Estimating Distributed Generation and Loads for Voltage Profile Optimal Regulation

In MV distribution systems it is very important to account for the impact of Distributed Generation (DG) on the nodal voltage profile. A key issue is to guarantee adequate performance of the voltage control system acting on the On-Load Tap Changer (OLTC) of the HV/MV transformer. Referring to the case of a distribution system with the DG connected at a single node, a simple but effective OLTC control scheme is proposed to account for both load and DG variations. It keeps the classical structure of the OLTC control system, using only local measurements of voltage and current at transformer MV terminals, and avoiding data exchange with DG. To this aim, the effects of the changes of loads and of DG power injection must be distinguished and separately evaluated. The present paper focuses on the problem of estimating distributed generation and loads and proposes a specific procedure. Numerical simulations of a basic case study are presented to give evidence of the performance of the estimating procedure.