A new operation method for grid-connected PV system considering voltage regulation in distribution system

This paper presents a grid-connected photovoltaic (PV) system with the new operation method considering voltage regulation in distribution system. In proposed system, PV system adjusts real power and reactive power injection at connection point, in order to maintain the overall system voltage within acceptable range and improve power quality. It consists of modeling of PV array, inverter and inverter controller using PSCAD/EMTDC, and development of operation method of PV generation for voltage regulation in distribution system. PV array modeling is accomplished using 2-diode model which is generally used, and inverter with control system is implemented using proposed operation method based on instantaneous power theory and hysteresis current control. Proposed operation method consists of 3 stages control and using that operation method, overall system effectiveness is improved. To validate the effectiveness of the proposed system, it is compared with system with conventional operation under variable case such that connection, disconnection, load changes and voltage sag using PSCAD/EMTDC.