VP2-10 Advanced Study of Lateral Inter-Laminar Faults in Laminated Magnetic Cores with Homogenization Method
Creators: Shengze Gao
Yanhui Gao
Xiaojun Zhao
Hamed Hamzehbahmani
Weimin Guan and Kazuhiro Muramatsu
Publisher: name: IEEE
Year: 2025

1. Introduction Electrical steel laminations stacked by a set of grain-oriented (GO) silicon steels is generally implemented in magnetic cores of electromagnetic devices. During the manufacturing process, edge burrs can be generated when cutting the lamination. This will introduce the inter-laminar eddy currents on the lateral side of steels known as lateral inter-laminar faults [1, 2]. When the lateral inter-laminar faults occur, the simulation of the silicon laminated core with conventional finite element method could be time consuming considering the specific structure of model. Thus, we proposed a homogenization method with equivalent electrical conductivity considering the inter-laminar eddy currents on the lateral side for saving the computing costs. For the experimental verification, the edge burrs are represented by the artificial faults with lead-free solder on the lateral side of lamination. The simulated results are compared to the measured results for validation. 2. Analysis model and method The analyzed and experimental laminated core model with solder on the lateral side is shown in Fig. 1. The laminated core is stacked with GO silicon steel M105-30P with the thickness of 0.3 mm, the electrical conductivity of 2.169×106 S/m, and the nominal lamination factor of 0.983. Sinusoidal excitation is imposed on y-direction. The proposed homogenization method considers the inter-laminar eddy currents by introducing the equivalent electrical conductivity. As the parameter of the equivalent electrical conductivity in the model is identified for a peak induction of 1.1 T and 50 Hz, it can be applied for the cases under other excitations. 3. Results The comparison results of the measured and the calculated classical eddy current losses by the homogenization model under different excitations are shown in Fig. 2. More investigations will be given in the full paper.References: [1] H. Hamzehbahmani, P. Anderson, J. Hall, and D. Fox, “Eddy current loss estimation of edge burr-affected magnetic laminations based on equivalent electrical network—Part II: analytical modeling and experimental results,” IEEE Trans. Power Delivery, vol. 29, no. 2, pp. 651-659, Apr. 2014. [2] H. Hamzehbahmani, “An enhanced analysis of inter-laminar faults in magnetic cores with grain oriented electrical steels for fault diagnosis and condition monitoring: theoretical background and experimental verification,” IEEE Trans. Instrumentation and Measurement, vol. 72, pp. 1-10, 2023, art no. 6002610.
1. Introduction Electrical steel laminations stacked by a set of grain-oriented (GO) silicon steels is generally implemented in magnetic cores of electromagnetic devices. During the manufacturing process, edge burrs can be generated when cutting the lamination. This will introduce the inter-laminar eddy currents on the lateral side of steels known as lateral inter-laminar faults [1, 2]. When the lateral inter-laminar faults occur, the simulation of the silicon laminated core with conventional finite element method could be time consuming considering the specific structure of model. Thus, we proposed a homogenization method with equivalent electrical conductivity considering the inter-laminar eddy currents on the lateral side for saving the computing costs. For the experimental verification, the edge burrs are represented by the artificial faults with lead-free solder on the lateral side of lamination. The simulated results are compared to the measured results for validation. 2. Analysis model and method The analyzed and experimental laminated core model with solder on the lateral side is shown in Fig. 1. The laminated core is stacked with GO silicon steel M105-30P with the thickness of 0.3 mm, the electrical conductivity of 2.169×106 S/m, and the nominal lamination factor of 0.983. Sinusoidal excitation is imposed on y-direction. The proposed homogenization method considers the inter-laminar eddy currents by introducing the equivalent electrical conductivity. As the parameter of the equivalent electrical conductivity in the model is identified for a peak induction of 1.1 T and 50 Hz, it can be applied for the cases under other excitations. 3. Results The comparison results of the measured and the calculated classical eddy current losses by the homogenization model under different excitations are shown in Fig. 2. More investigations will be given in the full paper.References: [1] H. Hamzehbahmani, P. Anderson, J. Hall, and D. Fox, “Eddy current loss estimation of edge burr-affected magnetic laminations based on equivalent electrical network—Part II: analytical modeling and experimental results,” IEEE Trans. Power Delivery, vol. 29, no. 2, pp. 651-659, Apr. 2014. [2] H. Hamzehbahmani, “An enhanced analysis of inter-laminar faults in magnetic cores with grain oriented electrical steels for fault diagnosis and condition monitoring: theoretical background and experimental verification,” IEEE Trans. Instrumentation and Measurement, vol. 72, pp. 1-10, 2023, art no. 6002610.