Capacity expansion planning of distribution substations considering PV penetration

This paper presents the capacity expansion planning of distribution substations to meet the criterion of customer service reliability by considering the impact of photovoltaic (PV) systems. The historical solar radiation data are collected and applied to derive the probability distribution of PV power generation using the Markov random procedure. With the land use available for PV system installation and the growth rate of PV penetration, the total capacity of PV systems within the service territory of a distribution system is determined for each study year. By the integration of probabilistic PV power generation model and the risk model of main transformer outage, the loss of load expectation (LOLE)of the study distribution system is analyzed according to the load growth of various types of customers. It is found that the capacity expansion of distribution main transformers to maintain the service reliability can be deferred effectively when the annual PV penetration is included in the distribution system planning.