The critical defect of the simplified lumped massspring shaft model in subsynchronous resonance (SSR) simulation study lies in that no detailed torque dynamics of the shaft can be obtained for the purpose of accurate fatigue analysis. To remedy such a situation

a cosimulation method by combining PSCAD and ANSYS is proposed and implemented. The simple shaft model with several masses in PSCAD is replaced with a complicated shaft model with several hundred masses in ANSYS

which makes the SSR study more complete and rigorous. Therefore

sufficiently detailed data are available for further fatigue analysis. Rotation speed and torque are used as the interfacing data between the two software. The data communication mechanism has been elegantly designed and implemented in order to fulfil cosimulation. With the SSR problem in an India power plant as an example

the detailed torque dynamics of specified shaft segments has been obtained and compared with the average torque provided with the simple model in PSCAD

which fully demonstrates the feasibility and effectiveness of our proposed method. This work is supported by National Natural Science Foundation of China (No. 51322701).