A novel differential protection scheme for AC microgrids based on discrete wavelet transform

•A differential protection scheme based on discrete wavelet transform is proposed.•The proposed method has a high-performance speed with a low sampling frequency.•The algorithm is reliable in a noisy environment and detects high impedance faults.•The protection scheme is independent of the topology of the microgrid. AC microgrids are being expanded due to their numerous advantages. However, the execution of distributed energy resources near by the demand side may cause various challenges for the protection scheme. An innovative wavelet-based differential technique is presented for AC microgrids protection in this research. The operation logic calculates differential current within a specified protection zone in the first step. The Discrete Wavelet Transform (DWT) is then used to acquire the approximate and detail coefficients of the differential current of the network. Proposed DWT can detect and classify the fault during utmost 6 milliseconds. Likewise, the proposed plan is independent of the fault impedances, fault location, and grid operating situations. Different fault scenarios are implemented and examined on the standard 6-bus IEC grid in PSCAD/EMTDC software to assess the effectiveness of the suggested plan. The obtained results indicate the proposed scheme is effective, quick, and precise in fault identification for both radial and ring microgrid topologies in comparison to existing methods.