Method for determining an estimated travel curve of an interrupter unit, and interrupter unit for a gas-insulated high or medium voltage device

A computer implemented method for determining an estimated travel curve of an interrupter unit of a high or medium voltage device, comprising the steps of:

• receiving a reference travel curve for the interrupter unit of the high or medium voltage device, wherein the reference travel curve describes relative positions of arcing contacts of the interrupter unit with regard to each other over time during an opening and/or closing operation of the interrupter unit,
• receiving auxiliary switch data representing transition timepoints of an auxiliary switch A and transition timepoints of an auxiliary switch B of the interrupter unit during opening and/or closing operation, wherein the auxiliary switch data has been acquired by performing multiple opening and/or closing operations of the interrupter unit,
• determining a sample mean, a sample variance, and/or a sample standard deviation of the received auxiliary switch data, and
• determining an estimated travel curve by a curve fitting process and by taking the received reference travel curve and the received auxiliary switch data into account.