Battery packs for electrical vehicles are sometimes housed to protect them from vehicle crashes, vibration, and stresses that may impact the structure. Typical battery packs include groups of battery cells connected in parallel to increase current flow, and in series to increase voltage. Measurements and monitoring of the battery cells, or groups thereof, typically require wires to be routed within the battery pack. It is also usually non-trivial to make electrical connections between a wire and a busbar. It would be advantageous to reduce the use of wire and connectors for monitoring a battery pack. It would also be advantageous to not have to include wire runs within the battery pack.
In some embodiments, a shear wall is configured to provide structural support to a battery system. The shear wall includes a support structure that is configured to provide rigidity to the battery system along at least one side of the battery system. The shear wall also includes a plurality of conductive traces layered onto the support structure. The plurality of conductive traces each include a first terminal configured to be coupled to a busbar of the battery system and a second terminal configured to be coupled to processing equipment. Accordingly, the conductive traces allow the processing equipment to measure, and optionally monitor, the voltage at one or more busbars, without having to install wire runs. In some embodiments, a busbar is connected to respective like-polarity terminals of a group of battery cells.
In some embodiments, the shear wall also includes at least one temperature sensor affixed to the support structure and corresponding conductive traces. These conductive traces include a first terminal configured to be coupled to the at least one temperature sensor, and a second terminal configured to be coupled to the processing equipment. Accordingly, the conductive traces allow the processing equipment to receive signals from one or more sensors, without having to install wire runs. In an illustrative example, a temperature sensor includes a thermistor, a thermocouple, or a resistance temperature detector.
In some embodiments, the shear wall includes an electrical connector, which includes respective pins coupled to each of the respective second terminals. In some embodiments, the processing equipment is coupled to a second electrical connector, and each of the second terminals is configured to be coupled to the processing equipment by connecting the first electrical connector and the second electrical connector. For example, a cable having plugs at both ends may couple the first and second connectors so that the processing equipment may measure voltages of the second terminals.
In some embodiments, the support structure is made at least in part of a flame-resistant glass-epoxy laminate. In some embodiments, the conductive traces include copper tracks bonded to the support structure. In some embodiments, the conductive traces may include gold, silver, or other metals. In some embodiments, the support structure includes at least one extension (e.g., a tab or other protrusion), which includes a conductive pad. The conductive pad is coupled to a first terminal, and the conductive pad is configured to be coupled to the busbar. Accordingly, the extension provides a coupling location for electrically coupling a busbar to conductive traces of the shear wall. For example, in some embodiments, a first terminal is configured to be coupled to the busbar by a screw terminal. In a further example, in some embodiments, the first terminal is configured to be coupled to the busbar by a welded connection.
In some embodiments, the shear wall is included in a battery system. For example, a battery system includes processing equipment, a plurality of battery cells connected to a plurality of busbars, at least one shroud, and a shear wall. The at least one shroud is configured to maintain an arrangement of the plurality of battery cells. The shear wall is configured to provide structural support to the at least one shroud and the arrangement of the plurality of battery cells. The shear wall includes a support structure coupled to the at least one shroud along at least one side of the at least one shroud. The shear wall also includes a plurality of conductive paths affixed to the support structure. The plurality of conductive paths each include a respective first terminal configured to be coupled to a respective busbar, and a respective second terminal configured to be coupled to the processing equipment.
The present disclosure, in accordance with one or more various embodiments, is described in detail with reference to the following figures. The drawings are provided for purposes of illustration only and merely depict typical or example embodiments. These drawings are provided to facilitate an understanding of the concepts disclosed herein and shall not be considered limiting of the breadth, scope, or applicability of these concepts. It should be noted that for clarity and ease of illustration these drawings are not necessarily made to scale.
A battery system may include an arranged (e.g., hexagonally close-packed) group of battery cells with parallel axes, with corresponding buttons (e.g., ends having like polarity) pointed in the same direction, a plastic shroud at either end of the collective cells (e.g., to provide support and maintain the arrangement), a set of busbars mounted to the shroud at the button ends of the cells (e.g., to couple cells to one another in series and parallel), and a shear wall arranged along at least one side of the battery system configured to provide structural rigidity.
In some embodiments, the shear wall is substantially a piece of nonconductive, fiber-reinforced composite. For example, the shear wall may be constructed of a flame-retardant fiberglass. In a further example, the shear wall may be constructed of a composite that fulfills the requirements of NEMA LI 1-1998 Grade FR-4. In a further example, the shear wall may be constructed from an injection-molded or pressure-formed, fiber-reinforced polymer.
In some embodiments, a shear wall may include a printed circuit, embedded circuit, or other suitable collection of conductors, which may be coupled to the busbars, battery cells, or both. In some embodiments, the shear wall may include conductive traces that electrically connect to respective pads on the shear wall, which may be electrically connected to a respective busbar.
In some embodiments, a battery system may include processing equipment that at least partially monitors or controls the voltage balance among one or more battery systems. Accordingly, the processing equipment may be configured to measure one or more voltage signals from one or more busbars, one or more cells, or both. The integration of conductive traces in the shear wall may provide easy-to-use and fast-to-install electrical connections between processing equipment and busbars without significant added cost (e.g., from running and terminating wires, and accompanying cable management).
Processing equipment 130 may include any suitable circuitry for processing signals received from conductive traces of shear wall 110 (e.g., via cable 132 and connector 131). For example, processing equipment 130 may include signal conditioning circuitry (e.g., filters, amplifiers, voltage dividers), an analog to digital converter, any other suitable circuitry, or any combination thereof. Processing equipment 130 may, in some embodiments, include a processor, a power supply, power management components (e.g., relays, filters, voltage regulators), input/output IO (e.g., GPIO, analog, digital), memory, communications equipment (e.g., CANbus hardware, Modbus hardware, or a WiFi module), any other suitable components, or any combination thereof. In some embodiments, processing equipment 130 may include one or more microprocessors, microcontrollers, digital signal processors, programmable logic devices, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), etc., and may include a multi-core processor. In some embodiments, processing equipment 130 may be distributed across multiple separate processors or processing units, for example, multiple of the same type of processing units or multiple different processors.
In some embodiments, processing equipment 130 executes instructions stored in memory for monitoring a battery system, managing a battery system, or both. In some embodiments, memory may be an electronic storage device that is part of processing equipment 130. For example, memory may be configured to store electronic data, computer software, or firmware, and may include random-access memory, read-only memory, hard drives, optical drives, solid state devices, or any other suitable fixed or removable storage devices, and/or any combination of the same. Nonvolatile memory may also be used (e.g., to launch a boot-up routine and other instructions).
In some embodiments, processing equipment 130 may be coupled to more than one shear wall (e.g., via any suitable number of cables and connectors), corresponding to more than one battery module or more than one section of a battery module. For example, processing equipment 130 may be configured to balance load across the battery modules based on measured voltages.
Shear wall 110 includes sensor 120, and corresponding conductive traces 121 and 122 for communicating sensor data from sensor 120, powering sensor 120, or both. Sensor 120 may include any suitable sensor such as, for example, a voltage sensor, a current sensor, an impedance sensor, a strain sensor (e.g., a strain gage connected to a Wheatstone Bridge circuit), a vibration sensor (e.g., a piezoelectric accelerometer), an optical sensor (e.g., a camera, photodetector, or photodiode), a proximity sensor (e.g., an ultrasound source and detector, or an infrared based system), any other suitable sensor, any suitable corresponding circuitry, or any combination thereof. In some embodiments, for example, a sensor may include surface-mount packaging (e.g., a surface-mount integrated circuit), through-hole packaging, or a combination thereof. In accordance with the present disclosure, a sensor may be bolted to, adhered to, welded to, printed on, embedded within, or otherwise affixed to, a support structure.
Sensor 120 may include, for example, any suitable type of temperature sensor such as a thermocouple, a thermopile, a thermistor, a resistive temperature detector (RTD), any other suitable temperature sensor, or any combination thereof. For example, in some embodiments, sensor 120 may include a thermistor connected across conductive traces 121 and 122. In some such embodiments, processing equipment 130 may be configured to measure a voltage across conductive traces 121 and 122 to determine a corresponding temperature of sensor 120, which may be indicative of a local temperature of shear wall 110. In a further example, in some embodiments, sensor 120 may include a thermocouple junction connected across conductive traces 121 and 122, which may include suitable respective metals corresponding to the thermocouple junction. In some such embodiments, processing equipment 130 may include a cold junction (e.g., which may be measured using a thermistor), and may be configured to measure a voltage across conductive traces 121 and 122, to determine a corresponding temperature of sensor 120 (e.g., based on the voltage, and the temperature of the cold junction), which may be indicative of a local temperature of shear wall 110. In some embodiments, a sensor may require more than two conductive traces. For example, in some embodiments, a sensor may include an RTD, which may require four conductive traces for an accurate measurement (e.g., using a four-wire measurement). In some embodiments, a sensor may require a single conductive trace. For example, a sensor may include a thermistor which may be grounded at one terminal, and only a single conductive trace is used (e.g., the processing equipment may measure the voltage of the single trace relative to a common ground). A shear wall, in accordance with the present disclosure, need not include any sensors, but may include any suitable number of sensors, each having any suitable number of corresponding conductive traces.
In some embodiments, shear wall 110 also includes first extension 111, which may include second terminals corresponding to respective first terminals (e.g., connected by respective conductive traces). First extension 111 may be configured to engage with a connector (e.g., connector 131), to couple conductive traces to conductors of the connector. In some embodiments, a shear wall need not include a first extension. For example, a shear wall may include a plurality of second terminals which may be respectively coupled to pins of an included connector, which may be configured to engage with a mating connector to couple the conductive traces to processing equipment.
As shown in
In some embodiments, conductive traces 170, 172, 174 and 176 may be formed on support structure 112 using printed circuit board (PCB) techniques. For example, a copper foil may be applied to support structure 112, and etched away (e.g., chemically etched) to leave conductive traces 170, 172, 174, and 176. In a further example, a copper foil may be applied to support structure 112, a photoresist applied, and excess copper may be etched away to leave conductive traces 170, 172, 174, and 176. In some embodiments, a multi-layer collection of conductive traces may be formed, wherein conductive traces may be separated by a layer of the support structure. In some embodiments, one or more ground planes (e.g., connected to a DC low output of a power supply, shielding, or chassis ground), power planes (e.g., connected to a DC high output of a power supply), or any other suitable conductive layers may be included in a shear wall. Conductive traces 170, 172, 174, and 176 may be formed using any suitable conductor such as, for example, copper, gold, silver, platinum, aluminum, graphite, an alloy, or a combination thereof, and need not all include the same material.
Connectors 230 and 236 may include any suitable type of electric connector such as, for example, a Deutsch DTM connector, a Molex® connector, a spade connector, a connector having pins, a spring terminal connector, a screw terminal connector, a d-sub connector (e.g., DB-9 connector), an RJ45 connector, an RJ11 connector, an Amphenol connector (e.g., a mil-spec twist-lock connector), a BNC connector, a PCB-mount header, any other suitable electrical connector having any combination of interconnect engagements of any suitable gender (e.g., pins, spades, plugs, sockets), or any combination thereof. In some embodiments, a shear wall may include one connector, more than one connector (e.g., as shown illustratively in
Extensions 213, 215, 217, 219, and 221 may be configured for arranging respective conductive pads 240, 242, 244, 246, 248, and 250 nearer to measurement locations (e.g., at battery cell terminals, busbars, or other suitable locations). In some embodiments, a shear wall need not include extensions. For example, a shear wall be a rectangle, or nearly a rectangle, and conductive pads may be located along an edge of the sheer wall, or any other suitable location of the shear wall.
Shear walls 310 and 312 are connected to shrouds 316 and 318 to provide rigidity to prevent deformation of the arrangement of battery cells 301-308 due to shear forces, or other forces which may cause deformation. For example, shear walls 310 and 312 may help lend rigidity to the arrangement of battery cells 301-308 in directions along axis 390, axis 392, an axis perpendicular to both axis 390 and axis 392 (e.g., directed into the page, or out of the page), or any combination thereof. In a further example, shear walls 310 and 312 may reduce a force on one or more of battery cells 301-308 (e.g., by reducing compressive forces along axis 392 from gravity). In a further example, in the context of an electric car having a battery system, shear walls 310 and 312 may provide rigidity in the event of a vehicle crash (e.g., increased loading from impact and vehicle deformation). In a further example, in the context of an electric car having a battery system, shear walls 310 and 312 may provide spatially controlled rigidity in the event of a vehicle crash (e.g., yield at predetermined locations, and hold rigid in other locations). Shear walls 310 and 312 may be connected to shrouds 316 and 318 by bolted connections, soldered connections, welded connections, brazed connections, crimp connections, tight fitment (e.g., interference press fit, snap features, tongue and groove), any other suitable connection type to form a suitably rigid structure, or any combination thereof.
Shear wall 310 includes support structure 311 and conductive traces 370, 372, 374, and 376, which provide conductive paths partially embedded in support structure 311 (as shown in
In accordance with the present disclosure, one or more busbars of battery system 300 may be monitored by processing equipment without the need for wire runs near and around the battery cells. In some embodiments, the integration of conductive paths (e.g., conductive traces 370, 372, 374, and 376) into shear wall 310 may provide a convenient path as compared to individual wires. For example, wires may require strain relief, and cable management hardware, and may be susceptible to snagging, shorting, vibrating, or getting in the way during assembly and maintenance. Shear wall 312, as shown in
In some embodiments, battery modules 610 and 612 may each include a plurality of battery cells (not shown in
Extensions 717 and 727 are plated with conductive material which are part of respective conductive traces 713 and 723. Although not shown in
Shear wall 712 is partially enclosed by shrouds 714 and 716 (e.g., which may be made of plastic) such that there is a substantially continuous length of shroud that is outboard of the shear wall. In some embodiments, shear wall 712 may be joined to each of shrouds 714 and 716 by, for example, adhesive bonding or ultrasonic welding.
A battery system may include any suitable arrangement of shrouds, shear walls, battery cells, busbars, processing equipment, any other suitable hardware, or any suitable combination thereof. For example, while busbars 711 and 721 are spaced away from extensions 717 and 727 in
The foregoing is merely illustrative of the principles of this disclosure and various modifications may be made by those skilled in the art without departing from the scope of this disclosure. The above described embodiments are presented for purposes of illustration and not of limitation. The present disclosure also can take many forms other than those explicitly described herein. Accordingly, it is emphasized that this disclosure is not limited to the explicitly disclosed methods, systems, and apparatuses, but is intended to include variations to and modifications thereof, which are within the spirit of the following claims.
This application is a continuation of U.S. patent application Ser. No. 15/937,794, filed Mar. 27, 2018, which is hereby incorporated by reference herein in its entirety.
Number | Date | Country | |
---|---|---|---|
Parent | 15937794 | Mar 2018 | US |
Child | 17386353 | US |