Grid Transient Stability Improvement with Increased PV Availability: A PV Inverter Reliability Enhancement Approach

PV generation is a key contributor to a carbon-neutral power system. With proper planning and operation, it has significant potential to improve system reliability as well. Nevertheless, solar availability is volatile which poses a challenge to ensure an uninterrupted grid-supporting performance. One critical factor leading to the loss of PV generation is PV inverter malfunctioning as it is the most frequent fault scenario in PV systems. Despite this, there is still inadequate study into PV inverter reliability, especially for online non-intrusive health monitoring methods. In addition, effective PV planning calls for quantitative study into PV impact on grid reliability. This paper is one of the first efforts to bridge this gap. We first reveal the significance of PV generation to grid reliability by studying its impact on grid transient performance in both DC and AC networks. It can work as an input to PV planning problems, for example, to determine the optimal siting and operation strategies. Then, we develop an online monitoring algorithm to provide situational awareness information into PV inverter health. At last, we develop fault-tolerant control strategies for PV inverters to enhance PV availability. A case study verifies the proposed work.