Apparatus and method for use in power supply systems

Abstract

1. An apparatus for use in an electrical power supply system, the apparatus comprising: a DC circuit breaker having a first terminal and a second terminal, the DC circuit breaker configured to automatically switch from a closed state to an open state during an overcurrent condition; a disconnector switch in series with the DC circuit breaker, the disconnector switch having a first terminal for connecting to a first polarity terminal of a DC power source, a second terminal for connecting to a second polarity terminal of the DC power source, and a common terminal connected to the first terminal of the DC circuit breaker, the disconnector switch having at least a first position in which the first terminal is connected to the common terminal and a second position in which the second terminal is connected to the common terminal; and an interlock mechanism coupled to the DC circuit breaker and the disconnector switch, the interlock mechanism configured to disable the DC circuit breaker from automatically switching from a closed state to an open state when the disconnector switch is in the second position during an overcurrent condition.

Description

Technical Field

[0001] The present disclosure relates to a direct current (DC) circuit breaker for use in a power supply system, and in particular to an apparatus and related method for disabling automatic opening of a DC circuit breaker in response to overcurrent when the power supply system is grounded for maintenance.

Background Art

[0002] DC power supply systems are widely used, for example, when supplying power to conductive rails of transport systems. Examples include railway and tramway infrastructures, where DC current is fed to an energized conductive rail of, for example, positive voltage, such as an energized third rail line or an energized overhead cable. Such power supply systems require automatic circuit breaker protection to quickly and automatically disconnect the energized conductive rail from the power supply in the event of an overcurrent condition. Such overcurrent can be caused by many types of events, such as damage to cable support structures, falling of cables or rails, accidental short-circuiting of an energized conductive rail to ground, or overload conditions in load devices using the power supply system.

[0003] Power supply systems also require a mechanism to put the conductive rails into a safe, e.g. grounded, maintenance state when personnel need to work on the infrastructure. This is to prevent any inadvertent connection of the conductive rail to a power source, or a lightning strike to a conductive rail somewhere in the network, from causing damage or harm to other parts of the infrastructure, or to personnel working on the infrastructure while the energized conductive rail is out of service.

[0004] In existing infrastructure, one method for ensuring safe maintenance of conductive rails is to manually install shorting bars or clamps between the conductive rail and the negative voltage return rail or grounded rail (sometimes called "rail junction"). More recently, another method of rail junction has been developed to improve efficiency and safety, involving the use of locally or remotely controlled switches. However, under certain installation configurations, it may be possible for negative return current to flow forward through the power supply system. This could cause a DC circuit breaker to trip in a junction configuration, leaving the conductive rail energized and unsafe.

[0005] Any listing or discussion of previously published documents or any background information in this specification should not necessarily be understood as an acknowledgment that such documents or background information are part of the current state of art or common general knowledge. One or more aspects / embodiments of this disclosure may or may not address one or more of the background issues. [Overview of the project]

[0006] According to the first aspect, a device for use in a power supply system, A DC circuit breaker having a first terminal and a second terminal, configured to automatically switch from a closed state to an open state during an overcurrent condition, A disconnector switch in series with a DC circuit breaker, wherein the disconnector switch has a first terminal for connecting to a first polarity terminal of a DC power supply, a second terminal for connecting to a second polarity terminal of a DC power supply, and a common terminal connected to the first terminal of the DC circuit breaker, and the disconnector switch has at least a first position where the first terminal is connected to the common terminal, and a second position where the second terminal is connected to the common terminal, An interlock mechanism coupled to a DC circuit breaker and a disconnector switch is provided, which is configured to prevent the DC circuit breaker from automatically switching from a closed state to an open state when the disconnector switch is in a second position during an overcurrent condition.

[0007] A DC circuit breaker may have a first contact and a second contact corresponding to a first terminal and a second terminal. The first contact and the second contact may be positioned on a first contact arm and a second contact arm of the DC circuit breaker, respectively, and at least one of the first contact arm and the second contact arm may be movable.

[0008] A DC circuit breaker may include a trip device configured to cause movement of at least one movable contact arm during an overcurrent condition, and an interlock mechanism may be coupled to the trip device and configured to disable the DC circuit breaker by preventing the trip device from operating.

[0009] The trip device may comprise an electromagnetic actuator having an armature mechanically coupled to at least one movable contact arm. The electromagnetic actuator may be configured to generate a magnetic flux in response to an overcurrent, causing movement of the armature and a corresponding movement of at least one movable contact arm.

[0010] The interlock mechanism may be configured to prevent the trip device from operating by preventing the armature from moving.

[0011] The armature may be mechanically coupled to at least one movable contact arm by a latch, and the interlock mechanism may be configured to prevent the trip device from operating by preventing the latch from moving.

[0012] An electromagnetic actuator may comprise a primary armature, which is mechanically coupled to at least one movable contact arm such that a magnetic flux causes movement of the primary armature and a corresponding movement of at least one movable contact arm, and a secondary armature configured to move when the magnetic flux exceeds a predetermined magnitude. Movement of the secondary armature may reduce the magnetic resistance of the electromagnetic actuator and induce movement of the primary armature, and an interlock mechanism may be configured to prevent the operation of a trip device by preventing movement of either the primary or secondary armature.

[0013] The interlock mechanism may be coupled to at least one movable contact arm of the DC circuit breaker and may be configured to disable the DC circuit breaker by preventing the movement of at least one movable contact arm.

[0014] The interlock mechanism may include a mechanical or electromechanical configuration that includes a block component configured to physically restrain the disconnector switch when it is in a second position by contacting at least one movable contact arm, armature, or latch, in order to prevent the aforementioned movement.

[0015] The interlock mechanism may be configured to prevent the trip device from operating by diverting the magnetic flux generated by the electromagnetic actuator, thereby preventing the armature from moving.

[0016] The interlock mechanism may include a soft magnetic material configured to separate the magnetic flux from the armature when the disconnector switch is in a second position in order to prevent the above movement.

[0017] The tripping device may be a direct or indirect type tripping device.

[0018] A direct-acting trip device may include an electromagnetic actuator. An indirect-acting trip device may include one or more of a protective relay and a transducer.

[0019] The interlock mechanism may be configured to allow the DC circuit breaker to automatically switch from the closed state to the open state when the disconnector switch is in the first position during an overcurrent condition.

[0020] The DC circuit breaker may be a unidirectional circuit breaker configured to automatically switch from a closed state to an open state in the forward direction during an overcurrent condition, and remain in the closed state regardless of the current level in the reverse direction.

[0021] The DC circuit breaker may be a bidirectional circuit breaker configured to automatically switch from a closed state to an open state in both the forward direction and the reverse direction during an overcurrent condition.

[0022] The forward direction may correspond to current flow from the first terminal to the second terminal of the DC circuit breaker, and the reverse direction may correspond to current flow from the second terminal to the first terminal of the DC circuit breaker.

[0023] The disconnector switch may be interlocked to prevent switching between the first position and the second position while the DC circuit breaker is in the closed state.

[0024] The disconnector switch may have a third position in which both the first terminal and the second terminal are electrically insulated from a common terminal.

[0025] The disconnector switch may include a visual position indicator that indicates the state thereof in the first, the second (or the third) position.

[0026] The second terminal of the DC circuit breaker may be coupled to a first conductive rail of a power supply system.

[0027] A first polarity connector of a DC power source may be coupled to an overhead cable or a third rail of a transportation system, and a second polarity connector of the DC power source may be coupled to a track of the transportation system.

[0028] A disconnecting switch may comprise: at least one movable contact arm electrically connected to a common terminal; a shutter mechanism configured to at least partially block a first gap between the at least one movable contact arm and a first terminal while the disconnecting switch is in a second position, and at least partially block a second gap between the at least one movable contact arm and a second terminal while the disconnecting switch is in a first position.

[0029] The at least one movable contact arm may comprise a single contact arm configured to pivot or translate between a first position in contact with the first terminal and a second position in contact with the second terminal. The shutter mechanism may comprise a first shutter and a second shutter. The first shutter may be configured to open and close a path between the single contact arm and the first terminal such that the first shutter opens while the single contact arm is in the first position and closes while the single contact arm is in the second position, and the second shutter may be configured to open and close a path between the single contact arm and the second terminal such that the second shutter opens while the single contact arm is in the second position and closes while the single contact arm is in the first position.

[0030] At least one movable contact arm may comprise a first reciprocating arm and a second reciprocating arm, each electrically connected to a common terminal. The first reciprocating arm may be movable between a non-contact position isolated from the first terminal and a contact position in contact with the first terminal, and the second reciprocating arm may be movable between a non-contact position isolated from the second terminal and a contact position in contact with the second terminal. The shutter mechanism may comprise a first shutter and a second shutter. The first shutter may be configured to open and close the path between the first reciprocating arm and the first terminal such that the first shutter is open when the first reciprocating arm is in the contact position and the second reciprocating arm is in the non-contact position, and closes when the first reciprocating arm is in the non-contact position and the second reciprocating arm is in the contact position. The second shutter may be configured to open and close the path between the second reciprocating arm and the second terminal, such that the second shutter is open when the second reciprocating arm is in the contact position and the first reciprocating arm is in the non-contact position, and closes when the second reciprocating arm is in the non-contact position and the first reciprocating arm is in the contact position.

[0031] The first and second reciprocating arms may be connected to each other via a seesaw mechanism and driven by a common motor such that the first reciprocating arm moves from a non-contact position to a contact position, while the second reciprocating arm moves from a contact position to a non-contact position, and vice versa.

[0032] The first and second reciprocating arms can be driven by their respective motors such that when the second reciprocating arm moves from a contact position to a non-contact position, the first reciprocating arm moves only from the non-contact position to the contact position, and when the first reciprocating arm moves from a contact position to a non-contact position, the second reciprocating arm moves only from the non-contact position to the contact position.

[0033] The first and second shutters may each include at least one door that is biased to close the path between at least one movable contact arm and its respective terminal, and the at least one movable contact arm may include an opening member configured to force the at least one door open against the bias as the at least one movable contact arm moves toward its respective terminal.

[0034] At least one door may comprise one or more hinged doors biased by a spring or gravity to close a path, and an opening member of at least one movable contact arm may be configured to push one or more hinged doors open against the spring or gravity bias as the at least one movable contact arm moves toward its respective terminal.

[0035] At least one door may include a pair of doors that meet to close a path. Each door may have a protruding member configured to engage with an opening member of at least one movable contact arm, the opening member may be shaped to wedge into and release the protruding member so as at least one movable contact arm moves toward its respective terminal, forcing the door open against a bias.

[0036] At least one movable contact arm of a DC circuit breaker and disconnector switch may be housed within an arc limiting enclosure, and the first and second terminals of the disconnector switch may be located outside the arc limiting enclosure. A shutter mechanism may be configured to open and close each path outside the arc limiting enclosure, through which at least one movable contact arm must move to contact the first and second terminals.

[0037] The first and second terminals of the disconnector switch can be separated from each other by an insulating barrier.

[0038] DC circuit breakers and disconnector switches may be formed on a common, removable unit of the power supply system.

[0039] A common, removable unit may be mounted on the wheel to facilitate removal from and reinstallation to the power supply system.

[0040] The common removable unit may further comprise one or more shunts, fuses, and transducers of the power supply system.

[0041] According to a second aspect, a method for configuring a power supply system, Connecting a disconnector switch to a DC power supply, wherein the first terminal of the disconnector switch is connected to the first polarity terminal of the DC power supply, and the second terminal of the disconnector switch is connected to the second polarity terminal of the DC power supply, and the disconnector switch has at least a first position where the first terminal is connected to a common terminal of the disconnector switch, and a second position where the second terminal is connected to a common terminal of the disconnector switch. The common terminal of the disconnector switch is connected to the first terminal of a DC circuit breaker, which has a first terminal and a second terminal and is configured to automatically switch from a closed state to an open state during an overcurrent condition. The interlock mechanism is coupled to the DC circuit breaker and disconnector switch, thereby enabling the interlock mechanism to disable the automatic switching of the DC circuit breaker from a closed state to an open state when the disconnector switch is in a second position during an overcurrent condition. Connecting the second terminal of the DC circuit breaker to the first power line, A method is provided which includes connecting the second terminal of a disconnector switch and the second polarity terminal of a DC power supply to a second power line.

[0042] The method may further include bringing the first and second power lines into operation by switching the disconnector switch to a first position and then setting the DC circuit breaker to a closed configuration.

[0043] The method may further include placing the first and second power lines into a safe maintenance state by switching the DC circuit breaker to the open position, then switching the disconnector switch to the second position, and then switching the DC circuit breaker to the closed position.

[0044] The first power line may be an energized (e.g., positive) conductive rail of a railway or tramway infrastructure, and the second power line may be a return (e.g., negative) conductive rail of a railway or tramway infrastructure.

[0045] According to the third embodiment, a conversion switch, The first terminal, the second terminal, and the common terminal, At least one movable contact arm is electrically connected to a common terminal and is movable between a first position in which a first terminal is connected to the common terminal and a second position in which a second terminal is connected to the common terminal. A changeover switch is provided, comprising a shutter mechanism configured to at least partially close a first gap between at least one movable contact arm and a first terminal while the changeover switch is in a second position, and to at least partially close a second gap between at least one movable contact arm and a second terminal while the changeover switch is in a first position.

[0046] The switching switch may be a disconnector switch for use in a power supply system, where the first terminal may be connected to the first polarity terminal of a DC power supply, and the second terminal may be connected to the second polarity terminal of a DC power supply.

[0047] According to the fourth aspect, a method for configuring a conversion switch, To provide a first terminal, a second terminal, and a common terminal, The connection involves electrically connecting at least one movable contact arm to a common terminal, wherein the at least one movable contact arm is movable between a first position where a first terminal is connected to the common terminal and a second position where a second terminal is connected to the common terminal. A method is provided that includes providing a shutter mechanism configured to at least partially close a first gap between at least one movable contact arm and a first terminal while a changeover switch is in a second position, and to at least partially close a second gap between at least one movable contact arm and a second terminal while the changeover switch is in a first position.

[0048] The method may further include moving at least one movable contact arm to a first position while closing a second gap using a shutter mechanism, or moving at least one movable contact arm to a second position while closing a first gap using a shutter mechanism.

[0049] According to a fifth aspect, an apparatus is provided which is substantially described herein with reference to the accompanying drawings and which is illustrated by the accompanying drawings.

[0050] The optional features described in relation to the disconnector switch of the device in the first embodiment are also applicable to the conversion switch of the third embodiment, if compatible.

[0051] The steps of any method disclosed herein do not need to be performed in the exact order disclosed unless expressly described or understood by those skilled in the art.

[0052] A corresponding computer program (which may or may not be recorded on a carrier) for carrying out one or more of the methods disclosed herein is also within the scope of this disclosure and is encompassed by one or more of the exemplary embodiments described.

[0053] This disclosure includes one or more corresponding aspects, exemplary embodiments, or features, either individually or in various combinations, whether specifically described in combination or individually (including in the claims). Corresponding means for performing one or more of the described functions are also within the scope of this disclosure.

[0054] Throughout this specification, descriptive terms relating to position, orientation, or movement, such as “left,” “right,” “up,” “down,” “horizontal,” and “vertical,” as well as any adjectives and adverbs derived therefrom, are used in the sense of the position, orientation, or movement of the device as shown in the drawings. However, such descriptive terms are not intended to limit in any way the intended use of the described or claimed invention.

[0055] The above summary is merely illustrative and is intended to be non-restrictive. [Brief explanation of the drawing]

[0056] Here, the explanation will be given primarily as an example, with reference to the attached schematic diagram. [Figure 1] This shows different states of electrical circuits for track connections. [Figure 2a] This shows the flow of fault current through the electrical circuit in a feeder configuration. [Figure 2b] This shows the flow of fault current through an electrical circuit in a junction configuration. [Figure 3] This shows the flow of fault current from an adjacent track through a power supply section to a nearby substation. [Figure 4a] This shows a device equipped with an interlock mechanism to address the scenario shown in Figure 3, where the device is in the unlocked state. [Figure 4b] Figure 4a shows a device with an interlock mechanism in a locked state. [Figure 5] This shows the tripping device of a DC circuit breaker that is in a tripped state. [Figure 6a] A more detailed view of the interlock mechanism in Figure 4a is shown. [Figure 6b] Figure 4b shows a more detailed view of the interlock mechanism. [Figure 7] Figure 3 shows another device with an interlock mechanism to address the scenario shown. [Figure 8a]This shows a disconnector / switch with a single movable contact arm configured to pivot. [Figure 8b] This shows a disconnector / switch with a single movable contact arm configured to produce translational motion. [Figure 9] Another disconnector / converter switch is shown, comprising first and second movable contact arms and their respective shutters. [Figure 10] Figure 9 shows a device equipped with a disconnector / switch, which has an additional opening member for opening each shutter. [Figure 11] An insulating barrier is shown to isolate the first and second terminals of the disconnector / switch. [Figure 12] Figure 9 shows a disconnector / converter switch, further comprising a visual position indicator, a fuse, and a transducer. [Figure 13] This shows a pull-out track equipped with a DC circuit breaker and disconnector / switch, removed from a power supply system cubicle. [Modes for carrying out the invention]

[0057] Figure 1a shows a schematic diagram of a power supply system for supplying power to conductive rails of railway infrastructure. A DC power supply 1 has a positive output terminal 2 and a negative output terminal 3. The DC power supply 1 may be a rectifier that receives alternating current (AC) input. The positive output terminal 2 is connected to a busbar 4 via a circuit breaker 5. The busbar 4 is connected to a disconnector switch 10 which is connected to a unidirectional circuit breaker 20. The negative output terminal 3 of the power supply 1 is connected to the negative return conductive rail 6 of the railway infrastructure. The circuit breaker 20 is connected to the positive conductive rail 7 of the railway infrastructure.

[0058] In one configuration, the positive conductive rail 7 may be an overhead cable or catenary suitable for current collection by a pantograph. In another configuration, the positive conductive rail may be a rigid conductor positioned alongside or between a third energized rail, such as a rail of a railway track. The negative return conductive rail 6 may be a railway track or a tram track.

[0059] The disconnector switch 10 has a first terminal 11 which is electrically connected to the busbar 4 and thereby electrically connected to the positive output terminal 2 of the power supply 1. The disconnector switch 10 has a second terminal 12 which is electrically connected to the negative output terminal 3 and the negative return conductive rail 6 of the power supply 1. The disconnector switch 10 has a third terminal which can be described as a common terminal 13 connected to the first terminal 21 of the unidirectional circuit breaker 20. The disconnector switch 10 has a first position in which its first terminal 11 is electrically connected to the common terminal 13, and a second position in which its second terminal 12 is connected to the common terminal 13, for example, a single-pole, two-position configuration.

[0060] The circuit breaker 20 has a first terminal 21 and a second terminal 22, and in this example is unidirectional in the sense that it is configured to automatically open its contacts when it detects a first (forward) overcurrent condition with respect to the current flowing from the first terminal 21 to the second terminal 22, but does not automatically open its contacts in the case of a reverse current flow or overcurrent flow, i.e., a current flowing from the second terminal 22 to the first terminal 21. The circuit breaker 20 can be configured to trip forward at any suitable current level that is considered an overcurrent condition.

[0061] Busbar 4 can supply power to other disconnectors and circuit breaker devices not shown in the drawings, for example, it is configured to supply power to other segments of conductive rails 6, 7 in railway infrastructure.

[0062] During use, the power supply system is in a normal operating ("feeder") configuration as shown in Figure 1a, and power is supplied from power source 1 to rails 6 and 7 by a closed circuit breaker 5 (as shown), a disconnector switch 10 in a first position (with terminals 11 and 13 connected) as shown, and a closed circuit breaker 20 (as shown).

[0063] In order to make the power supply system a safe ("jointed") configuration for maintenance purposes, not only must the connection between busbar 4 and positive conductive rail 7 be broken, but the positive and negative rails 6 and 7 must also be short-circuited together.

[0064] In the first step, as shown in Figure 1b, the circuit breaker 20 is set to the open state by intentionally tripping the circuit breaker, for example, by manual override or electronic actuation, or by an actual overcurrent fault condition that causes the circuit breaker to open automatically. It can be seen that the disconnector switch 10 is now offloaded and can be safely switched to the second position (with terminals 12 and 13 connected), as shown in Figure 1c.

[0065] In Figure 1c, the disconnector switch 10 is at this point in the second position, connecting the second terminal 12 to the common terminal 13. Thus, the negative conductive rail 6 and the negative terminal 3 of the power supply 1 are coupled to the first terminal 21 of the circuit breaker. At this point, the circuit breaker 20 is reset or otherwise closes its circuit breaker contacts, effectively short-circuiting the positive conductive rail 7 and the negative conductive rail 6 together, leaving the conductive rail 7 in a safe state for maintenance, as shown in Figure 1d. To reconnect the power supply system to an operational state, the steps described above are reversed.

[0066] In the configuration shown, the positive terminal 2 of power supply 1 has a first polarity and is connected to the disconnector switch 10, the circuit breaker 20, and the "energized" conductive rail 7, while the negative terminal 3 has a second polarity and is connected to a "safe" negative return rail 6 that is generally held at or near ground potential. However, it will be recognized that this can be reversed by connecting the positive terminal 2 of the power supply as a "safe" potential at or near ground potential, and the negative terminal 3 supplying power to the "energized" conductive rail 7. In this regard, the first and second polarities of the power supply terminals can be reversed.

[0067] The disconnector switch 10 may also be provided with a third stable position (not shown) corresponding to an intermediate or "insulated" position in which neither the first terminal 11 nor the second terminal 12 is electrically connected to the common terminal 13, so that both the first and second terminals 11 and 12 are electrically isolated from the common terminal 13. In this way, the conductive rail 7 can be completely isolated from the positive and negative output terminals 2 and 3 of the power supply 1.

[0068] Figures 2a and 2b are schematic diagrams of a power supply system showing the flow of overcurrent (fault current) through the electrical circuit of Figure 1 in a feeder and junction configuration, respectively. As shown in Figure 2a, when the overcurrent flows from the busbar towards the cable in the feeder configuration, the unidirectional circuit breaker 20 trips, disconnecting the energized conductive rail 7 from the power source 1. On the other hand, as shown in Figure 2b, when the overcurrent flows from the cable towards the junction in the junction configuration, the circuit breaker 20 remains closed to allow the current to flow to earth via the negative return rail 6. The unidirectional nature of the circuit breaker 20 ensures that inadvertent or accidental connection of the rail 7 to the power source, or its exposure to discharges such as lightning strikes, does not cause the circuit breaker 20 to trip to an open state, leaving the conductive rail 7 potentially energized and unsafe.

[0069] However, as mentioned in the background technology section, there is a scenario in which a negative return current may flow forward through the power supply system, which could cause the DC circuit breaker 20 to trip in the junction configuration.

[0070] Figure 3 is a schematic diagram showing a section of railway including eastbound tracks 71 and westbound tracks 72. DC power for the railway is provided by a series of substations 73 spaced along the tracks. The substations 73 convert AC power to DC and increase the voltage to compensate for losses due to the inefficiency of the conductive rails 7. Between these substations 73 are feeder section (TP) stations 74 used to connect and disconnect adjacent sections 7a-7e of the conductive rails 7. Unfortunately, many TP stations 74 do not have rectifier power supplies 1 and therefore do not have local negative terminals. Thus, if the conductive rails 7 of one track 72 are energized (the westbound track in this example) and the conductive rails 7 of the nearest track 71 are grounded (the eastbound track in this example), up to 50% of the negative return current 75 on the westbound track 72 can flow forward through the TP station 74 towards the negative terminal of the power supply 1 located at the nearest substation 73. If a fault 8 on the energized (westbound) track 72 generates an overcurrent 75, this could then trip the unidirectional circuit breaker in the TP station 74, potentially leaving the grounded conductive rail 7 on the nearby (eastbound) track 71 energized and unsafe.

[0071] Apparatus and related methods that can address this problem are described here. Other examples shown in the drawings are provided with reference numerals corresponding to similar features of the aforementioned examples. These numbered features may appear in the drawings but may not be directly mentioned in the description of these particular examples. They are still provided in the drawings to aid in the understanding of further examples, particularly in relation to similar features of the aforementioned examples.

[0072] Figures 4a and 4b show side views of an example of a device for use in a power supply system. In addition to the DC circuit breaker 20 and disconnector switch 10 described above, the device includes an interlock mechanism 9. The interlock mechanism 9 is coupled to the DC circuit breaker 20 and the disconnector switch 10 and is configured to prevent the DC circuit breaker 20 from automatically switching from the closed state to the open state when the disconnector switch 10 is in a second position (i.e., the joined state) during an overcurrent condition. This helps to ensure the continuity of the join. Given that the interlock mechanism 9 is included, the DC circuit breaker 20 no longer needs to be unidirectional. Therefore, the DC circuit breaker 20 may be a bidirectional circuit breaker configured to automatically switch from the closed state to the open state in both the forward and reverse directions during an overcurrent condition.

[0073] The DC circuit breaker 20 has first and second contacts corresponding to a first terminal 21 and a second terminal 22 (the first terminal 21 is not visible from this viewpoint). The first and second contacts are located on a first contact arm 14 and a second contact arm 15 of the DC circuit breaker 20, respectively. In this example, the first contact arm 14 is movable by rotating around a pivot shaft 16, while the second contact arm 15 is fixed in place, but both contact arms 14 and 15 may be movable. When the DC circuit breaker 20 is closed, the first and second contacts are in physical (and therefore electrically) contact with each other to allow current to flow between them.

[0074] The DC circuit breaker 20 also includes an actuator 17 configured to cause movement of a movable contact arm 14 in response to a control signal that opens the DC circuit breaker 20, and a trip device 18 comprising an armature 19 configured to cause movement of the movable contact arm 14 during an overcurrent condition. The movement of the movable contact arm 14 separates the first and second contacts from each other, forming a contact gap, thereby switching the DC circuit breaker 20 from a closed state to an open state. An optional arc displacement mechanism can also be seen in Figures 4a and 4b. This includes a soft magnetic winding 23 configured to generate magnetic flux in response to a control signal or overcurrent. The end 24 of the soft magnetic winding 23 is positioned on the opposite side of the contact gap and is shaped to form a magnetic flux gap that crosses the contact gap. Furthermore, the end 24 of the soft magnetic winding 23 is also shaped to branch upward towards the magnetic flux gap toward an arc suppressor such as an arc chute (not shown). When an electric arc is formed between the first and second contacts of the DC circuit breaker 20, the magnetic flux traversing the contact gap guides the arc toward an arc suppressor, which rapidly suppresses the arc.

[0075] The actuator 17 may include any existing mechanism for opening the DC circuit breaker 20. In Figures 4a and 4b, the actuator 17 takes the form of an electromagnetic latch configured to release stored energy in a compression spring, causing the plunger 25 to move linearly. The plunger 25 then rotates around the pivot shaft 16 and contacts a movable contact arm 14, separating the first and second contacts.

[0076] Figure 5 shows a schematic representation of the trip device 18 in more detail. In this example, the trip device 18 is a direct-acting trip device comprising an electromagnetic actuator, but alternatively, it may be an indirect-acting trip device (e.g., including a protective relay or transducer). The electromagnetic actuator comprises a permanent magnet 26 and an adjacent (primary) armature 19 mechanically coupled to a movable contact arm. The armature 19 forms part of a yoke 28 with a predetermined gap 29. The magnetic flux 30 from the permanent magnet 26 provides a holding force to the armature 19 against the accumulated force of the compression spring 31. In an overcurrent condition, current flows through the coil 32 of the electromagnetic actuator, inducing a magnetic flux 33 in the yoke 28 that counteracts the magnetic flux 30 from the permanent magnet 26. At a predetermined magnitude of the overcurrent (and therefore the magnetic flux 33), the accumulated force of the compression spring 31 exceeds the holding force of the permanent magnet 26, releasing the armature 19. The predetermined magnitude of the overcurrent / magnetic flux 33 is determined at least in part by the size of the gap 29 within the yoke 28. The armature 19 is then accelerated forward under the action of a spring 31, which causes the movable contact arm to move and trip the DC circuit breaker.

[0077] In some examples, the electromagnetic actuator may further include a secondary armature 27 configured to move when the magnetic flux 33 in the yoke 28 exceeds a predetermined magnitude. As shown in Figure 5, the movement of the secondary armature 27 reduces the magnetic resistance of the yoke 28, inducing movement of the primary armature 19. This helps prevent the trip device from becoming gradually unstable as the current approaches a predetermined magnitude. Instead, the secondary armature 27 provides a step change to the trip flux 33, which ensures that the trip device opens the DC circuit breaker at the correct current level.

[0078] As shown in the apparatus of Figures 4a and 4b, the interlock mechanism 9 is coupled between the disconnector switch 10 and the trip device 20 (the mechanical coupling between the trip device 18 and the movable contact arm 14 is not shown). When the disconnector switch 10 is in the first position (Figure 4a), the interlock mechanism 9 is in an unlocked state, allowing movement of the primary armature 19 in an overcurrent condition. This allows the DC circuit breaker 20 to disconnect the energized conductive rail from the power supply when the apparatus is in a feeder configuration. However, when the disconnector switch 10 is in the second position (Figure 4b), the interlock mechanism 9 is in a locked state, preventing (e.g., limiting or even preventing) movement of the primary armature 19 in an overcurrent condition. This disables the DC circuit breaker 20 from automatically switching from the closed state to the open state when the apparatus is in a coupled configuration.

[0079] Figures 6a and 6b show more detail of the interlock mechanism 9 in Figures 4a and 4b in side views. As shown, the interlock mechanism 9 comprises a mechanical configuration (but alternatively, an electromechanical configuration) fixed to the actuator 17 by a first bracket 34 and a second bracket 35. The mechanical configuration has a proximal link arm 36, an intermediate link arm 37, and a distal link arm 38, which are pivotally coupled to each other by a pivot shaft 39. One end of the proximal link arm 36 is pivotally coupled to the disconnector switch 10 by a slide connector 40, and the proximal link arm 36 and the intermediate link arm 37 are pivotally coupled to the first bracket 34 by a further pivot shaft 39. The distal link arm 38 is pivotally coupled to the second bracket 35 at its midpoint and has a block component 41 at one end. To help ensure that the interlock mechanism 9 functions repeatedly, the intermediate link arm 37 is equipped with a spring 42. This prevents problems related to tolerances between components between different units and between the operation of the same unit, so that the disconnector switch 10 may stop at a slightly different position each time due to external factors such as motor voltage.

[0080] When the disconnector switch 10 switches from the first position to the second position, the interlock mechanism 9 changes from the configuration shown in Figure 6a to the configuration shown in Figure 6b. As shown, the slide connector 40 moves to the right, rotating the proximal link arm 36 in a more vertical direction around the connecting pivot axis 39. This raises the connected ends of the intermediate link arm 37 and the distal link arm 38. Since the distal link arm 38 is pivotally coupled to the second bracket 35 at its midpoint, the distal link arm 38 rotates in a more horizontal direction such that the block member 41 abuts against the (primary) armature 19 of the electromagnetic actuator, thereby preventing the movement of the (primary) armature 19.

[0081] Figure 7 shows a perspective view of another example of the device. In this example, the electromagnetic actuator of the trip device 18 comprises a fixed core 43 and a movable core 44. The movable core 44 is attached to an armature 45, which is further mechanically coupled to a movable contact arm 14 by a latch 46. As shown, the latch 46 is configured to rotate around a first pivot axis 47. In the event of an overcurrent, the flow of current through the fixed core 43 generates a magnetic flux that attracts the movable core 44. This results in a downward movement of the armature 45, causing the latch 46 to rotate around the first pivot axis 47 and the corresponding rotation of the movable contact arm 14 around a second pivot axis 48.

[0082] To prevent the corresponding movement of the movable contact arm 14, the interlock mechanism 9 is configured to prevent the movement of the latch 46. To achieve this, the interlock mechanism 9 includes a block component 41 in the form of a hook that is coupled between the latch 46 and the movable contact arm 14 when the disconnector switch is in a second position. In an alternative configuration, the hook 41 may instead be coupled between the armature 45 and the movable contact arm 14.

[0083] In a further example (not shown), the interlock mechanism 9 may be configured to disable the trip device 18 magnetically rather than mechanically. In this scenario, the interlock mechanism 9 may be configured to bypass the magnetic flux 33 generated by the electromagnetic actuator, thereby preventing the movement of the armatures 19, 45. This can be achieved by forming the interlock mechanism 9 from a soft magnetic material configured to separate the magnetic flux 33 from the armatures 19, 45 or the moving core 44.

[0084] Furthermore, instead of disabling the DC circuit breaker 20 by preventing the operation of the trip device 18, the interlock mechanism 9 may be configured to be coupled to the movable contact arm 14 itself, thereby preventing the movement of the movable contact arm 14. Although not shown, it will be understood that this can be achieved using various different (electro)mechanical interlock configurations, including a block component 41 configured to contact and physically restrain the movable contact arm 14.

[0085] The apparatus described herein may be modified to include an interlock system that prevents the disconnector switch 10 from operating in one or both directions when the circuit breaker 20 is in the closed position. Furthermore, if the disconnector switch 10 is provided with a third ("isolated") position, the interlock system may be configured to prevent the disconnector switch 10 from switching to one or more of the first, second, and third positions.

[0086] Figure 8a shows a schematic diagram of a disconnector switch 10 in series with a DC circuit breaker 20 housed in a grounded cubicle 49. In this example, the disconnector switch 10 includes a movable contact arm 50 electrically connected to a common terminal 13, configured to pivot between a first position (connected to a positive busbar) that contacts a first terminal 11 and a second position (connected to a negative busbar) that contacts a second terminal 12.

[0087] Figure 8b shows an alternative disconnector switch 10 configured such that a movable contact arm 50 undergoes translational motion between a first position and a second position. In this example, the movable contact arm 50 is mounted on a drive screw 77, which is rotated by a motor 59 and a gearbox 76 to drive the movable contact arm 50 along the axis of the drive screw 77. The movable contact arm 50 includes a connector 79 having male and female portions 80 and 81 for forming physical (and electrical) connections with corresponding portions 80', 81' on the first terminal 11 and the second terminal 12. To accommodate lateral movement without disconnecting from the common terminal 13, a section of the movable contact arm 50 is formed from a flexible conductive material 78 (e.g., a bendable metal strip such as flexible copper).

[0088] However, the problem with the disconnector switch 10 is the proximity of the first terminal 11 and the second terminal 12. In order to switch between the first and second positions, terminals 11 and 12 are typically located relatively close to each other. This creates the possibility of a flashover (or arc flash) between terminals 11 and 12 with a high positive-to-negative fault current of up to 200,000 A.

[0089] The device may be configured to address this problem by incorporating a shutter mechanism driven by a movable contact arm 50 into the disconnector switch 10. The shutter mechanism may be configured to at least partially close a first gap 51 between the movable contact arm 50 and the first terminal 11 while the disconnector switch 10 is in the second position, and to at least partially close a second gap 52 between the movable contact arm 50 and the second terminal 12 while the disconnector switch 10 is in the first position. By closing the gaps 51 and 52 between the movable contact arm 50 and the other terminals, the likelihood of an electric arc forming between terminals 11 and 12 is reduced. Although there is still a possibility of a flashover occurring between the first (positive) terminal 11 and the grounded cubicle 49, the fault current from positive to ground is likely to be less than 15,000 A. Therefore, the presence of the shutter mechanism reduces the maximum potential fault current and the severity of the electric explosion during a flashover event.

[0090] Although not shown in Figure 8a or 8b, an example of a shutter mechanism comprises first and second shutters. The first and second shutters may include a conductive material (e.g., formed from a metal or alloy such as steel) or an electrically insulating material (e.g., formed from polycarbonate or another electrically insulating material). In this example, the first shutter is configured to open and close the path between the movable contact arm 50 and the first terminal 11, such that the first shutter is open when the movable contact arm 50 is in a first position and closes when the movable contact arm 50 is in a second position. Similarly, the second shutter is configured to open and close the path between the movable contact arm 50 and the second terminal 12, such that the second shutter is open when the movable contact arm 50 is in a second position and closes when the movable contact arm 50 is in a first position.

[0091] Figure 9 shows another example of a disconnector switch 10 in a plan view. In this example, the movable contact arm 50 comprises a first reciprocating arm 53 and a second reciprocating arm 54, each electrically connected to a common terminal 13. The first reciprocating arm 53 is movable between a non-contact position isolated from the first terminal 11 and a contact position in contact with the first terminal 11, and the second reciprocating arm 54 is movable between a non-contact position isolated from the second terminal 12 and a contact position in contact with the second terminal 12. In this example, it is important that the gap 55 between the first terminal 11 and the second terminal 12 is closed, which helps to prevent direct flashover between them, and that the paths between each reciprocating arm 53, 54 and their respective terminals 11, 12 are closed when the reciprocating arms 53, 54 are in the non-contact position. This is because the first reciprocating arm 53 and the second reciprocating arm 54 are electrically connected to each other and therefore at the same potential. In this way, closing the path helps prevent indirect flashover from occurring between the first terminal 11 and the second terminal 12 via the first reciprocating arm 53 and the second reciprocating arm 54.

[0092] The shutter mechanism in this example also comprises a first shutter 56 and a second shutter 57. The first shutter 56 is configured to open and close the path between the first reciprocating arm 53 and the first terminal 11, such that the first shutter 56 is open when the first reciprocating arm 53 is in the contact position and the second reciprocating arm 54 is in the non-contact position, and closes when the first reciprocating arm 53 is in the non-contact position and the second reciprocating arm 54 is in the contact position. Similarly, the second shutter 57 is configured to open and close the path between the second reciprocating arm 54 and the second terminal 12, such that the second shutter 57 is open when the second reciprocating arm 54 is in the contact position and the first reciprocating arm 53 is in the non-contact position, and closes when the second reciprocating arm 54 is in the non-contact position and the first reciprocating arm 53 is in the contact position.

[0093] As shown in Figure 9, the first and second reciprocating arms 53 and 54 are connected to each other via a seesaw mechanism 58 and are driven by a common motor 59 such that the first reciprocating arm 53 moves from a non-contact position to a contact position, while the second reciprocating arm 54 moves from a contact position to a non-contact position, and vice versa. Nevertheless, the first and second reciprocating arms 53 and 54 may be driven by their respective motors such that when the second reciprocating arm 54 moves from a contact position to a non-contact position, the first reciprocating arm 53 moves only from a non-contact position to a contact position, and when the first reciprocating arm 53 moves from a contact position to a non-contact position, the second reciprocating arm 54 moves only from a non-contact position to a contact position. In the former configuration, there may be short intervals in which both the first shutter 56 and the second shutter 57 are partially open simultaneously. Thus, the latter configuration may provide a slightly higher level of arc protection.

[0094] The first shutter 56 and the second shutter 57 may each include at least one door 60 biased to close the path between at least one movable contact arm 50 and the respective terminals 11, 12, and the at least one movable contact arm 50 may include an opening member 61 configured to force the at least one door 60 open against the bias as the at least one movable contact arm 50 moves toward the respective terminals 11, 12. For example, the shutters 56, 57 may include a single hinged door or a pair of hinged doors 60 biased by a spring or gravity, and the opening member may be configured to push the door 60 against the spring / gravity bias. It is also possible to use electronic control configured to send signals to one or more sliding doors to open or close them based on the sensed position of at least one movable contact arm 50.

[0095] Figure 10 shows a perspective view of the disconnector switch 10 of Figure 9 connected to the DC circuit breaker 20 shown in Figure 4. As can be seen in this figure, the first shutter 56 and the second shutter 57 each have a pair of doors 60 that close together under the force of a spring 62 to close the path, and each has a protruding member 63 configured to engage with an opening member 61 of the respective movable contact arms 53, 54. Furthermore, the opening members 61 of the movable contact arms 53, 54 are shaped to wedge into and release the protruding member 63 so as the movable contact arms 53, 54 move toward their respective terminals 11, 12, the doors 60 are forced open against the spring force. When the movable contact arms 53, 54 retract from their respective terminals 11, 12, the spring force closes the doors 60 again, reducing the risk of flashover.

[0096] Figure 11 shows a more detailed view of the first terminal 11 and the second terminal 12 of the disconnector switch 10. In this example, the first terminal 11 and the second terminal 12 are separated from each other by an electrical insulation barrier 64 (formed, for example, from polycarbonate or another electrical insulating material). The insulation barrier 64 works to close the gap 55 between the first terminal 11 and the second terminal 12, helping to prevent direct flashover between them. Also, in some examples, at least one movable contact arm 50 of the DC circuit breaker 20 and the disconnector switch 10 may be housed in an arc-limiting enclosure to suppress any arc generated therein (for example, as in the grounding cubicle 49 shown in Figure 8a). In this scenario, the first terminal 11 and the second terminal 12 of the disconnector switch 10 may be located outside the arc limiting enclosure, and the shutter mechanism may be configured to open and close each path outside the arc limiting enclosure, such that at least one movable contact arm 50 must move to contact the first terminal 11 and the second terminal 12. In this way, arcs caused by faults within the arc limiting enclosure are sufficiently suppressed to avoid injury to persons near the device, while the shutter mechanism works to prevent arcs between the first terminal 11 and the second terminal 12 of the disconnector switch 10, which could otherwise result in a significant flow of fault current.

[0097] Figure 12 is a perspective view of another example of the disconnector switch 10. In this example, the disconnector switch 10 further comprises a visual position indicator 65 that indicates its state in a first or second position (or, if applicable, a third insulated position). The visual position indicator 65 is provided by a driven indicator semaphore, but other types are possible. For example, the casing 66 of the disconnector switch 10 may include a window that provides a view of the associated moving part. The disconnector switch 10 also comprises a fuse, a transducer, and any other electronic circuitry 67 necessary to control the disconnector switch 10.

[0098] Figure 13 shows a common removable unit 68 removed from the cubicle 70 of the power supply system. The DC circuit breaker and disconnector switch are incorporated into the common removable unit 68, which brings them together and simplifies the implementation of the interlock mechanism coupled between them. In this example, the common removable unit 68 is mounted on wheels 69 to form a pull-out track to facilitate removal from and reinstallation to the power supply system. The cubicle 70 itself may be grounded as shown in the schematic diagram of Figure 8a.

[0099] This configuration allows for easy access to DC circuit breakers and disconnector switches for maintenance or emergency replacement without requiring a prolonged busbar shutdown at a substation (which could be an expensive exercise) or even a portion of the rail network (which is usually even more expensive) in the event of a failure of any component. Furthermore, one pull-out track 68 can be quickly swapped with another track to restore the rail network as needed.

[0100] In some examples, one or more shunts, fuses, and transducers (or any other traction power voltage components 67) of the power supply system may also be incorporated into a common removable unit / track 68. This further enhances the safety, maintainability, and testing of the equipment by allowing the electronic protection system to be fully tested from the shunt to the transducer while it is isolated from the DC traction power.

[0101] This device is described in the context of a power supply system for supplying power to conductive rails 6, 7 of railway or tramway infrastructure. However, this device can be more broadly applied to any power supply system in which conductors that are normally at a live potential must be grounded or short-circuited to conductors at a safe potential when under maintenance or in a downtime state.

[0102] The applicant discloses each individual feature described herein, and any combination of two or more such features, individually, insofar as such features or combinations can be made in whole under this specification, in light of the common general knowledge of those skilled in the art, regardless of whether such features or combinations of features solve any problem disclosed herein and without limiting the scope of the claims. The applicant indicates that the disclosed aspects / embodiments may consist of any individual features or combinations of features. In consideration of the foregoing, it will be apparent to those skilled in the art that various modifications can be made within the scope of this disclosure.

Claims

1. A device for use in a power supply system, A DC circuit breaker having a first terminal and a second terminal, configured to automatically switch from a closed state to an open state during an overcurrent condition, A disconnector switch in series with the DC circuit breaker, wherein the disconnector switch has a first terminal for connecting to a first polarity terminal of a DC power supply, a second terminal for connecting to a second polarity terminal of the DC power supply, and a common terminal connected to the first terminal of the DC circuit breaker, and the disconnector switch has at least a first position in which the first terminal is connected to the common terminal, and a second position in which the second terminal is connected to the common terminal, An interlock mechanism coupled to the DC circuit breaker and the disconnector switch, configured to prevent the DC circuit breaker from automatically switching from the closed state to the open state when the disconnector switch is in the second position during the overcurrent condition, A device equipped with the following features.

2. The DC circuit breaker comprises a first contact and a second contact corresponding to the first terminal and the second terminal, the first contact and the second contact being positioned on a first contact arm and a second contact arm of the DC circuit breaker, respectively, and at least one of the first contact arm and the second contact arm being movable. The apparatus according to claim 1.

3. The DC circuit breaker includes a trip device configured to cause movement of at least one of the first and second contact arms for the DC circuit breaker during the overcurrent condition, The interlock mechanism is coupled to the trip device and is configured to disable the DC circuit breaker by preventing the trip device from operating. The apparatus according to claim 2.

4. The trip device comprises an electromagnetic actuator having an armature mechanically coupled to at least one of the first and second contact arms, which is a movable contact arm for a DC circuit breaker. The electromagnetic actuator is configured to generate a magnetic flux in response to an overcurrent that causes the movement of the armature and the corresponding movement of at least one of the first and second contact arms, which is a movable contact arm for a DC circuit breaker. The apparatus according to claim 3.

5. The interlock mechanism is configured to prevent the trip device from operating by preventing the armature from moving. The apparatus according to claim 4.

6. The armature is mechanically coupled by a latch to at least one of the first and second contact arms, which is a movable contact arm for a DC circuit breaker, and the interlock mechanism is configured to prevent the operation of the trip device by preventing the movement of the latch. The apparatus according to claim 4.

7. The aforementioned electromagnetic actuator A primary armature, wherein the magnetic flux is mechanically coupled to at least one of the first and second contact arms, which is a movable contact arm for a DC circuit breaker, such that the magnetic flux causes movement of the primary armature and corresponding movement of at least one of the first and second contact arms, which is a movable contact arm for a DC circuit breaker. A secondary armature configured to move when the magnetic flux exceeds a predetermined magnitude, wherein the movement of the secondary armature reduces the magnetic resistance of the electromagnetic actuator and induces the movement of the primary armature. Equipped with, The interlock mechanism is configured to prevent the trip device from operating by preventing the movement of the primary armature or the secondary armature. The apparatus according to claim 4.

8. The interlock mechanism is configured to prevent the trip device from operating by diverting the magnetic flux generated by the electromagnetic actuator, thereby preventing the movement of the armature. The apparatus according to claim 4.

9. The interlock mechanism includes a soft magnetic material configured to prevent the movement of the armature by separating the magnetic flux from the armature when the disconnector switch is in the second position. The apparatus according to claim 8.

10. The interlock mechanism is coupled to at least one of the first and second contact arms of the DC circuit breaker, and is configured to disable the DC circuit breaker by preventing the movement of at least one of the first and second contact arms. The apparatus according to claim 2.

11. The aforementioned disconnector switch At least one movable contact arm for a disconnector switch, electrically connected to the aforementioned common terminal, A shutter mechanism configured to at least partially close a first gap between the at least one movable contact arm for the disconnector switch and the first terminal while the disconnector switch is in the second position, and to at least partially close a second gap between the at least one movable contact arm for the disconnector switch and the second terminal while the disconnector switch is in the first position, The apparatus according to any one of claims 1 to 10, comprising:

12. The at least one movable contact arm for the disconnector switch comprises a first reciprocating arm and a second reciprocating arm, each electrically connected to the common terminal, wherein the first reciprocating arm is movable between a non-contact position isolated from the first terminal and a contact position in contact with the first terminal, and the second reciprocating arm is movable between a non-contact position isolated from the second terminal and a contact position in contact with the second terminal. The shutter mechanism comprises a first shutter and a second shutter, wherein the first shutter is configured to open and close the path between the first reciprocating arm and the first terminal, such that it is open when the first reciprocating arm is in the contact position and the second reciprocating arm is in the non-contact position, and closes when the first reciprocating arm is in the non-contact position and the second reciprocating arm is in the contact position; and the second shutter is configured to open and close the path between the second reciprocating arm and the second terminal, such that it is open when the second reciprocating arm is in the contact position and the first reciprocating arm is in the non-contact position, and closes when the second reciprocating arm is in the non-contact position and the first reciprocating arm is in the contact position. The apparatus according to claim 11.

13. The first reciprocating arm and the second reciprocating arm are connected to each other via a seesaw mechanism and are driven by a common motor such that the first reciprocating arm moves from the non-contact position to the contact position, while the second reciprocating arm moves from the contact position to the non-contact position, and vice versa. The apparatus according to claim 12.

14. The first and second reciprocating arms are driven by their respective motors such that when the second reciprocating arm moves from the contact position to the non-contact position, the first reciprocating arm moves only from the non-contact position to the contact position, and when the first reciprocating arm moves from the contact position to the non-contact position, the second reciprocating arm moves only from the non-contact position to the contact position. The apparatus according to claim 12.

15. The at least one movable contact arm for the disconnector switch includes a single contact arm configured to pivot or translate between a first position in contact with the first terminal and a second position in contact with the second terminal, The shutter mechanism comprises a first shutter and a second shutter, wherein the first shutter is configured to open and close the path between the single contact arm and the first terminal, such that it is open when the single contact arm is in a first position and closed when the single contact arm is in a second position, and the second shutter is configured to open and close the path between the single contact arm and the second terminal, such that it is open when the single contact arm is in a second position and closed when the single contact arm is in a first position. The apparatus according to claim 11.

16. The first shutter and the second shutter each include at least one door that is biased to close the path between the at least one movable contact arm for the disconnector switch and its respective terminal, As the movable contact arm for the disconnector switch moves toward each of the terminals, the movable contact arm for the disconnector switch is provided with an opening member configured to forcibly open the at least one door against the biasing force, The apparatus according to any one of claims 12 to 15.

17. The at least one door includes a pair of doors that meet to close the path, each door having a protruding member configured to engage with the opening member of the movable contact arm for the at least one disconnector switch, the opening member being shaped to wedge into and separate from the protruding member so as the movable contact arm for the at least one disconnector switch moves toward the respective terminals, forcing the door open against the bias. The apparatus according to claim 16.

18. The DC circuit breaker and the at least one movable contact arm for the disconnector switch of the disconnector switch are housed within an arc limiting enclosure, the first terminal and the second terminal of the disconnector switch are located outside the arc limiting enclosure, and the shutter mechanism is configured to open and close the respective paths outside the arc limiting enclosure through which the at least one movable contact arm for the disconnector switch must move to contact the first terminal and the second terminal. The apparatus according to any one of claims 11 to 17.

19. The first terminal and the second terminal of the disconnector switch are separated from each other by an insulating barrier. The apparatus according to any one of claims 1 to 18.

20. The DC circuit breaker and disconnector switch are formed on a common, removable unit of the power supply system. The apparatus according to any one of claims 1 to 19.

21. The aforementioned common removable unit is mounted on the wheel to facilitate removal from and reinstallation to the power supply system. The apparatus according to claim 20.

22. The common removable unit further comprises one or more shunts, fuses, and transducers of the power supply system. The apparatus according to claim 20 or 21.

23. A method for configuring a power supply system, The disconnector switch is connected to a DC power supply, so that the first terminal of the disconnector switch is connected to the first polarity terminal of the DC power supply, and the second terminal of the disconnector switch is connected to the second polarity terminal of the DC power supply, and the disconnector switch has at least a first position in which the first terminal is connected to the common terminal of the disconnector switch, and a second position in which the second terminal is connected to the common terminal of the disconnector switch. The common terminal of the disconnector switch is connected to the first terminal of a DC circuit breaker having a first terminal and a second terminal, which is configured to automatically switch from a closed state to an open state during an overcurrent condition. An interlock mechanism is coupled to the DC circuit breaker and the disconnector switch, thereby enabling the interlock mechanism to disable the automatic switching of the DC circuit breaker from the closed state to the open state when the disconnector switch is in the second position during the overcurrent condition. Connecting the second terminal of the DC circuit breaker to the first power line, The second terminal of the disconnector switch and the second polarity terminal of the DC power supply are connected to a second power line. Methods that include...

24. Includes computer code configured to perform the method described in claim 23, Computer program.

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