Augmented automatic choosing control of filter type for nonlinear systems and its application to power systems

2012 ◽  
Vol 7 (5) ◽  
pp. 502-508
Author(s):  
Hitoshi Takata ◽  
Tomohiro Hachino ◽  
Seiji Motoyama ◽  
Kazutomo Yunokuchi ◽  
Kimihisa Kawabata
Keyword(s):  
Nonlinear Systems ◽  
Power Systems ◽  
Filter Type

scholarly journals Nonlinear Systems of Volterra Equations with Piecewise Smooth Kernels: Numerical Solution and Application for Power Systems Operation

Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1257 ◽  
Author(s):  
Denis Sidorov ◽  
Aleksandr Tynda ◽  
Ildar Muftahov ◽  
Aliona Dreglea ◽  
Fang Liu
Keyword(s):  
Nonlinear Systems ◽  
Power Systems ◽  
Numerical Method ◽  
Storage Systems ◽  
Piecewise Smooth ◽  
Volterra Equations ◽  
Dynamical Models ◽  
Smooth Kernels ◽  
Power Systems Operation ◽  
Real World Problems

The evolutionary integral dynamical models of storage systems are addressed. Such models are based on systems of weakly regular nonlinear Volterra integral equations with piecewise smooth kernels. These equations can have non-unique solutions that depend on free parameters. The objective of this paper was two-fold. First, the iterative numerical method based on the modified Newton–Kantorovich iterative process is proposed for a solution of the nonlinear systems of such weakly regular Volterra equations. Second, the proposed numerical method was tested both on synthetic examples and real world problems related to the dynamic analysis of microgrids with energy storage systems.

scholarly journals Studying State Convergence of Input-to-State Stable Systems with Applications to Power System Analysis

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 92 ◽  
Author(s):  
Antonio T. Alexandridis
Keyword(s):  
Nonlinear Systems ◽  
Power Systems ◽  
Power System ◽  
System Analysis ◽  
Nonlinear Models ◽  
Sufficient Conditions ◽  
Stability And Convergence ◽  
Convergence To Equilibrium ◽  
Analysis Tool ◽  
Wide Range

In stability studies, the response of a system enforced by external, known or unknown, inputs is of great importance. Although such an analysis is quite easy for linear systems, it becomes a cumbersome task when nonlinearities exist in the system model. Nevertheless, most of the real-world systems are externally enforced nonlinear systems with nonzero equilibriums. Representative examples in this category include power systems, where studies on stability and convergence to equilibrium constitute crucial objectives. Driven by this need, the aim of the present work is twofold: First, to substantially complete the theoretical infrastructure by establishing globally valid sufficient conditions for externally enforced nonlinear systems that converge to nonzero equilibriums and, second, to deploy an efficient method easily applicable on practical problems as it is analyzed in detail on a typical power system example. To that end, in the theoretical first part of the paper, a rigorous nonlinear analysis is developed. Particularly, starting from the well-established nonlinear systems theory based on Lyapunov techniques and on the input-to-state stability (ISS) notion, it is proven after a systematic and lengthy analysis that ISS can also guarantee convergence to nonzero equilibrium. Two theorems and two corollaries are established to provide the sufficient conditions. As shown in the paper, the main stability and convergence objectives for externally enforced systems are fulfilled if simple exponential or asymptotic converging conditions can be proven for the unforced system. Then, global or local convergence is established, respectively, while for the latter case, a novel method based on a distance-like measure for determining the region of attraction (RoA) is proposed. The theoretical results are examined on classic power system generation nonlinear models. The power system examples are suitably selected in order to effectively demonstrate the proposed method as a stability analysis tool and to validate all the particular steps, especially that of evaluating the RoA. The examined system results clearly verify the theoretical part, indicating a rather wide range of applications in power systems.

Improving the power factor correction in the presence of harmonics by reducing the effect of resonance and harmonics

2016 ◽  
Vol 3 (2) ◽  
pp. 282
Author(s):  
Saber M. Saleh ◽  
Mohamed E. Arafa
Keyword(s):  
Power Systems ◽  
Power Factor ◽  
Electrical Networks ◽  
Current Harmonics ◽  
In Series ◽  
Filter Type ◽  
Protective Relays ◽  
Tuning Frequency ◽  
Power Factor Improvement ◽  
Voltage Harmonics

Harmonics in electrical networks occur as a result of non-linear loads.  It has an effect on power factor improvement using capacitors in terms of increasing the unbalance current between units. In addition, the occurrence of resonance and result in the exit of capacitors from service by the protective relays to protect the units from collapse. The main objective of this research is the real-time study of improving the power factor with reducing the effect of the resonance and harmonics on the power system. This reduction can be done using filters, consist of reactors and capacitors connected in series or in parallel or series and parallel together to reduce the current harmonics or voltage harmonics. Single Tuned filter type (passive filter) is used which presents very low impedance at the tuning frequency, through which all current of that particular frequency will be diverted. This research presents two practical power systems 11kV source in Fayoum substation and 13.8kV source in New Badr substation connected to power factor Improvement circuit. These models simulated by Matlab at different unbalance currents and harmonics. Also, it presents the design of the series reactor and the harmonics filter which satisfy the minimum effect of resonance and harmonics.

scholarly journals An Augmented Automatic Choosing Control of a Formal Linearization Filter Type for Nonlinear Systems

2014 ◽  
Vol 18 (1) ◽  
pp. 63-70
Author(s):  
Tomohiro Hachino ◽  
Hitoshi Takata ◽  
Soichiro Osako ◽  
Kazutomo Yunokuchi ◽  
Hiromi Miyajima ◽  
...  
Keyword(s):  
Nonlinear Systems ◽  
Filter Type ◽  
Formal Linearization
Sign in / Sign up

Export Citation Format

Share Document