Surface impedance implementation of high frequency conductor losses using susceptance element equivalent circuit model and model order reduction

Author(s):  
Stephen Dumas ◽  
Madhavan Swaminathan
2017 ◽  
Vol 4 (3) ◽  
pp. 115-129 ◽  
Author(s):  
Wiebold Wurpts ◽  
Jens Twiefel ◽  
Francois Brouet

Abstract Equivalent circuits are often the first choice for the modeling of piezoelectric systems, as they allow for the consideration of the complete electro-mechanical system with one or even more modes. The parameters of the equivalent circuit model are identified by a measured or simulated frequency response. In this contribution a method for a direct modal condensation of the equivalent parameters for arbitrary FE structures and loads is described and discussed. First the proposed method is demonstrated for a continuous piezoelectric rod and then applied to discrete finite element models. The derived equivalent circuit has an identical appearance to the classical solution, but additionally allows arbitrarily load conditions. Furthermore, the structure of the derived equivalent circuit depends on whether short- or open-circuited modes are used for the modal expansion. The influence of truncated modes is discussed utilizing residual terms, leading to a better understanding of the circuit parameters. Additionally the model based approaches in the third part an experimental parameter identification procedure for many modes is presented as well. The influence of the load and the quality of the model order reduction are discussed for piezoelectric rods. The methods are demonstrated for a base excited energy harvesting system an ultrasonic grubber.


2021 ◽  
Vol 11 (10) ◽  
pp. 4631
Author(s):  
Yu Chen ◽  
Xiaoqing Ji ◽  
Zhongyong Zhao

The accurate establishment of the equivalent circuit model of the synchronous machine windings’ broadband characteristics is the basis for the study of high-frequency machine problems, such as winding fault diagnosis and electromagnetic interference prediction. Therefore, this paper proposes a modeling method for synchronous machine winding based on broadband characteristics. Firstly, the single-phase high-frequency lumped parameter circuit model of synchronous machine winding is introduced, then the broadband characteristics of the port are analyzed by using the state space model, and then the equivalent circuit parameters are identified by using an optimization algorithm combined with the measured broadband impedance characteristics of port. Finally, experimental verification and comparison experiments are carried out on a 5-kW synchronous machine. The experimental results show that the proposed modeling method identifies the impedance curve of the circuit parameters with a high degree of agreement with the measured impedance curve, which indicates that the modeling method is feasible. In addition, the comparative experimental results show that, compared with the engineering exploratory calculation method, the proposed parameter identification method has stronger adaptability to the measured data and a certain robustness. Compared with the black box model, the parameters of the proposed model have a certain physical meaning, and the agreement with the actual impedance characteristic curve is higher than that of the black box model.


1990 ◽  
Vol 38 (4) ◽  
pp. 1019-1021 ◽  
Author(s):  
Tamotsu KOIZUMI ◽  
Masawa KAKEMI ◽  
Kazunori KATAYAMA ◽  
Hirohiko INADA ◽  
Kazuyoshi SUDEJI ◽  
...  

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