 2021): • wykształcenie i umiejętności: promowanie uczestnictwa w uczeniu się przez całe życie; • rynek pracy: zwiększenie wskaźnika aktywności zawodowej starszych pracowników i kobiet; • polityka środowiskowa: zmniejszenie poziomu zanieczyszczenia powietrza i emisji dwutlenku węgla; • opieka zdrowotna: poprawa efektywności opieki zdrowotnej i długoterminowej; • konkurencja i regulacje: złagodzenie przepisów biznesowych i usprawnienie postępowań upadłościowych. Rekomendacja dla polityki gospodarczej w Polsce na najbliższe lata powinna uwzględniać następujące aspekty: zapewnienie spójności polityki fiskalnej i monetarnej (tzw. policy mix) oraz przywrócenie wiarygodności każdej z tych polityk, stabilizacja finansów publicznych, wzmocnienie wolnorynkowego podejścia w gospodarce, uruchamianie KPO, pobudzanie inwestycji, w tym transformacja energetyczna, niezależność banków od polityki. Wskazano na następujące zagrożenia dla polskiej gospodarki: inflacja, wzrost cen energii, konflikt między Rosją a Ukrainą, COVID-19, mniejsza konsumpcja, rosnące bezrobocie. Aby chronić polską gospodarkę i jej pomagać, powinno się uwzględniać wiele różnych aspektów w szeroko rozumianych obszarach polityki fiskalnej i makroekonomicznej. Trzeba rozważyć współpracę wszystkich instytucji z rządem w celu wybrania najlepszych opcji ochrony polskiej gospodarki. Należy wskazać zatem na współpracę środowiska akademickiego ze środowiskiem politycznym w celu wybrania najlepszej opcji gospodarczej w zaistniałej sytuacji.
Źródło:
Nowoczesne Systemy Zarządzania; 2023, 18, 1; 95-102
1896-9380
2719-860X
Pojawia się w:
Nowoczesne Systemy Zarządzania
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Current ripple reduction for finite control set model predictive control strategy of grid-tied inverter with reference current compensation
Autorzy:
Jin, Nan
Fan, Wuchuang
Fang, Jie
Wu, Jie
Shen, Yongpeng
Powiązania:
https://bibliotekanauki.pl/articles/2202542.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
cost function
current ripple reduction
finite control set model predictive control
FCS-MPC
grid-tied inverter
reference current compensation
RCC
Opis:
In the finite control set model predictive control (FCS-MPC) strategy of the grid-tied inverter, the current ripple (CR) affects the selection of optimal voltage vectors, which leads to the increase of output current ripples. In order to solve this problem, this paper proposes a CR reduction method based on reference current compensation (RCC) for the FCS-MPC strategy of grid-tied inverters. Firstly, the influence of the CR on optimal voltage vector selection is analyzed. The conventional CR prediction method is improved, which uses inverter output voltage and grid voltage to calculate current ripples based on the space state equation. It makes up for the shortcomings that the conventional CR prediction method cannot predict in some switching states. The improved CR method is more suitable for the FCS-MPC strategy. In addition, the differences between the two cost functions are compared through visual analysis. It is found that the sensitivity of the square cost function to small errors is better than that of the absolute value function. Finally, the predicted CR is used to compensate the reference current. The compensated reference current is substituted into the square cost function to reduce the CR. The experimental results show that the proposed method reduces the CR by 47.3%. The total harmonic distortion (THD) of output current is reduced from 3.86% to 2.96%.
Źródło:
Archives of Electrical Engineering; 2023, 72, 1; 5--22
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 1002

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