Outlet LCL does not tell the mode conversions distributed in the power-line network : Transmission line theory of common-mode current and LCL

コンセント　デ　LCL　ヲ　ハカッテモ　デンリョクセンモウ　ニ　ブンプ　スル　モード　ヘンカン　ハ　ワカラナイ　コモンモード　デンリュウ　ト　LCL　ノ　デンソウセンロテキ　トリアツカイ

キタガワ, マサヒロ

Kitagawa, Masahiro

漏洩電磁界

コモンモード

差動モード

不平衡

モード変換

LCL

ISN

power line communications (PLC)

radiated electric field

common mode

differential mode

unbalance

mode conversion

The common-mode (CM) current generated at the unbalance elements distributed in the power-line network from the differential-mode (DM) signal is the origin of the radiated emission from the power-line communications (PLC). The LCL measured at the outlet is often used as a measure of the unbalance in power-line network. We have analyzed the mode conversion by the unbalance element at a distance of l from the outlet on the power-line and derived the LCL and the CM current. We have shown that the LCL measured at the outlet underestimates the CM current in the power-line due to the CM propagation loss between the unbalance element and the outlet. We have also shown that the ISN connected to the PLC modem cannot emulate the mode conversion at the remote unbalance element in the power-line network and does not restrict the field strength of the radiated emission from the power-line. The PLC regulation based on the CM current measured using the ISN with the outlet LCL has no rational.