How to quickly screen for EMC pre-testing of frequency converters

Conducting EMC pre-testing during the inverter R&D phase can quickly identify problems and save later costs. Pre-testing does not require a standard laboratory, but basic equipment is necessary: spectrum analyzer, near-field probe, artificial power network, and electrostatic discharge gun. The rapid screening process includes: conducted emission pre-testing, using a LISN and spectrum analyzer to scan the power input noise and compare it to standard limit lines (a rough limit line can be made). Radiated emission pre-testing, using a near-field probe to scan for hotspots on the equipment surface, gaps, cables, and PCB, or performing a rough far-field scan in an open area (such as a parking lot) using an antenna and spectrum analyzer.

Immunity pre-testing, using an electrostatic discharge gun to discharge accessible points and check functionality; using a burst pulse generator to inject interference into the power lines. Key areas to check include known weak points: IGBT switching nodes, DC buses, drive circuits, and communication interfaces. The key to pre-testing is comparison and trend analysis; by comparing data before and after rectification, the effectiveness of measures can be determined. A pre-test checklist should be established, using typical solutions from [Company Name] as a rectification library. Although pre-testing is not precise enough, it can identify most serious problems, bringing EMC risks forward.