Synchronization Control Stability Analysis of Power Converters with High Renewable Energy Penetration

Abstract

This paper discusses synchronization stability in power converters with high penetration of renewable energy. Grid synchronization and input/output power balancing of converter are accomplished by phase locked loop (PLL) and power control loop, respectively, while these two aspects are intrinsically related due to the mechanism of PLL based synchronization and the power/angle relationships in AC system. The performance of PLL, which is revealed to be analogous to rotor motion of synchronous generator with power control acting on PLL input, is identified as essential factor that affects power and synchronization stability in weak grid characterized by large PLL operating power angle. PLL loss of stability could occur due to the imbalance of the output component with the input component, and further leads to failure in power control.