| Abstract |
Harmonic components in the output waveform of an inverter cause magnetic noise to the loads, such as motors or transformers. In this paper, we discuss quantitatively the noise by several voltage source inverters. By applying the equivalent noise voltage to estimate the relationship between the magnetic noise and the harmonics, we can predict in advance that the noise by multi-pulse inverter changes widely by pulse number of the output waveform, and then the noise by multi-step inverter can be reduced in comparison with multi-pulse inverter. We can show the validity of our predictions by experimental results of the magnetic noise caused from the load transformer. And then, we investigate also the noise generated from the output transformers to construct the output voltages in the double connected inverters. We try to reduce the total noise added from the load and the output transformers by applying connection with a output transformer only. |
