Frequency Control of Low Inertia Microgids in Presence of Wind and Solar Units Using Fuzzy-neural Controllers

Abstract

Balance between generating power and load demand is one of the most important challenges of power systems which directly affects frequency stability. Power imbalances can cause the operation of relays and frequency instability, as a result. On the other hand, in a microgrid, increasing the penetration factor of wind and solar energy can cause lack of frequency control due to uncertainty of generating output power and also low inertia of these resources compared to other conventional sources. Furthermore, Adjusting the gain of droop and inertia control loops is very effective on frequency stability performance. However, due to the wind speed and solar radiation fluctuations as well as load changes, it seems impossible adjusting the mentioned control coefficients with conventional PI controllers expecting the best response in all conditions. Therefore, this paper, by modeling load changes and wind and solar generating power and the participation of battery energy storage and diesel generators in the microgrid, proposes a control method based on virtual inertia compensation and also a fuzzy-neural controller for faster performance and more robustness. In the end, the results of this control strategy will be compared with other conventional controllers.