AC microgrid DC circuit breaker DC grids DC transmission line EV transmission lines Hilbert-Huang transform History of engineering & technology IEC 61850 GOOSE protocol MMC-HVDC Technology: general issues adaptive auto-reclosing adaptive protection bidirectional DCCB building integrated photovoltaic (BIPV) coordination optimization coppers stabilizer decentralized protection scheme distributed generation energy dissipation external elements fault analysis fault current fault current limiting feature fault protection hierarchical protection system high temperature hybrid DCCB inverse-time over-current protection lightning attachment characteristics lightning energy withstand capability