S Shokoohi - MSC-Instrumentation and Control Unit, Iranian Oil Pipelines and Telecommunication Company, Kermanshah, Iran
H. Bevrani - Associate PROFESSOR-Departmant of Electrical and Computer Engineering, Faculty of Electrocal Engineering, University of Kurdistan,Sanandaj, Oran
J Moshtagh - Associate PROFESSOR-Departmant of Electrical and Computer Engineering, Faculty of Electrocal Engineering, University of Kurdistan,Sanandaj, Oran
S Ahmadi - Bachelor of Scince-Departman of Electrical and Computer Engineering,Urmia University,Urmia,Iran

With increasing the presence of Microgrids (MGs) in the power systems, investigationg the MG stability during transient faults is necessary. Thisstudy investigates the transient stability analysis of a MG supplied by multiple multiple inverter interfaced distributed generations (IIDGs) during fault. The transient stability of a MG is highly depends on the IIDGs control strategy.A MG, simulated on Matlab/Simulink. including three IIDGs and two local loads connected to the IEeE 37-node distribution system is considered as test system. Simulation results show that the MG may lose its stability due to the IIDG s transient over-currents durng fault.By adding a trnsient current control loop to the voltage source inverter (VSI) control stategy, the IIDG s output currents are limited during fsult.In the connected mode, an external fault is applied to the MG. By using an appropriate tuninig based on fuzzy logic method, the transient loop controller coefficients is optimally tuned. The simulations results show the good performance and fast dynamic of the proposed control approach: also the transient stability enhancement of MG, obviously.

Transient stability, Inverter interfaced distrbuted genertion, Fault current, Generalized droop contro;, Transient control loop, and Modulation index