Frequency stability and control of a power system with large PV plants using PMU information

Integrating large photovoltaic (PV) plants into the grid poses challenges to maintaining the system´s stability during small and large disturbances. A PV system´s output power fluctuates according to the weather conditions (irradiance and temperature), season, and geographic location. The power fluctuations of the PV plants raise frequency and voltage stability issues. This paper presents the impact of a large PV plant on the frequency stability of a power system under small and large disturbances. With automatic generation control and phasor measurement unit information, the power generations of conventional generators are adjusted to mitigate the frequency deviation. Furthermore, the effects of increased PV penetration in a given power system area are examined.