Comparative study of conventional modulation schemes in terms of conducted and radiated EMI generated by three-phase inverters

In this paper, a comparative study is carried out between the carrier (SPWM), third harmonic injection (THIPWM), and space vector (SVPWM) modulation schemes in terms of conducted (common and differential modes) and radiated electromagnetic interference (EMI) generated by three-phase two-level voltage source inverters. For this purpose, an experimental setup of the converter feeding an induction machine is developed with the aim to measure the conducted emission propagated back into the dc source and the radiated field in the vicinity of the power conversion device. Experimental results are given and analyzed in time and frequency domains. The comparative study between the three modulation methods carried out in the frequency domain shows that the SVPWM method has better EMI performance. Moreover, a high frequency model of the converter feeding the induction machine is simulated using SPICE-based simulation software. Good agreement is found between the experimental and simulation results in terms of conducted interferences.