Method for assessing remaining life of rotating electrical machine and device for assessing remaining life of rotating electrical machine

A method of maintaining a rotating electrical machine that, includes an insulator, the method comprising:

• assessing a remaining life of the rotating electrical machine, the assessing including
• acquiring, as actual running performance data about the rotating electrical machine, a running time of, and the number of times of activation/shutdown of, the rotating electrical machine, and acquiring, as electrical data about the rotating electrical machine, a dielectric tangent, a rapid current increase voltage value, a current increase rate, and a maximum discharge charge amount,
• storing, in advance, in a memory, an association relationship between the maximum discharge charge amount and a residual withstand voltage value as a first table, and an association relationship between the rapid current increase voltage value and the residual withstand voltage value as a second table,
• calculating, as a first index value, an estimation value of the residual withstand voltage value of the rotating electrical machine based on the actual running performance data,
• calculating, as a second index value, an estimation value of the residual withstand voltage value of the rotating electrical machine, with use of the first table, from the maximum discharge charge amount,
• calculating, as a third index value, an estimation value of the residual withstand voltage value of the rotating electrical machine, with use of the second table, from the rapid current increase voltage value,
• calculating, as a fourth index value, an estimation value of the residual withstand voltage value of the rotating electrical machine by performing analysis that uses a Mahalanobis-Taguchi (MT) method on each piece of the electrical data, and
• assessing the remaining life of the rotating electrical machine by estimating the remaining life of the rotating electrical machine based on results of a comparison of four index values from the first index value to the fourth index value with a value indicating an anti-surge voltage protection limit and a value indicating a safe running limit;
• generating an efficient maintenance plan and schedule for the rotating electrical machine based on the assessed remaining life of the rotating electrical machine;
• and
• performing maintenance on the rotating electrical machine according to the generated efficient maintenance plan and schedule for the rotating electrical machine.