The renewable energy resources have the potential stability issues, e.g. small signal instability, due to the interaction among multiple power electronic devices (PEDs) in a multi-infeed power electronic system (MIPES), especially connected to weak grids. As a high-controllability device, the STATCOMs can be a potential choice to enhance the system’s small-signal stability. However, how the location of STATCOMs influences the system’s stability in a structure-preserving MIPES has not been investigated. This paper explores this issue and an indicator is proposed for optimal placement of STATCOMs with respect to small signal stability through the eigenvalue sensitivity technique. The merit of this proposed indicator is that the calculation is simple since it is only related with the network structure and the PEDs’ capacities, which can be easily applied in large-scaled MIPES. Simulation results verify the efficacy of this indicator.

small signal stability, STATCOM, optimal placement, power electronic device (PED)