1 Scope
This part of IEC 61000 provides guidance on principles which can be used as the basis for determining the
requirements for the connection of unbalanced installations (i.e. three-phase installations causing voltage unbalance) to MV, HV and EHV public
power systems (LV installations are covered in other IEC documents). For the purposes
of this report, an unbalanced installation means a three-phase installation (which may be a load or a generator) that produces
voltage unbalance on the system. The connection of single-phase installations is not
specifically addressed, as the connection of such installations is under the control
of the system operator or owner . The general principles however may be adapted when considering the connection of
single-phase installations. The primary objective is to provide guidance to system
operators or owners on engineering practices, which will facilitate the provision
of adequate service quality for all connected customers . In addressing installations, this document is not intended to replace equipment
standards for emission limits.
The report addresses the allocation of the capacity of the system to absorb disturbances.
It does not address how to mitigate disturbances, nor does it address how the capacity
of the system can be increased.
Since the guidelines outlined in this report are necessarily based on certain simplifying
assumptions, there is no guarantee that this approach will always provide the optimum
solution for all unbalanced load situations. The recommended approach should be used
with flexibility and judg...