EP2822104A1

EP2822104A1 - Subsea female electrical connector and method of connecting a subsea connector

Info

Publication number: EP2822104A1
Application number: EP13175336.0A
Authority: EP
Inventors: Paul Midtun; Tor-Odd Ronhovd
Original assignee: ABB Technology AG
Current assignee: ABB Schweiz AG
Priority date: 2013-07-05
Filing date: 2013-07-05
Publication date: 2015-01-07
Anticipated expiration: 2033-07-05
Also published as: EP2822104B1

Abstract

The present disclosure relates a subsea female electrical connector (1). The subsea female electrical connector (1) comprises a housing (3) forming a chamber (7), a socket (9) arranged in the chamber (7) and adapted to receive a male conductor rod, a dielectric fluid (11) contained in the chamber (7), and a male connector interface (5). The male connector interface (5) comprises a fluid blocking member (5a), and the male connector interface (5) has a channel (5d) adapted to receive the male conductor rod and guide the male conductor rod into the chamber (7). The fluid blocking member (5a) has a single continuous surface blocking the channel (5d) to thereby prevent fluid from flowing out from and into the chamber (7) through the channel (5d). A subsea connector is also presented herein.

Description

TECHNICAL FIELD

The present disclosure generally relates to electrical connectors and in particular to a subsea female electrical connector and to a subsea connector comprising such a female electrical connector and a male electrical conductor.

BACKGROUND

In recent years, there has been a growing interest in electrical installations on the sea floor in depths from a few tens of meters to even kilometres. Machineries such as pumps and compressors are employed in subsea production of oil and gas. Such machinery is driven by electric motors.
The operation of subsea machinery depends on reliable power distribution and the possibility of connecting/disconnecting power consuming devices subsea. US4373767 discloses a plug and socket type electrical connector for connection underwater. The female part of the connector contains a socket element enclosed in a dielectric fluid filled chamber which is sealed by a penetrable seal element. The plug or male part of the connector has an extended contact probe of round cross-section which penetrates the seal element to enter the socket and complete the connection, the two connector parts having housings with a threaded connection for securing the connector. The penetrable seal is specifically designed to accommodate repeated insertion and withdrawal of a male probe of round cross-section without loss of dielectric fluid or water leakage.
Existing subsea connectors have complicated design rendering them expensive, thereby limiting the application of subsea equipment. In view of this, there is a need to improve existing subsea connector designs.

SUMMARY

In view of the above, a general object of the present disclosure is to provide a subsea female electrical connector which solves or at least mitigates the problems of the prior art.
Hence, according to a first aspect of the present disclosure, there is provided a subsea female electrical connector comprising: a housing forming a chamber; a socket arranged in the chamber and adapted to receive a male conductor rod; a dielectric fluid contained in the chamber; and a male connector interface comprising a fluid blocking member and a channel, which channel is adapted to receive the male conductor rod and guide the male conductor rod into the chamber and the socket, wherein the fluid blocking member has a single continuous surface blocking the channel thereby preventing fluid from flowing out from and into the chamber through the channel.
By means of a fluid blocking member that has a single continuous surface blocking the channel, a simpler and hence more reliable underwater female electrical connector design may be obtained than what has previously been possible. Moreover, the dielectric fluid contained in the chamber may be utilised to flush the male electrical connector with which the female electrical connector mates to thereby remove sea water from the interface between the female and male connectors in the process of interconnection. The subsea female electrical connector retains its internal dielectric properties by means of the dielectric fluid that remains in the chamber after interconnection. The present disclosure hence provides a simple, disposable in the sense that it allows for one mating with a male connector, underwater female electrical conductor design.
According to one embodiment the fluid blocking member has a thickness which allows the fluid blocking member to be ruptured by the male conductor rod when the subsea female electrical connector is mated with a subsea male electrical connector having a male conductor rod. Thus, the subsea female electrical connector is protected from water when lowered subsea by means of the fluid blocking member, and as noted above, dielectric fluid is able to flow from the chamber via the channel to remove water from the space formed between the female and male connectors. The chamber will thus provide dielectric properties by means of the dielectric fluid contained therein, without any traces of water when the male and female connectors have been interconnected.
According to one embodiment the channel is provided with a shoulder defining a narrower channel section at a chamber facing end of the channel than a channel section at a fluid blocking member facing end of the channel.
One embodiment comprises an annular seal arranged to abut the shoulder, wherein the annular seal is dimensioned to receive the male conductor rod. The annular seal may thereby be retained in the channel when the male conductor rod has perforated/ruptured the fluid blocking member upon mating and is moved into position to connect with the socket of the female connector. The annular seal hence forms a seal around the male conductor rod which in a sense may be seen as a piston as it penetrates the channel for connection with the socket.
According to one embodiment the annular seal is adapted to block fluid from entering the chamber and to allow excess dielectric fluid to exit the subsea female electrical connector when the male conductor rod has been received by the annular seal. The annular seal thus allows dielectric fluid to flow from the chamber and pass through the channel when dielectric fluid in the chamber is subject to an overpressure as a result of the male conductor rod deforming and rupturing the fluid blocking member and penetrating the chamber, while preventing fluid such as sea water to enter the female connector.
According to one embodiment the male connector interface has a shape corresponding to a shape of a subsea male electrical connector with which it is to mate to such that essentially the entire male connector interface abuts the subsea male electrical connector.
According to one embodiment the fluid blocking member extends along the entire cross-sectional dimension of the subsea female electrical connector in level with the male connector interface. Thereby a simpler and more robust design of the female connector may be provided.
According to one embodiment the dielectric fluid fills the entire volume of the chamber. Thus, no air pockets may form within the chamber. Moreover, dielectric fluid which is less compressible than e.g. air, exits the female connector with one-to-one correspondence to each volume unit occupied by the male conductor rod when it has ruptured the fluid blocking member.
According to one embodiment the dielectric fluid has a density which is less than a density of water. The dielectric fluid will thereby be maintained between any sea water present at the male connector to be mated with the female connector. Efficient removal of sea water may thereby be obtained. Moreover, sea water will not be able to enter into the chamber. Thereby the dielectric properties obtained in the chamber by means of the dielectric fluid may be maintained when the female connector and male connector have mated.
According to one embodiment, the dielectric fluid is oil or an ester. Advantageously, the dielectric fluid is biodegradable such that dielectric fluid flushed out from the chamber of the female connector into sea water may be biodegraded to thereby minimize sea water contamination.
According to one embodiment the fluid blocking member is arranged at that end of the channel which is furthest away from the chamber. A ruptured fluid blocking member can thereby be exchanged for a new, intact fluid blocking member without having to disassemble the subsea female electrical connector in case the subsea female electrical connector is to be reused for additional mating after disconnection from a subsea male electrical connector.
According to one embodiment the channel has a cross-sectional dimension which essentially corresponds to a cross-sectional dimension of the male conductor rod. The mechanical withstand strength of the subsea female electrical connector in general, and the fluid blocking member in particular, may thus be maximised. Especially, the relatively thin portion, with lower mechanical withstand strength, of the male connector interface defined by the fluid blocking member portion which blocks the channel, may be kept minimal.
According to one embodiment the fluid blocking member is a single-use fluid blocking member.
According to a second aspect of the present disclosure there is provided a subsea connector comprising a subsea female electrical connector according to the first aspect presented herein, and a subsea male electrical connector having a male conductor rod and arranged to interconnect with the subsea female electrical connector.
According to a third aspect of the present disclosure there is provided a method of connecting a subsea female electrical connector and a subsea male electrical connector, wherein the subsea female electrical connector comprises a housing forming a chamber, a socket arranged in the chamber and adapted to receive a male conductor rod, a dielectric fluid contained in the chamber, and a male connector interface comprising a fluid blocking member and a channel, which channel is adapted to receive the male conductor rod and guide the male conductor rod into the chamber and the socket, wherein the method comprises: a) bringing the subsea female electrical connector and the subsea male electrical connector together such that a male conductor rod of the subsea male electrical connector abuts the fluid blocking member; and b) rupturing the fluid blocking member by means of the male conductor rod, wherein dielectric fluid from the chamber flushes the subsea male electrical connector.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, etc., unless explicitly stated otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

The specific embodiments of the inventive concept will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1a is a schematic longitudinal section of an example of a subsea female electrical connector;
Fig. 1b is a close-up view of a portion of the subsea female electrical connector in Fig 1a;
Fig. 2 schematically depicts the subsea female electrical connector in Fig. 1 and a subsea male electrical connector prior to mating thereof;
Figs 3a-c shows the mating process of the subsea female electrical connector and subsea male electrical connector in Fig. 2; and
Fig. 4 is a flowchart of a method of connecting a subsea female electrical connector with a subsea male electrical connector.

DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplifying embodiments are shown. The inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description.
The subsea female electrical connector presented herein enables subsea mating with a corresponding male electrical connector while maintaining dielectric properties of both the subsea female electrical connector and the male electrical connector post-mating. The subsea female electrical connector may for example be adapted to high voltage (HV) or medium voltage (MV) applications. To this end, the subsea female connector presented herein may for example be a high voltage subsea female electrical connector or a medium voltage subsea female electrical connector.
Fig. 1a depicts a schematic longitudinal section of an example of a subsea female electrical connector 1. The subsea female electrical connector 1 comprises a housing 3 forming a chamber 7, and a dielectric fluid 11. The dielectric fluid 11 is contained in the chamber 7. The dielectric fluid 11 may advantageously be a dielectric liquid, such as oil or an ester. The dielectric fluid 11 may beneficially be biodegradable. According to one variation, the dielectric fluid 11 fills the entire volume of the chamber 7. Preferably, the dielectric fluid 11 has a density which is less than a density of water. Especially, it is beneficial if the density of the dielectric fluid 11 is less than that of the body of water in which the subsea female electrical connector 1 is to be installed and utilised.
The subsea electrical female connector 1 is adapted to withstand ambient pressure at a depth at which the subsea female electrical connector 1 is intended to be utilised. Such a depth may be anywhere from a few tens of metres to several thousand metres, for example 2000-4000 m, the latter corresponding to a pressure of about 200 bar to 400 bar. The housing 3 may for example be made of plastic, steel, a combination thereof, or any other suitable material which can withstand the high pressure and wear applied and provided by deep sea water. Furthermore, the dielectric fluid 11 is arranged to counteract deformation of the housing 3.
The subsea female electrical connector 1 further comprises a male connector interface 5 adapted to face a subsea male electrical connector for mating therewith. The housing 3 and the male connector interface 5 define the walls of the chamber 7. The male connector interface 5 defines a floor 5c of the chamber 7. A socket 9 is arranged in the subsea female electrical connector 1, adapted to connect with a male conductor rod when the subsea female electrical connector 1 is mated with a subsea male electrical connector. In particular, the socket 9 is arranged to receive a male conductor rod. When the socket 9 is in electrical connection with a male conductor rod, the subsea connector formed by the subsea female electrical connector 1 and a subsea male electrical connector is able to provide power to subsea machinery provided that the subsea female electrical connector 1 is connected to a power source.
As previously mentioned, the male connector interface 5 defines that end of the subsea female electrical connector 1 which is adapted to mate with a subsea male electrical connector. The male connector interface 5 has a channel 5d and comprises a fluid blocking member 5a. The channel 5d is adapted to receive a male conductor rod and guide the male conductor rod into the chamber 7 such that the male conductor rod can mate with the socket 9. According to one variation of subsea female electrical connector 1, the fluid blocking member 5a is arranged at that end of the channel 5d which is furthest away from the chamber 7, as shown in Figs 1a and b. According to this variation, the channel 5d extends from the chamber 7 to the fluid blocking member 5a. Alternatively, the fluid blocking member may be arranged at an inner end of the channel, i.e. at that end which is closest to the chamber.
The fluid blocking member 5a has a single continuous surface adapted to block the channel 7 to thereby prevent fluid from flowing out from and into the chamber 7 through the channel 5d. The single continuous surface defines an external surface of the subsea female electrical connector 1 and the male connector interface 5. The fluid blocking member 5a hence covers or obstructs the mouth of the channel 7, thus preventing fluid communication between the chamber 7 and the environment surrounding the subsea female electrical connector 1. With a single continuous surface is meant, in mathematical terms, a topological connected set of points forming the surface. Each pair of points in the continuous surface may hence be connected by a line for which each point forms part of the continuous surface. In other words, the continuous surface does not have any openings. The fluid blocking member 5a has a thickness which allows the fluid blocking member 5a to be ruptured by a male conductor rod when the subsea female electrical connector is mated with a subsea male electrical connector. The force applied by the male conductor rod during mating hence ruptures the fluid blocking member 5a. The fluid blocking member 5a is hence provided with an opening for a male conductor rod only after the male conductor has ruptured the fluid blocking member 5a in a mating operation. Prior to mating, the chamber is isolated from the environment surrounding the subsea female electrical connector by means of the fluid blocking member 5a.
The fluid blocking member 5a may according to one variation have an extension which covers the entire cross-sectional dimension of the subsea female electrical connector 1 in level with the male connector interface 5. The fluid blocking member 5a may hence have a cross-sectional dimension corresponding to essentially the entire bottom end face of the subsea female electrical connector 1. Alternatively, the fluid blocking member may have a dimension which essentially corresponds to the dimension of the mouth of the channel at that end of the channel at which the fluid blocking member is arranged. The fluid blocking member could of course have any dimension in between these two extremes.
According to the example in Figs 1a-b, the male connector interface 5 comprises a floor member 5h which is thicker than the fluid blocking member 5a. The floor member 5h has mechanical strength designed to withstand subsea ambient pressure at the depth at which the subsea female electrical connector is intended to be used. A through opening in the floor member 5h defines the channel 5d. The channel 5d is provided with a shoulder 5g extending along at least part of the periphery of the channel 7. According to one variation, the shoulder 5g defines a narrower channel section at a chamber facing end of the channel 5d than a channel section at a fluid blocking member facing end of the channel 5d.
According to one variation, the subsea female electrical connector 1 comprises an annular seal 5f adapted to abut the shoulder 5g. The annular seal 5f is dimensioned to receive a male conductor rod. The annular seal 5f is adapted to block fluid from entering the chamber 7 and to allow excess dielectric fluid 11 to exit the subsea female electrical connector 1 when a male conductor rod has been received by the annular seal 5f. The annular seal may for example be an axial shaft seal. When a male conductor rod has ruptured or perforated the fluid blocking member 5a and further penetrated the channel 7, the annular seal 5f will act as a unidirectional seal ring around the male conductor rod.
The male connector interface 5 may according to one variation have a shape corresponding to a shape of a subsea male electrical connector with which it is to mate in such a manner that essentially the entire male connector interface 5 abuts the subsea male electrical connector.
The subsea female electrical connector 1 is advantageously utilised with a subsea male electrical connector that may be of multiple mating-type. Fig. 2 depicts a longitudinal sectional view of a subsea female electrical connector 1 and a subsea male electrical connector 13 prior to mating. The subsea male electrical connector 13 comprises a male conductor rod 15 arranged to mate with the socket 9 of the subsea female electrical connector 1.
Mating operation of the subsea female electrical connector 1 with subsea male electrical connector 13 will now be described with reference to Figs 3a-3c, and Fig. 4. In a typical situation, the mating is performed subsea. Prior to mating the subsea male electrical connector 13 and in particular the male conductor rod 15 are immersed in water 17. Any water 17 should be removed before the subsea female electrical connector 1 and subsea male electrical connector 13 is interconnected in order to obtain the required dielectric properties of the interconnected subsea connector.
In Fig. 3a, the subsea female electrical connector 1 and a subsea male electrical connector 13 have been brought together, and the male connector interface 5 faces and is aligned with the subsea male electrical connector 13, as also illustrated in Fig. 4 in step a). The male conductor rod 15 then ruptures the fluid blocking member 5a in a step b). Fig. 3b depicts when the male conductor rod 15 has ruptured and penetrated the fluid blocking member 5a. An amount of dielectric fluid corresponding to the volume occupied by the male connector rod 15 in the channel 5d and chamber 7 is forced out from the subsea female electrical connector 1 through the channel 5d. Any water 17 contained in the space between the male connector interface 5 and the subsea male electrical connector 13 is flushed out from the space created between the mating connectors 1 and 13 into the surrounding water, as indicated by arrow A. In variations comprising the annular seal 5f, the annular seal 5f prevents water from entering the chamber 7 during the mating operation. Moreover, in cases where the density of the dielectric fluid is less than that of the surrounding water, the dielectric fluid that is forced out from the subsea female electrical connector, which for example may be arranged vertically above the subsea male electrical connector, will act as a barrier between said connector and water. Efficient removal of any water in the space created between the two connectors may thereby be obtained.
Fig. 3c shows a fully interconnected subsea female electrical and male electrical connector 1 and 13 forming subsea connector 19. The interconnection may for example be carried out by a threaded connection. For example, the external surface of the subsea female electrical connector and the internal surface of the subsea male electrical connector may be threaded. Other interconnection methods are also envisaged, as would be apparent to the skilled person.
The subsea female electrical connector is a disposable device which allows for a single mating with a subsea male electrical connector. The fluid blocking member is a single-use fluid blocking member. For reuse of a subsea female electrical connector that has previously been interconnected with a subsea male electrical connector, a ruptured fluid blocking member may be replaced when it has been refilled with dielectric fluid.
It is envisaged that the underwater female electrical connector presented herein find applications within the oil and gas industry for example for subsea HVDC/HVAC power transmission and power distribution systems, as well as offshore power generation such as wind energy, tidal energy, wave energy, and ocean current energy.
The inventive concept has mainly been described above with reference to a few examples. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended claims. The subsea female electrical connector may for example be adapted to mate with a subsea male electrical connector which has more than one male conductor rod. In this case, the male connector interface may comprise a matching number of channels.

Claims

A subsea female electrical connector (1) comprising:
a housing (3) forming a chamber (7),

a socket (9) arranged in the chamber (7) and adapted to receive a male conductor rod (15),

a dielectric fluid (11) contained in the chamber (7), and

a male connector interface (5) comprising a fluid blocking member (5a) and a channel (5d), which channel (5d) is adapted to receive the male conductor rod (15) and guide the male conductor rod (15) into the chamber (7) and the socket (9), wherein the fluid blocking member (5a) has a surface blocking the channel (5d) thereby preventing fluid from flowing out from and into the chamber (7) through the channel (5d).
The subsea female electrical connector (1) as claimed in claim 1, wherein the fluid blocking member (5a) has a thickness which allows the fluid blocking member (5a) to be ruptured by the male conductor rod (15) when the subsea female electrical connector (1) is mated with a subsea male electrical connector (13) having a male conductor rod (15).
The subsea female electrical connector (1) as claimed in claim 1 or 2, wherein the channel (5d) is provided with a shoulder (5g) defining a narrower channel section at a chamber facing end of the channel (5d) than a channel section at a fluid blocking member facing end of the channel (5d).
The subsea female electrical connector (1) as claimed in claim 3, comprising an annular seal (5f) arranged to abut the shoulder (5g), wherein the annular seal (5f) is dimensioned to receive the male conductor rod (15).
The subsea female electrical connector (1) as claimed in claim 4, wherein the annular seal (5f) is adapted to block fluid from entering the chamber (7) and to allow excess dielectric fluid (11) to exit the subsea female electrical connector when the male conductor rod (15) has been received by the annular seal (5f).
The subsea female electrical connector (1) as claimed in any of the preceding claims, wherein the male connector interface (5) has a shape corresponding to a shape of a subsea male electrical connector (13) with which it is to mate to such that essentially the entire male connector interface (5) abuts the subsea male electrical connector (13).
The subsea female electrical connector (1) as claimed in any of the preceding claims, wherein the fluid blocking member (5a) extends along the entire cross-sectional dimension of the subsea female electrical connector (1) in level with the male connector interface (5).
The subsea female electrical connector (1) as claimed in any of the preceding claims, wherein the dielectric fluid (11) fills the entire volume of the chamber (7).
The subsea female electrical connector (1) as claimed in any of the preceding claims, wherein the dielectric fluid (11) has a density which is less than a density of water.
The subsea female electrical connector (1) as claimed in any of the preceding claims, wherein the dielectric fluid (11) is oil or an ester.
The subsea female electrical connector (1) as claimed in any of the preceding claims, wherein the fluid blocking member (5a) is arranged at that end of the channel (5d) which is furthest away from the chamber (7).
The subsea female electrical connector (1) as claimed in any of the preceding claims, wherein the channel (5d) has a cross-sectional dimension which essentially corresponds to a cross-sectional dimension of the male conductor rod (15).
The subsea female electrical connector (1), wherein the fluid blocking member (5a) is a single-use fluid blocking member.
A subsea electrical connector (19) comprising:
a subsea female electrical connector (1) as claimed in any of claims 1-13, and

a subsea male electrical connector (13) having a male conductor rod (15) and arranged to interconnect with the subsea female electrical connector (1).
A method of connecting a subsea female electrical connector (1) and a subsea male electrical connector (13), wherein the subsea female electrical connector (1) comprises a housing (3) forming a chamber (7), a socket (9) arranged in the chamber (7) and adapted to receive a male conductor rod (15), a dielectric fluid (11) contained in the chamber (7), and a male connector interface (5) comprising a fluid blocking member (5a) and a channel (5d), which channel (5d) is adapted to receive the male conductor rod (15) and guide the male conductor rod (15) into the chamber (7) and the socket (9), wherein the method comprises:
a) bringing the subsea female electrical connector (1) and the subsea male electrical connector (13) together such that a male conductor rod (15) of the subsea male electrical connector (13) abuts the fluid blocking member (5a), and

b) rupturing the fluid blocking member (5a) by means of the male conductor rod (15), wherein dielectric fluid from the chamber (7) flushes the subsea male electrical connector (13).