Microcontroller Assist Fault Detection for Microgrids Based on Discrete Wavelet Transform

Microgrids are small independent network of electricity which has its own sources of power generation. Microgrids work independently and can also take power from main grid. Most microgrids have inverter based distributed generations and energy storage System (ESS) which makes fault detection and isolation challenging for classical fault detection methods due to lower current contribution by distributed energy resources. Fault detection and isolation is the major challenge in operation of microgrids and essential for safe and reliable functioning of load connected. This paper proposes a novel approach for microgrid protection using discreet wavelet transform (DWT) which is a very efficient signal processing tool, this approach uses multiresolution analysis of three phase current signals by wavelet decomposition. The spectral entropy of the three-phase current signals are calculated in real time in a Microcontroller which gives the trip signal to circuit breaker by breaker control logic at different fault conditions. This system is verified as controller hardware in loop (CHIL) with a real-time digital simulator (RTDS) and microgrid model developed in RSCAD. Test and Simulation results shows that the proposed microgrid protection scheme is accurate and evades the problems faced by classical protection schemes in microgrid protection. This Protection scheme is easy to implement and does not require any complex or expensive equipment's.