Mitsuhiko Kanda

Reduction of Radiated Emission from PLC Systems by Studying Electrical Unbalance of the PLC Device and T-ISN

The relation among the common-mode current generated by PLC system, the longitudinal conversion loss (LCL) and the common-mode impedance (Zcm) of the T-ISN and the electrical unbalance that exists in the PLC device is investigated in order to realize a low emission PLC device. It is necessary to decrease the common-mode current to reduce the radiated emission generated from PLC system. In this case, the LCL and the common-mode impedance of the outlet are examined. For this examination, the formula of the common-mode current, the LCL, and the common-mode impedance is obtained. First of all, the relation among the common-mode current, the LCL and the common-mode impedance is shown. Next, the influence of the electrical balancing of the PLC device on the common-mode current reduction is shown. The effectiveness of the improvement of balancing by means of the components layout and the wirings of the PLC device is shown.

Common mode impedance model of power electronic equipment to evaluate noise reduction effect of a line noise filter

Line noise filters are used to suppress the conductive noise on AC-mains. A common mode impedance model of equipment is proposed in order to evaluate the noise reduction effect of line noise filters. First, the article describe how the common mode impedance model is obtained from the equipment equivalent circuit model. Next, in a comparison of the impedance calculated from the model with the measured impedance, it is concluded that the common mode impedance model is useful for prediction of common mode noise suppression.

A study evaluation method for line noise filters using common mode output impedance of electrical equipment

Line noise filters are used to suppress conductive noise of electrical equipment and apparatus. Performance of these filters is evaluated by insertion loss. Such evaluation requires the output impedance for common mode noise from equipment. However, the impedance of the equipment under operation is not examined in general. This paper examines the output impedance of the equipment under operation. First, the impedance values are obtained by measurement. From evaluation results of the filters (common mode capacitor) insertion loss, it is shown that impedance obtained in this paper is effective for verification of line noise filters. Next, an equivalent circuit of the equipment is studied. It is shown that impedance calculated from this equivalent circuit is also effective.