A Hierarchical Regionalization-Based Load Shedding Plan to Recover Frequency and Voltage in Microgrid

In microgrids, where the holistically centralized techniques do not meet the speed requirement, regionalization can be a viable solution to improve and speed up protection and control applications. This paper presents a fast regionalized approach to mitigate the microgrid voltage and frequency deviations simultaneously. The regionalization technique is on the basis of a multidimensional distance criterion known as Mahalanobis index which can be executed at several load levels in a parallel manner. In contrast to the existing district-based methods which lead to unified areas from the geographic point of view, the new technique regionalizes the network without enforcing geographic distance condition, with more degree of freedom. This feature assures faster and more effective voltage and frequency recovery. Since the load model inlfuences the voltage and frequency of the grid particularly in abnormal conditions, a hybrid load model dedicated to low-voltage distribution systems is employed here. To appraise and compare the performance and accuracy of the proposed plan with an existing one, the standard IEEE 37-bus distribution system is assayed. The steady state results and dynamic responses attest to the superiority of the proposed plan and guarantee satisfactory fulfillment for real-world practices.