Generally, the maximum power transfer through a transmission line can be increased by reducing the line reactance. To achieve this goal, series compensation of the line (by putting series capacitors) has been practiced for long. Interestingly, once the series capacitance is put in the line and varied, resonance phenomenon is observed which is created between the electrical network and the mechanical components of the whole power system. The resonance creates low frequency oscillations (lower than the power freq.) whose magnitude grows with time and ultimately damages the shafts.

For further detail and modeling you can go through the following books:

1. Anderson, P. M., Subsynchronous resonance in power systems, New York, IEEE

Press, 1990.

2. Yu, Y., Electric power system dynamics, New York, Academic Press, 1983

Adding to the above a few material that may helpful

Thank You Ashik Ahmed 

 Thanks Pavan Kumar A. V.