Switching Capacitor Strategy for fully exploiting potential of EMI filters

다국어 초록 (Multilingual Abstract)

In DC/AC inverter systems, the saturation of the common mode (CM) inductor caused by common mode voltage is an important issue in electromagnetic interference (EMI) filter design. Especially for off-the-shelf EMI filter products, the CM voltages, switching frequency, modulation strategy and CM path impedance are often unknown, which is more likely to cause core saturation due to CM path resonance. Although the saturation issues can be avoided by increasing the design margin of magnetic cores, they are often unacceptably expensive in high-power systems. This paper proposes a capacitor adjustment strategy for preventing saturation of CM choke which is suitable for general EMI filters. The principle is to make the filter corner frequency far away from the switching frequency of inverters. The cost of proposed strategy is low. It only needs to detect the volt-seconds on the CM chokes to adjust the number of the connected Y capacitors.

목차 (Table of Contents)

• Abstract
• I. INTRODUCTION
• II. ANALYSIS OF VOLT-SECOND FOR CM INDUCTORS
• III. CAPACITOR ADJUSTMENT STRATEGY
• IV. EXPERIMENTAL RESULTS
• V. CONCLUSIONS
• REFERENCES