In a power system, it is known that parameters may carry small errors due to the weather conditions, such as temperature and humidity changes, as well as gross errors due to the miscommunication between the control center and circuit breakers and tap changers. Those incorrect parameters may cause biased state estimates, which may have serious results. Therefore, those parameter errors should be identified and corrected. Considering the increasing number of Phasor Measurement Units (PMUs), in this paper it is proposed to use PMU measurements in local parameter estimation. The developed parameter estimation will employ the robust Least Absolute Value (LAV) estimator to obtain unbiased estimates even in the presence of bad measurements.