A HEM-Based Sensitivity Analysis Method for Fast Voltage Stability Assessment in Distribution Power Network

The increased penetration of distributed energy resource and power electronics-based loads cause rapid voltage fluctuations in distribution networks, affecting secure operation the grid threatening high-quality delivery to customers. It is great importance conduct fast accurate stability assessment for better understanding operational risks providing effective timely controls mitigating identified risks. Traditionally, Jacobian matrix-based sensitivity analysis methods are used evaluate stability, however they suffer from ill-conditioned load flow problem caused by numerical stability. To effectively resolve this issue, paper presents a novel Holomorphic embedding method (HEM)-based approach that can capture information stressed operating conditions when calculation becomes ill-conditioned. An criterion also proposed approximate instability point using structural partial with different orders. effectiveness verified via simulations conducted on IEEE 33-bus 69-bus test systems.