Modeling of EM Radiation from Shielded Power Electronic Systems

Author: Giorgi Kapanadze
Keywords: EMC, EM simulations, shielded electronic systems
Annotation:

With the development hybrid cars and fully electrical vehicles the modern automotive industry has a strong demand for reliable and cost-efficient power electronics. High voltage power electronics modules, such as inverters, DC/DC converters and on-board chargers, are based on power MOSFETs and IGBTs that are used as switches for reducing the overall size of modules. During the design of the modules many requirements should be fulfilled, among them are electromagnetic interference and compatibility requirements to ensure safety of personnel and proper operation of other electronic systems in the vehicle. To provide the maximum EMI suppression proper shielding and grounding concepts must be used. Shielding should include not only enclosures of modules but also cable shielding. One of the aims of diploma work is to measure transfer impedance of high voltage cable intended for EV applications. Based on measurement results a proper analytical model and parameter values were chosen for accurate representation of cable shielding characteristic. Another important topic of diploma is investigation of resonant effects related to different grounding topologies of a shielded system. Measurements of crosstalk and radiated field were performed using specially designed test-banch and disturbance source. Computer modeling of system helps to explain behavior of ground loops, which could deteriorate the system performance and lead to exceeding of limits prescribed by automotive EMI standards for conducted- and radiated-emissions. Modeling techniques, and system models are described in details. Results are compared to measurements for various grounding conditions that are typical for automotive electrical power train systems.