Voltage Stability Analysis and Quantitative of Power Systems Considering LVRT of Renewable Energy

As renewable energy rapidly develops, the proportion of renewable energy capacity in power systems is increasing, leading to various voltage stability challenges. Two novel voltage instability phenomena, “repeated low voltage ride-through” and “continuous low voltage ride-through”, have emerged in renewable energy power systems with low voltage ride-through (LVRT) capability. This paper develops a model of a renewable energy power system and analyzes the fundamental causes of these instability phenomena. Furthermore, the paper derives the quantitative relationships among these instability phenomena, line impedance, and the active and reactive power outputs of renewable energy sources. The explicit expressions for the corresponding instability boundaries are derived. Finally, the electromagnetic transient simulation tool, PSCAD, is utilized for simulation and verification.