Observer-Pattern Modeling and Slow-Scale Bifurcation Analysis of Two-Stage Boost Inverters

2017 ◽  
Vol 27 (06) ◽  
pp. 1750096 ◽  
Author(s):  
Hao Zhang ◽  
Xiaojin Wan ◽  
Weijie Li ◽  
Honghui Ding ◽  
Chuanzhi Yi
Keyword(s):  
Bifurcation Analysis ◽  
Second Harmonic ◽  
Underlying Mechanism ◽  
Analysis Method ◽  
Two Stage ◽  
Time Variance ◽  
Eigenvalue Sensitivity ◽  
Averaged Equations ◽  
Pattern Modeling ◽  
Theoretical Results

This paper deals with modeling and bifurcation analysis of two-stage Boost inverters. Since the effect of the nonlinear interactions between source-stage converter and load-stage inverter causes the “hidden” second-harmonic current at the input of the downstream H-bridge inverter, an observer-pattern modeling method is proposed by removing time variance originating from both fundamental frequency and hidden second harmonics in the derived averaged equations. Based on the proposed observer-pattern model, the underlying mechanism of slow-scale instability behavior is uncovered with the help of eigenvalue analysis method. Then eigenvalue sensitivity analysis is used to select some key system parameters of two-stage Boost inverter, and some behavior boundaries are given to provide some design-oriented information for optimizing the circuit. Finally, these theoretical results are verified by numerical simulations and circuit experiment.

Design-Oriented Analysis of Slow-Scale Bifurcations in Single Phase DC–AC Inverters via Autonomous Transformation Approach

2017 ◽  
Vol 27 (06) ◽  
pp. 1750086 ◽  
Author(s):  
Hao Zhang ◽  
Honghui Ding ◽  
Chuanzhi Yi
Keyword(s):  
Theoretical Analysis ◽  
Circuit Design ◽  
Single Phase ◽  
Underlying Mechanism ◽  
System Stability ◽  
Equivalent Model ◽  
Eigenvalue Sensitivity ◽  
Physical Experiments ◽  
Averaged Model ◽  
Theoretical Results

This paper deals with the design-oriented analysis of slow-scale bifurcations in single phase DC–AC inverters. Since DC–AC inverter belongs to a class of nonautonomous piecewise systems with periodic equilibrium orbits, the original averaged model has to be translated into an equivalent autonomous one via a virtual rotating coordinate transformation in order to simplify the theoretical analysis. Based on the virtual equivalent model, eigenvalue sensitivity is used to estimate the effect of the important parameters on the system stability. Furthermore, theoretical analysis is performed to identify slow-scale bifurcation behaviors by judging in what way the eigenvalue loci of the Jacobian matrix move under the variation of some important parameters. In particular, the underlying mechanism of the slow-scale unstable phenomenon is uncovered and discussed thoroughly. In addition, some behavior boundaries are given in the parameter space, which are suitable for optimizing the circuit design. Finally, physical experiments are performed to verify the above theoretical results.

Symmetry-breaking bifurcations in resonant surface waves

1989 ◽  
Vol 199 ◽  
pp. 495-518 ◽  
Author(s):  
Z. C. Feng ◽  
P. R. Sethna
Keyword(s):  
Normal Form ◽  
Symmetry Breaking ◽  
Surface Waves ◽  
Bifurcation Analysis ◽  
Internal Resonance ◽  
Travelling Waves ◽  
Chaotic Behaviour ◽  
Derived Set ◽  
Parameter Values ◽  
Theoretical Results

Surface waves in a nearly square container subjected to vertical oscillations are studied. The theoretical results are based on the analysis of a derived set of normal form equations, which represent perturbations of systems with 1:1 internal resonance and with D4 symmetry. Bifurcation analysis of these equations shows that the system is capable of periodic and quasi-periodic standing as well as travelling waves. The analysis also identifies parameter values at which chaotic behaviour is to be expected. The theoretical results are verified with the aid of some experiments.

Study on Energy Consumption Analysis Method of Distributed Cryogenic Separation System

2013 ◽  
Vol 732-733 ◽  
pp. 52-56
Author(s):  
Zhi Guo Wang ◽  
Lei Zhang ◽  
Chai Ling Yin
Keyword(s):  
Energy Use ◽  
Exergy Analysis ◽  
Waste Heat ◽  
Engineering Practice ◽  
Analysis Method ◽  
Analysis Model ◽  
Two Stage ◽  
Separation Plant ◽  
Flow Energy ◽  
Saving Effect

Cryogenic separation method is the main method to recycle NGL (Natural Gas Liquid). Oilfield two-stage expansion NGL cryogenic separation plant is a complex system composed of varieties of material flow, energy flow and equipments, is a typical distributed energy use system composed of three parts, energy supply, energy use and waste heat recovery. In this paper, according to the process characteristics of two-stage expansion cryogenic separation plant, three-box analysis method was used, the system was compartmentalized into six subsystems, represented the exergy analysis model of system—unit—equipment, given the specific analysis process and the assessment rules for the NGL system. Using the practical operational data, the writers conduct the exergy analysis on the operational working condition of Daqing oilfield NGL system. Based on the calculation results, this paper raises some proposals to improve the operational efficiency, and achieved a good energy saving effect in engineering practice.

scholarly journals The Two-Stage Game Approach to Coalition Formation: Where We Stand and Ways to Go

Games ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 3 ◽  
Author(s):  
Achim Hagen ◽  
Pierre von Mouche ◽  
Hans-Peter Weikard
Keyword(s):  
Public Good ◽  
Coalition Formation ◽  
Qualitative Properties ◽  
Research Strategies ◽  
Two Stage ◽  
Second Stage ◽  
Coalition Structures ◽  
Stage Game ◽  
Theoretical Results

Coalition formation is often analysed in an almost non-cooperative way, as a two-stage game that consists of a first stage comprising membership actions and a second stage with physical actions, such as the provision of a public good. We formalised this widely used approach for the case where actions are simultaneous in each stage. Herein, we give special attention to the case of a symmetric physical game. Various theoretical results, in particular, for cartel games, are provided. As they are crucial, recent results on the uniqueness of coalitional equilibria of Cournot-like physical games are reconsidered. Various concrete examples are included. Finally, we discuss research strategies to obtain results about equilibrium coalition structures with abstract physical games in terms of qualitative properties of their primitives.

Bifurcation Analysis of a Dynamical Model for the Innate Immune Response to Initial Pulmonary Infections

2020 ◽  
Vol 30 (16) ◽  
pp. 2050252
Author(s):  
Shujing Shi ◽  
Jicai Huang ◽  
Jing Wen ◽  
Shigui Ruan
Keyword(s):  
Hopf Bifurcation ◽  
Bifurcation Analysis ◽  
Polymorphonuclear Leukocytes ◽  
Homoclinic Orbits ◽  
Organ Damage ◽  
Innate Immune ◽  
Dynamical Model ◽  
System Response ◽  
Pulmonary Infections ◽  
Theoretical Results

It has been reported that COVID-19 patients had an increased neutrophil count and a decreased lymphocyte count in the severe phase and neutrophils may contribute to organ damage and mortality. In this paper, we present the bifurcation analysis of a dynamical model for the initial innate system response to pulmonary infection. The model describes the interaction between a pathogen and neutrophilis (also known as polymorphonuclear leukocytes). It is shown that the system undergoes a sequence of bifurcations including subcritical and supercritical Bogdanov–Takens bifurcations, Hopf bifurcation, and degenerate Hopf bifurcation as the parameters vary, and the model exhibits rich dynamics such as the existence of multiple coexistent periodic oscillations, homoclinic orbits, bistability and tristability, etc. Numerical simulations are presented to explain the theoretical results.

scholarly journals A two-stage multi-criteria analysis method for planning renewable energy use and carbon saving

Energy ◽  
2020 ◽  
Vol 199 ◽  
pp. 117475 ◽  
Author(s):  
Asam Ahmed ◽  
Setiadi Wicaksono Sutrisno ◽  
Siming You
Keyword(s):  
Renewable Energy ◽  
Energy Use ◽  
Analysis Method ◽  
Two Stage ◽  
Multi Criteria Analysis

scholarly journals Innovation and product market concentration: Schumpeter, arrow, and the inverted U-shape curve

2020 ◽  
Author(s):  
Flavio Delbono ◽  
Luca Lambertini
Keyword(s):  
Numerical Simulations ◽  
Empirical Research ◽  
Product Market ◽  
Market Concentration ◽  
Relative Strength ◽  
Stage Model ◽  
Two Stage ◽  
Shape Curve ◽  
The Relationship ◽  
Theoretical Results

Abstract We investigate the relationship between market concentration and industry innovative effort within a familiar two-stage model of R&D race in which firms compete à la Cournot in the product market. With the help of numerical simulations, we show that such a setting is rich enough to generate Arrovian, Schumpeterian, and inverted U curves. We interpret these different patterns on the basis of the relative strength of the technological incentive and the strategic incentive. We then bridge our theoretical results and some recent empirical research.

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