Dc voltage estimation in three-phase grid-connected inverters
Abstract
Renewable energies such as wind and photovoltaic powers are adopted very popularly with increasing capacity via grid-connected inverters. The input power source of the inverters is usually in the form of direct current and varies according to weather conditions. The value of the input voltage needs to be determined exactly because it affects the output current harmonics of inverters by modulation index. In order to measure this value, the existing methods usually use isolated voltage sensors based on Hall effect sensor. This paper proposes a method for estimating the direct-current voltage value of inverters without using sensors in order to decrease cost and space for grid-connected inverters. The presented strategy contributes to reducing the costs of inverters while ensuring the power quality of inverter outputs. The simulated results on Matlab/ Simulink have validated the performance of the proposed method.
Moraref