Analysis and Optimization of High-Frequency Switching Oscillation Conducted CM Current Considering Parasitic Parameters Based on a Half-Bridge Power Module

• Published in: IEEE transactions on power electronics 2023-10, Vol.38 (10), p.1-15
• Main Authors: Yang, Qingshou, Wang, Laili, Qi, Zhiyuan, Lu, Xiaohui, Ma, Zaojun, Yang, Fengtao, Wang, Haihua
• Format: Article
• Language: English
• Subjects: Buck converters; Circuits; common mode current; Electric bridges; Electric converters; Electromagnetic interference; electromagnetic interference (EMI); Inductance; Insulated gate bipolar transistors; Layouts; Modules; MOSFET; Multichip modules; Noise propagation; Optimization; Oscillation; Oscillators; Parameters; parasitic parameters; Parasitics (electronics); Principles; Propagation; Schottky diodes; Silicon carbide; Switches; Switching
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2023.3291893

The SiC MOSFETs with anti-parallel SiC SBDs without reverse recovery can significantly reduce turn-on switching loss. However, this will exacerbate the oscillation during switching process, making the more serious electromagnetic interference (EMI) problem. This paper analyzes the influence of the power module parasitic parameters on the propagation path and proposes the optimization principle for the first time. Firstly, the high-frequency switching oscillation noise source (HO-S) and the propagation path considering power module parasitic parameters based on a double pulse test (DPT) circuit are analyzed. Secondly, the HO-CM current mathematical model is established during switching oscillation process to clarify the relationship among noise source (NS), propagation path, and high-frequency switching oscillation conduction common mode (HO-CM) current. Then, in order to reduce HO-CM current, the optimization principle of HO-CM current excited by HO-S is proposed. The HO-CM current can be canceled by optimizing the power module layout or Busbar parasitic inductance. Finally, the effect of power module parasitic parameters on HO-CM current is verified and the HO-CM currents of power modules with different packaging layouts are compared in the experimental part. This method can reduce the HO-CM current spectrum of the critical conduction mode (CRM) or discontinuous conduction mode (DCM) Buck converter by more than 10dB. The analysis of the effect of power module parasitic parameters on HO-CM current can guide power module layout design or power module selection based on different working conditions of half-bridge converter.