A Robust Controller Design for Load Frequency Control in Islanded Microgrid Clusters

A Robust Controller Design for Load Frequency Control in Islanded Microgrid Clusters

In this paper, virtual inertia control (VIC) is suggested to increase the frequency stability in islanded microgrid (MG) clusters. The aim of the suggested control method is to improve damping characteristic of MG clusters including different distributed generations (DGs). The optimal/robust values of the VIC parameters are tuned by a μ-synthesis robust control method. The proposed robust/optimal VIC-based control method is confirmed by various scenarios. Computer simulation and hardware-in-the-loop (HIL) tests are used to show the effectiveness of the suggested method in increasing the damping of the power system. Clearly, different characteristics of the dynamic responses and the results show the practicality of the suggested robust VIC.

Renewable energy resources have inherently a low inertia, since they have no rotating part. Hence, large frequency deviation occurs when the microgrid contains high-penetration RESs. This paper suggests virtual inertia control to enhance the inertia of renewable energy resources in islanded microgrid clusters considering high RES penetration, uncertainties, and nonlinearities. To achieve robust and optimal VIC and to decrease the impact of dynamic perturbations and uncertainties, a μ-synthesis method is used. In the structure of the suggested VIC, there are both the inertial response characteristics of original synchronous generator and the fast dynamics of power electronic interfaces. The suggested method can compensate the lack of inertia in the MG clusters. As discussed, robust controllers are designed to reduce the impacts of wind farm, photovoltaic, and load disturbances and dynamic perturbations. It is shown that in the case of using the structured uncertainty (μ approach), the obtained controller demonstrates better performance. It is demonstrated that in the case of utilizing the structured uncertainty, the controller shows a satisfactory performance. Islanded microgrid clusters are utilized to confirm the efficiency of the suggested VIC. The simulation and HIL results confirm that the suggested controller can reduce the frequency deviations considerably and also show superior performance of the suggested VIC in the presence of high RES penetration and heavy loading.

مراجع:

Mohammad Reza Ghodsi, Alireza Tavakoli, Amin Samanfar, "A Robust Controller Design for Load Frequency Control in Islanded Microgrid Clusters", International Transactions on Electrical Energy Systems, vol. 2022, Article ID 4218067, 12 pages, 2022. https://doi.org/10.1155/2022/4218067

https://onlinelibrary.wiley.com/doi/10.1155/2022/4218067