Small-signal Modeling And Analysis Of Hydro-photovoltaic Power Generation System

With energy crisis and environmental protection situation becoming serious,more attention was paid to photovoltaic power generation which is clean, green and renewable. Under the impetus of national policy, the PV industry has been rapid developing in recent years. The proportion of PV stations in power supply increases gradually. Affected by light and environment temperature, the output power of PV station is fluctuant and random. Hydro is well-regulated power supply performance, ability to quickly adjust to accommodate photovoltaic hydropower changes. Hydropower can better cooperate with photovoltaics, set up an integrated power system in order to ensure continuity of supply and reliability. Small signal stability analysis of power systems is one of the most basic and most important task. So it is important to have a research on small signal stability of the hydro- photovoltaic system.In this paper, small-signal model of photovoltaic system are built, mainly for the modeling of the inverter and controller. For hydropower, small-signal model of the entire hydroelectric system are established, including the prime mover, the governor and the synchronous generator. Then we can get the small signal model of hydro- photovoltaic systems, which contain resistance loads, detailed derivation of the models are given, and the expressions of the state matrix elements are obtained.Finally, The modes and damping characteristics of the system are analyzed by eigenvalue, and the origins of the modes are obtained by participation factors analysis. The system parameters are well designed through the eigenvalue traces. The simulation models based on DIgSILENT are presented. The simulation results show that the small-signal modeling and analysis are correct.