DEVELOPMENT OF A NOVEL ADAPTIVE PROTECTION SCHEME FOR ACMICROGRID

Abstract

With the growing use of renewable energy sources (RES) and distributed generation, AC microgrids are becoming a viable option for improving the flexibility, efficiency, and resilience of power distribution networks. However, to guarantee the dependable functioning of microgrids, it is necessary to have strong protection systems that can quickly detect, and isolate faulty part form the healthy system while also preserving the stability of the system. A novel adaptive differential current based protection technique is proposed in this paper to detect the fault in AC microgrid. For the fault detection, power cepstrum difference of both end of a unit line is used. The cepstrum technique, an advanced signal processing method, offers notable benefits for fault diagnosis in these systems. This technique involves analyzing the cepstrum, which is obtained by taking the inverse Fourier transform of the logarithm of the power spectrum, to identify periodicities in the frequency domain that correspond to fault frequencies. By transforming and deconvolving the signal, cepstrum analysis can isolate and enhance fault characteristics, making it particularly effective for detecting the fault frequencies and fundamental frequency in the microgrid system. This paper explores the application of the cepstrum technique in fault detection, detailing its theoretical foundation, implementation methods, and practical benefits of this technique. The proposed technique is implemented and tested on the standard 3- phase, 4 wire a mesh connected 4- bus AC microgrid in MATLAB/ Simulink software to assess the effectiveness of the proposed technique. The proposed test system is designed and simulated in PSCAD-EMTDC software, while MATLAB programming interface is used for developing and testing the proposed algorithm.