Wyniki wyszukiwania - BazTech

1

Non-linear control of DC-DC converters for battery power management in electric vehicle application

Araria Rabah, Negadi Karim, Boudiaf Mohamed, Marignetti Fabrizio

Przegląd Elektrotechniczny

|

2020

|

R. 96, nr 3

82--88

EN

In this paper, we use two DC/DC boost-buck converters powered a direct current motor. The boost converter ensures an energy flux for an ideal operation of the vehicle even in case of battery voltage drop. The buck converter his role is to controls and drives the electric motor at different operating conditions. To exploit the proposed approach in the automotive field, experimental tests were carried out. The performances obtained show the usefulness of this system for a better energy management of an electric vehicle and an ideal control under different operating conditions, mostly at nominal operation, in the presence of a load torque and even in case of battery chamber failure. The whole system has been tested experimentally using two microcontroller Arduino, We use Lyapunov nonlinear advanced control strategy and its performance has been analysed.

PL

W tym artykule wykorzystujemy dwa przekształtniki DC-DC typu boost-buck do zasilania silnika prądu stałego. Przekształtnik doładowania zapewnia strumień energii dla idealnej pracy pojazdu, nawet w przypadku spadku napięcia akumulatora. Jego rola polega na sterowaniu i zasilaniu silnika elektrycznego w różnych warunkach pracy. Aby wykorzystać proponowane podejście w branży motoryzacyjnej, przeprowadzono testy eksperymentalne. Uzyskane wyniki wskazują na przydatność tego systemu do lepszego zarządzania energią pojazdu elektrycznego i idealnego sterowania w różnych warunkach pracy, głównie przy pracy nominalnej, w obecności momentu obciążenia, a nawet w przypadku awarii celki akumulatora. Cały system został przetestowany eksperymentalnie przy użyciu dwóch mikrokontrolerów Arduino. Używamy nieliniowej zaawansowanej strategii sterowania bazującej na metodzie Lyapunova, a jego działanie zostało zilustrowano i przeanalizowane.

2

Lyapunov function for cosmological dynamical system

Szydłowski M., Krawiec A.

Demonstratio Mathematica

|

2017

|

Vol. 50, nr 1

51--55

EN

We prove the asymptotic global stability of the de Sitter solution in the Friedmann-Robertson-Walker conservative and dissipative cosmology. In the proof we construct a Lyapunov function in an exact form and establish its relationship with the first integral of dynamical system determining evolution of the flat Universe. Our result is that de-Sitter solution is asymptotically stable solution for general form of equation of state p = p(p, H), where dependence on the Hubble function H means that the effect of dissipation are included.

3

An unconditionally positive and global stability preserving NSFD scheme for an epidemic model with vaccination

Ding D., Ma Q., Ding X.

International Journal of Applied Mathematics and Computer Science

|

2014

|

Vol. 24, no. 3

635--646

EN

In this paper, a NonStandard Finite Difference (NSFD) scheme is constructed, which can be used to determine numerical solutions for an epidemic model with vaccination. Here the NSFD method is employed to derive a set of difference equations for the epidemic model with vaccination. We show that difference equations have the same dynamics as the original differential system, such as the positivity of the solutions and the stability of the equilibria, without being restricted by the time step. Our proof of global stability utilizes the method of Lyapunov functions. Numerical simulation illustrates the effectiveness of our results.

4

Generalized practical stability analysis of discontinuous dynamical systems

Zhai G., Michel A. N.

International Journal of Applied Mathematics and Computer Science

|

2004

|

Vol. 14, no 1

5-12

EN

In practice, one is not only interested in the qualitative characterizations provided by the Lyapunov stability, but also in quantitative information concerning the system behavior, including estimates of trajectory bounds, possibly over finite time intervals. This type of information has been ascertained in the past in a systematic manner using the concept of practical stability. In the present paper, we give a new definition of generalized practical stability (abbreviated as GP-stability) and establish some sufficient conditions concerning GP-stability for a wide class of discontinuous dynamical systems. As in the classical Lyapunov theory, our results constitute a Direct Method, making use of auxiliary scalar-valued Lyapunov-like functions. These functions, however, have properties that differ significantly from the usual Lyapunov functions. We demonstrate the applicability of our results by means of several specific examples.