In order to effectively improve the numerical calculation accuracy of transformer core vibration and reveal the influence mechanism of mechanical behavior on transformer core vibration, a magnetic-mechanical coupling characteristic modeling and vibration numerical calculation method of transformer core considering clamping force and friction is proposed. The nonlinear relationship between the clamping force and the friction force is quantified from the microscopic scale, and the dynamic rolling direction contact stiffness of the joint surface is obtained, and the friction contact model of the clamp-insulation-core structure is constructed. Based on the mechanical-electrical analogy theory, an equivalent vibration circuit model that can describe the vibration of transformer core under different clamping forces is established, and the accurate calculation of vibration is realized by numerical simulation method. Compared with the calculation results without considering friction, the vibration displacement calculation results considering the influence of friction are closer to the actual experimental measurement values. © Beijing Paike Culture Commu. Co., Ltd. 2026.

A new algorithm for numerical identification of the static Preisach hysteresis model is proposed for more accurate estimation of dc-biasing hysteresis curves and hysteresis loss of the grain-oriented silicon steel sheet. Based on the experimental asymmetric major hysteresis loop under dc-biased magnetization, two sets of first-order reversal curves corresponding to ascending and descending branches, respectively, are numerically generated for construction of the Everett function. According to the equivalent field separation technique, a dynamic hysteresis model is established by parameter extraction of excess loss, and then used for simulation of dc-biasing dynamic hysteretic behaviors. The consistency between the simulated results and the measured ones demonstrates the effectiveness of the proposed method. The effect of dc bias on iron loss is analyzed as well.

An experimental platform is employed to measure the static and dynamic hysteresis as well as iron loss properties of grain oriented (GO) silicon steel sheet (B27R095) under nonsinusoidal excitation, such as harmonic and DC bias. Based on the Preisach model, an improved Loss model is presented to simulate the dynamic hysteresis and loss characteristics of the silicon steel materials under harmonic or DC bias excitation. Comparison between the simulated results and the measured ones verifies the accuracy of the proposed model. The influence of different characteristic quantities of the harmonic and DC bias on the separation of various losses is analyzed in detail. © 2020 IEEE.

The measurement of DC magnetic properties of soft magnetic materials is carried out by using the static performance testing system (SPTS). The measured limiting hysteresis loop is used to generate the first-order reversal curves (FORCs), which can be effectively applied to the modeling of hysteretic characteristics and verification of hysteresis model. Consequently measurement of FORCs in experiment is unnecessary, whereas efficiency and accuracy of parameter identification can be guaranteed to enhances the applicability of the Preisach model. The concentric hysteresis loops and high-order reversal curves are simulated by using the H-based Preisach model, and a good agreement between the measured and simulated results verifies the accuracy and effectiveness of the proposed method. © 2017 - IOS Press and the authors. All rights reserved.