Wideband Mechanism Model and Parameter Extracting for High-Power High-Voltage High-Frequency Transformers

• Published in: IEEE transactions on power electronics Vol. 31; no. 5; pp. 3444 - 3455
• Main Authors: Liu, Chen, Qi, Lei, Cui, Xiang, Shen, Zhiyuan, Wei, Xiaoguang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-05-2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Capacitance; Coils (windings); Electric currents; Electromagnetics; Electrostatics; Finite element analysis; finite-element method; Frequencies; grounding; HF transformers; Inductance; Magnetic cores; Mathematical models; modeling; Power transformer insulation; Prototypes; Resonant frequencies; Short circuits; Transformers; Wideband; Windings; Finite-element method; high-frequency (HF) transformers; modeling; grounding
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2015.2464722

The high-power high-voltage high-frequency transformer (H 3 T) is a key equipment to develop the isolated high-power dc-dc converter. In this paper, a wideband mechanism model is proposed to analyze the external behaviors of the H 3 T. This model is characterized by elaborate considerations on magnetic and capacitive effects of the H 3 T, including electrostatic couplings between windings, magnetic core, and the enclosure, with parameters which have explicit physical meanings. In terms of large number of turns and racetrack windings of the H 3 T, a finite-element method based on weighted algorithm is used to extract model inductance and capacitance parameters. To verify the proposed model and corresponding parameter extraction method, impedance characteristics of an H 3 T prototype under open circuit, short circuit, and load conditions are measured and simulated over a wide frequency band. The results show that the proposed model is valid up to 300 kHz. Besides, when one or two windings of the H 3 T are grounded, the proposed model may be reduced to traditional six or three capacitance models due to changes of winding-to-ground capacitances, which may account for shift of resonant frequencies. The proposed model and corresponding analyses are helpful to electromagnetic design and external behavior investigations of the H 3 T.