Composite Reliability of PV-Integrated Systems Incorporating Probabilistic Capacity Outages

This paper proposes an improved model for the reliability assessment of photovoltaic (PV) composite systems. The integration of PV systems in existing power grids can help alleviate the reliability challenges. However, the intermittency and component failures associated with PV systems can hinder a reliable operation. Along with the varying failure/repair rates of PV components, the operation and network constraints of power grids can pose difficulties in the integration of PV systems for reliable operation. In this paper, a reliability assessment tool for PV composite systems is developed considering the variable availability of power electronic components, system operation, and network constraints. The effects of irradiance and ambient temperature variability on the failure and repair rates of PV farm components are modeled using a power-loss model. Discrete probability distribution of PV array outages is formulated using the tensor representation of capacity outages. The outage model is then deployed in a state-sampling-based Monte Carlo simulation framework to assess the composite system reliability while enforcing the grid operation and line loading constraints. Case studies are performed on the modified WSCC 9-bus system to illustrate the efficacy of the proposed model in the reliability assessment of PV composite systems.