Methods for the assessment of emission levels for disturbing installations connected to low and medium voltage networks

In public distribution networks the distribution network operator (DNO) is responsible for the voltage quality at all points of supply. In Europe the DNO have to guarantee specified values for voltage quality parameters according to EN 50160. While the emissions of smaller equipment in LV networks (rated current below 16A) are limited by appropriate standards (IEC 61000-3-x), the connection of larger installations (load and generation) or a bulk of small but identical devices has to be approved by the DNO as the case arises. The "Technical Rules for Assessment of Network Disturbances" (TR) contain guidelines for the approval of connection inquiries in low and medium voltage networks. In December 2007 the second edition of the TR was published by the respective associations of DNO of the four countries Austria (A), Switzerland (CH), Germany (D) and Czech Republic (CZ). The paper gives an overview of the contents of this revised edition. It shortly describes the principles of the assessment procedures. To clarify the easiness of application the assessment of distorting loads (harmonics) is explained in more detail and a numerical example is given. A short discussion of specific issues for generating installations concludes the paper.