Mitigation of Voltage Unbalances Using a Line Voltage Regulator

With an increasing percentage of single-phase distributed energy resources and modern single-phase loads in the low voltage network, challenges are increasing for voltage grid operators. Especially the power quality in rural areas with long power cables is at risk. Voltage regulators such as on-load tap changers (OLTCs) or line-voltage regulators (LVRs) provide a feasible option for grid reinforcements. The focus of this paper is on the capability of the LVR to mitigate voltage unbalances and on a corresponding novel four step evaluation concept. Therefore, the necessary simulation environment, including load and generation models, is established. To evaluate the capability of the LVR, also the performance of an OLTC and a Zic-Zac-Loadbalancer are analysed. With three static worst case Scenarios the novel evaluation concept is applied. The simulations show an improved single-phase power integration with the LVR and OLTC regarding voltage unbalances.