Impact Assessment of common-Mode interference on communication cable in a Motor Drive System: Modified Bulk Current Injection Approach

Abstract

Adjacent communication network coupling disturbances due to conducted electromagnetic interference (EMI) coupling and near field coupling is a growing concern for high-frequency motor drives. The performance of the communication network is majorly compromised due to considerable common-mode (CM) current induced into communication cable due to high dV/ dt and di/dt of wide band gap (WBG) devices-based motor drives. Estimation of such CM current is a non-trivial task owing to the complex coupling mechanism between the motor drive cables and the communication network. This paper studies the EMI noise problem in a WBG device's motor drive varying with grounding mechanism and layout design. Firstly, the impact of grounding has been explored on conducted and near-field (NF) radiated noise propagation paths. This paper uses high precision dobot (robotic arm) based near field sniffing mechanism for the same Secondly, a high-frequency cable and motor modeling technique is introduced to predict the EMI noise source and propagation path. This paper uses impedance analysis and Ansys Q3D Extractor is a parasitic extraction tool-based approach for modeling. Lastly, the paper also provides a novel modified bulk current injection testing (MBCI), and NF mapping technique has been provided to explore the adverse impact of EMI coupling on communication cables. This is an empirical, simpler, and cost-efficient approach for analysis, estimation, and mitigation of the common mode coupling between motor drives and adjacent communication networks.