An improved recursive assessment method of Thevenin equivalent parameters based on PMU measurement

To quickly obtain the Thevenin equivalent parameters and achieve on-line monitoring bus voltage, an improved recursive assessment method for the Thevenin equivalent parameters is proposed, which uses differential variables to reflect parameters change, and the expressions of parameters are deduced by principle of circuits. According to the characteristics of the bus voltage and current by phasor measurement units (PMU), the power-side equivalent impedance regarded as start initial value for the improved method is calculated. This method is simply deduced with less computation. The analysis results of IEEE 14 bus system demonstrate that the method can be used for on-line tracing the Thevenin equivalent parameters effectively and rapidly and be applied in actual power systems.