EP4661041A1

EP4661041A1 - Subsea disconnector

Info

Publication number: EP4661041A1
Application number: EP24179481.7A
Authority: EP
Inventors: David Schaeffer; Stefan Valdemarsson
Original assignee: ABB Schweiz AG
Current assignee: ABB Schweiz AG
Priority date: 2024-06-03
Filing date: 2024-06-03
Publication date: 2025-12-10

Abstract

A subsea disconnector (1) comprising: a first contact terminal (5) comprising an electrically conductive first flexible contact interface element (5a), a linear magnetic actuator (9) comprising: a yoke (9a) having an axial channel (9d) extending along a longitudinal axis of the subsea disconnector (1), a closing coil (11a) wound around the yoke (9a), an opening coil (11b) wound around the yoke (9a), wherein the opening coil (11b) is axially fully offset from the closing coil (11a), the opening coil (11a) being arranged axially further away from the first contact terminal (5) than the closing coil (11a) is from the first contact terminal (5), an axially movable pushrod (13) arranged in the axial channel (9d), the pushrod (13) comprising an electrically conducting moving contact (13a), a first magnetic plunger (15a) attached to the pushrod (13), a second magnetic plunger (15b) attached to the pushrod (13), arranged axially further away from the first contact terminal (5) than the first magnetic plunger (11a) is from the first contact terminal (5); a second contact terminal (7) comprising an electrically conductive second flexible contact interface element (7a) receiving the moving contact (13a) and being in electrical contact with the moving contact (13a), wherein the pushrod is configured to move between a closed position and an open position.

Description

TECHNICAL FIELD

The present disclosure relates to subsea disconnectors.

BACKGROUND

Electric systems may be installed on the seabed, for example in the oil and gas industry. The components of the electric system may for example be arranged in pressure-compensated tanks at a pressure of up to 500 bar, i.e., at depths down to 5000 m. The components may be transformers, power converters, pumps, switchgear and the like. Moreover, mechanical disconnectors are used to connect, disconnect, reconfigure, and bypass the different components of the electrical system. The electrical system reliability is dependent on the reliability of the mechanical disconnectors. Due to the challenges in accessing components installed subsea typically no maintenance is possible during the lifetime of an electric system. It is therefore necessary that the disconnectors are designed to be robust.

SUMMARY

In view of the above, a general object of the present disclosure is to provide a subsea disconnector that solves or at least mitigates the problems of the prior art.
There is hence according to a first aspect of the present disclosure provided a subsea disconnector comprising: a first contact terminal comprising an electrically conductive first flexible contact interface element, a linear magnetic actuator comprising: a yoke having an axial channel extending along a longitudinal axis of the subsea disconnector, a closing coil wound around the yoke, an opening coil wound around the yoke, wherein the opening coil is axially fully offset from the closing coil, the opening coil being arranged axially further away from the first contact terminal than the closing coil is from the first contact terminal, an axially movable pushrod arranged in the axial channel, the pushrod comprising an electrically conducting moving contact, a first magnetic plunger attached to the pushrod, a second magnetic plunger attached to the pushrod, arranged axially further away from the first contact terminal than the first magnetic plunger is from the first contact terminal; a second contact terminal comprising an electrically conductive second flexible contact interface element receiving the moving contact and being in electrical contact with the moving contact, wherein the pushrod is configured to move between a closed position in which the first magnetic plunger is axially aligned with the closing coil and the moving contact is received by and electrically contacts the first flexible contact interface element such that the moving contact is in electrical contact with the first contact terminal and the second contact terminal simultaneously, and an open position in which the second magnetic plunger is axially aligned with the opening coil and the moving contact is disengaged from and axially spaced apart from the first flexible contact interface element, and wherein the pushrod is configured to be set in the closed position by energizing of only the closing coil of the opening coil and the closing coil, and wherein the pushrod is configured to be set in the open position by energizing of only the opening coil of the opening coil and the closing coil.
Due to the simple design of the subsea disconnector, with only one moving component in the form of the pushrod equipped with the first and second magnetic plunger, the disconnector is mechanically robust, and able to withstand temperature variations between e.g., o°C and 80°C, which the subsea disconnector may experience when there is no load and at full continuous load, respectively.
That the first magnetic plunger and the second magnetic plunger are "magnetic" means that these plungers are attracted by a magnet, but they are in themselves not magnets. The first magnetic plunger and the second magnetic plunger are thus neither permanent magnets nor electromagnets. Magnets such as permanent magnets degrade when subjected to high temperature and temperature cycles over a long period of time. Magnetic materials will not degrade to the same extent as for example permanent magnets, and thus the subsea disconnector will be more robust and reliable during its expected lifetime of 30-40 years.
The first flexible contact interface element and the second flexible contact interface element provide electrical contact between the first contact terminal and the moving contact and the second contact terminal and the moving contact, respectively, due to their flexibility both during contraction and expansion of the moving contact and the first and second contact terminals because of thermal cycles. Moreover, the first flexible contact interface element and the second flexible contact interface element provide friction between the first contact terminal and the moving contact and the second contact terminal and the moving contact, respectively. This facilitates a bistable functionality of the pushrod in its open and closed position.
According to one embodiment the first flexible contact interface element is a first canted spring. Due to its resilience, the canted spring provides good mechanical contact with the moving contact. Moreover, it allows dielectric fluid that may be arranged inside the subsea connector to pass between the turns of the coil of the canted spring to cool down the first contact terminal.
According to one embodiment the second flexible contact interface element is a second canted spring.
According to one embodiment the pushrod comprises an electrically insulating material which electrically insulates the moving contact from the first magnetic plunger.
According to one embodiment the first magnetic plunger and the second magnetic plunger consist of non-magnetised ferromagnetic material, such as construction steel.
According to one embodiment the first magnetic plunger and the second magnetic plunger are magnetically insulated from each other.
According to one embodiment the pushrod comprises a non-magnetic sheet arranged between the first magnetic plunger and the second magnetic plunger.
According to one embodiment the first contact terminal comprises a first flexible contact interface element housing having a first axial through-opening provided with an inner surface having a circumferentially extending first groove, wherein the first flexible contact interface element is arranged in the first groove.
According to one embodiment the first axial through-opening forms a first opening into the subsea disconnector.
According to one embodiment the second contact terminal comprises a second flexible contact interface element housing having a second axial through-opening provided with an inner surface having a circumferentially extending second groove, wherein the second flexible contact interface element is arranged in the second groove.
According to one embodiment the yoke has an axial yoke through-opening which opens into the axial channel of the yoke, the axial yoke through-opening forming a second opening into the subsea disconnector.
According to one embodiment the first axial through-opening and the axial yoke through-opening are arranged at opposite axial ends of the subsea disconnector.
One embodiment comprises an electrically insulating housing mounted to the yoke and extending to the first contact terminal, the first contact terminal being mounted to the housing.
According to one embodiment the yoke is made of the same material as the first magnetic plunger and the second magnetic plunger.
There is according to a second aspect of the present disclosure provided a subsea electric module comprising: a tank, a subsea according to the first aspect arranged in the tank, and dielectric liquid arranged in the tank, the dielectric liquid surrounding and filling the subsea disconnector.
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. 1 schematically shows a partial section of an example of a subsea disconnector; and
Fig. 2 schematically shows a subsea electric module comprising a subsea disconnector.

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.
Fig. 1 shows an example of a subsea disconnector 1.
The subsea disconnector 1 comprises a housing 3. The housing 3 may be electrically insulating.
The subsea disconnector 1 comprises a first contact terminal 5 and a second contact terminal 7. The first contact terminal 5 and the second contact terminal 7 are fixedly arranged relative to each other.
The first contact terminal 5 is electrically conductive. The first contact terminal 5 may be made of metal. The first contact terminal 5 may comprise a metallic surface plating such as a silver or a silver-alloy plating.
The second contact terminal 7, which is partially cut open in Fig. 1, is electrically conductive. The second contact terminal 7 may be made of metal. The second contact terminal 7 may comprise a metallic surface plating such as a silver or a silver-alloy plating.
The first contact terminal 5 comprises an electrically conductive first flexible contact interface element 5a. The first flexible contact interface element 5a may be a first canted spring.
The first flexible contact interface element 5a may comprise a metallic surface plating such as a silver or a silver-alloy plating.
The first contact terminal 5 may comprise a first flexible contact interface element housing 5b. The first flexible contact interface element housing 5a has a first axial through-opening 5c. The first axial through-opening 5c has an inner surface that has a circumferentially extending first groove. The first flexible contact interface element 5a may be arranged in the first groove. For example, if the first flexible contact interface element 5a is a first canted spring, the first canted spring, which is annular, extends circumferentially along the entire circumferential length of the first groove.
The second contact terminal 7 comprises an electrically conductive second flexible contact interface element 7a. The second flexible contact interface element 7a may be a second canted spring.
The second flexible contact interface element 7a may comprise a metallic surface plating such as a silver or a silver-alloy plating.
The second contact terminal 7 may comprise a second flexible contact interface element housing 7b. The second flexible contact interface element housing 7b has a second axial through-opening 7c. The second axial through-opening 7c is axially aligned with the first axial through-opening 5c. The second axial through-opening 7c has an inner surface that has a circumferentially extending second groove. The second flexible contact interface element 7a may be arranged in the second groove. For example, if the second flexible contact interface element 7a is a second canted spring, the second canted spring, which is annular, extends circumferentially along the entire circumferential length of the second groove.
The subsea disconnector 1 comprises a linear magnetic actuator 9. The linear magnetic actuator 9 comprises a yoke 9a. The yoke 9a has a first yoke end 9b and a second yoke end 9c opposite to the first yoke end 9b. The yoke 9a has an axial channel 9d extending along a longitudinal axis of the subsea disconnector 1. The axial channel 9d extends through the yoke 9a from the first yoke end 9b to the second yoke end 9c. The axial channel 9d is axially aligned with the first axial through-opening 5c and with the second axial through-opening 7c.
The yoke 9a has an axial yoke through-opening 9e which opens into the axial channel 9d of the yoke 9a. The axial yoke through-opening 9e is arranged at an opposite end of the subsea disconnector 1 in relation to the first axial through-opening 5c. The axial yoke through-opening 9e may be axially aligned with the first axial through-opening 5c and with the second axial through-opening 7c.
The first axial through-opening of the first contact terminal 5 forms a first opening into the subsea disconnector 1. The axial yoke through-opening 9e forms a second opening into the subsea disconnector 1.
The linear magnetic actuator 9 comprises a closing coil 11a and an opening coil 11b. Each of the closing coil 11a and the opening coil 11b is wound around the yoke 9a, outside or inside of the yoke 9a.
The linear magnetic actuator 9 may comprise a coil holder 10 holding the closing coil 11a and the opening coil 11b. The coil holder 10 may be made of a polymer material such as a thermoplastic material.
The closing coil 11a is arranged with a plurality of turns around the axial channel 9d.
The closing coil 11a may for example be wound with an inductance of at least 0.2 H, without the yoke 9a.
The opening coil 11b is arranged with a plurality of turns around the axial channel 9d.
The opening coil 11b may be wound with an inductance of at least 0.2 H, without the yoke 9a.
The opening coil 11b is axially fully offset from the closing coil along the longitudinal axis of the subsea disconnector 1, which coincides with the centre axis of the axial channel 9d of the yoke 9a. The opening coil 11b is arranged further away from the first contact terminal 5 than the closing coil 11a is from the first contact terminal 5.
The second contact terminal 7 is arranged between the first contact terminal 5 and the first yoke end 9b, along the longitudinal axis of the subsea disconnector 1.
The housing 3 is mounted to the yoke 9a and extends to the first contact terminal 5. The first contact terminal 5 is mounted to the housing 3. The second contact terminal 7 is mounted to the housing 3.
The linear magnetic actuator 9 comprises an axially movable pushrod 13. The pushrod 13 is arranged in the axial channel 9d. In particular, a portion of the pushrod 13 is arranged in the axial channel 9d and a portion of the pushrod 13 is arranged outside the axial channel 9d.
The pushrod 13 comprises an electrically conducting moving contact 13a. The moving contact 13a may form an axial end portion of the pushrod 13. The moving contact 13a extends through the second flexible contact interface element housing 7b and through the second flexible contact interface element 7a. The moving contact 13a is in electrical contact with the second flexible contact interface element 7a.
The linear magnetic actuator 9 comprises a first magnetic plunger 15a attached to the pushrod 13, and a second magnetic plunger 15b attached to the pushrod 13. The second magnetic plunger 15b is arranged axially further away from the moving contact 13a than the first magnetic plunger 15a.
The first magnetic plunger 15a may comprise or consist of a non-magnetised ferromagnetic material, for example construction steel.
The second magnetic plunger 15b may comprise or consist of a non-magnetised ferromagnetic material, for example construction steel.
The yoke 9a may according to one example be made of the same material as the first magnetic plunger 15a and/or the second magnetic plunger 15b.
The first magnetic plunger 15a and the second magnetic plunger 15b are magnetically insulated from each other. The pushrod 13 may for example comprise a non-magnetic sheet 17 arranged between the first magnetic plunger 15a and the second magnetic plunger 15b. The non-magnetic sheet may for example comprise austenitic stainless steel, aluminium, a polymeric material, or a composite material.
The pushrod 13 comprises an electrically insulating material, such as a polymeric and/or composite material, which electrically insulates the moving contact 13a from the first magnetic plunger 15a. The electrically insulating material also electrically insulates the moving contact 13a from the second magnetic plunger 15b.
In operation, the subsea disconnector 1 is filled with a dielectric liquid, filling the entire interior of the subsea disconnector 1. The dielectric liquid may for example be an oil such as transformer oil. The linear magnetic actuator 9 is completely immersed in the dielectric liquid.
The polymer material of the coil holder 10 may be selected to be compatible with the dielectric liquid.
In operation of the subsea disconnector 1, the closing coil 11a and the opening coil 11b are connected to a power supply or to a respective power supply. The power supply may for example be an external capacitor bank. The closing coil 11a and the opening coil 11b may form part of separate electronic circuits having different power supplies or alternatively they may share the same power supply. Each electronic circuits may comprise a respective semiconductor switch, such as an insulated-gate bipolar transistor (IGBT) connected to the power supply, and a control unit which triggers the semiconductor switch to be set in its on state to become electrically conductive to energise the closing coil 11a and the opening coil 11b, respectively. A freewheeling diode may be provided for interrupting DC current to the closing coil 11a and the opening coil 11b.
The pushrod 13 is configured to move to a closed position by energizing of only the closing coil 11a of the closing coil 11a and the opening coil 11b, and an open position, shown in Fig. 1, by energizing only the opening coil 11b of the closing coil 11a and the opening coil 11b. The two opposite directions in which the pushrod 13 can move is illustrated by the arrows A.
The linear magnetic actuator 9 is bistable. The closing coil 11a is only energised for a short amount of time to set the pushrod 13 in the closed position from the open position. After the pushrod 13 has reached the closed position, the closing coil 11a is deenergised. The pushrod 13 however maintains its closed position until the opening coil 11b is energised, causing the pushrod 13 to move to the open position. After the pushrod 13 has reached the open position, the opening coil 11b is deenergised. The pushrod 13 maintains its open position until the closing coil 11a is energised, causing the pushrod 13 to move to the closed position. The bistable functionality is obtained due to the friction provided by the first flexible contact interface element 5a and the second flexible contact interface element 7a around the moving contact 13a.
The amplitude of the current through the closing coil 11a and the opening coil 11b when they are energized may be the same.
The moving contact 13a extends through and is in electrical contact with the second flexible contact interface element 7a, and thus with the second contact terminal 7, both in the closed position and in the open position of the pushrod 13.
In the closed position of the pushrod 13, the first magnetic plunger 15a is axially aligned with the closing coil 11a as the closing coil 11a magnetically attracts the first magnetic plunger 15a. The moving contact 13a is received by and electrically contacts the first flexible contact interface element 5a, while simultaneously also electrically contacting the second contact terminal 7. The axial length of the moving contact 13a is thus longer than the axial distance between the first contact terminal 5 and the second contact terminal 7.
In the open position of the pushrod 13, the second magnetic plunger 15b is axially aligned with the opening coil 11b as the opening coil 11b magnetically attracts the second magnetic plunger 15b, which is axially closer to the opening coil 11b than the first magnetic plunger 15a is to the opening coil 11b. In the open position, the moving contact 13a is disengaged from and axially spaced apart from the first flexible contact interface element 5a as a result of the pushrod 13 moving linearly away from the first contact terminal 5 when the opening coil 11b becomes energised and attracts the second magnetic plunger 15b.
The dielectric liquid can pass through the subsea disconnector 1 via the first axial through-opening 5c, the second axial through-opening 7c, and the axial yoke through-opening 9e via natural convection to efficiently cool the first electrical terminal 5 and the second electrical terminal 7.
The subsea disconnector 1 may be provided with a mechanical damping functionality, to brake the movement of the pushrod 13 when operated to reach the closed position and the open position. As the dielectric liquid pressure builds up in the axial channel 9d between the second yoke end 9c and the second magnetic plunger 15b due to linear movement of the second magnetic plunger 15b towards the open position, dielectric liquid passes through the axial yoke through-opening 9e for pressure relief and damping. The axial yoke through-opening 9e may be sized to produce an optimum damping effect when the pushrod 13 is actuated by energizing the opening coil 11b. Similarly, the first axial through-opening 5c provides pressure relief when the pushrod 13 is moved in the opposite direction, towards the first contact terminal 5.
The subsea disconnector 1 may comprise means for determining the position feedback of the pushrod 13, i.e., whether the pushrod 13 is in the closed position or in the open position. The electronic circuits for operating the linear magnetic actuator 9 may be protected against overcurrent, with the semiconductor switches turning off when a predetermined current limit is reached. The subsea disconnector 1 may comprise a control unit which may temporarily set the current limit to a lower value so as not to trigger the semiconducting switches, to determine the position of the pushrod 13. The current limit with the lower value may be high enough to detect it but low enough to not saturate the material of the yoke and/or the first and second magnetic plungers, and low enough not to actuate the pushrod 13. The subsea disconnector 1 may comprise a timer configured to estimate the rise time to reach the current limit with the lower value. The rise time depends on the inductance of the closing coil 11a and of the opening coil 11b, which in turn depends on the position of the pushrod 13. The control unit may further be configured to determine the resistance of the closing coil 11a and the opening coil 11b based on e.g., the current measurement. Based on the resistance and the rise time, the position of the pushrod 13 can be determined by the control unit. As an example, a look-up table with the position of the pushrod 13 associated with different rise times may be used to determine the position of the pushrod 13.
Fig. 2 schematically shows an example of a subsea electric module 19. The subsea electric module 19 is configured to be installed on the seabed as part of a subsea electrical infrastructure.
The subsea electric module 19 may have an internal pressure equal to or essentially equal to the ambient hydrostatic pressure, which for example may be in a range of 10 to 500 or more bar.
The subsea electric module 19 comprises a tank 21. The tank 21 is a pressure-compensated tank. The subsea electric module 19 is filled with a dielectric liquid 23 such as an oil, e.g., transformer oil. The dielectric liquid counteracts the external hydrostatic pressure exerted on the tank 21.
The subsea electric module comprises one or more subsea disconnectors 1, arranged inside the tank 21.
Each subsea disconnector 1 may be arranged horizontally in the tank 21. The pushrod 13 or pushrods 13 may thus extend horizontally inside the tank 21.
The subsea disconnectors 1 are also filled with the dielectric liquid 23.
One or more capacitor banks may be located outside the tank 23, for example in an external tank with e.g., a one bar pressure inside, electrically connected to the one or more subsea disconnectors 1 arranged inside the tank 21. The capacitor bank or banks are arranged to energize the closing coil 11a and the closing coil 11b.
The subsea electric module 19 may form part of a subsea electric system comprising components selected from the group of: power transformers, motors, power converters, and pumps.
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.

Claims

Subsea disconnector (1) comprising:
- a first contact terminal (5) comprising an electrically conductive first flexible contact interface element (5a),

- a linear magnetic actuator (9) comprising:
a yoke (9a) having an axial channel (9d) extending along a longitudinal axis of the subsea disconnector (1),

a closing coil (11a) wound around the yoke (9a),

an opening coil (11b) wound around the yoke (9a), wherein the opening coil (11b) is axially fully offset from the closing coil (11a), the opening coil (11a) being arranged axially further away from the first contact terminal (5) than the closing coil (11a) is from the first contact terminal (5),

an axially movable pushrod (13) arranged in the axial channel (9d), the pushrod (13) comprising an electrically conducting moving contact (13a),

a first magnetic plunger (15a) attached to the pushrod (13),

a second magnetic plunger (15b) attached to the pushrod (13), arranged axially further away from the first contact terminal (5) than the first magnetic plunger (11a) is from the first contact terminal (5);

- a second contact terminal (7) comprising an electrically conductive second flexible contact interface element (7a) receiving the moving contact (13a) and being in electrical contact with the moving contact (13a),

wherein the pushrod (13) is configured to move between a closed position in which the first magnetic plunger (15a) is axially aligned with the closing coil (11a) and the moving contact (13a) is received by and electrically contacts the first flexible contact interface element (5a) such that the moving contact (13a) is in electrical contact with the first contact terminal (5) and the second contact terminal (7) simultaneously, and an open position in which the second magnetic plunger (15b) is axially aligned with the opening coil (11b) and the moving contact (13a) is disengaged from and axially spaced apart from the first flexible contact interface element (5a), and

wherein the pushrod (13) is configured to be set in the closed position by energizing of only the closing coil (11a) of the opening coil (11b) and the closing coil (11a), and wherein the pushrod (13) is configured to be set in the open position by energizing of only the opening coil (11b) of the opening coil (11b) and the closing coil (11a).
Subsea disconnector (1) as claimed in claim 1, wherein the first flexible contact interface element (5a) is a first canted spring.
Subsea disconnector (1) as claimed in claim 1 or 2, wherein the second flexible contact interface element (7) is a second canted spring.
Subsea disconnector (1) as claimed in any of the preceding claims, wherein the pushrod (13) comprises an electrically insulating material which electrically insulates the moving contact (13a) from the first magnetic plunger (15a).
Subsea disconnector (1) as claimed in any of the preceding claims, wherein the first magnetic plunger (15a) and the second magnetic plunger (15b) consist of non-magnetised ferromagnetic material, such as construction steel.
Subsea disconnector (1) as claimed in any of the preceding claims, wherein the first magnetic plunger (15a) and the second magnetic plunger (15b) are magnetically insulated from each other.
Subsea disconnector (1) as claimed in claim 6, wherein the pushrod (13) comprises a non-magnetic sheet (17) arranged between the first magnetic plunger (15a) and the second magnetic plunger (15b).
Subsea disconnector (1) as claimed in any of the preceding claims, wherein the first contact terminal (5) comprises a first flexible contact interface element housing (5b) having a first axial through-opening (5c) provided with an inner surface having a circumferentially extending first groove, wherein the first flexible contact interface element (5a) is arranged in the first groove.
Subsea disconnector (1) as claimed in claim 8, wherein the first axial through-opening (5c) forms a first opening into the subsea disconnector (1).
Subsea disconnector (1) as claimed in any of the preceding claims, wherein the second contact terminal (7) comprises a second flexible contact interface element housing (7b) having a second axial through-opening (7c) provided with an inner surface having a circumferentially extending second groove, wherein the second flexible contact interface element (7a) is arranged in the second groove.
Subsea disconnector (1) as claimed in any of the preceding claims, wherein the yoke (9a) has an axial yoke through-opening (9e) which opens into the axial channel (9d) of the yoke (9a), the axial yoke through-opening (9d) forming a second opening into the subsea disconnector (1).
Subsea disconnector (1) as claimed in claim 11 dependent of claim 9, wherein the first axial through-opening (5c) and the axial yoke through-opening (9e) are arranged at opposite axial ends of the subsea disconnector (1).
Subsea disconnector (1) as claimed in any of the preceding claims, comprising an electrically insulating housing (3) mounted to the yoke (9a) and extending to the first contact terminal (5), the first contact terminal (5) being mounted to the housing (3).
Subsea disconnector (1) as claimed in any of the preceding claims, wherein the yoke (9a) is made of the same material as the first magnetic plunger (15a) and the second magnetic plunger (15b).
Subsea electric module (19) comprising:
a tank (21),

a subsea disconnector (1) as claimed in any of the preceding claims arranged in the tank (21), and

dielectric liquid (23) arranged in the tank (21), the dielectric liquid (23) surrounding and filling the subsea disconnector (1).