Transient Stability Analysis of Distribution Networks with High DG Penetration During Islanding Events

The growing integration of distributed generation (DG) in power distribution networks raises significant transient stability-related issues in the event of unintended islanding situations. This paper examines the dynamic characteristics of synchronous and inverter-based DGs operating in islanded mode with the objective of pinpointing prime stability issues and suggesting enhancements. A high penetrative DG level-amended IEEE ۳۴-bus test system (۳۰–۸۰%) was developed in MATLAB/Simulink, where islanding operations were simulated under different power imbalance and fault conditions. The setup included synchronous DGs (diesel) and inverter DGs (solar) to observe their transient response in terms of parameters such as frequency deviation (Δf), voltage sag (ΔV), and recovery time. Results showed that synchronous DGs exhibited better inertia-based stability with ۲۵% less frequency deviation compared to inverter-based DGs under islanding. Inverter-based DGs with virtual inertia control showed ۴۰% less recovery time when subject to a ۵۰% load-generation mismatch. Voltage stability was affected dramatically by DG location, as units that were edge-connected rode ۱۵% more adverse voltage sags than their central-connected counterparts. These results underscore the necessity for hybrid control methods that leverage the inertia benefits of synchronous DGs while inheriting the malleability of inverter-based systems. The work offers practical guidelines to grid operators for increasing stability in DG-dominated networks and suggests further investigation into real-time adaptive protection schemes.

کلیدواژه ها:

Distributed generation ، transient stability ، islanding ، virtual inertia ، voltage sag