Electrically powered vehicle battery combination electrical / fluid connector

Abstract

The present disclosure provides a powered vehicle battery combination electrical / fluid connector. A motorized vehicle system is presented. The powered vehicle system has a traction battery incorporating a plurality of electrically connected array modules submerged in a cooling fluid. A sensing component coupled with the at least one array module and submerged in the cooling fluid is configured to detect a voltage drop when a contamination level of the fluid reaches a threshold to increase conductivity. The sensed voltage drop is communicated to a traction battery monitoring system, enabling prospective management of cooling fluid integrity.

Description

Technical Field

[0001] This disclosure relates to a battery cooling system for electric vehicles. Background Technology

[0002] Immersion cooling systems provide a method for controlling temperature in high-voltage battery systems, including battery cells and exposed high-voltage components. However, maintaining proper electrical isolation is essential for performance in these systems. The dielectric strength of the immersion coolant plays a role in this isolation. Contamination of the fluid can impair its dielectric properties. Conventional methods used to detect isolation faults between the high-voltage positive or negative electrode and chassis ground cannot detect dielectric breakdown in the coolant caused by contamination. Summary of the Invention

[0003] In one aspect of this disclosure, an electrified vehicle system is proposed. The electrified vehicle system includes: a traction battery; a plurality of electrically connected array modules within the traction battery, the plurality of electrically connected array modules being immersed in a cooling fluid; and a sensing element coupled to at least one of the array modules and in contact with the cooling fluid, the sensing element being configured to detect a voltage drop on the sensing element when the contamination level in the cooling fluid reaches a threshold that increases the conductivity of the cooling fluid, and to report the voltage drop on the sensing element to a traction battery monitoring system. The sensing element may be a high-precision resistive shunt. The sensing element may also be a current sensor having both low-precision range capability and high-precision range capability. In other configurations, the electrified vehicle system may further include a plurality of sensing elements, each coupled to a corresponding array module. The traction battery monitoring system may be configured to correlate the reported voltage drop with vehicle diagnostic data to determine the contamination level of the cooling fluid. The traction battery monitoring system may also be configured to classify the contamination level of the cooling fluid as low, medium, or high. The traction battery monitoring system may also be configured to disable one of the array modules based on the contamination level. The traction battery can also be connected to the traction component.

[0004] In another aspect of this disclosure, an electrified vehicle system is proposed. The electrified vehicle system includes: a traction battery; at least one array within the traction battery, the at least one array being immersed in a cooling fluid; and a sensing element within the cooling fluid, the sensing element being configured to: detect a change in the dielectric properties of the cooling fluid when a contamination level in the cooling fluid reaches a threshold that alters the dielectric strength of the cooling fluid; measure the change in the dielectric properties caused by a voltage flow through the cooling fluid from the at least one array; and transmit the measured change in dielectric properties to a traction battery monitoring system. The dielectric strength of the cooling fluid is measured by the sensing element and may include at least one of the conductivity, dielectric constant, or impedance of the cooling fluid. The sensing element may include multiple electrodes positioned at different locations within the cooling fluid. The electrified vehicle system may also include multiple sensing elements, each associated with a different array within the traction battery. The traction battery monitoring system may also be configured to establish a baseline measurement of the electrical properties and detect deviations relative to the baseline measurement. The traction battery monitoring system may also be configured to classify the deviations as indicating low, medium, or high contamination. The traction battery monitoring system can also be configured to correlate measured changes in electrical properties with vehicle diagnostic data to determine the level of contamination in the coolant. The diagnostic data may include measurements of the coolant temperature. The traction battery monitoring system can also be configured to disable at least one array based on measured changes in electrical properties. The traction battery may be connected to a traction component.

[0005] In another aspect of this disclosure, a battery module is proposed. The battery module includes: a housing having a plurality of arrays within the housing; an immersion cooling fluid within the housing, the immersion cooling fluid contacting positive and negative terminals of the plurality of arrays; a contamination detection circuit coupled to at least one of the plurality of arrays and in contact with the immersion cooling fluid, the contamination detection circuit being configured to detect a current through the immersion cooling fluid between the positive and negative terminals when a contamination level in the immersion cooling fluid reaches a threshold for completing an electrical path; and a battery module monitoring system configured to receive data indicating the current from the contamination detection circuit due to a contamination level in the immersion cooling fluid, and to disable one of the plurality of arrays based on determining that the contamination level has reached the threshold. The battery module monitoring system may also be configured to adjust the charging rate of the plurality of arrays based on the determined contamination level. Attached Figure Description

[0006] Figure 1It is a schematic diagram of an electrified vehicle system according to one or more aspects of this disclosure;

[0007] Figure 2 These are schematic diagrams of electrified vehicle systems according to one or more aspects of this disclosure; and

[0008] Figure 3 It is a block diagram of an electrified vehicle system according to one or more aspects of this disclosure. Detailed Implementation

[0009] Detailed embodiments are disclosed herein as needed; however, it should be understood that the disclosed embodiments are merely representative and may be embodied in various and alternative forms. The drawings are not necessarily drawn to scale; some features may be enlarged or minimized to show details of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to employ embodiments of the claimed subject matter in different ways.

[0010] The introduction of immersion cooling technology in high-voltage (HV) battery systems for electric vehicles has enabled new forms of thermal management and performance optimization. This approach, involving immersing the battery cells and associated HV components in a specially formulated dielectric fluid, offers advantages over conventional air or liquid cooling methods. Benefits include increased heat transfer capacity, a greater degree of uniform temperature distribution across the battery pack, and the potential for increased energy density. However, maintaining the integrity of electrical isolation within the system can be challenging when using immersion cooling technology.

[0011] Dielectric fluids are an integral part of immersion cooling systems. Dielectric fluids are specially designed materials that balance a variety of properties. Exemplary immersion coolants possess high dielectric strength for maintaining electrical isolation, low viscosity for efficient cycling, high thermal conductivity for efficient heat dissipation, chemical stability to prevent degradation under varying conditions, and low toxicity for environmental sustainability. Selection of immersion cooling fluids includes silicone oils, synthetic hydrocarbons, and specialized fluorinated liquids. Each type of fluid is provided with a property profile, and the selection process involves considering the specific requirements of the battery system, including operating temperature range, expected lifespan, and stability considerations.

[0012] The dielectric strength of the immersion coolant plays a role in the stability and functionality of HV battery systems. The dielectric strength of the immersion coolant allows the fluid to act as an effective insulator, preventing accidental electrical connections between HV components or between HV components and the vehicle chassis. However, the dielectric strength of the fluid can be compromised by various forms of contamination. Moisture ingress, even in trace amounts, can reduce the fluid's dielectric strength. Particulate matter that may enter the system from external sources or be generated internally through component wear can create conductive pathways within the fluid. Over time, the fluid itself may undergo chemical degradation due to thermal stress or reactions with battery materials. In the event of cell damage, leakage of battery electrolyte into the coolant tank can also affect its insulating properties.

[0013] Methods for detecting isolation faults in HV battery systems focus on monitoring the electrical isolation between the HV positive (HV+) or HV negative (HV-) terminal and chassis ground. These methods may not be sufficient to fully address the specific challenges posed by immersion cooling systems. A consideration in immersion cooling systems is the possibility of a dual-fault scenario, where contamination of the coolant fluid could lead to a connection between both HV+ and HV- terminals and chassis ground. This situation needs to be considered due to its impact on the battery, necessitating the development of improved detection and monitoring systems.

[0014] This disclosure presents a method for detecting and monitoring dielectric breakdown in an immersion-cooled HV battery system. The proposed system utilizes high-precision current measurement techniques to detect minute currents that may indicate the onset of fluid contamination or dielectric breakdown. This is achieved by placing a high-precision shunt or advanced current sensor capable of measuring currents in the microamp to milliamp range. These sensors are configured to detect the current flowing through the cooling fluid between the HV+ and HV- components, thereby providing an early indication of potential isolation problems.

[0015] The current measurement system can be integrated into the battery management system (BMS) or with a dedicated battery pack sensor module (BPSM), thereby allowing for enhanced diagnostic capabilities. This analysis correlates current measurements with a wide range of existing diagnostic data, including cell voltage variations, battery pack self-discharge rates, and abnormal temperature distribution. The algorithm processes this data to distinguish between normal operating currents and those indicating dielectric breakdown, enabling the system to identify potential problems with high accuracy and minimal false alarms.

[0016] The proposed method considers implementing isolated monitoring at the array or module level, rather than relying solely on battery pack-level checks. Each battery array can be equipped with its own BPSM, capable of independently performing localized isolated checks. This granular approach allows for precise fault localization, enabling the system to distinguish between array-specific issues and system-wide contamination events. The distributed nature of this monitoring system enhances overall reliability and provides data for predictive maintenance and fault diagnosis.

[0017] This disclosure can also incorporate passive measurement techniques configured to operate with minimal power consumption. This allows for continuous vigilance against developing faults, even when the vehicle is in a dormant state. The system can also perform rapid checks upon wakeup from the BMS or BPSM to allow for the rapid detection of potential problems without significantly impacting the vehicle's energy efficiency.

[0018] A tiered response system can be used to manage responses to detected faults. The severity of the detected problem determines the appropriate action, ranging from activating diagnostic fault codes or indicators for minor cases, to limiting charge / discharge rates or power output for more serious cases, and up to complete vehicle start-stop and immediate protocol activation for the most severe events. This approach balances user convenience with operational reliability to maintain vehicle functionality where possible.

[0019] Integrating monitoring points (including pump and cooler controllers) within a fluid circulation system can increase the system's monitoring capabilities. By utilizing redundant checks on both the high-pressure and low-pressure sides of the pump / cooler system, the proposed method can provide a comprehensive view of the fluid health throughout the entire circulation path.

[0020] The implementation of this detection system can involve specially configured hardware and software components. High-precision resistive shunts or advanced Hall effect sensors can be used for current measurement, capable of detecting even the slightest anomalies in the current. The BMS and BPSM software can be further combined with machine learning algorithms that analyze current data in real time, taking into account factors such as normal leakage current, temperature-dependent changes in fluid conductivity, and transient currents during vehicle operation or charging.

[0021] Each BPSM can be equipped with a dedicated microcontroller capable of independently performing isolation checks, contributing to a robust and fault-tolerant system architecture. Data from all arrays can be aggregated and analyzed by a central BMS, which can employ pattern recognition technology to identify and differentiate between systemic problems and localized faults. This distributed yet integrated approach allows for comprehensive monitoring while enabling rapid and accurate fault diagnosis.

[0022] Passive measurement systems can also be combined with ultra-low-power components, allowing for periodic checks even during extended periods of vehicle inactivity. This enables the detection of slowly developing faults that might otherwise be overlooked between driving cycles, improving reliability and performance.

[0023] Figures 1 to 2 This is a schematic diagram of the battery monitoring system 10 within an electrified vehicle system. The traction battery 12 has an HV positive terminal 14 and an HV negative terminal 16. The HV positive terminal 14 and HV negative terminal 16 serve as the main power conduits for the electric vehicle's powertrain. The traction battery 12 includes multiple array modules (not depicted separately in these figures) that are electrically interconnected to form a high-capacity energy storage system capable of powering the vehicle's electric motor and auxiliary systems.

[0024] The immersion cooling fluid 18, which completely surrounds the battery components, has multiple functions. The immersion cooling fluid 18 provides heat dissipation from the individual battery cells, ensuring a uniform temperature distribution across the entire traction battery 12, and acts as a dielectric to maintain electrical isolation between high-voltage components. Under normal operating conditions, the immersion cooling fluid 18 is configured to be non-conductive, thereby maintaining the electrical integrity of the battery system.

[0025] The battery monitoring system 10 includes a sensing element 20. The sensing element 20 may be a precision resistor / shunt positioned in direct contact with the immersion cooling fluid 18. The primary function of the sensing element 20 is to measure minute currents that may arise due to changes in the electrical properties of the immersion cooling fluid 18. The sensing element 20 may be able to detect extremely small voltage drops across itself, which serve as a sensitive indicator of changes in the fluid's conductivity.

[0026] System 10 includes a positive contactor 22 and a negative contactor 24. These are high-voltage switching devices that control the electrical connection between the traction battery 12 and the HV load 26. These contactors 22 and 24 serve as a means to allow for rapid electrical isolation of the battery 12 from the rest of the vehicle's HV system in the event of a detected fault or during maintenance procedures.

[0027] The high-resistance component 28 represents the substantially electrical isolation maintained between the traction battery 12 and the chassis ground 30. The high-resistance component 28 maintains the electrical integrity of the vehicle, thereby effectively preventing unintended current paths between the traction battery 12 and the vehicle's conductive body structure.

[0028] HV load 26 represents the electrical load from various HV components in the vehicle that draw power from the traction battery 12. This may include, but is not limited to, the electric drive motor, power electronics for motor control, and the HV heater or air conditioning compressor. Chassis ground 30 provides a common reference point for all vehicle electrical systems and ensures that any stray currents have a predetermined path to ground.

[0029] The physical contact between the immersion coolant 18 and the HV positive terminal 14, HV negative terminal 16, and chassis ground wire 30 allows the immersion coolant 18 to normalize the temperature of these components. Under normal conditions, the dielectric properties of the immersion coolant 18 prevent any current from flowing between these points. However, if contaminants seep into the fluid and alter its electrical properties, potential current paths may form. Sensing element 20 is configured and positioned to detect these currents, which manifest as small but measurable voltage drops across the components.

[0030] Figures 1 to 2 The arrangement of the battery monitoring system 10 shown allows for continuous, real-time monitoring of the condition of the cooling fluid. Any increase in the conductivity of the submerged cooling fluid 18 (which may be caused by the presence of conductive contaminants 32 or by disruption of the molecular structure of the submerged cooling fluid 18) may result in a detectable current flowing through the sensing element 20. This current generates a voltage drop across the sensing element 20, which can be accurately measured and analyzed by the battery monitoring system 10. Figure 2 As shown, when the conductive contaminant 32 has reached the threshold level, the circuit 34 between the HV positive terminal 14 and the HV negative terminal 16 is completed.

[0031] Figure 3 This is a block diagram of the entire electrified vehicle system 36, showing the relationship between major components and subsystems. The traction battery 38 is an HV battery pack that serves as the primary energy storage unit for the electrified vehicle, providing the necessary power to drive the vehicle and operate its numerous electrical systems. The traction battery 38 includes... Figures 1 to 2 The array module and battery monitoring system 10 are described in the diagram. An on-board charger 40 is connected to the traction battery 38. This on-board charger 40 converts AC power from an external charging station into DC power required to charge the traction battery 38. The on-board charger 40 connected to the traction battery 38 represents a high-voltage DC charging circuit. This circuit can be designed to handle high power levels, typically in the range of 50kW to 350kW, depending on the vehicle's fast-charging capability.

[0032] Power electronics 42 are also connected to traction battery 38. Power electronics 42 serves as an interface between traction battery 38 and traction motor 44. Power electronics 42 may include an inverter system that converts DC power from traction battery 38 into AC power required by traction motor 44. Additionally, power electronics 42 can manage bidirectional power flow, thereby enabling regenerative braking by converting kinetic energy back into electrical energy to recharge battery 38. Power electronics 42 may be connected to traction motor 44, which may include HV power circuitry. HV circuitry can be configured to handle high currents, typically exceeding 1000 amperes during peak loads or regenerative braking events.

[0033] The traction motor 44 is the vehicle's main propulsion unit, responsible for converting electrical energy from the battery 38 into mechanical energy. The traction motor 44 can be of various types, such as a permanent magnet synchronous motor or an induction motor. The power electronics 42 connected to the traction motor 44 represent a high-voltage AC power circuit that supplies controlled, variable-frequency, and variable-amplitude power required to effectively operate the traction motor 44 across a wide range of speeds and torques.

[0034] The battery management system 46 is the control unit of the electric powertrain system, which monitors and manages various aspects of the operation of the traction motor 44 and the traction battery 38. The battery management system 46 is connected to the traction battery 38, power electronics 42, and traction motor 44. These connections represent control and communication circuits that allow the battery management system to monitor and control these components. These circuits carry various signals, including battery cell voltage and temperature data, state of charge and state of health estimates, coolant contamination sensor data, power demand signals to the motor controller, charging current and voltage control signals, and fault detection and mitigation commands.

[0035] The thermal management system 48 includes a traction battery 38, power electronics 42, and a traction motor 44. This system is responsible for maintaining the optimal operating temperature of these components. It includes an immersion cooling system for the traction battery 38 and may also include liquid or air cooling systems for the power electronics 42 and the traction motor 44. The thermal management system 48 plays a role in the efficiency, performance, and lifespan of the electric powertrain components. It can incorporate advanced features such as heat pumps for cabin climate control and battery pre-conditioning.

[0036] The electrical connections 50 between HV components carry the main power flow within the system, such as from battery 38 to motor 44 during high-load events, or from charger 40 to battery 38 during charging. These circuits are designed to handle voltages typically ranging from 400 volts to 800 volts in modern electric vehicles, with some systems pushing up to 1000 volts for improved efficiency.

[0037] Control and communication connections 52 allow the battery management system 46 to monitor and control various aspects of the powertrain operation. For example, control and communication connections 52 to the traction motor 44 carry speed and torque control signals, while control and communication connections 52 to the traction battery 38 include data from the thermal management system 48, individual cell voltages, temperatures, and other battery monitoring sensors. These communication lines can utilize automotive-grade protocols, such as Controller Area Network (CAN), or other protocols such as automotive Ethernet.

[0038] While representative embodiments have been described above, these embodiments are not intended to describe all possible forms of the invention. The wording used in this specification is descriptive rather than limiting, and it should be understood that various changes may be made without departing from the claimed subject matter. Furthermore, features of various embodiments may be combined to form other embodiments not explicitly described or shown, but within the scope of the claimed subject matter.

[0039] According to the present invention, an electrified vehicle system is provided, comprising: a traction battery; an array of multiple electrically connected modules within the traction battery, the array of multiple electrically connected modules being immersed in a cooling fluid; and a sensing component, the sensing component being coupled to at least one of the electrically connected array modules and in contact with the cooling fluid, the sensing component being configured to detect a voltage drop on the sensing component when a contamination level in the cooling fluid reaches a threshold that increases the conductivity of the cooling fluid, and to report the voltage drop on the sensing component to a traction battery monitoring system.

[0040] According to an embodiment, the sensing component is a high-precision resistive shunt.

[0041] According to an embodiment, the sensing component is a current sensor with both low-precision range capability and high-precision range capability.

[0042] According to an embodiment, the present invention is further characterized by a plurality of sensing components, each sensing component being connected to a corresponding array module.

[0043] According to an embodiment, the traction battery monitoring system is configured to correlate the reported voltage drop with vehicle diagnostic data to determine the contamination level of the cooling fluid.

[0044] According to an embodiment, the traction battery monitoring system is also configured to classify the contamination level of the cooling fluid according to a predetermined category.

[0045] According to an embodiment, the traction battery monitoring system is also configured to disable one of the array modules of the electrical connection based on the pollution level.

[0046] According to an embodiment, the traction battery is connected to the traction component.

[0047] According to the present invention, an electrified vehicle system is provided, comprising: a traction battery; at least one array within the traction battery, the at least one array being immersed in a cooling fluid; and a sensing element within the cooling fluid, the sensing element being configured to: detect a change in the dielectric properties of the cooling fluid when a contamination level in the cooling fluid reaches a threshold that alters the dielectric strength of the cooling fluid; measure the change in the dielectric properties caused by a voltage flow from the at least one array through the cooling fluid; and transmit the measured change in dielectric properties to a traction battery monitoring system.

[0048] According to an embodiment, the dielectric strength of the cooling fluid is measured by the sensing component, and the dielectric strength includes at least one of the conductivity, dielectric constant, or impedance of the cooling fluid.

[0049] According to an embodiment, the sensing element includes multiple electrodes positioned at different locations within the cooling fluid.

[0050] According to an embodiment, the invention is further characterized by a plurality of sensing elements, each of which is associated with a different array within the traction battery.

[0051] According to an embodiment, the traction battery monitoring system is configured to establish a baseline measurement of the dielectric properties and detect deviations relative to the baseline measurement.

[0052] According to an embodiment, the traction battery monitoring system is also configured to classify the deviation as one of a plurality of predefined categories.

[0053] According to an embodiment, the traction battery monitoring system is configured to correlate measured changes in electrical properties with vehicle diagnostic data to determine the contamination level of the cooling fluid.

[0054] According to an embodiment, the diagnostic data includes temperature measurements of the cooling fluid.

[0055] According to an embodiment, the traction battery monitoring system is also configured to disable the at least one array based on measured changes in electrical properties.

[0056] According to an embodiment, the traction battery is connected to the traction component.

[0057] According to the present invention, a battery module is provided, comprising: a housing; a plurality of arrays within the housing; an immersion cooling fluid within the housing, the immersion cooling fluid contacting positive and negative terminals of the plurality of arrays; a contamination detection circuit coupled to at least one of the plurality of arrays and in contact with the immersion cooling fluid, the contamination detection circuit being configured to detect a current through the immersion cooling fluid between the positive and negative terminals when a contamination level in the immersion cooling fluid reaches a threshold for completing an electrical path; and a battery module monitoring system configured to receive data indicating the current from the contamination detection circuit due to a contamination level in the immersion cooling fluid, and to disable one of the plurality of arrays based on the contamination level having reached the threshold.

[0058] According to an embodiment, the battery module monitoring system is further configured to adjust the charging rate of the plurality of arrays based on the pollution level.

Claims

1. An electrified vehicle system, comprising: Traction battery; Multiple electrically connected array modules are located within the traction battery and are immersed in cooling fluid. as well as A sensing component, which is coupled to at least one of the electrically connected array modules and in contact with the cooling fluid, is configured to detect a voltage drop on the sensing component when the contamination level in the cooling fluid reaches a threshold that increases the conductivity of the cooling fluid, and to report the voltage drop on the sensing component to the traction battery monitoring system.

2. The electric vehicle system according to claim 1, wherein the sensing component is a high-precision resistive shunt.

3. The electric vehicle system according to claim 1, wherein the sensing component is a current sensor having both low-precision range capability and high-precision range capability.

4. The electric vehicle system according to claim 1 further includes a plurality of sensing components, each sensing component being connected to a corresponding array module.

5. The electrified vehicle system of claim 1, wherein the traction battery monitoring system is configured to correlate the reported voltage drop with vehicle diagnostic data to determine the contamination level of the cooling fluid.

6. The electrified vehicle system of claim 5, wherein the traction battery monitoring system is further configured to classify the contamination level of the cooling fluid according to a predetermined category.

7. The electrified vehicle system of claim 6, wherein the traction battery monitoring system is further configured to disable one of the array modules of the electrical connection based on the pollution level.

8. The electric vehicle system of claim 1, wherein the traction battery is connected to the traction component.

9. An electrified vehicle system comprising: Traction battery; At least one array within the traction battery, the at least one array being immersed in a cooling fluid; as well as A sensing element within the cooling fluid is configured to: detect a change in the dielectric properties of the cooling fluid when the contamination level in the cooling fluid reaches a threshold that alters the dielectric strength of the cooling fluid; measure the change in the dielectric properties caused by a voltage flow from the at least one array through the cooling fluid; and transmit the measured change in dielectric properties to a traction battery monitoring system.

10. The electrified vehicle system of claim 9, wherein the dielectric strength of the cooling fluid is measured by the sensing element, the dielectric strength comprising at least one of the conductivity, dielectric constant, or impedance of the cooling fluid.

11. The electric vehicle system of claim 9, wherein the sensing element comprises a plurality of electrodes positioned at different locations within the cooling fluid.

12. The electric vehicle system of claim 9, further comprising a plurality of sensing elements, each sensing element being associated with a different array within the traction battery.

13. The electrified vehicle system of claim 9, wherein the traction battery monitoring system is configured to establish a baseline measurement of the dielectric properties and detect deviations relative to the baseline measurement.

14. The electrified vehicle system of claim 13, wherein the traction battery monitoring system is further configured to classify the deviation as indicating one of a plurality of predefined categories.

15. The electrified vehicle system of claim 9, wherein the traction battery monitoring system is configured to correlate measured changes in electrical properties with vehicle diagnostic data to determine the contamination level of the cooling fluid.

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