Investigating Power Sharing and Frequency Deviationof Islanded Microgrid Considering Different ControlStrategies and Droop Coefficients

Microgrid is defined as controllable unit whichincludes Distributed Generations, loads, energy storages andcontrol devices. It can be operated in grid connected andislanding modes. Voltage and frequency control and powersharing between DGs are an issue of a great importance inislanding operation of microgrid. Two main control strategies forDGs are active-reactive power control and voltage-frequencycontrol. Droop control is usually used to control power sharingbetween DGs in islanding mode. Selections of appropriate controlstrategy and droop coefficient have a strong effect on themicrogrid performance. This paper analyzes the influence ofcontrol strategy and droop coefficient selection on the powersharing and frequency deviation of islanded microgrid. A singlebus microgrid that consists of two parallel DGs is simulated usingMATLAB/Simulink. Five cases are considered for investigations.

Keywords:

Distributed Generation , Droop Control , Islanding operation , PQ control , Vf control