Fading-Kalman-filter-based on-line voltage stability monitoring method

The invention discloses a fading-Kalman-filter-based on-line voltage stability monitoring method. The method comprises: a parameter of a simplified Thevenin equivalent model of a power system is identified by using local information of a power grid; with consideration of a measurement error and a noise of real-time data, parameter calculation results of adjacent two times as input data of on-lineequivalent model parameters are processed and parameters of an uncertain model are estimated by using a fading Kalman filter algorithm; and with the parameters of the uncertain model, an impedance modulus margin index is calculated, accurate and stable on-line margin monitoring is carried out on the system by monitoring a stability index of a local voltage in real time, and the monitored margin value is compared with a safety margin threshold to determine a weak point and a safety and stability level of the system. According to the method provided by the invention, the method has the high capability for suppressing the local measurement information error and noises and has the excellent robust and tracking performances; the interference on the filtering by the accumulated error is reduced;accurate on-line voltage stable level monitoring is realized; and the support is provided for the safe operation of the power system.