Device and method for realizing direct-current networking of ship electric propulsion system

The invention discloses a device and method for realizing direct-current networking of a ship electric propulsion system. A differential protection principle is applied to direct-current networking toserve as main protection of direct-current busbar short circuit, and then an alternating-current circuit breaker at the front end of a rectifier serves as instantaneous protection in main protectionof the busbar short circuit, so that the direct-current circuit breaker is only used at a buscouple switch of the whole ship direct-current networking, and the direct-current circuit breaker is switched off when a corresponding busbar is short-circuited. In addition, a direct-current fuse at the front end of an inverter is used as short-time delay protection in main protection of direct-current busbar short circuit. According to the invention, the fault busbar can be disconnected accurately and selectively, the influence area of the short-circuit fault is controlled within the minimum range, and the use of the direct-c