NOTE 2 A PEN conductor is a protective earthedneutral conductor combining the functions of both a protective conductor and a neutral conductor.
注2： PEN导线是指将保护导线和中性导线两种功能结合在一起的保护接地中性线。
2
In the article the author analysises and discusses earthedneutral system. Methods of electric resistance and autotracking arcextinguishing coil in neutral point are discussed.
The effect of DC earthed pol current on the neutralearthed transformer is analysed. The methods of reducing THD DC current which flows into transformer windings are introduced.