| 主权项 |
1. A fault protection system of a power system of a dynamically positioned vessel, wherein the power system is separated into two or more power system sections each comprising a bus section of a power distribution bus, wherein the bus sections are connected by bus ties in a ring configuration, and wherein each power system section comprises two or more power system subsections each comprising a bus subsection of the power distribution bus, the bus subsections of the same power system section being connected by one or more bus couplers, wherein each bus subsection comprises a connection to a generator and a connection to a thruster drive of the dynamically positioned vessel, wherein the fault protection system comprises:
a fault isolation system including for each power system section (a) a bus tie circuit breaker for breaking the connection provided by a respective bus tie to another power system section, and (b) one or more bus coupler circuit breakers for breaking one or more connections provided by one or more bus couplers between the two or more power subsections of the respective power system section, the fault isolation system being configured to implement a differential over-current protection scheme for operating at least the bus tie circuit breaker and the one or more bus coupler circuit breakers, a generator ride through system comprising for each power system subsection an excitation limiter for the generator coupled to the respective bus subsection, the generator ride through system being adapted to limit the excitation field current provided to the generator upon occurrence of a fault, and a thruster drive ride through system comprising at least one thruster drive power source distinct from the generators of the power system and configured to provide electric energy to a DC bus of a variable frequency drive (VFD) of the thruster drive of each power system subsection during a temporary post-fault period after occurrence of a fault so as to maintain the voltage on the DC bus above a predetermined voltage threshold, such that a respective thruster drive power source is configured to supply electrical energy to a respective DC bus of the VFD of a respective thruster drive during the temporary post-fault period to maintain the voltage on the DC bus above a defined minimum threshold, wherein the fault protection system is configured, upon the occurrence of a fault in the power system, to isolate the fault by tripping the component of the power subsection in which the fault occurred and/or by opening one or more circuit breakers in the power system subsection in which the fault is located, and to continue operation of the power system with the remaining bus tie circuit breakers and bus coupler circuit breakers closed. |
