Optimizing line-voltage-regulators with regard to power quality

Abstract

The rapid expansion of distributed energy resources in the low voltage grid causes voltage limit violations, especially in rural areas with little electric load. To solve this issue without costly grid reinforcement, one approach is the use of smart devices such as line-voltage-regulators. However, the majority of these devices carry out stepped voltage adjustments, which cause a negative effect on the dynamic voltage characteristic. For this reason, this paper deals with a novel line-voltage-regulator and its power quality optimized control. The novel setup enables a continuous voltage regulation in a robust way by using variable inductors. The control design focuses on mitigating side-effects like harmonic distortion emission and increased grid impedance. Finally, a laboratory analysis evaluates the novel line-voltage regulator in comparison to a stepped one with regard to power quality.