Pareto Optimal Smart Inverter Curve Selection for High Photovoltaic Penetration

The dynamic operation of Smart Inverters (SIs) is of great importance for effective photovoltaic (PV) system integration. More functionalities are being demanded from SIs to allow for effective voltage and frequency control of the grid, more importantly at high PV penetration levels. This paper presents a multi-objective algorithm for four SI settings (Volt-VAR, Volt-Watt, Dynamic Reactive Current Injection (DRCI) and Constant Power Factor) which minimizes system active power loss, flattens voltage profiles, and implements a conservative voltage reduction (CVR) using the IEEE 34 node distribution feeder with three units of PVs integrated. The multi-objective optimization is solved using the Non-dominated Sorting Genetic Algorithm II (NSGA-II). The Pareto solutions for the proposed algorithm is presented. A comparative performance analysis (based on the multi-objective formulation and their Pareto solutions) of these SI functions is also presented. The results show 70 different Pareto front solutions with 70 possible Volt-VAR, Volt-Watt, DRCI and constant PF values. Depending on the objective of higher priority, an SI curve can be selected from the Pareto optimal solutions.