Fuzzy-logic based Autonomous Operation of Small-scale Microgrid in Emergency

Abstract

In this paper, an autonomous operation algorithm of small-scale MG in emergency based on a fuzzy logic is proposed. The proposed algorithm is implemented as an application program named EMC (emergency controller) for MG EMS (energy management system) and it use an iterative judgment and control in a very short cycle using the alarm/event type data, unlike typical application programs that utilize snapshot type datasets. We propose a fuzzy-based decision logic to overcome the communication problems and bad data in the field which is difficult to apply autonomous operation. In order to distinguish between malfunction and internal/external faults of the MG, the membership function based on the overcurrent and the low alarm is presented and the fuzzy inference is performed using it. Also, the module configuration for EMC is presented, which consists of emergency classification module, fuzzy logic module, multiple emergency processing module and control processing module. The validity and applicability of the proposed algorithm was demonstrated using the 500 kW campus microgrid of the Chonnam National University constructed with KEPCO (Korean Electric Power Corporation). The reliability and economic efficiency of the system can be improved benefitting from the ability of autonomous handle of the emergency situation with proposed algorithm.