Impacts of Large Scale and High Voltage Level Photovoltaic Penetration on the Security and Stability of Power System

Grid-connected photovoltaic (PV) systems are developing increasingly in recent years due to many associated economic and environmental factors and provoking control and operation problems to utilities. Most of all, it also touches the essence of management mechanism of power systems. Concerning with voltage and frequency stability, electricity quality and short-term load forecasting, the possible influences on the secure and stable operation of power system brought by grid-connected photovoltaic systems are analyzed in detail, and the possible side effects that might bring to distribution system are also investigated from the view point of relay protection, reliability of power supply, electricity metering, real time monitoring and regulating, etc. Additionally, the new requirements that might bring to network simulation and calculation technology by grid-connected photovoltaic systems are also discussed, and the technical challenges and possible solutions when large amounts of PV systems are connected to high voltage level power grid are both presented.