PROJECT TITLE :

Impact of Dynamic Behavior of Photovoltaic Power Generation Systems on Short-Term Voltage Stability

ABSTRACT:

In this study, we investigate the impact of the dynamic behavior of photovoltaic (PV) power generation systems on short-term voltage stability of the transmission system. Initial, the impact of the fault ride-through capability of a PV model is studied by setting several recovery speeds of the active current output when the operation of the PV system is interrupted because of a voltage sag. The results are analyzed by using transient P-V curves and a stability boundary, that has been proposed in our previous analysis. Further, we show that the installation of PVs severely impairs the short-term voltage stability if the PVs shut off after a voltage sag, and its recovery speed is low. Next, two countermeasures to regulate short-term voltage instability phenomena are tested. One is that the operation of the PV system at a leading power factor in the normal state, and the other is the dynamic reactive power management by the inverters of the PV system after a voltage sag. Numerical examples are meted out for a one-load infinite-bus Power System and a 5-machine five-load power system. The results show that these countermeasures will play a substantial role in preventing the voltage instability phenomena caused when a PV system is suddenly interrupted as a result of of a fault.