Augmented State Estimation Method for Fault Location Based on On-line Parameter Identification of PMU Measurement Data

When a fault occurs in power grid, accurate and timely fault location is of great significance in reducing fault losses. With the rapid development of synchronous phasor measurement technology, the high-precision big data brought by the synchronous phasor measurement brings many possibilities to the on-line fault diagnosis of the distribution network. This paper proposed an augmented state estimation fault location method based on on-line parameter identification. By using the initial and terminal voltage and current phasor measured by PMU, the relationship between voltage and current along the positive sequence network and negative sequence network is deduced. The line parameters and the fault information (the fault distance and the voltage phasor of the fault point) are augmented into the state quantity, and the state estimation is performed together with the original node state quantity to realize on-line parameter identification and accurate fault location. The radial distribution network model is built in PSCAD. The simulation results verify the correctness and high precision of the proposed algorithm.