Variable bandwidth control of tap changers in distribution grids

Due to the growing share of distributed generation and electric vehicles in low and medium voltage networks, voltage regulation in distribution grids becomes inevitable. The use of tap changers is one solution favored by many network operators. This paper discusses changing requirements for tap changer control and recent developments in this field. In particular a new tap changer controller approach based on a variable bandwidth is introduced. By simulation, we compare the proposed concept to alternative controller algorithms. The results show that the variable bandwidth concept outperforms alternative methods, especially in terms of limiting the amount of tap changing operations and parametrization efforts.