Adaptive on-load tap-changing voltage control for active distribution networks

The basic prerequisites for the correct operation of the classic on-load tap-changing voltage control (CVC) are that the distribution network (DN) is passive. However, by installing distributed generators (DGs), today's DNs become increasingly active. Consequently, by measuring only the current and voltage magnitudes at the on-load tap-changing transformer secondary side, its automatic voltage regulator receives a false image of the DN load. In such a case, it is impossible to determine the optimal voltage value at the transformer secondary side in all possible states. Therefore, the CVC must be adapted to the new situation. This paper presents a simple, efficient, and inexpensive adaptive on-load tap-changing voltage control (AVC) for active DN with DGs and customers placed on different feeders. The adaptation refers only to the false image of DN load correction, based on the DN load assessment without the influence of DG. Practically, this correction is realized by minimal investment into the existing equipment and infrastructure. Thus, complicated methods requiring an expensive upgrade of DN in terms of communication infrastructure expansion, installation of new sensors and control devices, their coordination, and integration with modern IT/OT systems are avoided. The verification of the AVC is performed in real-life in the real-world active DN.