Oscillation Dynamics Analysis in Photovoltaic-Diesel Combined Black Start for Islanded Microgrids

Black start is vital for power system recovery after large-scale outages. This study analyzes oscillations observed during photovoltaics (PV)-diesel combined black start in an islanded microgrid in China, focusing on the dynamics of renewable energy and power electronic devices. Oscillations occurred after the static var generator (SVG) and/or PV system was connected during auxiliary equipment startup, causing PV disconnection and black start failure. The analysis results show many harmonic and interharmonic components in the start-up process, and the interaction between SVG, PV, and grid is the primary cause. This study highlights the need for oscillation risk assessments and advanced monitoring systems to improve stability in black start processes involving renewable energy.