Risk Assessment of Post-Fault Temporary Overvoltage Using Generalized Short-Circuit Ratio

Temporary overvoltage (TOV) is becoming one challenge for the integration of significant power electronics resources into a power system. To adequately assess the risk of TOV in a Multi-Infeed Power Electronic System (MIPES), a comprehensive methodology is proposed in this paper. The paper starts with analyzing the mechanism of TOV, which reveals that TOV is dominated by excessive reactive power resulting from control lagging of converters. Then, the principle of estimating the level of TOV for a Voltage Source Converter (VSC) connecting to an infinite bus is introduced. After that, a methodology based on the concept of generalized short-circuit ratio for overvoltage (gSCR-TOV) is introduced to quantify the risk of TOV in a MIPES. To localize the weakest node, the weighted sensitivity matrix is proposed to pinpoint the bus subject to highest TOV in a MIPES. Finally, case studies of EMT time-domain simulations are carried out and verifies the effectiveness of the proposed methodologies.