Electromagnetic Analysis of a Large Hydrogenerator during Symmetrical Grid Fault in a Power System Network

Hydropower is one of the most reliable renewable sources of electricity generation. Due to wear and tear, aging, oscillations, unexpected faults in the line, and renewable integration, etc, transients and instability are instigated in the grid consequently harming the hydrogenerator. These electromagnetic anomalies have an impact on the dynamics, stability, and power quality at the generator side. This research investigates the electromagnetic behaviour of a hydrogenerator using the finite element analysis method in ANSYS under the exposure of symmetrical line fault in the power system, essentially a three-phase fault. A comparison is made based on simulations performed on a 250 MW salient pole synchronous generator installed at a large hydropower plant excited by ideal field excitation and the affected field current due to symmetrical fault in the line.