Real-time small signal stability analysis of the power electronic-based components in contemporary distribution systems

Power Electronic-based Components (PECs) can provide excellent features such as, load regulation, high power factor, and transient performance, especially in the large scale distribution systems. Accordingly, contemporary power distribution systems or Power Electronic-based Distribution Systems (PEDS) are highly penetrated with the Renewable Energy Resources (RERs) as well as innovative PECs such as, Solid State Transformers (SSTs) and inverters. Therefore, they are prone to exhibit negative impedance instability in consequence of high power factor and constant-power nature of the individual components in the system. Thus, small-signal as well as large-signal stability assessments of the PEDS play prominent role in operational (real-time) stage of the systems analyses. In this paper new small-signal stability analysis technique is developed based on d − q impedance measurement and Nyquist criterion that is capable of investigating the systems' small-signal stability in real-time. Furthermore, small-signal stability of a sample PEDS comprised from a SST connected to the source and variable load is investigated through the proposed method and with utilizing Real-Time Digital Simulator (RTDS) platform.