Nonlinear dynamic behaviors such as the bifurcation and chaos of DC‐DC converters with switching constant power load are studied in this paper. Based on the consideration of constant power load switching, a discrete iterative mapping model of the system including the switching process is established, and its Lyapunov exponent spectrum algorithm is derived. The main procedure of the algorithm is as follows: Firstly, the system is divided into six smooth segments, and the zero‐time discontinuous mapping of the load and mode switching is introduced. Secondly, the local mapping of each smooth segment and the zero‐time discontinuous mapping of the switching phase are used to construct the composite Poincaré mapping of the system by the chain rule, and then the discrete iterative mapping model of the system is established. Finally, the Lyapunov exponent spectrum algorithm of the system is derived based on the model to determine the type of nonlinear dynamic behavior of the system. This algorithm overcomes the problems of the existing methods, which lead to inaccurate results due to the neglect of the switching process, and achieves the purpose of accurately describing the dynamic characteristics of power electronic circuits. The simulation and experimental results have verified the validity of the proposed model and algorithm. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

中文翻译：

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计算具有恒定开关负载的DC-DC转换器的Lyapunov指数谱的方法

本文研究了具有开关恒定功率负载的非线性动态行为，例如DC-DC转换器的分叉和混沌。基于恒功率负载切换的考虑，建立了包含切换过程的系统离散迭代映射模型，并推导了其Lyapunov指数谱算法。该算法的主要过程如下：首先，将系统分为六个平滑段，并引入了负载和模式切换的零时不连续映射。其次，利用每个链段的局部映射和开关相位的零时不连续映射，通过链式规则构造系统的复合庞加莱映射，然后建立系统的离散迭代映射模型。最后，根据模型推导了系统的Lyapunov指数谱算法，确定了系统的非线性动力学行为的类型。该算法克服了现有方法存在的问题，由于忽略了开关过程而导致结果不准确，达到了准确描述电力电子电路动态特性的目的。仿真和实验结果验证了所提模型和算法的有效性。©2020日本电气工程师学会。由John Wiley＆Sons，Inc.发布 由于忽略了开关过程而导致结果不准确，从而达到了准确描述电力电子电路动态特性的目的。仿真和实验结果验证了所提模型和算法的有效性。©2020日本电气工程师学会。由John Wiley＆Sons，Inc.发布 由于忽略了开关过程而导致结果不准确，从而达到了准确描述电力电子电路动态特性的目的。仿真和实验结果验证了所提模型和算法的有效性。©2020日本电气工程师学会。由John Wiley＆Sons，Inc.发布