Robust state estimation method based on maximum exponential square

State estimation is a fundamental function of energy management system (EMS) and has been practically used for many years. However, traditional weighted least square (WLS)-based state estimator still suffer problems when conforming errors exist. In this study, a maximum exponential square (MES) state estimation method is proposed, which is formulated as a maximisation problem with an exponential square objective function. As a special type of M-estimator, the main characteristic of an MES estimator is that it can automatically suppress bad data and its calculation is fast, and so it is suitable for practical applications. A large number of tests have been performed to verify the performance of an MES estimator in suppressing bad data. Tests on a real provincial power system have also been performed to verify the calculation efficiency and estimation accuracy of an MES estimator.