Validating Response of AC Microgrid to Line-to-Line Short Circuit in Islanded Mode Using Dynamic Analysis

Abstract

This paper is presented in an attempt to validate the dynamic response of a microgrid to line-to-line short circuit. The microgrid components include two identical Wind Turbine Generators (WTGs) tied to a 100MVA, 13.8kV utility via a Point of Common Coupling (PCC). The utility-microgrid testbed is modeled in SIMPOWERSystems® using two Doubly-Fed Induction Generators (DFIGs) in the microgrid side. While in islanded operating mode, line-to-line short circuit fault is applied at 6.0s and withdrawn at 8.0s, obtaining a 50.0s dynamic response of the system for different fault locations, under voltage and reactive power control regimes of the wind turbine controller. For measurement purpose, the absolute value of the stator complex voltage is transformed to reference frame. Bidirectional power flow between the two feeders is established in the study. The study also confirms that the microgrid composed of DFIGs offer reactive power management capability, particularly by presenting superior performance when stressed under Q control regime than under V control regime. Finally, the response of the testbed to line-to-line short circuit has been validated and shown to be consistent with established short circuit theory.

Grid-connected Response Verification of AC Microgrid under Single Line-to-ground Short Circuit

“…This paper therefore presents verification of the responses of the microgrid testbed to single line-to-ground short circuit in grid-connected mode under voltage and reactive power control regimes using dynamic analysis. Dynamic analysis depicts the sub-transient, transient and steady-state variation of critical parameters of the system [14]. Design of engineering systems require performance prediction and optimization using system models [15][16][17][18].…”

Islanded Mode Response Verification of AC Microgrid under Symmetrical and Non-symmetrical Short Circuits

“…Using dynamic analysis, this work presents verification of the responses of a microgrid testbed to short circuits of the type: line-to-ground, line-to-line, double line-to-ground, bolted three phase and crosscountry. Dynamic analysis depicts the sub-transient, transient and steady-state variation of critical parameters of the system [12]. In addition to protective systems, power systems require control devices for optimal operation [13].…”