Parameter identification of fractional-order time delay system based on Legendre wavelet

Wang, Zishuo; Wang, Chunyang; Ding, Lianghua; Wang, Zeng; Liang, Shuning

doi:10.1016/j.ymssp.2021.108141

Cited by 26 publications

(7 citation statements)

References 32 publications

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“…There is a significant difference in terminal voltage' numerical values of switch Q when switching transient at the macro circuit scale and micro device scale. IGBT switching is a process with multi-scale properties [22]. Based on WD and RA, Eq (9) represents the terminal voltage u ce of Q.…”

Section: Plos Onementioning

confidence: 99%

Construction and simulation of a joint scale model for power electronic converters based on wavelet decomposition and reconstruction algorithms

2024

PLoS ONE

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In power electronics systems, system design and operation often involve multiple time and space scales, ranging from nanosecond switching dynamics to hour-level system operation behavior. Due to the complexity of these systems and the rise of wide-gap semiconductor technology, a series of multi-scale phenomena have emerged that are difficult to ignore. The high frequency of switching operations makes multi-scale effects particularly significant, including the fast dynamic response of the power loop, EMI, and heat conduction problems. They are key factors that must be considered in the design to ensure the efficient and reliable operation of power electronic devices. This study proposes the construction and simulation of a joint scale model for power electronic converters based on wavelet decomposition and reconstruction algorithms to address the multi-scale phenomenon and limitations of single-scale power electronic converters. Firstly, a joint scale model for power electronic converters at both macro and micro-scales was established, targeting both single-scale models and simple combinations of multiple scale models for power electronic converters. The traditional single-scale model is sufficient to describe the average behavior of the converter, but it has serious limitations in capturing fast transient processes and high-frequency switching behavior in power electronic systems. These limitations often manifest themselves when there is a need to capture fine timescales of detail. By transforming between the time domain and the frequency domain, wavelet decomposition enables the model to capture both macroscopic average characteristics and microscopic transient dynamics. The wavelet reconstruction algorithm can simulate all kinds of fast changes in the actual working process more accurately and compress irrelevant information while retaining key signal features, so as to optimize the simulation performance of the model. Secondly, this algorithm is used to analyze BC in short time scale. Finally, the short time scale characteristics of power electronic converters are analyzed. Experimental results show that the fusion of wavelet decomposition and reconstruction algorithm enhances the accuracy of the power electronic converter model and improves the performance of the system. The model achieves an error reduction of nearly 3% in the calculation step size of 10-7s, which has a significant impact on the high precision requirements of high-frequency operations. In addition, the optimal calculation step size of 8×10-8s achieves an error reduction of more than 14%, making an important contribution to the transient analysis and fine structure simulation. The wavelet algorithm can improve the accuracy of multi-scale modeling in power electronic system and reduce the simulation time. The reduction of error not only shows the improvement of the accuracy of the model, but also shows its practical significance in the design and test of the actual power electronic system. The reduction in error reveals the ability to more accurately predict and mitigate potential performance problems in matching tests with actual hardware, as well as its ability to adapt to emerging wide bandgap semiconductor materials and structures.

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Section: Plos Onementioning

confidence: 99%

Construction and simulation of a joint scale model for power electronic converters based on wavelet decomposition and reconstruction algorithms

2024

PLoS ONE

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“…Chen et al [ 14 ] proposed an effective identification model based on the Bayesian theorem for systems with unknown time delay. Wang et al [ 15 ] proposed a parameter identification method of a fractional-order time delay system based on the Legendre wavelet, which reduces the effect of noise on the accuracy of parameter identification. Hofmann et al [ 16 ] proposed an offline time-delay identification strategy based on falling film evaporator pilot plant experiments and obtained good results in both validation experiments, with and without evaporation.…”

Section: Introductionmentioning

confidence: 99%

Multi-Delay Identification of Rare Earth Extraction Process Based on Improved Time-Correlation Analysis

Liu

Yang

et al. 2023

Sensors

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The rare earth extraction process has significant time delay characteristics, making it challenging to identify the time delay and establish an accurate mathematical model. This paper proposes a multi-delay identification method based on improved time-correlation analysis. Firstly, the data are preprocessed by grey relational analysis, and the time delay sequence and time-correlation data matrix are constructed. The time-correlation analysis matrix is defined, and the H∞ norm quantifies the correlation degree of the data sequence. Thus the multi-delay identification problem is transformed into an integer optimization problem. Secondly, an improved discrete state transition algorithm is used for optimization to obtain multi-delay. Finally, based on an Neodymium (Nd) component content model constructed by a wavelet neural network, the performance of the proposed method is compared with the unimproved time delay identification method and the model without an identification method. The results show that the proposed algorithm improves optimization accuracy, convergence speed, and stability. The performance of the component content model after time delay identification is significantly improved using the proposed method, which verifies its effectiveness in the time delay identification of the rare earth extraction process.

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“…Fractional order PID controllers are a generalization of the classical PID controller into the fractional calculus domain and was first introduced by I. Podlubny [5]. Numerous works prove the superiority of fractional order PID controllers in terms of improved closed loop system performance, increased stability and robustness with the addition of two parameters, consisting of arbitrary orders of integration and differentiation [6], [7], [8], [9]. Even if tuning methodologies of fractional order PID controllers are abundant [10], fractional order autotuning strategies are scarce featuring various limitations.…”

Section: Introductionmentioning

confidence: 99%

Tuning Guidelines and Experimental Comparisons of Sine Based Auto-Tuning Methods for Fractional Order Controllers

et al. 2022

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Accurate process modeling is occasionally difficult. In such situations, auto-tuning methods enable the design of suitable controllers based on experimental data and predefined mathematical approaches. Fractional order PIDs have recently emerged as a generalization of the standard PID controller, but auto-tuning methods for these controllers are scarce. In this paper, three sine-test based methodologies are presented from a control engineer's perspective consisting of novel Sine-Test, FO-KC and FO-ZN methods, with clear design and implementation guidelines. The approaches are exemplified on a highly nonlinear experimental platform. An in depth comparison is performed based on experimental closed loop system performance for wide operating areas, tuning effort and complexity, with a focus on the suitability for industrial applications. The study aims at providing a solid foundation for practitioners that desire to explore auto-tuning possibilities, presenting tuning workflows and implementation guidelines, while also considering the challenges associated with real-life process.

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Parameter identification of fractional-order time delay system based on Legendre wavelet

Cited by 26 publications

References 32 publications

Construction and simulation of a joint scale model for power electronic converters based on wavelet decomposition and reconstruction algorithms

Construction and simulation of a joint scale model for power electronic converters based on wavelet decomposition and reconstruction algorithms

Multi-Delay Identification of Rare Earth Extraction Process Based on Improved Time-Correlation Analysis

Tuning Guidelines and Experimental Comparisons of Sine Based Auto-Tuning Methods for Fractional Order Controllers

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