Digital protection communication interruption detection method applicable to metro medium-voltage power supply system

The invention discloses a digital protection communication interruption detection method which is applicable to digital protection communication interruption detection for a substation in a metro medium-voltage power supply system. In a combined way of ordinary detection and novel real-time detection, by the digital protection communication interruption detection method, GOOSE (Generic object oriented substation event) communication interruption state can be quickly diagnosed, a communication overcurrent protection function can be rightly locked in real time, and a GOOSE network load can be effectively reduced; the digital protection communication interruption detection method is a simple, rapid and high-applicability GOOSE communication interruption detection scheme.