Optimal planning of PV inverter in the presence of capacitor bank in medium-voltage distribution networks

As the penetration level of the photovoltaic (PV) system increases over the coming decades, reverse power flows on the distribution feeder will happen and the associated voltage rise might lead to violations of voltage limits. The severity of the voltage regulation problem depends on the relative size and location of PV system, loads, and the distribution feeder topology. This paper proposes an approach to solve the voltage rise problem associated with PV system and to improve the total voltage deviation by optimally increasing the capacity of the PV inverter over the capacity of the PV modules in the presence of capacitor banks. An optimization model is constructed to calculate the optimal inverter capacity with minimizing the cost of PV inverter as well as the total voltage deviation on the distribution network. The overall system constraints are considered in the optimization model. The proposed approach is tested using the IEEE 119-node distribution network. The effectiveness of the proposed approach is demonstrated by calculating the optimal capacity of the PV inverter for mitigating the voltage rise problem and reducing the total voltage deviation.