Voltage stability monitoring from a transmission bus PMU

摘要

This paper examines the problem of monitoring long-term voltage instability from a PMU installed at any transmission bus. It is shown that the well known impedance matching condition on a radially connected load bus, as well as the Local Identification of Voltage Emergency Situations (LIVES) method based on LTC transformers can be generalized into a New LIVES Index (NLI) suitable for any transmission bus feeding a weak area of a system. Results on an IEEE voltage stability test system validate the dependability and security of the new index for the early detection of voltage instability. Moving average, as well as a new filtering method based on short-time Fourier transform are employed to reduce the effect of noise and short-term transients.