This paper presents the investigation on single pole tripping scheme of Nam Ngum 2 hydro power plant. The objective is to investigate and perform the simulation on the fault event which cause the generator instability and tripped from the system even though the transmission line between Nam Ngum 2 power plant and main grid was implemented with single-pole tripping scheme. The ATP-EMTP program has been used to conduct the transient stability study and modelling. The detailed model of hydro turbine governor, automatic voltage regulator (AVR), generator, transformer and transmission line are included in the simulation. The simulation result is presented and the comparison is made between the actual waveform which was recorded during the event and the simulated waveform to confirm the validity of the simulation model. The simulation result shown that the single-pole tripping could not help the generator to maintain the stability in this case. In addition, the model can be used to perform the parameters tuning for the better performance of the protection system.
Nam Ngum 2 Hydro Power Plant, Transient Stability, Single-pole Tripping Scheme, ATP-EMTP
