Stochastic Evaluation of Turbine-Generator Shaft Torsional Torques in an HVAC/DC Power System

This paper presents a Monte Carlo based approach to evaluate the maximum torsional torques induced in turbine-generator shafts during faults on a HVac/dc power system. In this context, investigations have been conducted on a large turbine-generator model taking into consideration the uncertainty of various factors associated with the practical operation of a power system. The results of these investigations are presented in the form of probability distributions of the maximum torsional torques induced in the turbine-generator shaft sections. A risk index that reflects the likelihood that the torque induced in a turbine-generator shaft exceeds its design value is also presented. Moreover, the paper presents a method for calculating the expected life expenditure ratio and the expected lifetime of turbine-generator shafts.