Sequential Dynamics in Photovoltaic Power Station Under Low Voltage Ride Through

The conventional simplification of a photovoltaic (PV) station as a one-off trip, in case of its failure in low voltage ride through (LVRT) is often inadequate for analyzing cascading failures in modern power systems with non-unique timescales. To address this issue, this paper proposes an efficient methodology to study the local dynamics in the PV station under LVRT. Firstly, an analytical voltage-distribution model and an event-timing algorithm are presented. The iterative use of the model and algorithm straightforwardly describes the sequential dynamics and associated events within the station. Secondly, the cascading mechanism of the avalanche trip-off phenomenon is explained using the proposed methodology. Furthermore, the accelerating effect of events is evaluated so as to identify the crucial factors affecting the cascading process. Finally, the cases studied in MATLAB/Simulink validate the proposed analytical methodology, and demonstrate the presented mechanism. This paper explores the precise behavior in the PV station. It hopefully provides a straightforward way to effectively predict and generally explain the cascading events within station in an analytical manner, instead of using detailed simulations.