This paper presents a non-invasive method for estimating output-line impedance using measurements local to the inverter. Impedance matching is widely used in the transmission of signals in many end applications across the industrial, communications, video, medical, test, measurement, and military markets. In the proposed work, an integral controller is designed in order to. As inverter-based loads and energy sources become increasingly prevalent, accurate estimation of line impedance between inverters and the grid is essential for optimizing performance and enhancing control strategies.