In this work, it is presented the use of the Broyden method as an alternative to the traditional Newton-Raphson method for online impedance estimation of an electrical grid. The estimation procedure used is based on the variation of active and reactive power injected into the grid by a three-phase inverter. To demonstrate that the Broyden method presents as a satisfactory substitute for the Newton-Raphson method, the performance of these two methods was compared taking into account the percentage error, processing time, and number of iterations during estimation. The analysis of the performance of the methods was carried out through real-time simulations.