Power system dynamic behavior with large scale solar energy integration

The paper presents a study for the impacts of solar energy integration on the power system dynamic stability. A detailed photovoltaic model incorporated active and reactive power controller is used to investigate the effect of replacement of conventional steam power station by solar system considering changing in size and location. The controller depends on decoupled inner d-q current control loops and outer dc voltage regulator. The critical fault clearing time (CCT) is used as indicator for the power system transient stability. CCT is used to identify the interaction between generating units following large disturbances and can be used to initiate preventive or remedial actions against system instability. The critical fault clearing times are determined and compared within different levels of photovoltaic (PV) power integration. The effect of insertion point of PV is considered to specify effect of the location from the viewpoint of power system dynamic. The results have revealed that the transient stability performance of the system deteriorates with increasing the replacement level of conventional power station by PV system and significantly affected by the location on integration. The simulation and analysis are implemented using PowerFactory (DigSILENT) software. The test system used during the analysis is 11-bus system.