Hiroyuki Asahara

BIFURCATION ANALYSIS IN A PWM CURRENT-CONTROLLED H-BRIDGE INVERTER

This paper introduces the complete bifurcation analysis in a PWM current-controlled H-Bridge inverter in a wide parameter space. First, we briefly explain the behavior of the waveform in the circuit in terms of the switched dynamical system. Then, the consecutive waveform during the duration of the clock interval is exactly discretized, and the return map is defined for the rigorous analysis. Using the map, we derive the one- and two-dimensional bifurcation diagrams, and discuss the specific property of each bifurcation phenomena in the circuit.

Qualitative analysis of an interrupted electric circuit with spike noise

Switching non-ideality and its effects have been reported in DC-DC converters. In this paper, we examine the qualitative property of an interrupted electric circuit with spike noise. First, we show the circuit model that have the switch interrupted by its own state and a periodic interval. Here, we artificially add spike noise via every switching action. Then, we explain its dynamics and derive the Poincare map for the rigorous analysis in a circuit with ideal switching and a circuit with spike noise, respectively. Finally, we discuss the dynamical effects of spike noise from experimental and analytical viewpoints based on the Poincare map and bifurcation diagrams. As a result, some dynamical effects of spike noise are clarified in terms of the invariant set, bifurcations, and existence regions of coexisting attractor. Copyright

Dynamical mechanism for interrupted circuit with switching delay

The unavoidable nonidealities with switching delay in current-mode-controlled buck converters have been reported in the literature. Investigations are carried out on the dynamical mechanism and its experimental validation on an interrupted circuit with switching delay. Switching delay is seen to influence a region of a two-valued function on a discrete map, and to induce the coexistence of a periodic orbit.

A search algorithm of bifurcation point in an impact oscillator with periodic threshold

In this paper, we propose a search algorithm of bifurcation point in an impact oscillator with periodic threshold. The algorithm based on the Poincaré map approach. In particular, we target the periodic threshold as the bifurcation analysis parameter. First, we define the composite Poincaré map of the two-dimensional impact oscillator. Next, we show the derivative of the Poincaré map with a parameter of the threshold. Finally, we apply the algorithm for a rigid overhead wire-pantograph system. The validity of the algorithm will be verified by the analyses results.

Theoretical and experimental analysis of a simple PWM-1 controlled interrupted electric circuit

In this paper, we analyze a simple PWM-1 controlled interrupted electric circuit in order to essentially understand the circuit fundamental characteristics. First, we explain the circuit dynamics, and then we define the return map by using the exact solution. Next, we focus on the existence region of the solution invariant interval and bifurcation phenomena in the circuit. In particular, we find the circuit has three types of the invariant interval depending on the parameter. We also clarify that the period-doubling bifurcation and the border-collision bifurcation effect in the existence region of the periodic solution in a wide parameter plane. Finally, the mathematical results are verified by the laboratory experiment. Copyright

Stability analysis of an interrupted circuit with fast-scale and slow-scale bifurcations

In this paper, we analyze stability of the fast-scale and slow-scale dynamics in an interrupted electric circuit. First, we show the full-bridge inverter, as the practical example, in which fast-scale and slow-scale bifurcations are observed. Next, we show our original circuit model and explain its dynamics. Using the sampled data model, we calculate stability of the fast-scale and slow-scale dynamics. Finally, we mathematically show that the period-doubling bifurcation, which occurs in the fast-scale dynamics, does not directly affect the stability of the slow-scale dynamics.

Analysis of an interrupted circuit with fast-slow bifurcation

In this paper, we discuss, with focus on the border-collision bifurcation, the relationship between the fast-scale bifurcation and the slow-scale bifurcation in an interrupted electric circuit. First, we show the circuit model and explain its dynamics. Then, we define the discrete map in the fast-scale dynamics and the slow-scale dynamics, respectively. Using the discrete map, we derive the 1-parameter bifurcation diagram in the slow-scale dynamics. Finally, we discuss how the border-collision bifurcation in the fast-scale dynamics affects the slow-scale bifurcation.

An experimental examination of a PWM-1 controlled interrupted electric circuit

This paper addresses the first experimental demonstration for the nonlinear dynamics in a simple PWM-1 controlled interrupted electric circuit with one dimensional discrete map. First, we show the circuit model and explain its dynamics. Then, the discrete map is mathematically defined for the rigorous analysis. Finally, we show the laboratory experiment and discuss about the circuits fundamental characteristics.

Experimental study of an interrupted electric circuit with spike noise

Analysis of switched dynamical systems have been done under the assumption of theoretical switching action. However, the numerous unexpected effects occur with the switching action in the practical systems. The main purpose of this paper is to examine the dynamical effect of spike noise in an interrupted electric circuit. We firstly propose a circuit model and explain its dynamics. Then, we construct return map both of the circuits that include ideal switching or spike noise, respectively. Finally, we introduce the dynamical effect of spike noise by comparing the return maps and the one parameter bifurcation diagrams based on the laboratory experiment. As the result, we introduce the basic characteristics that a part of return map in the circuit with spike noise becomes 2-valued function and its huge impact to the circuit dynamics.