Operational Challenges of Solar PV Plus Storage Power Plants and Modeling Recommendations

This paper reviews potential operational challenges facing hybrid power plants, particularly solar photovoltaic (PV) plus battery energy storage systems (BESS). Real-world operation has witnessed many challenges, e.g., overvoltage at fault recovery, oscillations during solar PV ramping up, large phase angle change during faults, etc. This paper reviews potential operational challenges while focusing on those caused by plant-level control and inverter-level control coordination. To this end, detailed plant-level frequency-power droop control and voltage control are presented. Effect of the communication delay from the plant level to the inverter level is examined. This paper also presents recommendations on how to test hybrid power plants to detect those potential operational challenges in the planning stage. The contribution of the paper is two-fold: 1) A list of operational challenges has been reviewed with several analyzed in detail and demonstrated in case studies. Modeling and testing recommendations to capture those challenges in the planning stage have been presented. 2) The paper presents the details of IBR controls at both the plant level and the inverter level, elucidating the connection between control parameters and operational challenges. Mitigation plans, e.g., control parameter tuning, can be derived based on the insights revealed from this research.