Adaptive frequency regulation strategy in multi-area microgrids including renewable energy and electric vehicles supported by virtual inertia

Abstract

With the increased level of penetration of distributed generators (DGs), renewable energy sources (RESs) in microgrids (μGs), the impact of damping, and low inertia effect on the grid stability increase in the situation of uncertainties. This leads to some important issues that happened in the power systems such as power fluctuaCVtions due to the variable nature of RESs, frequency regulation degradation, voltage rise, and excessive supply due to full DGs generation in the grid electricity. A solution to improve the stability is to provide inertia virtually by virtual synchronous generators (VSGs) that can be created using an appropriate control mechanism. Therefore, to overcome the aforementioned challenges, a robust control strategy should be applied. In this study, a new adaptive control technique for on-line tuning the integral controllers’ gains for power charging/discharging of plug-in electric vehicles (EVs) has been proposed using Harris hawks optimization (HHO) based Balloon Effect (BE) supported by a virtual inertia controller considering high-level penetration of RESs in islanded and interconnected μGs. The main target is to regulate the suggested μG frequency powered by a PV power source and a diesel generator in the presence of random load variations and flexible loads for enhancing system robustness and validity in face of parametric uncertainties and disturbances. The time delay caused by the communication process between the area and the control center is considered for the interconnected μGs dynamic model. The discussion and analysis of the results show that the suggested control strategy has a better performance on frequency regulation, and maintaining the stability of the μG system as compared to another powerful controller called coefficient diagram method (CDM) in presence/absence of the virtual inertia control loop.