A subsea substation system including: an oil-filled water impermeable enclosure; an AC-transformer, and at least one overcurrent device electrically connected to the AC-transformer, the at least one overcurrent device, the AC-transformer, and the electrical connections between them are accommodated in the oil-filled water impermeable enclosure, wherein the enclosure includes thermal zones within the enclosure, wherein the AC-transformer is arranged in a first thermal zone and the overcurrent devices are arranged in a second thermal zone of the enclosure, a thermal layer separate the first thermal zone and the second thermal zone, the at least one thermal layer is configured to allow oil flow between the thermal zones while reducing heat flow between the zones.

A subsea switchgear for switching the power supply to plural subsea loads includes a subsea enclosure, to allow the deployment of the subsea switchgear at a subsea location; a power input for receiving AC electrical power from a power source; at least two power outputs for giving out AC electrical power; and a power distribution bus for distributing the received AC electrical power to the at least two power outputs. In at least one embodiment, between each power output and the power distribution bus, a contactor is connected which is controllable to connect or disconnect the respective power output from the power distribution bus.

A subsea switchgear for switching the power supply to plural subsea loads includes a subsea enclosure, to allow the deployment of the subsea switchgear at a subsea location; a power input for receiving AC electrical power from a power source; at least two power outputs for giving out AC electrical power; and a power distribution bus for distributing the received AC electrical power to the at least two power outputs. In at least one embodiment, between each power output and the power distribution bus, a contactor is connected which is controllable to connect or disconnect the respective power output from the power distribution bus.

A tank for a circuit breaker has a body defining an interior volume and having opposing ends. An flange is at each end of the body with the flanges defining a central longitudinal axis of the body. The body has an internal surface defining a top portion of the tank disposed substantially above the axis and defining a bottom portion of the tank disposed substantially below the axis. The top portion is spaced from the axis as defined by at least a first radius from the axis. The bottom portion is spaced from the axis as defined by at least a second radius from axis. The second radius is greater than the first radius so as to reduce an electric field intensity on the bottom portion of the body and thus reduce effects of foreign particles within the interior volume, regardless of phase rotation.

A tank for a circuit breaker has a body defining an interior volume and having opposing ends. An flange is at each end of the body with the flanges defining a central longitudinal axis of the body. The body has an internal surface defining a top portion of the tank disposed substantially above the axis and defining a bottom portion of the tank disposed substantially below the axis. The top portion is spaced from the axis as defined by at least a first radius from the axis. The bottom portion is spaced from the axis as defined by at least a second radius from axis. The second radius is greater than the first radius so as to reduce an electric field intensity on the bottom portion of the body and thus reduce effects of foreign particles within the interior volume, regardless of phase rotation.

Circuit interrupting devices, power distribution switchgear assemblies, and pole units for power distribution are provided. A circuit interrupting device includes a solid insulation housing, a disconnect, a window, and an insulating fluid. The solid insulation housing defines a first external opening and a first cavity extending into the solid insulation housing from the first external opening. The disconnect has a moving contact in selective engagement with a stationary contact in the first cavity. The window is secured to the solid insulation housing at the first external opening. The insulating fluid is disposed within the first cavity. The window, the solid insulation housing, or a combination thereof is configured to form a trap region that is in fluid communication with the first cavity and is configured to trap air bubbles in the insulating fluid.

Circuit interrupting devices, power distribution switchgear assemblies, and pole units for power distribution are provided. A circuit interrupting device includes a solid insulation housing, a disconnect, a window, and an insulating fluid. The solid insulation housing defines a first external opening and a first cavity extending into the solid insulation housing from the first external opening. The disconnect has a moving contact in selective engagement with a stationary contact in the first cavity. The window is secured to the solid insulation housing at the first external opening. The insulating fluid is disposed within the first cavity. The window, the solid insulation housing, or a combination thereof is configured to form a trap region that is in fluid communication with the first cavity and is configured to trap air bubbles in the insulating fluid.

A tank for a circuit breaker has a body defining an interior volume and having opposing ends. An flange is at each end of the body with the flanges defining a central longitudinal axis of the body. The body has an internal surface defining a top portion of the tank disposed substantially above the axis and defining a bottom portion of the tank disposed substantially below the axis. The top portion is spaced from the axis as defined by at least a first radius from the axis. The bottom portion is spaced from the axis as defined by at least a second radius from axis. The second radius is greater than the first radius so as to reduce an electric field intensity on the bottom portion of the body and thus reduce effects of foreign particles within the interior volume, regardless of phase rotation.

A tank for a circuit breaker has a body defining an interior volume and having opposing ends. An flange is at each end of the body with the flanges defining a central longitudinal axis of the body. The body has an internal surface defining a top portion of the tank disposed substantially above the axis and defining a bottom portion of the tank disposed substantially below the axis. The top portion is spaced from the axis as defined by at least a first radius from the axis. The bottom portion is spaced from the axis as defined by at least a second radius from axis. The second radius is greater than the first radius so as to reduce an electric field intensity on the bottom portion of the body and thus reduce effects of foreign particles within the interior volume, regardless of phase rotation.