Small-signal stability assessment of a single-phase solid state transformer through PHIL experiment

摘要

Power electronic-based components (PECs) such as solid state transformers (SSTs), fault isolation devices (FIDs), power electronic-based converters, and motor drives provide highly useful features such as, load regulation, high power factor injection, and improved transient performance for power electronic-based distribution systems (PEDS). In contemporary power systems, which have high penetrations of renewable energy resources, as well as the inclusion of PECs. However, the drawback of including PECs in the system is that they can operate as negative impedances while connected to the constant power loads (CPLs) in the PEDS and CPLs are prone to small-signal instability due to their high power factor and constant-power nature in the system. Therefore, small-signal stability of the PEDS plays a prominent role in the systems analysis. In this paper, a new small-signal stability analysis method, based on d-q impedance measurement and generalised Nyquist criterion (GNC), is developed, and the stability of an SST is comprehensively investigated under various loading conditions and through power hardware-in-the-loop (PHIL) experimentation.