Renewable Integration in Hybrid AC/DC Systems Using a Multi-Port Autonomous Reconfigurable Solar Power Plant (MARS)

Abstract

As the penetration of utility-scale solar photovoltaic (PV) power plants increases, the inertia in the system is reduced and there will be increased primary frequency response requirements. To increase inertia and improve the primary frequency response, grid-forming inverters connecting PV to grid and energy storage systems (ESSs) may play an important role. Moreover, high-voltage direct current (HVdc) links can also be an enabler to transfer remote PV power generation and to improve grid stability. That is, with increased penetration of PV, discrete development of PV and ESS connecting to transmission ac grid and HVdc links is one of the solutions for stable operation of the grid. In this paper, an integrated concept for integration of PV and ESS to transmission ac grid and HVdc links is proposed that is named as multi-port autonomous reconfigurable solar power plant (MARS). The integrated development incorporates advanced control methods to provide inertial and primary frequency response, reactive power support, and transient stability to manage PV and ESS resources. In this paper, high-fidelity switched system model of the integrated system and grids are developed and detailed simulation results are provided to showcase the stable operation of the integrated system and provision of grid support functions.