Adaptive control strategy for improved dynamic performance of two islanded inter-connected micro-grids

Abstract

Micro-grids with proper control should be able to maintain stability and achieve the best response when subjected to different disturbances. Traditionally, power electronic converters used in micro-grids are controlled using linear fixed parameter controllers such as, conventional PI controller and droop controller, which are unable to mitigate such disturbances efficiently over a wide range of operating conditions. An adaptive self-tuning controller that can adapt in real-time as operating conditions change is investigated in this paper. An adaptive self-tuning controller based on recursive least squares identification and pole-shifting control is designed and implemented on the dispatchable sources connected boost converter in two connected micro-grids. Its performance is compared with the fixed parameter PI controller. Parameters of the PI controller and gains of the self-tuning adaptive controller are optimized using an advanced optimization technique called global Porcellio Scaber algorithm. Effectiveness of the proposed controller is investigated on a two inter-connected micro-grids system isolated from the grid under various scenarios such as load variations and weather conditions fluctuations. Simulation results verify that the system response based on the proposed pole-shift controller is better than the classical PI controller under various operating conditions.