Patent ID: 11909201
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 12:
13. A fault recovery method for a multi-terminal DC power transmission system,
the multi-terminal DC power transmission system comprising:
a multi-terminal DC power grid including a plurality of protection zones, each protection zone being divided from an adjacent protection zone by a DC circuit breaker;
a plurality of individual protective devices provided corresponding to the protection zones; and
a common control device connected to the individual protective devices via a first communication network,
the fault recovery method comprising:
when detecting, by any one of the individual protective devices, change in voltage or current in a corresponding protection zone due to fault occurrence in any of the protection zones, outputting, by the individual protective device, a fault signal pertaining to the fault occurrence to the common control device via the first communication network, and opening, by the individual protective device, a DC circuit breaker that divides the corresponding protection zone such that the corresponding protection zone is disconnected from the multi-terminal DC power grid and deenergized;
estimating, by the common control device, a fault occurrence zone where a fault occurs among the protection zones, based on a plurality of received fault signals, each being the output fault signal; and
requesting, by the common control device, an individual protective device of the plurality of individual protective devices, corresponding to a deenergized protection zone of the plurality of protection zones to reclose the DC circuit breaker that divides the deenergized protection zone such that the deenergized protection zone is restored.