Strategic Use of Synchronized Phasor Measurements to Improve Network Parameter Error Detection

The Normalized Lagrange Multiplier (NLM) test is generally effective for network parameter error identification, but suffers occasional detection failures even in the presence of substantial parameter errors. This paper exploits synchronized phasor measurements to address this issue. The parameters whose errors may go undetected are identified, and an index is defined to quantify the power of the NLM test for different parameters. Additional indices to gauge the impact of different parameter errors on the state estimation solution are also derived. Finally, a strategy for using phasor measurement units (PMUs) to avoid parameter error detection failures is presented by formulating an optimization problem using these derived indices. Simulation results are provided to illustrate the benefits brought by the strategic use of PMUs, and to validate the proposed problem formulation and solution.