Solutions to minimize conducted EMI in power electronic circuits

The problem of electromagnetic compatibility has gained increasingly more attention, especially in the field of power electronics. To minimize EMI several solutions have been presented in literature mainly based on EMI filters. In this paper, the authors show experimentally that conducted EMI can be significantly reduced in power converters by minimizing the total stray inductance of each inverter phase leg. The goal of this study is to explore whether EMI filters can be avoided altogether by proper design of the inverter. A prototype inverter was developed to minimize loop inductance and compare conducted EMI with standard designs.

I. Introduction

The increasing operating frequency of power semiconductors in power electronic systems has risen EMI problems in the field of electrical engineering. The very short rise and fall times of voltages and currents in power electronic converters lead to a significant level of energy in the range of radio frequencies. Both radiated and conducted emissions are produced [1]. Moreover, the problem of electromagnetic compatibility has become important for companies involved in the design and development of electronic and electrical equipment, especially since the EC Directive 89/336 has been published [2].