Analysis and evaluation of near field noise voltage on power electronics circuits

Design procedure for power electronics circuit structures has recently been discussed for high power density circuits or thin structure converters. Then the control circuit may be connected close to the power circuit. When a pulse current flows into the power circuit, it radiates a magnetic field and it may produce a near field noise voltage in the control circuit and this can be a cause of malfunction. Therefore it is important that the near field noise voltage is evaluated for power electronics circuits. In this paper, a malfunction of a low-voltage circuit close to a power circuit is demonstrated, and the measurement results of the near field noise voltage using a small area loop antenna with a buck chopper circuit of 20 A and 100 kHz are shown. In addition, it is analytically explained that the noise voltage may affect the control circuits in high power density circuits.