Patent Application
20210020347
This disclosure relates to inductors and more specifically to thermal management of inductors.
Electric vehicles may include a voltage converter (e.g., a DC-DC converter) connected between the battery and the electric machine. Electric vehicles that have AC electric machines also include an inverter connected between the DC-DC converter and each electric machine. A voltage converter increases (“boosts”) or decreases (“bucks”) the voltage potential to facilitate torque capability optimization. The DC-DC converter includes an inductor (or reactor), switches and diodes. A typical inductor includes a conductive coil that is wound around a magnetic core. The inductor generates heat as current flows through the coil and core.
According to on embodiment, an inductor includes a magnetic core having opposing first and second plates spaced apart from each other and a plurality of cooling pillars extending from the first plate to the second plate. The pillars are positioned such that a network of channels is formed between the plates and the pillars. A conductor is arranged in a plurality of coils. Each of the coils are supported by one of the pillars such that the coils are disposed between the first and second plates to be cooled by the channels.
According to another embodiment, an inductor assembly includes a magnetic core and a conductor. The magnetic core includes a body having at least one inner side defining an opening and a plurality of fins projecting outwardly from the body such that gaps are defined between the fins. The body and the fins are formed of a common material. The conductor is wrapped around the body such that a portion of the conductor is disposed in the gaps.
According to yet another embodiment, an inductor assembly includes a magnetic core having a base, a plurality of cooling pillars extending from the base such that the pillars are spaced apart from each other, and a top supported on the pillars. A conductor is wrapped around each of the pillars such that at least a portion of the conductor is exposed to an airflow channel defined between the pillars.
Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
Vehicles may include an electric powertrain that includes at least one traction motor for powering driven wheels. The traction motor may be powered by a traction battery. The battery is a high-voltage battery capable of outputting. electrical. power to operate the motor. The battery also receives electrical power from the motor when operating as a generators. A high-voltage bus electrically connects the battery to the motor. The vehicle may include one or more controllers for operating various components. The vehicle controllers generally include any number of microprocessors, ASICs, ICs, memory (e.g., FLASH, ROM, RAM, EPROM and/or EEPROM) and software code to co-act with one another to perform a series of operations. The controllers also include predetermined data, or “look-up tables” that are based on calculations and test data and stored within the memory. The controllers communicate with other vehicle systems and each other over one or more wired or wireless vehicle connections using common bus protocols (e.g., CAN and LIN).
The vehicle may include a DC-DC converter or variable voltage converter (VVC) and an inverter. The VVC and the inverter are electrically connected between the battery and the motor. The VVC 10 may “boost” or increases the voltage potential of the electrical power provided by the battery and may “buck” or decreases the voltage potential of the electrical power provided to the battery. The inverter inverts the DC power supplied by the battery (through the VVC 10) to AC power for operating the motor. The inverter also rectifies AC to DC.
Referring to
The following Figures and related text describe example inductors according to one or more aspects of this disclosure.
Referring to
In the illustrated embodiment, the core 52 includes opposing first and second plates 58, 60 spaced apart from each other by a distance (D). The plates may be planar and substantially parallel to each. Used herein, “substantially parallel” means within plus-or-minus five degrees of parallel. The plates 58, 60 define inner sides 62 and 64, respectively. The plates 58, 60 may be rectangular as shown or another shape.
The core 52 further includes a plurality of cooling pillars 66 extending from the inner surface 62 of the first plate to the inner surface 64 of the second plate. The pillars 66 may be substantially perpendicular to the plates 58, 60. Used herein, “substantially perpendicular” means within plus-or-minus five degrees of perpendicular. The pillars 66 may be attached to one or more of the plates 58, 60, or may be integrally formed with one of the plates. For example, the pillars 66 may be integrally formed with the plate 58 and subsequently joined to the plate 60 after the conductor 54 is installed. The pillars 66 may be attached by fasteners, welding, bonding, compression, mechanical interlock, and the like. The pillars 66 are arranged in. an array 68 with spacing between the pillars 66. The pillars 66, in cooperation with the plates 58, 60, define a network of channels 70 for cooling the inductor 50. The pillars 66 act as cooling fins that exchange heat with a working fluid (e.g., air) within the channels 70 and conduct magnetic flux since they are a portion of the core 52. The plates 58, 60 and the cooling pillars 66 may be formed of a common, e.g., same, material. The pillars 66 may be cylindrical (as shown) with end faces 74 attached to the plates and cylindrical sidewalls 76 forming outer surfaces of the pillars 66. In other embodiments, the pillars 66 may be prismatic such as a rectangular prism.
Each of the coils 56 is wrapped around one of the cooling pillars 66 with the coils being wound on the sidewall 76. The pillars 66 are dual purpose: they support the coils 56 and act as cooling fins. In some embodiments, all of the coils 56 may be part of the same circuit and connected in series or parallel. Alternatively, the conductor 54 may include multiple inductor circuits. For example, a first set of the coils are connected to each other to form a first inductor circuit, and a second set of the coils are connected to each other to form a second inductor circuit. Placing the coils 56 on the pillars 66 puts the coils 56 at least partially in the flow channels 70 so that they are in direct contact with the cooling medium, e.g., air.
The inductor 50 may be air-cooled passively, or a fan or similar circulation device may generate an airstream that circulates through the airflow channels 70. The airstream absorbs heat from the pillars 66, the plates 58, 60, and the coils 56 as it passes therethrough to thermally regulate the inductor 50. The inductor could also be liquid cooled.
Referring to
In other embodiments, the inductor may be liquid cooled. The inductor may be disposed within a cavity configured to circulate a liquid working fluid, such as oil, therethrough so that the liquid working fluid passes by the pillars to exchange heat with the core and the coils. The liquid-cooled inductor assembly includes a circulation device (e.g., a pump) for circulating coolant. Alternatively, the inductor may be disposed on a cold-plate. For example, one of the plates may be supported on a cold plate the circulates liquid coolant therethrough. Here, the inductor is cooled by a combination of the cold plate and heat transfer between the pillars and the air. The heat transfer with the air may be passive or an airstream may be sent through the inductor.
One or more conductors 218 are wrapped around the core 202. The conductors 218 are wrapped around the body 204 to form one or more coils 220 around the inner sides 208 and the outer sides 210. The coil 220 is warped to be between the fins 212. The coils need not be wrapped around all four sides. For example, the conductor may include two coils wrapped around opposing sides. The inductor 200 may include one or more inductor circuits as described above.
The inductor 200 may be passively air-cooled or an associated fan may provide an airstream through the inductor. The fins 212 (as well as the body) are configured to exchange heat with the air to cool the inductor 200. The inductor 200 may be part of an inductor assembly similar to that of
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and can be desirable for particular applications.
