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Journal articles on the topic 'Stat space averaging'

Author: Grafiati

Published: 7 June 2025

Last updated: 16 July 2025

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1

Tahri, Ghrissi, Fatima Tahri, and Ali Tahri. "Fractional order PID controller design of a DC-DC multilevel boost converter using the Nelder-Mead optimization." International Journal of Power Electronics and Drive Systems (IJPEDS) 15, no. 4 (2024): 2409–21. https://doi.org/10.11591/ijpeds.v15.i4.pp2409-2421.

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This paper aims to present and analyze the fractional order proportional-integral-derivative (FOPID) control technique of the DC-DC two-level boost converter. The state-space averaged (SSA) method is used to build a small-signal converter mathematical model, which is a crucial task for the control design. A FOPID controller based on the Nelder-Mead optimization algorithm and an artificial intelligence strategy based on a fuzzy logic controller (FLC) are both designed for the voltage mode control (VMC) approach and operate on the continuous conduction mode (CCM). Various step changes in the input voltage amplitude and output load are applied to analyze the performance of the proposed control techniques. In addition, detailed simulation results using the MATLAB-Simulink system are extensively discussed.

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Batlle, Carles, Enric Fossas, Robert Griñó, and Sonia Martínez. "GENERALIZED STATE SPACE AVERAGING FOR PORT CONTROLLED HAMILTONIAN SYSTEMS." IFAC Proceedings Volumes 38, no. 1 (2005): 836–41. http://dx.doi.org/10.3182/20050703-6-cz-1902.00795.

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3

Pfau, Bastian, Thomas Breunung, Fadi Dohnal, and Richard Markert. "Averaging in Parametrically Excited Systems – A State Space Formulation." MATEC Web of Conferences 83 (2016): 05008. http://dx.doi.org/10.1051/matecconf/20168305008.

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4

Witulski, A. F., and R. W. Erickson. "Extension of state-space averaging to resonant switches and beyond." IEEE Transactions on Power Electronics 5, no. 1 (1990): 98–109. http://dx.doi.org/10.1109/63.46004.

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5

Tamilarasi, M., and R. Seyezhai. "State Space Averaged Modeling and Power Loss Computations for Fuel Cell Powered Four-Phase Interleaved Boost Converter." Advanced Materials Research 984-985 (July 2014): 1037–45. http://dx.doi.org/10.4028/www.scientific.net/amr.984-985.1037.

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This paper investigates the state space averaging of a four-phase Interleaved Boost Converter (IBC) powered by fuel cells. The state space averaging technique is a method to model the converter as time independent which is defined by a set of differential equations which will be useful for designing the controllers [18]. In this paper, mathematical models developed using state space averaging technique are presented for the proposed IBC. The power loss calculations are also computed. Simulation of IBC with fuel cell as the source is carried out in MATLAB and the results are presented and discussed.

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6

Iwata, Akihiko, Yoichiro Tabata, and Shigeo Ueguri. "Analysis of asymmetrical magnetization of transformer by state-space averaging method." IEEJ Transactions on Industry Applications 108, no. 6 (1988): 557–64. http://dx.doi.org/10.1541/ieejias.108.557.

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7

Avinash, Kumar. "MODELLING AND SIMULATION OF FULL-BRIDGE SERIES RESONANT CONVERTER BASED ON GENERALIZED STATE SPACE AVERAGING." GLOBAL JOURNAL OF ENGINEERING SCIENCE AND RESEARCHES 4, no. 12 (2017): 49–56. https://doi.org/10.5281/zenodo.1117672.

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The resonant converters have advantages for high power or high frequency power conversion. The small signal modeling technique based on the generalized state space averaging method is applied to full-bridge series resonant DC/DC converter. According to the simulation, the open loop frequency characteristic curve is obtained from MATLAB, this paper analyzes the influence of duty ratio, input voltage to frequency characteristics, then build a close loop simulation circuit with MATLAB, the simulation results shows that, the small signal model has good controllability, generalized state space averaging method is more accurate to series resonant converter modeling.The equivalent circuit model can predict the dynamic behavior very well when switching frequency is below, close to or above resonant frequency.  

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8

Wang, Ping, Can Liu, and Lin Guo. "Modeling and Simulation of Full-Bridge Series Resonant Converter Based on Generalized State Space Averaging." Applied Mechanics and Materials 347-350 (August 2013): 1828–32. http://dx.doi.org/10.4028/www.scientific.net/amm.347-350.1828.

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The small signal modeling technique based on the generalized state space averaging method is applied to single phase full-bridge resonant DC/DC converter .According to the simulation, the frequency characteristic curve is obtained from MATLAB, this paper analyzes the influence of the duty ratio, input voltage to frequency characteristics, then builds a closed loop simulation circuit with PSIM software, the simulation results show that, the small signal model has good controllability and anti disturbance resistance, generalized state space averaging method is more accurate to series resonant converter modeling.

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9

Mahdavi, J., A. Emaadi, M. D. Bellar, and M. Ehsani. "Analysis of power electronic converters using the generalized state-space averaging approach." IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications 44, no. 8 (1997): 767–70. http://dx.doi.org/10.1109/81.611275.

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10

Jianping Xu and C. Q. Lee. "Generalized state-space averaging approach for a class of periodically switched networks." IEEE Transactions on Circuits and Systems I: Fundamental Theory and Applications 44, no. 11 (1997): 1078–81. http://dx.doi.org/10.1109/81.641772.

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11

Green, A. W. "Modelling a push—pull parallel resonant convertor using generalised state-space averaging." IEE Proceedings B Electric Power Applications 140, no. 6 (1993): 350. http://dx.doi.org/10.1049/ip-b.1993.0045.

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12

Rudenko, Yu V. "FEATURES OF CALCULATION OF SEMICONDUCTOR VOLTAGE CONVERTERS BASED ON STATE SPACE AVERAGING." Praci Institutu elektrodinamiki Nacionalanoi akademii nauk Ukraini 2020, no. 56 (2020): 64–71. http://dx.doi.org/10.15407/publishing2020.56.064.

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13

Nonejad, Nima. "Predicting equity premium using dynamic model averaging. Does the state–space representation matter?" North American Journal of Economics and Finance 57 (July 2021): 101442. http://dx.doi.org/10.1016/j.najef.2021.101442.

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14

Sun, Zhenchuan, and Jiasheng Zhang. "A New Modeling and Analysis Approach Based on State-Space Averaging for Converters." International Journal of Smart Home 10, no. 10 (2016): 259–70. http://dx.doi.org/10.14257/ijsh.2016.10.10.24.

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15

Bekir Yildiz, Ali. "Large-signal analysis of DC motor drive system using state-space averaging technique." Energy Conversion and Management 49, no. 11 (2008): 3069–74. http://dx.doi.org/10.1016/j.enconman.2008.06.001.

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16

Smith, Matthew C. "The sensitivity of stellar feedback to IMF averaging versus IMF sampling in galaxy formation simulations." Monthly Notices of the Royal Astronomical Society 502, no. 4 (2021): 5417–37. http://dx.doi.org/10.1093/mnras/stab291.

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ABSTRACT Galaxy formation simulations frequently use initial mass function (IMF) averaged feedback prescriptions, where star particles are assumed to represent single stellar populations that fully sample the IMF. This approximation breaks down at high mass resolution, where stochastic variations in stellar populations become important. We discuss various schemes to populate star particles with stellar masses explicitly sampled from the IMF. We use Monte Carlo numerical experiments to examine the ability of the schemes to reproduce an input IMF in an unbiased manner while conserving mass. We present our preferred scheme which can easily be added to pre-existing star formation prescriptions. We then carry out a series of high-resolution isolated simulations of dwarf galaxies with supernovae (SNe), photoionization, and photoelectric heating to compare the differences between using IMF averaged feedback and explicitly sampling the IMF. We find that if SNe are the only form of feedback, triggering individual SNe from IMF averaged rates gives identical results to IMF sampling. However, we find that photoionization is more effective at regulating star formation when IMF averaged rates are used, creating more, smaller H ii regions than the rare, bright sources produced by IMF sampling. We note that the increased efficiency of the IMF averaged feedback versus IMF sampling is not necessarily a general trend and may be reversed depending on feedback channel, resolution and other details. However, IMF sampling is always the more physically motivated approach. We conservatively suggest that it should be used for star particles less massive than $\sim 500\, \mathrm{M_\odot }$.

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17

Jamri. "Modeling and Control of a Photovoltaic Energy System Using the State-Space Averaging Technique." American Journal of Applied Sciences 7, no. 5 (2010): 682–91. http://dx.doi.org/10.3844/ajassp.2010.682.691.

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18

Ebrahimi, Hadi, and Hassan El-Kishky. "A novel Generalized State-Space Averaging (GSSA) model for advanced aircraft electric power systems." Energy Conversion and Management 89 (January 2015): 507–24. http://dx.doi.org/10.1016/j.enconman.2014.10.014.

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19

Shete, Sangeeta, and Prasad Joshi. "Comparative study of state space averaging and PWM with extra element theorem techniques for complex cascaded DC-DC Buck converter." Acta Polytechnica 63, no. 1 (2023): 50–64. http://dx.doi.org/10.14311/ap.2023.63.0050.

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Until now, most commonly used state space averaging and PWM techniques have been applied to different converter topologies and their advantages and disadvantages were stated. However, the superiority of an analytical technique was not justified based on a parametric comparison of these techniques for the same converter topology. Hence, in this paper, first time a comparative evaluation of two commonly used modelling techniques for fourth order converter is presented. The first approach makes use of a state-space averaging of the converter and is based on analytical manipulations using different state representations of the converter. The second approach is based on PWM switch modelling with an extra element theorem and consists of topological manipulations. The two modelling techniques are applied to the same complex cascaded DC-DC Buck converter and a transfer function is obtained. These techniques are compared for different features and the study concludes that state space modelling technique is systematic and less complicated than PWM switch modelling with an extra element theorem for a higher order converter.

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20

Ngamkong, Phurich, Pijit Kochcha, Kongpan Areerak, Sarawut Sujitjorn, and Kongpol Areerak. "Applications of the generalized state-space averaging method to modelling of DC–DC power converters." Mathematical and Computer Modelling of Dynamical Systems 18, no. 3 (2012): 243–60. http://dx.doi.org/10.1080/13873954.2011.635377.

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21

Tsuda, Yuichi, and Daniel J. Scheeres. "State Transition Matrix Approximation Using a Generalized Averaging Method." Journal of Guidance, Control, and Dynamics 32, no. 6 (2009): 1781–94. http://dx.doi.org/10.2514/1.44142.

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22

Korotyeyev, Igor. "Steady-state analysis of DC converter using Galerkin’s method." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 38, no. 6 (2019): 2057–69. http://dx.doi.org/10.1108/compel-02-2019-0062.

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Purpose The purpose of this paper is to present the Galerkin method for analysis of steady-state processes in periodically time-varying circuits. Design/methodology/approach A converter circuit working on a time-varying load is often controlled by different signals. In the case of incommensurable frequencies, one can find a steady-state process only via calculation of a transient process. As the obtained results will not be periodical, one must repeat this procedure to calculate the steady-state process on a different time interval. The proposed methodology is based on the expansion of ordinary differential equations with one time variable into a domain of two independent variables of time. In this case, the steady-state process will be periodical. This process is calculated by the use of the Galerkin method with bases and weight functions in the form of the double Fourier series. Findings Expansion of differential equations and use of the Galerkin method enable discovery of the steady-state processes in converter circuits. Steady-state processes in the circuits of buck and boost converters are calculated and results are compared with numerical and generalized state-space averaging methods. Originality/value The Galerkin method is used to find a steady-state process in a converter circuit with a time-varying load. Processes in such a load depend on two incommensurable signals. The state-space averaging method is generalized for extended differential equations. A balance of active power for extended equations is shown.

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23

Mei, Yan. "Study on Sliding Mode Control in Bidirectional DC/DC Converter Based on State Space Averaging Method." Applied Mechanics and Materials 678 (October 2014): 399–405. http://dx.doi.org/10.4028/www.scientific.net/amm.678.399.

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Bidirectional DC/DC converter is used for the battery charging and discharging. The sliding mode controller based on state space averaging algorithm is used for controlling bidirectional DC/DC converter. Two kinds of working modes, buck mode and boost mode, have been analyzed and three kinds of working states which are consisted by two working modes have been deeply discussed, and the automatic switch logic diagram when battery charging and discharging through the bidirectional DC/DC converter has been presented. Situation of system based on S1, S2 conducting alternately has been studied, and the simulations were also presented. According to the results, the characteristics of good stability and transient can be confirmed.

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24

Emadi, A. "Modeling and Analysis of Multiconverter DC Power Electronic Systems Using the Generalized State-Space Averaging Method." IEEE Transactions on Industrial Electronics 51, no. 3 (2004): 661–68. http://dx.doi.org/10.1109/tie.2004.825339.

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25

Emadi, A. "Modeling of Power Electronic Loads in AC Distribution Systems Using the Generalized State-Space Averaging Method." IEEE Transactions on Industrial Electronics 51, no. 5 (2004): 992–1000. http://dx.doi.org/10.1109/tie.2004.834950.

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26

Bai, Lei, and Jin-Yong Bae. "A Study on the Modeling of Flyback Converter for LED Power Based on State-space Averaging." Journal of Power System Engineering 27, no. 3 (2023): 57–70. http://dx.doi.org/10.9726/kspse.2023.27.3.057.

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27

Hani, Maan H., Christopher C. Hayward, Matthew E. Orr, et al. "Variations in the slope of the resolved star-forming main sequence: a tool for constraining the mass of star-forming regions." Monthly Notices of the Royal Astronomical Society: Letters 493, no. 1 (2020): L87—L91. http://dx.doi.org/10.1093/mnrasl/slaa013.

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ABSTRACT The correlation between galaxies’ integrated stellar masses and star formation rates (the ‘star formation main sequence’, SFMS) is a well-established scaling relation. Recently, surveys have found a relationship between the star formation rate (SFR) and stellar mass surface densities on kpc and sub-kpc scales (the ‘resolved SFMS’, rSFMS). In this work, we demonstrate that the rSFMS emerges naturally in Feedback In Realistic Environments 2 (FIRE-2) zoom-in simulations of Milky Way-mass galaxies. We make SFR and stellar mass maps of the simulated galaxies at a variety of spatial resolutions and star formation averaging time-scales and fit the rSFMS using multiple methods from the literature. While the absolute value of the SFMS slope (αMS) depends on the fitting method, the slope is steeper for longer star formation time-scales and lower spatial resolutions regardless of the fitting method employed. We present a toy model that quantitatively captures the dependence of the simulated galaxies’ αMS on spatial resolution and use it to illustrate how this dependence can be used to constrain the characteristic mass of star-forming clumps.

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28

Rudenko, Yu V. "MODELING OF PROCESSES ON THE BASIS OF STATE SPACE AVERAGING IN BOOST CONVERTER WITH MAGNETICALLY COUPLED ELEMENTS." Praci Institutu elektrodinamiki Nacionalanoi akademii nauk Ukraini 2021, no. 58 (2021): 44–54. http://dx.doi.org/10.15407/publishing2021.58.044.

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The features of the state-space average method using Lagrange's theorems for calculation of processes in the boost converter with magnetically coupled elements (with autotransformer connection of inductors) in continuous currents mode are considered. A mathematical model of the converter based on relative variables has been developed, which makes it possible to calculate processes in a wide range of parameters taking into account the degree of magnetic coupling between inductive elements, including the definition of constant and pulsating components. It is shown that to obtain a complete system of the algebraic equations as a mathematical model of converters, which provides its single solution, it is advisable to additionally use the ratio according to energy balance in reactive elements in a steady state at the operation intervals of the converter during commutation period. The boundary dependences of boost converter parameters with magnetically coupled elements between the modes of discontinuous and continuous currents are calculated. The relative characteristics of the converter have been studied, which demonstrate the influence of imperfection of the magnetic coupling in the regulation zone of the relative duration value of switching interval. Ref. 21, fig. 6.

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29

Wang, Lei, Xinchang Deng, Pingping Han, et al. "Electromagnetic Transient Modeling and Simulation of Power Converters Based on a Piecewise Generalized State Space Averaging Method." IEEE Access 7 (2019): 12241–51. http://dx.doi.org/10.1109/access.2019.2891122.

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30

Mahdavi, J., M. R. Nasiri, A. Agah, and A. Emadi. "Application of Neural Networks and State-Space Averaging to DC/DC PWM Converters in Sliding-Mode Operation." IEEE/ASME Transactions on Mechatronics 10, no. 1 (2005): 60–67. http://dx.doi.org/10.1109/tmech.2004.842227.

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31

Wang, Lei, Xinchang Deng, Junxian Hou, and Tiezhu Wang. "Electromagnetic transient modelling and simulation of power converters based on a piecewise generalised state–space averaging method." Journal of Engineering 2019, no. 16 (2019): 1607–14. http://dx.doi.org/10.1049/joe.2018.8621.

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32

Al-Hattami, Ahmed, Shakir Saat, Yusmarnita Yusop, Md Rabiul Awal, A. H. M. Shapri, and Huzaimah Husin. "Enhancing efficiency and stability in CPT systems: a state feedback controller approach." International Journal of Power Electronics and Drive Systems 16, no. 1 (2025): 225–34. https://doi.org/10.11591/ijpeds.v16.i1.pp225-234.

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This work aims to present an innovative design and simulation of an auto-tuning capacitive power transfer (CPT) system. The system utilizes a Class-E converter, renowned for its exceptional efficiency. Challenges arise when trying to regulate the output voltage of a Class-E converter in the presence of load fluctuations, leading to an escalation in switching losses. By employing first harmonic approximation (FHA) and generalized state space averaging (GSSA), a state-space model of the system is constructed to effectively address this problem. The output voltage is regulated by a state feedback controller developed using the Lyapunov approach. This paper presents a comparative analysis of a traditional PID controller and a recently suggested state feedback controller, with a primary emphasis on system stabilization. The study examines the similarities and differences between the two controllers. The efficacy of the proposed controller design is demonstrated through the utilization of simulation data. Furthermore, these results confirm the validity of the comparative study, making it a substantial contribution to the field of CPT systems.

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Eko, Setiawan, Hirata Takuya, and Hodaka Ichijo. "Accurate Symbolic Steady State Modeling of Buck Converter." International Journal of Electrical and Computer Engineering (IJECE) 7, no. 5 (2017): 2374–81. https://doi.org/10.11591/ijece.v7i5.pp2374-2381.

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Steady state analysis is fundamental to any electric and electronic circuit design. Buck converter is one of most popular power electronics circuit and has been analyzed in various situations. Although the behavior of buck converters can be understood approximately by the well-known state space averaging method, little is known in the sense of detailed behavior or exact solution to equations. In this paper a steady state analysis of buck converter is proposed which allows the exact calculation of steady state response. Our exact solution is expressed as a Fourier series. Our result is compared with numerical calculation to be verified. Our method copes with more complicated problems such as describing average power and root-mean-square power that are most critical issues in power electronics circuit.

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MENDAŠ, ISTOK. "CLASSIFICATION OF DENSITY MATRICES FOR A FOUR-STATE SYSTEM." International Journal of Quantum Information 07, no. 01 (2009): 323–48. http://dx.doi.org/10.1142/s0219749909004682.

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Properties and structure of the 15-dimensional parameter space of four-state density matrices are examined using the SU(4) generator expansion. Appropriate classification of one-, two- and three-parameter density matrices is obtained, based on the sameness of the characteristic polynomial of density matrices belonging to a given type. It is found that in the one parameter case of 15 different density matrices only three distinct types exist, while in the two parameter case 105 different density matrices group into 11 distinct types. In the three parameter case appropriate classification of 455 different density matrices into 44 types is determined. Two- and three-dimensional cross sections of the space of generalized Bloch vectors are illustrated by randomly drawing matrices for several types of density matrices, providing some insight into the intricate and complex structure of the space of density matrices for a four-state system. Positions of the representative points corresponding to the pure states are found for all types. Global properties of observables are determined by generating, by the Monte Carlo sampling method, and averaging over nearly all density matrices pertaining to a given type.

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Wei, Lingfeng, Smadar Naoz, Thea Faridani, and Will M. Farr. "Relativistic Dynamical Stability Criterion of Multiplanet Systems with a Distant Companion." Astrophysical Journal 923, no. 1 (2021): 118. http://dx.doi.org/10.3847/1538-4357/ac2c70.

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Abstract Multiplanetary systems are prevalent in our Galaxy. The long-term stability of such systems may be disrupted if a distant inclined companion excites the eccentricity and inclination of the inner planets via the eccentric Kozai–Lidov mechanism. However, the star–planet and the planet–planet interactions can help stabilize the system. In this work, we extend the previous stability criterion that only considered the companion–planet and planet–planet interactions by also accounting for short-range forces or effects, specifically, relativistic precession induced by the host star. A general analytical stability criterion is developed for planetary systems with N inner planets and a relatively distant inclined perturber by comparing precession rates of relevant dynamical effects. Furthermore, we demonstrate as examples that in systems with two and three inner planets, the analytical criterion is consistent with numerical simulations using a combination of Gauss’s averaging method and direct N-body integration. Finally, the criterion is applied to observed systems, constraining the orbital parameter space of a possible undiscovered companion. This new stability criterion extends the parameter space in which an inclined companion of multiplanet systems can inhabit.

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Millar, Russell B., and Renate Meyer. "Bayesian state-space modeling of age-structured data: fitting a model is just the beginning." Canadian Journal of Fisheries and Aquatic Sciences 57, no. 1 (2000): 43–50. http://dx.doi.org/10.1139/f99-169.

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Explicit modeling of process variability in the dynamics of fisheries is motivated by a desire to incorporate more realism into stock assessment models, and much recent research effort has been devoted to the computational features of fitting state-space models for this purpose. Here, we extend the Bayesian application of nonlinear state-space modeling to sequential population analysis of age-structured data using a model formulation that allows for unreported catches and incidental fishing mortality. It is shown that, once a familiarity with the general-purpose Bayesian software BUGS is acquired, implementing a state-space model is a relatively simple task. Indeed, this application requires just 18 lines of code in its entirety and does not require the programmer to know the formulae for any prior density functions or likelihoods. Consequently, we suggest that this methodology may permit the implementation phase of nonlinear state-space modeling to be relegated, thereby allowing more effort to be devoted to the challenging issues of model checking, selection/averaging, sensitivity, and prior specification.

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Brett, Carlton E., Patrick I. McLauglin, and Gordon C. Baird. "Eo-Ulrichian to Neo-Ulrichian views: The renaissance of "layer-cake stratigraphy"." Stratigraphy 4, no. 2-3 (2007): 201–15. http://dx.doi.org/10.29041/strat.04.2.14.

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Classical notions of “layer-cake stratigraphy" have been denigrated as representing an antiquated “Neptunian" view of the geologic record with the American paleontologist-stratigrapher E.O. Ulrich vilified as its quintessential advocate. Some of the extreme “layer-cake" interpretations of E.O. Ulrich are demonstrably incorrect, especially where applied in marginal marine and terrestrial settings. However, close scrutiny of Ulrich’s work suggests that the bulk was correct and demonstrated considerable insight for the time. Subsequent development of facies concepts revolutionized geologists’ view of time-space relationships in stratigraphy, but rather than focusing on facies patterns within the established stratigraphic (layer-cake) frameworks many geologists in North America came to view strata as parts of diachronous facies mosaics. Recent advances in the development of event and sequence stratigraphic paradigms are beginning to swing the pendulum back the other way. Possible causes of “layer-cake" patterns are numerous and varied, including: (1) parallelism of depositional strike and outcrop belts, especially in foreland basins, (2) very widespread environmental belts developed in low-relief cratonic areas, (3) time-averaging homogenizes facies to a limited extent, resulting in a very subtle signature of lateral change, (4) condensed beds (hardgrounds, bone beds, ironstones, etc.) often form in responses to extrabasinal forces, thus they cross-cut facies, and (5) large events (i.e. hurricanes, floods, tsunamis, eruptions, etc.) are “over represented" in the rock record. A revised (“Neo-Ulrichian") layer-cake paradigm carries many of the original correct empirical observations of pattern, noted by Ulrich, recast in terms of event and sequence stratigraphy.

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38

Herbst, Gernot. "A Building-Block Approach to State-Space Modeling of DC-DC Converter Systems." J 2, no. 3 (2019): 247–67. http://dx.doi.org/10.3390/j2030018.

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Small-signal models of DC-DC converters are often based on a state-space averaging approach, from which both control-oriented and other frequency-domain characteristics, such as input or output impedance, can be derived. Updating these models when extending the converter by filters or non-trivial loads, or adding control loops, can become a tedious task, however. To simplify this potentially error-prone process, a modular modeling approach is being proposed in this article. It consists of small state-space models for certain building blocks of a converter system on the one hand, and standardized operations for connecting these subsystem models to an overall converter system model on the other hand. The resulting state-space system model builds upon a two-port converter description and allows the extraction of control-oriented and impedance characteristics at any modeling stage, be it open loop or closed loop, single converter or series connections of converters. The ease of creating more complex models enabled by the proposed approach is also demonstrated with examples comprising multiple control loops or cascaded converters.

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39

Gujrati, Purushottam Das. "Foundations of Nonequilibrium Statistical Mechanics in Extended State Space." Foundations 3, no. 3 (2023): 419–548. http://dx.doi.org/10.3390/foundations3030030.

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The review provides a pedagogical but comprehensive introduction to the foundations of a recently proposed statistical mechanics (μNEQT) of a stable nonequilibrium thermodynamic body, which may be either isolated or interacting. It is an extension of the well-established equilibrium statistical mechanics by considering microstates mk in an extended state space in which macrostates (obtained by ensemble averaging A^) are uniquely specified so they share many properties of stable equilibrium macrostates. The extension requires an appropriate extended state space, three distinct infinitessimals dα=(d,de,di) operating on various quantities q during a process, and the concept of reduction. The mechanical process quantities (no stochasticity) like macrowork are given by A^dαq, but the stochastic quantities C^αq like macroheat emerge from the commutator C^α of dα and A^. Under the very common assumptions of quasi-additivity and quasi-independence, exchange microquantities deqk such as exchange microwork and microheat become nonfluctuating over mk as will be explained, a fact that does not seem to have been appreciated so far in diverse branches of modern statistical thermodynamics (fluctuation theorems, quantum thermodynamics, stochastic thermodynamics, etc.) that all use exchange quantities. In contrast, dqk and diqk are always fluctuating. There is no analog of the first law for a microstate as the latter is a purely mechanical construct. The second law emerges as a consequence of the stability of the system, and cannot be violated unless stability is abandoned. There is also an important thermodynamic identity diQ≡diW≥0 with important physical implications as it generalizes the well-known result of Count Rumford and the Gouy-Stodola theorem of classical thermodynamics. The μNEQT has far-reaching consequences with new results, and presents a new understanding of thermodynamics even of an isolated system at the microstate level, which has been an unsolved problem. We end the review by applying it to three different problems of fundamental interest.

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Dahmer-Hahn, L. G., R. Riffel, A. Rodríguez-Ardila, et al. "Stellar populations in local AGNs: evidence for enhanced star formation in the inner 100 pc." Monthly Notices of the Royal Astronomical Society 509, no. 3 (2021): 4653–68. http://dx.doi.org/10.1093/mnras/stab3382.

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ABSTRACT In modern models and simulations of galactic evolution, the star formation in massive galaxies is regulated by an ad hoc active galactic nuclei (AGN) feedback process. However, the physics and the extension of such effects on the star formation history of galaxies is matter of vivid debate. In order to shed some light in the AGN effects over the star formation, we analysed the inner 500 × 500 pc of a sample of 14 Seyfert galaxies using GMOS and MUSE integral field spectroscopy. We fitted the continuum spectra in order to derive stellar age, metallicity, velocity, and velocity dispersion maps in each source. After stacking our sample and averaging their properties, we found that the contribution of young SP, as well as that of AGN featureless continuum both peak at the nucleus. The fraction of intermediate-age SPs is smaller in the nucleus if compared to outer regions, and the contribution of old SPs vary very little within our field of view (FoV). We also found no variation of velocity dispersion or metallicity within our FoV. Lastly, we detected an increase in the dust reddening towards the center of the galaxies. These results lead us to conclude that AGN phenomenon is usually related to a recent star formation episode in the circumnuclear region.

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Klein, Ygal Y., and Boaz Katz. "Analytic Understanding of the Resonant Nature of Kozai–Lidov Cycles with a Precessing Quadrupole Potential." Astrophysical Journal Letters 953, no. 1 (2023): L10. http://dx.doi.org/10.3847/2041-8213/aceae7.

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Abstract The very long-term evolution of the hierarchical restricted three-body problem with a slightly aligned precessing quadrupole potential is studied analytically. This problem describes the evolution of a star and a planet that are perturbed either by a (circular and not too inclined) binary star system or by one other star and a second more distant star, as well as a perturbation by one distant star and the host galaxy or a compact-object binary system orbiting a massive black hole in nonspherical nuclear star clusters. Previous numerical experiments have shown that when the precession frequency is comparable to the Kozai–Lidov timescale, long-term evolution emerges that involves extremely high eccentricities with potential applications for a broad scope of astrophysical phenomena, including systems with merging black holes, neutron stars, or white dwarfs. By averaging the secular equations of motion over the Kozai–Lidov cycles (KLCs), we solve the problem analytically in the neighborhood of the KLC fixed point where the eccentricity vector is close to unity and aligned with the quadrupole axis and for a precession rate similar to the Kozai–Lidov timescale. In this regime the dynamics is dominated by a resonance between the perturbation frequency and the precession frequency of the eccentricity vector. While the quantitative evolution of the system is not reproduced by the solution far away from this fixed point, it sheds light on the qualitative behavior.

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Setiawan, Eko, Takuya Hirata, and Ichijo Hodaka. "Accurate Symbolic Steady State Modeling of Buck Converter." International Journal of Electrical and Computer Engineering (IJECE) 7, no. 5 (2017): 2374. http://dx.doi.org/10.11591/ijece.v7i5.pp2374-2381.

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<p>Steady state analysis is fundamental to any electric and electronic circuit design. Buck converter is one of most popular power electronics circuit and has been analyzed in various situations. Although the behavior of buck converters can be understood approximately by the well-known state space averaging method, little is known in the sense of detailed behavior or exact solution to equations. In this paper a steady state analysis of buck converter is proposed which allows the exact calculation of steady state response. Our exact solution is expressed as a Fourier series. Our result is compared with numerical calculation to be verified. Our method copes with more complicated problems such as describing average power and root-mean-square power that are most critical issues in power electronics circuit.</p>

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Rimmalapudi, Sita R., Sheldon S. Williamson, Adel Nasiri, and Ali Emadi. "Validation of Generalized State Space Averaging Method for Modeling and Simulation of Power Electronic Converters for Renewable Energy Systems." Journal of Electrical Engineering and Technology 2, no. 2 (2007): 231–40. http://dx.doi.org/10.5370/jeet.2007.2.2.231.

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Karabanov, Alexander, Anniek van der Drift, Luke J. Edwards, Ilya Kuprov, and Walter Köckenberger. "Quantum mechanical simulation of solid effect dynamic nuclear polarisation using Krylov–Bogolyubov time averaging and a restricted state-space." Physical Chemistry Chemical Physics 14, no. 8 (2012): 2658. http://dx.doi.org/10.1039/c2cp23233b.

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Fang, Wan, Houjun Tang, and Wei Liu. "Modeling and Analyzing an Inductive Contactless Power Transfer System for Artificial Hearts Using the Generalized State Space Averaging Method." Journal of Computational and Theoretical Nanoscience 4, no. 7 (2007): 1412–16. http://dx.doi.org/10.1166/jctn.2007.2433.

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O., F. Bondarenko, V. Kozhushko Yu., O. Karbivska T., O. Zheliazkov Y., and S. Safronov P. "STABILITY ANALYSIS OF HYBRID ENERGY STORAGE BASED ON SUPERCAPACITOR AND BATTERY." Electrical engineering & electromechanics, no. 5 (October 27, 2020): 31–37. https://doi.org/10.20998/2074-272X.2020.5.05.

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<em>The<strong> aim </strong>of the work is to analyze the stability of the battery-supercapacitor hybrid storage of power supply for resistance micro-welding equipment, considering the possible variation of the system parameters and taking into account parallel series resistance of the circuit components.<strong> Methodology</strong>. The sufficient accurate mathematical model of the hybrid energy storage system to stability analysis has been obtained by the state-space average method. According to the state-space averaging method, PWM switching converters are described by separate circuit topologies for each switching period. The system of differential equations for each time interval has been derived by use of the Kirchhoff rules. The small-signal model transfer function of the SEPIC converter has been obtained by applying the Laplace transform to linear state equations averaged over one switching cycle. Finally, the Nyquist stability criterion has been considered to evaluate the stability of the proposed energy storage system. <strong>Results</strong>. Bode diagrams of an open-loop system for different values of the duty cycle, average load current, and input voltage have been obtained by using MATLAB software. The gain margin ranges from 14.6 dB to 26.4 dB and the phase margin ranges from 45.4 degrees to 54.8 degrees. From these results, it is obvious that the proposed system meets the stability criteria regardless of the aforementioned parameter fluctuations. <strong>Originality</strong>. The high-efficiency energy storage system for micro resistance welding technology has been proposed. Developing of the energy storage system according to the battery semi-active hybrid topology enables to control the Li-ion battery discharge current within the maximum allowable value. SEPIC converter utilization ensures the high-efficient operation of the power supply despite the battery charge state. Moreover, this topology allows implementing series and parallel configuration of both batteries and supercapacitors to obtain the required value of voltage and current. <strong>Practical significance. </strong>The mathematical model of the SEPIC converter has been developed by applying the state-space averaging technique. The stability analysis for parameter variation, such as duty cycle and the average load current, the input voltage has been performed by using Nyquist criteria<strong>. </strong></em>

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Muhammad, Wasif Umar, Yahaya Norzaihar, and Baharudin Zuhairi. "State-space averaged modeling and transfer function derivation of DC-DC boost converter for high-brightness led lighting applications." TELKOMNIKA Telecommunication, Computing, Electronics and Control 17, no. 2 (2019): 1006–13. https://doi.org/10.12928/TELKOMNIKA.v17i2.10272.

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This paper presents dynamic analysis of a boost type DC-DC converter for high-brightness LED (HBLED) driving applications. The steady state operation in presence of all system parasitics has been discussed for continuous conduction mode (CCM). The state-space averaging, energy conservation principle and standard linearization are used to derive ac small signal control to inductor current open-loop transfer function of the converter. The derived transfer function can be further used in designing a robust feed-back control network for the system. In the end frequency and transient responses of the derived transfer function are obtained for a given set of component values, hence to provide a useful guide for control design engineers.

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Al-Hattami, Ahmed, Shakir Saat, Yusmarnita Yusop, Md Rabiul Awal, A. H. M. Shapri, and Huzaimah Husin. "Enhancing efficiency and stability in CPT systems: a state feedback controller approach." International Journal of Power Electronics and Drive Systems (IJPEDS) 16, no. 1 (2025): 225. https://doi.org/10.11591/ijpeds.v16.i1.pp225-234.

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This work aims to present an innovative design and simulation of an auto-tuning capacitive power transfer (CPT) system. The system utilizes a Class-E converter, renowned for its exceptional efficiency. Challenges arise when trying to regulate the output voltage of a Class-E converter in the presence of load fluctuations, leading to an escalation in switching losses. By employing first harmonic approximation (FHA) and generalized state space averaging (GSSA), a state-space model of the system is constructed to effectively address this problem. The output voltage is regulated by a state feedback controller developed using the Lyapunov approach. This paper presents a comparative analysis of a traditional PID controller and a recently suggested state feedback controller, with a primary emphasis on system stabilization. The study examines the similarities and differences between the two controllers. The efficacy of the proposed controller design is demonstrated through the utilization of simulation data. Furthermore, these results confirm the validity of the comparative study, making it a substantial contribution to the field of CPT systems.

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Caplar, Neven, and Sandro Tacchella. "Stochastic modelling of star-formation histories I: the scatter of the star-forming main sequence." Monthly Notices of the Royal Astronomical Society 487, no. 3 (2019): 3845–69. http://dx.doi.org/10.1093/mnras/stz1449.

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ABSTRACT We present a framework for modelling the star-formation histories of galaxies as a stochastic process. We define this stochastic process through a power spectrum density with a functional form of a broken power law. Star-formation histories are correlated on short time-scales, the strength of this correlation described by a power-law slope, α, and they decorrelate to resemble white noise over a time-scale that is proportional to the time-scale of the break in the power spectrum density, τbreak. We use this framework to explore the properties of the stochastic process that, we assume, gives rise to the log-normal scatter about the relationship between star-formation rate and stellar mass, the so-called galaxy star-forming main sequence. Specifically, we show how the measurements of the normalization and width (σMS) of the main sequence, measured in several passbands that probe different time-scales, give a constraint on the parameters of the underlying power spectrum density. We first derive these results analytically for a simplified case where we model observations by averaging over the recent star-formation history. We then run numerical simulations to find results for more realistic observational cases. As a proof of concept, we use observational estimates of the main sequence scatter at z ∼ 0 and M⋆ ≈ 1010 M⊙ measured in H α, UV+IR, and the u-band. The result is degenerate in the τbreak-α space, but if we assume α = 2, we measure $\tau _{\rm break}=170^{+169}_{-85}~\mathrm{Myr}$. This implies that star-formation histories of galaxies lose ‘memory’ of their previous activity on a time-scale of ∼200 Myr.

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Solar, Martín, Patricia B. Tissera, and Jose A. Hernandez-Jimenez. "Azimuthal variations of oxygen abundance profiles in star-forming regions of disc galaxies in EAGLE simulations." Monthly Notices of the Royal Astronomical Society 491, no. 4 (2019): 4894–901. http://dx.doi.org/10.1093/mnras/stz2853.

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ABSTRACT The exploration of the spatial distribution of chemical abundances in star-forming regions of galactic discs can help us to understand the complex interplay of physical processes that regulate the star formation activity and the chemical enrichment across a galaxy. We study the azimuthal variations of the normalized oxygen abundance profiles in the highest numerical resolution run of the Evolution and Assembly of GaLaxies and their Environments (EAGLE) Project at $z$ = 0. We use young stellar populations to trace the abundances of star-forming regions. Oxygen profiles are estimated along different line of sights from a centrally located observer. The mean azimuthal variation in the EAGLE discs are ∼0.12 ± 0.03 dex $R_{\rm eff}^{-1}$ for slopes and ∼0.12 ± 0.03 dex for the zero-points, in agreement with previous works. Metallicity gradients measured along random directions correlate with those determined by averaging over the whole discs, although with a large dispersion. We find a slight trend for higher azimuthal variations in the disc components of low star-forming and bulge-dominated galaxies. We also investigate the metallicity profiles of stellar populations with higher and lower levels of enrichment than the average metallicity profiles, and we find that high star-forming regions with high metallicity tend to have slightly shallower metallicity slopes compared with the overall metallicity gradient. The simulated azimuthal variations in the EAGLE discs are in agreement with observations, although the large variety of metallicity gradients would encourage further exploration of the metal mixing in numerical simulations.

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