Detailed Modeling and Integration Study of Grid-Connected Solar PV Generation with Energy Storage and Power-Factor Control Capability

This paper presents the results of a modeling and integration study of solar power plants to evaluate their transient impact on electrical power transmission systems.  A generic solar generation model was developed based on manufacturers’ data to analytically relate the incoming irradiance and module temperature to the solar plant’s generation output. A popular two-staged dc-ac power conversion scheme was adopted. The major contributions of this study are (1) the development of a modified incremental conductance (IncCond) maximum power point tracking  (MPPT) algorithm than can effectively improve the MPPT performance of a solar module/array; (2) the development of an interface between solar power plants and the transmission grid, including both active and reactive power injection control, such that the impact of intermittent solar generation (e.g., due to cloud transients) on the grid can be evaluated; and (3) the development of an electrical circuit model for a battery energy storage system (BESS), the interface between the BESS and the grid, and the frequency control scheme. A Matlab-implementation of the developed models and algorithms was performed to provide a flexible integrated tool for studying the impact of increasing penetration levels of solar generation and developing better control schemes to compensate for varied amounts of solar  intermittence.