Abstract: A direct electric heating (DEH) system for heating a subsea pipeline is provided. The DEH system includes a subsea power cable adapted to be coupled to a three phase electric power source. The DEH system further includes two or more subsea DEH modules. Each subsea module of the two or more subsea DEH modules is provided for heating a different pipeline section of the subsea pipeline.

Abstract: A fault protection system for a power system of a dynamically positioned vessel is provided. The power system is separated into two or more power system sections, each including a bus section of a power distribution bus. The bus sections are connected by bus ties in a ring configuration. Each bus section includes a connection to a generator and a connection to a thruster drive of the dynamically positioned vessel. The fault protection system includes a fault isolation system which includes for each power system section a bus tie circuit breaker for breaking the connection provided by the bus tie.

Abstract: A power supply system configured to couple to a power distribution bus of a marine vessel and to power a plurality of electric motors coupled to the power distribution bus. The power supply system includes a generator configured to generate electric power and a control system coupled to the generator and configured to control the output voltage of the generator based on a voltage setpoint. The control system includes a measuring unit configured to measure a parameter of the electric power generated by the generator and a control unit configured to control the voltage setpoint for the output voltage of the generator based on the measured parameter.

Abstract: A fault detection system for subsea pipeline direct electrical heating cables is provided. The fault detection system includes a first ammeter for measuring a first phase current, a second ammeter for measuring a second phase current, and a third ammeter for measuring a third phase current. The fault detection system also includes a first calculation unit for calculating a negative sequence current from the first phase current, the second phase current, and the third phase current, and a first detection unit for detecting a change in the negative sequence current.

Abstract: A fault detection system for subsea pipeline direct electrical heating cables is provided. The fault detection system includes a first ammeter for measuring a first phase current, a second ammeter for measuring a second phase current, and a third ammeter for measuring a third phase current. The fault detection system also includes a first calculation unit for calculating a negative sequence current from the first phase current, the second phase current, and the third phase current, and a first detection unit for detecting a change in the negative sequence current.

Abstract: A fault protection system of a power system of a dynamically positioned vessel is provided. The power system has a power distribution bus having three or more bus subsections, electric connections including bus ties which connect the bus subsections in a ring configuration, and circuit breakers connected between the bus subsections. The fault protection system includes a generator circuit breaker for coupling a generator to a bus subsection, feeder circuit breaker(s) for coupling load(s) to the bus subsection, a first circuit breaker for connecting one end of the bus subsection to a bus tie that provides an electric connection to another bus subsection, the first circuit breaker being a bus tie breaker, a second circuit breaker for coupling another end of the bus subsection to a further bus subsection, protection relays for operating the circuit breakers, and communication links between protection relays that exchange information via said communication links.

Abstract: A direct electric heating (DEH) system for heating a subsea pipeline is provided. The DEH system includes a subsea power cable adapted to be coupled to a three phase electric power source. The DEH system further includes two or more subsea DEH modules. Each subsea module of the two or more subsea DEH modules is provided for heating a different pipeline section of the subsea pipeline.

Abstract: A method of detecting a fault in a subsea power cable or in a direct electric heating system including a subsea power cable is provided. Measuring points are distributed along the subsea power cable. The method includes measuring at each measuring point a current in the subsea power cable and comparing the currents measured at the different measuring points.

Abstract: A power supply system configured to couple to a power distribution bus of a marine vessel and to power a plurality of electric motors coupled to the power distribution bus. The power supply system includes a generator configured to generate electric power and a control system coupled to the generator and configured to control the output voltage of the generator based on a voltage setpoint. The control system includes a measuring unit configured to measure a parameter of the electric power generated by the generator and a control unit configured to control the voltage setpoint for the output voltage of the generator based on the measured parameter.

Abstract: In a power supply arrangement for supplying electrical power to the pipeline, the power supply arrangement for direct electrical heating of a pipeline system has basically a three phase transformer, a symmetrization unit, and a compensation unit. The three phase transformer is adapted to support a single phase load connected between a first and a second phase of the transformer. The transformer has at least one first tap changer at a high voltage side of the transformer. The symmetrization unit has a first capacitor connected between the first phase and a third phase of the transformer and an inductor connected between the second phase and the third phase of the transformer. The compensation unit has a second capacitor connected between the first phase and the second phase of the transformer. The first tap changer, the first capacitor, the second capacitor and the inductor are adapted to be varied on-load.

Abstract: A fault protection system of a power system of a dynamically positioned vessel is provided. The power system has a power distribution bus having three or more bus subsections, electric connections including bus ties which connect the bus subsections in a ring configuration, and circuit breakers connected between the bus subsections. The fault protection system includes a generator circuit breaker for coupling a generator to a bus subsection, feeder circuit breaker(s) for coupling load(s) to the bus subsection, a first circuit breaker for connecting one end of the bus subsection to a bus tie that provides an electric connection to another bus subsection, the first circuit breaker being a bus tie breaker, a second circuit breaker for coupling another end of the bus subsection to a further bus subsection, protection relays for operating the circuit breakers, and communication links between protection relays that exchange information via said communication links.

Abstract: A fault protection system for a power system of a dynamically positioned vessel is provided. The power system is separated into two or more power system sections, each including a bus section of a power distribution bus. The bus sections are connected by bus ties in a ring configuration. Each bus section includes a connection to a generator and a connection to a thruster drive of the dynamically positioned vessel. The fault protection system includes a fault isolation system which includes for each power system section a bus tie circuit breaker for breaking the connection provided by the bus tie.

Abstract: In a power supply arrangement for supplying electrical power to the pipeline, the power supply arrangement for direct electrical heating of a pipeline system has basically a three phase transformer, a symmetrization unit, and a compensation unit. The three phase transformer is adapted to support a single phase load connected between a first and a second phase of the transformer. The transformer has at least one first tap changer at a high voltage side of the transformer. The symmetrization unit has a first capacitor connected between the first phase and a third phase of the transformer and an inductor connected between the second phase and the third phase of the transformer. The compensation unit has a second capacitor connected between the first phase and the second phase of the transformer. The first tap changer, the first capacitor, the second capacitor and the inductor are adapted to be varied on-load.