Integrated Control and Protection Scheme for Seamless Operation of Microgrid

This paper presents the integrated control and protection scheme for the seamless operations of the microgrid. The proposed control scheme is designed according to the IEEE standard 2030.8. The proposed control scheme regulates the voltage and frequency (V-f) of microgrid within a standard operating range set by the IEC 61727, IEEE 2030.8, and IEEE 1547 standards under steady state and dynamic conditions in grid connected and islanded modes of operation. The decentralized control scheme is presented to control the distributed energy resources (DERs) in the microgrid including the plug-n-play feature for the integration of DERs to the microgrid. The microgrid test system with the proposed control scheme is implemented in Matlab/SimScape together with an islanding detection scheme based on the rate of change of frequency (ROCOF). Further, an adaptive protection scheme is used when any fault occurs in the microgrid during both operating modes, and an over/under voltage-based power balance control scheme is used to connect/disconnect the non-essential load when voltage/frequency (V-f) exceeds standard operating ranges. Results show that the proposed integrated scheme has the ability to ensure the seamless operations of the microgrid under different operating scenarios.