The invention provides an event detection method and
system for a mechanical overspeed test of a
steam turbine generator unit, relates to the technical field of state monitoring and fault diagnosis of
electric power equipment, and aims to solve the problems that existing mechanical overspeed test recognition is prone to
false alarm and missing alarm, and positioning at a critical moment is not accurate. The method comprises the following steps: acquiring the active power of a generator and the rotating speed of a
steam turbine, carrying out preprocessing and rolling
smoothing processing to obtain a
smoothing power and
smoothing rotating speed sequence, determining a first key time point based on the smoothing power sequence, carrying out segmented
backtracking and descending
trend detection on the smoothing power sequence, and determining a second key time point. And carrying out descending track detection on the smooth rotating speed sequence, determining a third key time point,
backtracking the smooth rotating speed sequence, determining a fourth key time point, determining a fifth key time point based on the original rotating speed, and judging whether a mechanical overspeed test is carried out or not. According to the invention, problems in the prior art are solved, and reliable and automatic identification and accurate event definition of the mechanical overspeed test are realized.