Impacts of Control Parameters on Small-Signal Stability in a Hybrid-Synchronization-Based Grid-Connected Inverter System

Recently, a hybrid synchronization control (HSC) that integrates phase locked loop (PLL) into the power synchronization control (PSL) is proposed. Some research results have clarified the HSC-based has better transient stability performance. However, impacts of control parameters on the small-signal stability in an HSC-based grid-connected inverter system is unclear under different grid strengths, which is inconvenient to design of parameters. As a result, in this paper, a full-order state-space model of the HSC-based grid-connected inverter system is built. Furthermore, by using eigenvalues analysis method, influence laws of main control parameters on small-signal stability in the HSC-based grid-connected inverter system are revealed under different grid strengths. Finally, the correctness of theoretical analysis is verified by time-domain simulation in MATLAB/Simulink. This work is hoped to provide a design orientation of parameters in HSC-based inverters for maintaining expected margin of small-signal stability under different grid strengths.