Contactor assembly and method for sequential switching using a sacrificial pole

Abstract

Embodiments of the present disclosure relate to contactor assemblies that include a sacrificial pole for improved current break performance. In a particular embodiment, a contactor assembly is disclosed that includes one or more main poles configured to conduct electrical current and a sacrificial pole configured to remain non-conductive during normal operation and to conduct current during a current interruption event.

Description

CONTACTOR ASSEMBLY AND METHOD FOR SEQUENTIAL SWITCHING USING A SACRIFICIAL POLEBACKGROUND

[0001] Electromechanical switching devices, such as contactors and relays, are used to establish or interrupt electrical current flow in a controlled manner and are essential components in electric vehicle power systems. These devices are commonly employed to switch high-current pathways between the vehicle’s battery pack and various electrical subsystems, including charging interfaces, traction inverters, and auxiliary power modules.

[0002] In conventional contactors, all poles typically open simultaneously during a current interruption event. This concurrent opening can result in electrical arcing at each contact interface, leading to erosion of the contact surfaces and an increase in contact resistance. Elevated resistance not only generates excessive heat during subsequent operation — particularly during high-current charging — but may also reduce system isolation, efficiency and limit the battery’s ability to accept the target charge current. Over time, such degradation can impact both performance and safety in electric vehicle power systems.SUMMARY

[0003] The following summary is meant to help one skilled in the art understand the various presently disclosed combinations of features. It is not meant to unduly limit the scope of any pending or future claims relating to the disclosure.

[0004] Embodiments of the present disclosure relate to contactor assemblies that include a sacrificial pole with potentially a series break resistor for improved performance during current interruption events. In these embodiments, the main poles open before the sacrificial pole during a current interruption event. The sacrificial pole and series break resistor, which are not used during normal charging, absorb the arc energy associated with the break load.

[0005] Because the sacrificial pole is not responsible for conducting charging current, any damage to its contacts from arcing is inconsequential. This structure preserves the integrity of the main poles, thereby improving contactor lifespan and performance without the need for complex mitigation mechanisms.

[0006] In a particular embodiment, a contactor assembly is disclosed that includes one or more main poles configured to conduct electrical current and a sacrificial pole configured to remain non-conductive during normal operation and to conduct current during a current interruption event.

[0007] In another embodiment, an electric vehicle is disclosed that includes a high-voltage battery, a charging port configured to receive power from an external charging source, and a power distribution unit electrically coupled to the high-voltage battery and the charging port. The power distribution unit comprises at least one contactor configured to selectively couple the high-voltage battery7to the charging port. In this embodiment, the at least one contactor comprises one or more main poles configured to conduct charging current during operation and a sacrificial pole configured to remain non-conductive during normal charging operation and to conduct current during a current interruption event to mitigate arcing at the one or more main poles.

[0008] In another embodiment, a method of operating a contactor assembly having a sacrificial pole is disclosed that includes coupling a contactor assembly to a power source. In this embodiment, the contactor assembly comprises a first main pole, a second main pole, and a sacrificial pole. The method also includes detecting a current interruption event and in response detecting the current interruption event, opening the first main pole and the second main pole while maintaining the sacrificial pole in a closed state. In this embodiment, the method also includes after opening the first main pole and the second main pole, subsequently opening the sacrificial pole to interrupt current flow through the contactor assembly.

[0009] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular descriptions of exemplary embodiments of the invention as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts of exemplary' embodiments of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] One or more aspects of the present disclosure are discussed below with reference to the accompanying Figures, ft will be appreciated that for simplicity and clarity of illustration, elements show n in the drawings have not necessarily been drawn accurately or to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity7or several physical components may be included in one functional block or element. Further, where considered appropriate, reference numerals may be repeated among the drawings to indicate corresponding or analogous elements. For purposes of clarity', however, not every7component may be labeled in every drawing. The Figures are provided for the purposes of illustration and explanation and are not intended to be limiting. In the Figures:

[0011] FIG. 1 is a schematic of a know n high voltage distribution system for an electric vehicle.

[0012] FIG. 2A is a schematic of an example high voltage distribution system including a contactor with a sacrificial pole in accordance with at least one embodiment of the present disclosure.

[0013] FIG. 2B is a schematic of another example high voltage distribution system including a contactor with a sacrificial pole in accordance with at least one embodiment of the present disclosure.

[0014] FIG. 3 is an example switch assembly for a contactor with a sacrificial pole in accordance with at least one embodiment of the present disclosure.

[0015] FIG. 4 is an example switch assembly for a contactor with a sacrificial pole in accordance with at least one embodiment of the present disclosure.

[0016] FIG. 5A illustrates a graph showing the relationship between resistance and both current and contactor voltage during a switching event.

[0017] FIG. 5B illustrates a graph showing the relationship between resistance and both current and power.

[0018] FIG. 6 is a flow chart of an example method of operating a contactor assembly including a sacrificial pole in accordance with at least one embodiment of the present disclosure.

[0019] FIG. 7 is a flow chart of another example method of operating a contactor assembly including a sacrificial pole in accordance with at least one embodiment of the present disclosure.DETAILED DESCRIPTION

[0020] The terminology used herein for the purpose of describing particular examples is not intended to be limiting for further examples. Whenever a singular form such as “a”, "an" and “the” is used and using only a single element is neither explicitly or implicitly defined as being mandatory, further examples may also use plural elements to implement the same functionality. Likewise, when a functionality is subsequently described as being implemented using multiple elements, further examples may implement the same functionality using a single element or processing entity. It will be further understood that the terms “comprises”, “comprising”, “includes” and / or “including”, when used, specify7the presence of the stated features, integers, steps, operations, processes, acts, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, processes, acts, elements, components and / or any group thereof.

[0021] It will be understood that when an element is referred to as being “connected"’ or “coupled” to another element, the elements may be directly connected or coupled via one or more intervening elements. If two elements A and B are combined using an “or”, this is to be understood to disclose all possible combinations, i.e. only A, only B, as well as A and B. An alternative wording for the same combinations is “at least one of A and B”. The same applies for combinations of more than two elements.

[0022] Accordingly, while further examples are capable of various modifications and alternative forms, some particular examples thereof are shown in the figures and will subsequently be described in detail. However, this detailed description does not limit further examples to the particular forms described. Further examples may cover all modifications, equivalents, and alternatives falling within the scope of the disclosure. Like numbers refer to like or similar elements throughout the description of the figures, which may be implemented identically or in modified form when compared to one another while providing for the same or a similar functionality.

[0023] The ability to connect and disconnect electrical circuits is fundamental to the operation of electrical systems. One commonly used device for this purpose is a contactor, which serves as an electromechanical switch capable of transitioning between an open state, in which current flow is interrupted, and a closed state, in which current flows through the circuit. Contactors are typically positioned between a power source and one or more electrical loads and are used to control the delivery of electrical energy to those loads in response to control signals or system conditions.

[0024] As modem vehicles and systems become increasingly electrified, particularly with the widespread adoption of electric vehicles (EVs), the demand for high-performance switching devices has grown. In EVs, contactors play a critical role in managing high-voltage power distribution between battery systems, charging interfaces, and drivetrain components. In such applications, reliable switching and overcurrent protection are essential not only to ensure functional performance but also to prevent equipment damage and mitigate safety risks such as overheating, electrical arcing, or fire. These demands drive the need for improved contactor designs capable of maintaining electrical and thermal integrity under increasingly demanding operating conditions.

[0025] The present disclosure describes various embodiments of contact assemblies that incorporate features to improve switching behavior, increase reliability, and enhance safety. In particular, the embodiments include structural and operational configurations in which components of the contact assembly are integrated or sequenced in a manner that reduceswear on primary contacts and minimizes arc-induced degradation. The disclosed inventions are directed to contactors incorporating such assemblies, as well as electrical systems and power distribution architectures — such as those used in electric vehicles — that benefit from improved contactor performance.

[0026] For further explanation, FIG. 1 sets forth a schematic of a known design of a high voltage distribution system 100 for an electric vehicle. The high voltage distribution system 100 includes a power distribution unit (PDU) 102 coupled to a battery 104 including one or more battery cells 106. In some implementations, the PDU 102 is a megawatt charging system (MCS) PDU. In some examples, the PDU 102 includes a charge connector 108 including DC+ and DC- terminals that are couplable to a MCS charger. In some examples, the PDU includes a charge connector 112 including DC+ and DC- terminals that are couplable to a combined charging system (CCS) charger.

[0027] In some examples, the PDU 102 includes a DC+ contactor 114 that provides a switched connection between the DC+ terminals of the charging connectors 108, 112 and the DC+ terminals of the battery cells 106. The DC+ contactor 114 includes two or more poles (indicated by ‘m’) that respectively open and close the connection between the DC+ terminals of the charging connectors 108, 112 and the battery cells 106. In some examples, the PDU 102 includes a DC- contactor 116 that provides a switched connection between the DC- terminals of the charging connectors 108, 112 and the DC- terminals of the battery cells 106. The DC- contactor 116 includes two or more poles (indicated byLnf) that respectively open and close the connection between the DC- terminals of the charging connectors 108, 112 and the battery' cells 106. As shown in FIG. 1, the voltage across the DC+ and DC- lines of the PDU connectors is HV 1 the voltage across the DC+ and DC- lines of the battery is HV2. The PDU 102 also includes a current sensor 118.

[0028] During charging, the poles of the DC+ contactor 1 14 and the DC- contactor 116 are closed and charge current can flow. Due to the low effective contact resistance (-0.05 mOhm) of each pole of the contactor, the voltage difference during charging across each contactor is small (typically <0.3 V). However, if the contactors need to open due to an emergency, upon opening an arc can appear across the poles of each contactor causing damage to the contacts. This damage is a function of voltage, current, and the duration of the event. As illustrated in FIGS. 5A and 5B, during a ty pical breaking event the current (I) and voltage (V_contactor) are shown as a function of the resistance (R_contactor) across a contactor. It is shown that at zero resistance current is high and voltage low. At highresistance, current is low and voltage is high. Power (P_contactor=V_contactor*I) is reaching a maximum somewhere in between.

[0029] Embodiments in accordance with the present disclosure address the potential for contact damage by introducing a sacrificial pole into at least one contactor of the PDU. When a current break is required, the main poles are opened before the sacrificial pole. Shortly after the main poles are opened, the sacrificial pole will open and catch the break load. Damage to the contacts of the sacrificial pole is inconsequential as the sacrificial pole is not intended to cany' current during charging.

[0030] For further explanation, FIG. 2A sets forth a schematic of an example high voltage distribution system 200 for an electric vehicle in accordance with at least one embodiment of the present disclosure. The high voltage distribution system 200 includes a power distribution unit (PDU) 202 coupled to a battery 204 including one or more battery cells 206. In some implementations, the PDU 202 is configured as a megawatt charging system (MCS) PDU suitable for high-current DC fast charging. The PDU 202 may include multiple charging interfaces, such as a charge connector 208 with DC+ and DC- terminals compatible with an MCS charger, and optionally a second charge connector 212 with DC+ and DC- terminals compatible with a combined charging system (CCS) charger. These connectors provide flexibili ty for interfacing with different charging infrastructure ty pes. The PDU 202 also includes a current sensor 218.

[0031] The PDU 202 further includes one or more contactors for switching the electrical connection between the charge connectors and the battery' cells. In the illustrated embodiment, the PDU includes a DC+ contactor 214 configured to selectively couple the DC+ terminals of connectors 208 and 212 to the DC+ terminal of the battery cells 206. The DC+ contactor 214 includes multiple poles 220. 221, and 222 (generically referred to as ‘nr) with poles 222 and 220 each configured to open and close respective cunent paths.Similarly, the PDU 202 includes a DC- contactor 216 that provides a switched connection between the DC- terminals of the connectors and the DC- terminal of the battery' cells. The DC- contactor 216 likewise includes multiple poles 224 and 226. which function as main current-carrying paths during charging. In this embodiment, a third pole 228. referred to as a sacrificial pole, is incorporated within the DC- contactor 216.

[0032] The sacrificial pole 228 is configured to remain closed during a current interruption event until after the main poles 224 and 226 have fully opened. Specifically, in the event of an emergency disconnect — such as communication loss with the charging station, thermal fault, or other protective shutdown condition — the contactor control logic initiates a sequencein which the main poles 224 and 226 are opened first. As soon as the main poles break the circuit, the entire current load is temporarily redirected through the sacrificial pole 228, which remains closed for a brief interval to absorb the arc energy. During this moment, the voltage across the opened main poles is negligible, and the current is effectively zero due to the alternative closed path. The sacrificial pole 228 is then opened in a controlled manner to complete the interruption. The sacrificial pole can be closed or opened during normal operation. If it is in the closed state, it is not needed for carrying current during normal operation. This means that any wear or damage to its contact surfaces from arc energy is functionally isolated from the charging path. Additionally, as contact wear on the sacrificial pole increases, its resistance may rise, inherently reducing the peak current during future break events, thereby further self-mitigating the severity of arcing.

[0033] At the beginning of a charging session, the operation sequence is reversed. The sacrificial pole 228 is closed first, followed by the main poles 224 and 226. This ensures that any arc formation during contact closure occurs at the sacrificial pole rather than the main poles, thus preserving the integrity and electrical characteristics of the primary currentcarrying elements. By isolating both break and make arcing to a non-critical contact, the system enhances overall reliability’ and extends the service life of the main poles.

[0034] The inclusion of a sacrificial pole in the contactor assembly provides several technical advantages. It significantly improves current break performance by shielding the main poles from arcing damage, which in turn prevents increases in contact resistance, reduces thermal buildup, and mitigates performance degradation over time. The sacrificial pole also simplifies contactor design by reducing the need for complex arc suppression methods such as vacuum enclosures, magnetic arc blowout arrangements, or rapid mechanical actuation. This approach enables a more cost-effective and robust contactor architecture, particularly advantageous for high-power electric vehicle charging systems.

[0035] For further explanation, FIG. 2B sets forth a schematic of another example high voltage distribution system 201 for an electric vehicle incorporating a contactor with a sacrificial pole, in accordance with at least one embodiment of the present disclosure. The high voltage distribution system includes a power distribution unit (PDU) 252 coupled to a battery 204 including one or more battery cells 206. As in previous embodiments, the PDU 252 may be implemented as a megawatt charging system (MCS) PDU capable of interfacing with high-power DC charging infrastructure. The PDU 252 includes one or more charging interfaces, such as a charge connector 208 having DC+ and DC- terminals compatible with an MCS charger, and a charge connector 212 that supports a combined charging system(CCS) interface. These connectors allow the vehicle to operate with a variety of charging standards. The PDU 202 also includes a current sensor 218.

[0036] The PDU 252 includes multiple contactors that manage the electrical connectivity between the charging connectors and the battery. In the embodiment shown, a DC- contactor 266 is configured to switch the DC- path between the charging connectors 208, 212 and the negative terminal of the battery cells 206. The DC- contactor 266 comprises three main poles 274, 268. 276 (denoted genencally as "m’) and poles 276 and 274 serve as the principal current-carrying elements during charging and discharging operations.

[0037] Likewise, the PDU 252 includes a DC+ contactor 264 responsible for switching the connection between the DC+ terminals of the connectors and the positive terminal of the battery. The DC+ contactor 264 includes three main poles 270. 271, and 272, which function as the primary conduction paths for the charging current. In this embodiment, the DC+ contactor 264 is further equipped with a dedicated sacrificial pole 290. The sacrificial pole 290 is physically and electrically distinct from the main poles and is configured to operate out of phase with them during connection and disconnection events to mitigate arc-related damage.

[0038] During an emergency current interruption event, such as an unexpected disconnect initiated by the vehicle or charging station controller, the main poles 270, 271, and 272 of the DC+ contactor 264 are opened first. As these poles transition to the open state, the current path is momentarily redirected through the sacrificial pole 290, which remains closed. Because the main poles are fully open at this point, the voltage across their terminals is minimal and the current is effectively zero, preventing any significant arcing across their contact surfaces. The sacrificial pole 290, still carry ing the break load, is then opened in a controlled manner. While the sacrificial pole may experience contact erosion due to arcing, such degradation is functionally isolated from the main poles and does not affect the charging path. Over time, even as the resistance of the sacrificial pole increases, the resulting current during subsequent break events is naturally reduced due to the increased impedance, further limiting arc severity.

[0039] In the example of FIG. 2B. a brake resistor 291 is coupled in series with the sacrificial pole 290 to further moderate current levels and dissipate excess energy during the break event. Upon opening of the main poles, the charge current is diverted through the resistor 291, which absorbs a portion of the stored energy that would otherwise be imposed directly on the sacrificial contacts. In a particular embodiment, the value of the brake resistor R_brake 291 may range from approximately 10 milliohms to 100 milliohms, depending onthe system voltage and current levels. In at least one implementation, the brake resistor 291 is formed using a conductive strip composed of AISI 304 stainless steel, or by integrating the resistance element into the movable contact within the sacrificial pole assembly. This approach offers a simple and cost-effective method for energy dissipation without requiring active cooling or additional switching elements.

[0040] In a further embodiment illustrated in FIG. 2B, the DC+ contactor 264 is configured such that main poles 270 and 271 open concurrently during a current interruption event, while main pole 272 opens after a predetermined delay. In this configuration, main pole 272 temporarily maintains conduction after main poles 270 and 271 have opened, thereby functioning as a sacrificial pole for those two poles by absorbing the arc energy that would otherwise be imposed on them. After a predetermined interval (e.g., approximately 10 milliseconds), main pole 272 opens and the current is redirected through sacrificial pole 290, which is connected in series with brake resistor 291. Sacrificial pole 290 remains closed for an additional interval (e.g., approximately 10 milliseconds), during which it conducts the remaining interruption current and facilitates energy’ dissipation through the brake resistor. It is then opened in a controlled manner, effectively acting as a sacrificial pole for main pole 272. This sequential interruption scheme — where main pole 272 acts as a sacrificial element for main poles 270 and 271, and sacrificial pole 290 subsequently acts as a sacrificial element for main pole 272 — provides a distributed arcing strategy that minimizes wear on primary contacts, enhances thermal management, and extends the operational life of the contactor assembly.

[0041] In the embodiment of FIG. 2B, the DC+contactor 264 is shown w ith three main poles 270-272 operating in concert with sacrificial pole 290. However, one of ordinary' skill w ill appreciate that any number of main poles may be employed alongside a single sacrificial pole w ithout departing from the scope of this disclosure. For example, in a particular embodiment the contactor may comprise only one main pole configured to carry’ charging current during normal operation and one sacrificial pole configured to remain non-conductive until a current interruption event. During such an event, the sole main pole opens first, the sacrificial pole then absorbs the interruption current and associated arc energy, and finally the sacrificial pole opens to complete the break, thereby preserving the integrity of the primary contact.

[0042] In a particular embodiment, the connection sequence at the start of a charging session is the logical inverse of the break sequence. Initially, the sacrificial pole 290 is closed, establishing a preliminary low-current path. Shortly thereafter, the main poles 270, 271. and 272 are closed to form the primary conduction path for charging. This staged approachensures that any contact arcing that occurs during initial closure affects only the sacrificial pole, thereby preserving the contact surfaces of the main poles and maintaining low resistance throughout the life of the contactor assembly.

[0043] By incorporating a sacrificial pole and optional brake resistor into the contactor design, this embodiment improves current interruption performance while simplifying overall system architecture. The main poles are protected from arc-induced wear, minimizing increases in contact resistance and reducing thermal stress. Additionally, the need for costly arc suppression technologies — such as magnetic blowout structures, vacuum-sealed contacts, or ultra-fast actuation mechanisms — is reduced or eliminated. This results in a more robust, reliable, and cost-effective high-voltage switching solution suitable for high-power electric vehicle charging systems.

[0044] For further reference, FIG. 3 sets forth a diagram of a switch assembly 300 of a contactor — such as the contactor 216 shown in FIG. 2 A or the contactor 264 shown in FIG. 2B — that is capable of implementing a sacrificial pole in accordance with at least one embodiment of the present disclosure. The sw itch assembly 300 is part of a mechanically actuated system that uses a rotatable cam shaft 302 to sequentially operate multiple switch elements. A plurality of such switch assemblies may be arranged along the length of the cam shaft 302 (as further depicted in FIG. 4), enabling coordinated control of multiple poles — e.g., a first main pole, a second main pole, and a sacrificial pole — via rotation of a common actuator.

[0045] In the illustrated embodiment, each switch assembly 300 includes a fixed bus bar 306, which serves as the stationary electrical contact, and a deformable bus bar 305, which functions as the movable contact. The deformable bus bar 305 is mechanically linked to a rocker mechanism 308, which is in turn actuated by a rotating cam 301 mounted on the cam shaft 302.

[0046] The cam 301 includes one or more substantially flat regions 304 and at least one substantially round region 303, which engage the rocker 308 during rotation. The shape and orientation of these cam surfaces determine whether the associated switch is in the open or closed state. In a default (rest) configuration, the switch assembly 300 is normally closed, meaning the deformable bus bar 305 is biased into electrical contact with the fixed bus bar 306. The biasing force may be provided by a spring integrated with the rocker mechanism or the deformable contact itself.

[0047] As the cam shaft 302 rotates, the engagement profile between the cam 301 and the rocker 308 changes. When the substantially round portion 303 of the cam engages the rocker308, it pushes one end of the rocker downward. This lever action causes the opposite end of the rocker to move upward, thereby lifting and deforming the bus bar 305 away from the fixed bus bar 306. This opens the switch and interrupts the electrical path. When the cam rotates to a position where a flat region 304 engages the rocker 308, the rocker is no longer subjected to cam-induced displacement and is allowed to return to its neutral position under spring bias. This brings the deformable bus bar 305 back into contact with the fixed bus bar 306, thereby closing the switch and restoring conduction.

[0048] The mechanical advantage provided by the cam and rocker arrangement allows for precise control over the timing and sequence of switch actuation. In embodiments where the contactor comprises both main and sacrificial poles, the cam shaft may be rotated incrementally to actuate the poles in a predefined sequence — for example, opening the main poles before the sacrificial pole during a break event, and closing the sacrificial pole before the main poles during system startup. This timing control is critical to the performance of sacrificial pole-based interruption schemes, enabling protection of the main contacts without requiring separate actuators for each pole.

[0049] While the illustrated configuration is normally closed, it should be appreciated that the same mechanical design may be adapted to implement normally open configurations, wherein the default position holds the switch open, and mechanical actuation is required to establish contact.

[0050] This cam-actuated switch design provides a cost-effective and mechanically reliable solution for managing high-voltage switching in electric vehicles and similar applications, particularly where coordinated operation of multiple contacts is required to implement advanced protection and interruption strategies.

[0051] For further explanation, FIG. 4 sets forth an exploded view of an example multiswitch contactor assembly 400 in accordance with at least one embodiment of the present disclosure. The assembly 400 is configured to mechanically coordinate the actuation of multiple switch poles — such as main and sacrificial poles — using a common cam-driven mechanism. This integrated configuration enables precise sequencing of switch operations for high-voltage applications, such as electric vehicle power distribution systems.

[0052] The contactor assembly 400 includes a cam assembly 401 comprising three individual cams 402, 403, and 404 mounted along a cam shaft 405. The cams are contoured to provide a predefined actuation profile for each switch assembly positioned along the shaft. Rotation of the cam shaft 405 is controlled by an electric motor 406, which for example, may be steppertype or servo-controlled. The cam shaft 405 enables synchronized operation of multipleswitches using a compact and robust mechanical interface.

[0053] In the illustrated embodiment, the contactor assembly includes three switch assemblies, each comprising a fixed contact 410 and a deformable contact 408. The deformable contacts are biased into a closed position and are actuated by corresponding rockers 412, which serve as mechanical intermediaries between the cam profiles and the deformable contacts. Each rocker 412 is coupled to a bias spring that applies a restoring force, holding the deformable contact 408 against the fixed contact 410 when the rocker is not actuated. In this state, the switch is closed, and current may flow through the pole.

[0054] When a cam (e.g., cam 402) rotates such that its substantially round lobe engages the corresponding rocker 412, it exerts a downward force on one side of the rocker. This causes the opposite end of the rocker to rise, deforming the flexible contact 408 away from the fixed contact 410, thereby opening the switch. When the cam rotates to a position where a flat portion engages the rocker 412, the spring 414 pushes the rocker back into a neutral position, allowing the contact to return to the closed state.

[0055] The use of individually contoured cams for each switch assembly permits independent control of the timing and sequencing of contact operations. For example, in one configuration, two cams may be shaped to actuate the main poles simultaneously, while the third cam is phased to actuate the sacrificial pole with a time delay. This staggered actuation enables the sacrificial pole to close or open before or after the main poles, as required by the operational sequence (e.g.. main poles open first during a break event, followed by the sacrificial pole).

[0056] To support precise control and monitoring, the assembly may optionally include a position sensor (not show n in FIG. 4) to detect the angular position of the cam shaft 405. The sensor may be a non-contact sensor such as a magnetic or optical encoder, or a contacting device such as a potentiometer. The sensor output provides the absolute angular position of the cam shaft, which may be used both for real-time feedback control of the actuator and to communicate the contact state to a vehicle controller or battery management system (BMS). This integration allows for fault detection, diagnostics, and safe sequencing of power connections and disconnections under software control.

[0057] Although the contactor assembly with a sacrificial pole has been illustrated in the context of a high-efficiency contactor (HEC) utilizing a shared camshaft actuation mechanism (as shown in FIGS. 2-4), the concepts disclosed herein are broadly applicable to a variety of electromechanical switch architectures. The sacrificial pole implementation is not limited to systems where all poles are housed within a single mechanical enclosure oroperated by a common actuator.

[0058] In alternative embodiments, the main poles may be implemented in a first contactor — such as an HEC or any conventional multi-pole device — while the sacrificial pole is implemented separately in a different housing, or even using a distinct switching technology. For example, the sacrificial function may be realized using a low-cost mechanical relay, a solenoid-actuated contactor, or a solid-state switch depending on system requirements, cost constraints, and desired arc-handling capabilities. This separation allows for modular design flexibility and can simplify retrofit or upgrade strategies in existing vehicle platforms.

[0059] In some embodiments, the main and sacrificial contactors may be independently controlled but coordinated via a supervisory control system, such as a vehicle controller or charging controller. This provides additional configurability and may enable the integration of advanced protective features — such as redundant break paths, state-of-health monitoring for the sacrificial contactor, and adaptive arc mitigation timing based on environmental or electrical conditions.

[0060] Thus, the use of a sacrificial pole for improving current interruption performance is adaptable to a wide range of system configurations, including monolithic contactor assemblies, hybrid mechanical-electrical switching systems, and distributed contactor arrangements. The design flexibility afforded by this concept provides significant benefits in terms of performance, reliability, and manufacturability for next-generation electric vehicle power distribution systems.

[0061] For further explanation, FIG. 6 sets forth a flow chart for an example method of operating a contactor assembly including a sacrificial pole. The method includes coupling 602 a contactor assembly to a power source, the contactor assembly comprising a first main pole, a second main pole, and a sacrificial pole. Coupling 602 a contactor assembly to a power source may be carried out by electrically connecting the contactor assembly to a high- voltage battery pack using busbars or terminal lugs, which may be secured by fasteners, welds, or compression fittings. In some implementations, the contactor assembly is integrated within a power distribution unit that is pre-wired to the battery terminals, thereby establishing a fixed electrical path for charging and discharging. Coupling may also involve connecting the contactor to the electrical lines of a charging port, inverter, or other power interface within the system architecture. In addition, control and sensor lines may be connected to a vehicle control unit to enable coordinated operation of the first main pole, second main pole, and sacrificial pole during both charging and current interruption events. The method of FIG. 6 also includes detecting 604 a current interruption event. Detecting 604a current interruption event may be carried out by monitoring current flow through the contactor assembly using one or more current sensors (e.g., sensor 218) positioned in the power distribution path. The system may compare the measured current against expected thresholds to identify abnormal conditions such as overcurrent, reverse current, or sudden current loss. Detection may also be based on inputs from a vehicle controller, such as a communication fault with a charger or a thermal shutdown signal. In some embodiments, voltage sensing across the contactor terminals may be used in conjunction with current measurements to confirm a current interruption event requiring contactor actuation. In addition, the method of FIG. 6 includes in response detecting the current interruption event, opening 606 the first main pole and the second main pole while maintaining the sacrificial pole in a closed state. In response to detecting the current interruption event, opening 606 the first main pole and the second main pole while maintaining the sacrificial pole in a closed state may be carried out by actuating a camshaft or other mechanical actuator that sequentially opens the main poles based on predefined cam profiles. The control unit may command a motor to rotate the camshaft to a specific angular position corresponding to the open state of the main poles while leaving the sacrificial pole unaffected. Alternatively, individual actuators may be used to open the main poles first, with the sacrificial pole held closed under separate control logic or mechanical delay. In both cases, the timing is managed to ensure that the main poles open first to avoid arcing damage, while current continues to flow temporarily through the closed sacrificial poleThe method of FIG. 6 also includes after opening the first main pole and the second main pole, subsequently opening 608 the sacrificial pole to interrupt current flow through the contactor assembly. After opening the first main pole and the second main pole, subsequently opening 608 the sacrificial pole to interrupt current flow through the contactor assembly may be carried out by continuing rotation of the camshaft to a position that actuates the sacrificial pole's rocker mechanism. In embodiments using independent actuators, the control unit may issue a delayed command to open the sacrificial pole after verifying that the main poles have reached their open positions. A position sensor may provide feedback confirming proper sequencing before the sacrificial pole is actuated. The delayed opening ensures that the break current is directed through the sacrificial pole, allowing it to absorb any arc energy and thereby preserving the integrity of the main contacts.

[0062] This method offers a significant advantage over traditional contactor switching strategies by using a sacrificial pole to isolate arc energy from the primary current-carrying contacts. In conventional systems, simultaneous opening of all poles during a currentinterruption event can result in arc-induced damage to the main poles, increasing contact resistance, reducing efficiency, and shortening component life. By sequencing the opening such that the main poles disconnect first and the sacrificial pole opens last, the arc is deliberately diverted to a non-critical contact that does not conduct during normal operation. This controlled sequencing preserves the electrical and mechanical integrity' of the main poles, reduces thermal stress during subsequent charging cycles, and simplifies contactor design by avoiding the need for additional arc-suppression hardware.

[0063] For further explanation, FIG. 7 sets forth a flow chart for another example method of operating a contactor assembly including a sacrificial pole. The method of FIG. 7 is similar to the method of FIG. 6 in that the method of FIG. 7 includes all the elements of FIG. 6. In addition, the method of FIG. 7 also includes initiating 702 a charging sequence. Initiating 702 a charging sequence may be carried out by receiving a charging request from a vehicle control unit or an external charging station through a communication interface. The control system may then perform safety checks, including verification of battery state, contactor status, and voltage alignment between the charger and the battery. Once conditions are validated, the system may activate control signals to begin sequential closure of the contactor poles. This includes closing the sacrificial pole first to establish an initial conductive path, followed by closing the main poles to enable full charging current flow.

[0064] The method of FIG. 7 also includes closing 704 the sacrificial pole to establish an initial conductive path. Closing 704 the sacrificial pole to establish an initial conductive path may be carried out by actuating a mechanical or electromechanical actuator, such as a cam- driven mechanism or solenoid, under the control of a vehicle or charging controller. The actuator applies force to move the sacrificial pole's movable contact into engagement with its corresponding fixed contact, completing the circuit. In cam-based systems, the camshaft may be rotated to a specific angular position where the sacrificial pole transitions to a closed state while the main poles remain open. The closure of the sacrificial pole allows limited or controlled current flow, enabling precharging or arc management before the main poles are engaged.

[0065] In addition, the method of FIG. 7 also includes after the sacrificial pole is closed, closing 706 the first main pole and the second main pole. After the sacrificial pole is closed, closing 706 the first main pole and the second main pole may be carried out by continuing rotation of a camshaft to positions that actuate the rocker mechanisms associated with the main poles. In this process, the cam profiles are designed such that the main poles close sequentially or simultaneously only after the sacrificial pole has reached its fully closedposition. In systems using independent actuators, the control unit may issue timed or condition-based signals to energize the actuators for the main poles after verifying sacrificial pole closure. This sequence ensures that any arcing or inrush current is managed by the sacrificial pole, preserving the contact integrity of the main poles for ongoing charging operations.

[0066] This method improves charging reliability and contactor longevity by ensuring that arcing and inrush currents are managed by the sacrificial pole rather than the main poles. In conventional systems, simultaneous closure of all contacts during charging can expose the main poles to arcing, which degrades contact surfaces and increases resistance over time. By closing the sacrificial pole first, this method establishes a controlled conductive path that absorbs the initial energy’ associated with contact closure, allowing the main poles to engage under stable electrical conditions. This approach not only protects the primary currentcarrying contacts but also supports safer, more efficient charging operations — particularly in high-voltage systems where managing transient events is critical to maintaining performance and ensuring compliance with system-level safety standards.

[0067] The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, apparatuses, and methods, according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.Advantages and features of the present disclosure can be further described by the following statements:

[0068] 1. A contactor assembly comprising: one or more main poles configured to conduct electrical current; and a sacrificial pole configured to remain non-conductive during normal operation and to conduct current during a current interruption event.

[0069] 2. The contactor assembly of statement 1, wherein, during the current interruption event, the one or more main poles are configured to open prior to the sacrificial pole.

[0070] 3. The contactor assembly of any of statements 1-2, wherein the sacrificial pole is configured to conduct the interruption current after the one or more main poles have opened.

[0071] 4. The contactor assembly of any of statements 1-3, wherein, during initiation of a charging session, the sacrificial pole is configured to close before the one or more main poles.

[0072] 5. The contactor assembly of any of statements 1-4, wherein the contactor assembly is implemented as a charging contactor, and wherein the sacrificial pole is not configured to conduct charging current during normal operation.

[0073] 6. The contactor assembly of any of statements 1-5 further comprising a resistive element electrically connected in series with the sacrificial pole, the resistive element configured to dissipate energy during the current interruption event.

[0074] 7. The contactor assembly of any of statements 1-6, wherein the one or more main poles include a first main pole, a second main pole, and a third main pole; wherein, during the current interruption event: the first main pole and second main pole are configured to open concurrently; after a predetermined delay following the opening of the first main pole and the second main pole, the third main pole is configured to open; and the sacrificial pole is configured to open after the third main pole.

[0075] 8. The contactor assembly of any of statements 1-7 further comprising a connector configured to electrically couple the contactor assembly to a power distribution unit or a charging system.

[0076] 9. The contactor assembly of any of statements 1-8, wherein the one or more main poles, and the sacrificial pole are actuated by a common camshaft.

[0077] 10. The contactor assembly of any of statements 1-9, wherein the camshaft is driven by a motor and includes cam profiles configured to control the opening and closing timing of each pole.

[0078] 11. The contactor assembly of any of statements 1-10, further comprising a position sensor configured to detect a rotational position of the camshaft.

[0079] 12. The contactor assembly of any of statements 1-1 1, wherein the sacrificial pole is implemented as a normally closed contact.

[0080] 13. The contactor assembly of any of statements 1-12, wherein the sacrificial pole and the one or more main poles are housed within a common enclosure.

[0081] 14. The contactor assembly of any of statements 1-13. wherein the sacrificial pole is located in a separate housing from the one or more main poles.

[0082] 15. The contactor assembly of any of statements 1-14, wherein actuation of the sacrificial pole is timed to occur within a predetermined delay window relative to actuation of the one or more main poles.

[0083] 16. The contactor assembly of any of statements 1-15, wherein the contactor assembly is configured to operate in a high-voltage charging system for an electric vehicle.

[0084] 17. An electric vehicle comprising: a high-voltage battery; a charging port configured to receive power from an external charging source; and a power distribution unit electrically coupled to the high-voltage battery and the charging port, wherein the power distribution unit comprises at least one contactor configured to selectively couple the high-voltage battery to the charging port, the at least one contactor comprises: one or more main poles configured to conduct charging current during operation; and a sacrificial pole configured to remain non- conductive during normal charging operation and to conduct current during a current interruption event to mitigate arcing at the one or more main poles.

[0085] 18. The electric vehicle of statement 17, wherein, during the current interruption event, the one or more main poles are configured to open before the sacrificial pole and during initiation of a charging session, the sacrificial pole is configured to close before the one or more main poles.

[0086] 19. A method of operating a contactor assembly including a sacrificial pole, the method comprising: coupling a contactor assembly to a power source, the contactor assembly comprising a first main pole, a second main pole, and a sacrificial pole; detecting a current interruption event; in response detecting the current interruption event, opening the first main pole and the second main pole while maintaining the sacrificial pole in a closed state; and after opening the first main pole and the second main pole, subsequently opening the sacrificial pole to interrupt current flow through the contactor assembly.

[0087] 20. The method of statement 19, further comprising: initiating a charging sequence; closing the sacrificial pole to establish an initial conductive path; and after the sacrificial pole is closed, closing the first main pole and the second main pole.

[0088] It will be understood from the foregoing description that modifications and changes may be made in various embodiments of the present disclosure without departing from its true spirit. The descriptions in this specification are for purposes of illustration only and are not to be construed in a limiting sense. The scope of the present disclosure is limited only by the language of the following claims.

Claims

CLAIMSWhat is claimed is:

1. A contactor assembly comprising: one or more main poles configured to conduct electrical current; and a sacrificial pole configured to remain non-conductive during normal operation and to conduct current during a current interruption event.

2. The contactor assembly of claim 1, wherein, during the cunent interruption event, the one or more main poles are configured to open prior to the sacrificial pole.

3. The contactor assembly of claim 2, wherein the sacrificial pole is configured to conduct the interruption current after the one or more main poles have opened.

4. The contactor assembly of claim 1, wherein, during initiation of a charging session, the sacrificial pole is configured to close before the one or more main poles.

5. The contactor assembly of claim 1, wherein the contactor assembly is implemented as a charging contactor, and wherein the sacrificial pole is not configured to conduct charging current during normal operation.

6. The contactor assembly of claim 1 further comprising a resistive element electrically connected in series with the sacrificial pole, the resistive element configured to dissipate energy7during the current intermption event.

7. The contactor assembly of claim 6, wherein the one or more main poles include a first main pole, a second main pole, and a third main pole; wherein, during the current interruption event: the first main pole and second main pole are configured to open concurrently; after a predetermined delay following the opening of the first main pole and the second main pole, the third main pole is configured to open; and the sacrificial pole is configured to open after the third main pole.

8. The contactor assembly of claim 1 further comprising a connector configured to electrically couple the contactor assembly to a power distribution unit or a charging system.

9. The contactor assembly of claim 1, wherein the one or more main poles, and the sacrificial pole are actuated by a common camshaft.

10. The contactor assembly of claim 9, wherein the camshaft is driven by a motor and includes cam profiles configured to control the opening and closing timing of each pole.

11. The contactor assembly of claim 10, further comprising a position sensor configured to detect a rotational position of the camshaft.

12. The contactor assembly of claim 1, wherein the sacrificial pole is implemented as a normally closed contact.

13. The contactor assembly of claim 1, wherein the sacrificial pole and the one or more main poles are housed within a common enclosure.

14. The contactor assembly of claim 1, wherein the sacrificial pole is located in a separate housing from the one or more main poles.

15. The contactor assembly of claim 1, wherein actuation of the sacrificial pole is timed to occur within a predetermined delay window relative to actuation of the one or more main poles.

16. The contactor assembly of claim 1, wherein the contactor assembly is configured to operate in a high-voltage charging system for an electric vehicle.

17. An electric vehicle comprising: a high-voltage battery; a charging port configured to receive power from an external charging source; and a power distribution unit electrically coupled to the high-voltage battery and the charging port, wherein the power distribution unit comprises at least one contactor configured to selectively couple the high-voltage battery to the charging port, the at least one contactor comprises: one or more main poles configured to conduct charging current during operation; and a sacrificial pole configured to remain non-conductive during normal charging operation and to conduct current during a current interruption event to mitigate arcing at the one or more main poles.

18. The electric vehicle of claim 17, wherein, during the current interruption event, the one or more main poles are configured to open before the sacrificial pole and during initiation of a charging session, the sacrificial pole is configured to close before the one or more main poles.

19. A method of operating a contactor assembly including a sacrificial pole, the method comprising: coupling a contactor assembly to a power source, the contactor assembly comprising a first main pole, a second main pole, and a sacrificial pole; detecting a current interruption event;in response detecting the current interruption event, opening the first main pole and the second main pole while maintaining the sacrificial pole in a closed state; and after opening the first main pole and the second main pole, subsequently opening the sacrificial pole to interrupt current flow through the contactor assembly.

20. The method of claim 19, further comprising: initiating a charging sequence; closing the sacrificial pole to establish an initial conductive path; and after the sacrificial pole is closed, closing the first main pole and the second main pole.

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