Patent Application
20100320014
The present invention generally relates to power electronics that utilizes wide band gap power semi-conductors for automotive use.
In recent years, advances in technology, as well as ever-evolving tastes in style, have led to substantial changes in the design of automobiles. One of the changes involves the complexity of the electrical systems within automobiles, particularly alternative propulsion vehicles that utilize voltage supplies, such as hybrid, battery electric, and fuel cell vehicles. Such alternative propulsion vehicles typically use one or more electric motors, often powered by direct current (DC) power sources, perhaps in combination with another actuator, to drive the wheels.
Such vehicles often use two separate voltage sources, such as a battery and a fuel cell, to power the electric motors that drive the wheels. Power electronics, such as direct current-to-direct current (DC/DC) converters, are typically used to manage and transfer the DC power from one of the voltage sources and convert to more or less voltage. Also, due to the fact that alternative propulsion automobiles typically include direct current (DC) power supplies, direct current-to-alternating current (DC/AC) inverters (or power inverters) are also provided to invert the DC power to alternating current (AC) power, which is generally required by the motors.
Modern power electronics typically utilize electronic components, such as switches and diodes formed on silicon semiconductor substrates. Such components have undesirable characteristics, including relatively high switching losses when operated at high frequencies (e.g., over 16 kilohertz (kHz)). Additionally, because the operating temperatures of silicon devices differs substantially from some of the other components in the electrical system, multiple cooling systems, or “loops,” must used, which increases the complexity and manufacturing costs of the vehicles.
As the power demands on the electrical systems in alternative fuel vehicles continue to increase, there is an ever increasing need to maximize the electrical efficiency of such systems. There is also a constant desire to reduce the size of the components within the electrical systems in order to minimize the overall cost and weight of the vehicles.
Accordingly, it is desirable to provide power electronics (or a power electronics system) with improved performance characteristics to improve on the undesirable effects of using silicon devices. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent description taken in conjunction with the accompanying drawings and the foregoing technical field and background.
An automotive power electronics system is provided. The automotive power electronics system includes a support member and at least one electronic die mounted to the support member. The at least one electronic die has an integrated circuit formed thereon comprising at least one wide band gap transistor.
An automotive power electronics propulsion system is provided. The automotive power electronics propulsion system includes a support member and a plurality of electronic die mounted to the support member. Each electronic die includes a substrate having an integrated circuit formed thereon. The substrate of each electronic die includes a wide band gap semiconductor material, and each integrated circuit includes at least one wide band gap transistor.
An automotive propulsion system is provided. The automotive system includes an electric motor, at least one direct current (DC) power supply, a power inverter coupled to the electric motor and the at least one DC power supply, and a controller in operable communication with power inverter and coupled to the electric motor and the at least one DC power supply. The power inverter includes a support member and at least one electronic die mounted to the support member. The at least one electronic die has an integrated circuit formed thereon including at least one wide band gap transistor. The controller is configured to operate the at least one wide band gap transistor.
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and
The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, and brief summary, or the following detailed description.
The following description refers to elements or features being “connected” or “coupled” together. As used herein, “connected” may refer to one element/feature being mechanically joined to (or directly communicating with) another element/feature, and not necessarily directly. Likewise, “coupled” may refer to one element/feature being directly or indirectly joined to (or directly or indirectly communicating with) another element/feature, and not necessarily mechanically. However, it should be understood that although two elements may be described below, in one embodiment, as being “connected,” in alternative embodiments similar elements may be “coupled,” and vice versa. Thus, although the schematic diagrams shown herein depict example arrangements of elements, additional intervening elements, devices, features, or components may be present in an actual embodiment.
Further, various components and features described herein may be referred to using particular numerical descriptors, such as first, second, third, etc., as well as positional and/or angular descriptors, such as horizontal and vertical. However, such descriptors may be used solely for descriptive purposes relating to drawings and should not be construed as limiting, as the various components may be rearranged in other embodiments. It should also be understood that
The automobile 10 may be any one of a number of different types of automobiles, such as, for example, a sedan, a wagon, a truck, or a sport utility vehicle (SUV), and may be two-wheel drive (2WD) (i.e., rear-wheel drive or front-wheel drive), four-wheel drive (4WD), or all-wheel drive (AWD). The automobile 10 may also incorporate any one of, or combination of, a number of different types of engines, such as, for example, a gasoline or diesel fueled combustion engine, a “flex fuel vehicle” (FFV) engine (i.e., using a mixture of gasoline and alcohol), a gaseous compound (e.g., hydrogen and/or natural gas) fueled engine, a combustion/electric motor hybrid engine (i.e., such as in a hybrid electric vehicle (HEV)), and an electric motor.
In the exemplary embodiment illustrated in
As shown, the battery 22 and the FCPM 24 are in operable communication and/or electrically connected to the electronic control system 18 and the DC/DC converter system 26. Although not illustrated, the FCPM 24, in one embodiment, includes, amongst other components, a fuel cell having an anode, a cathode, an electrolyte, and a catalyst. As is commonly understood, the anode, or negative electrode, conducts electrons that are freed from, for example, hydrogen molecules so that they can be used in an external circuit. The cathode, or positive electrode (i.e., the positive post of the fuel cell), conducts the electrons back from the external circuit to the catalyst, where they can recombine with the hydrogen ions and oxygen to form water. The electrolyte, or proton exchange membrane, conducts only positively charged ions while blocking electrons. The catalyst facilitates the reaction of oxygen and hydrogen.
Although not shown, the DC/DC converter system 26 may also include a BDC controller in operable communication with the BDC converter 32. The BDC controller may be implemented within the electronic control system 18 (
The switch network comprises three pairs of series switches (e.g., FETs) with antiparallel diodes (i.e., antiparallel to each switch) corresponding to each of the phases. Each of the pairs of series switches comprises a first switch, or transistor, (i.e., a “high” switch) 64, 66, and 68 having a first terminal coupled to a positive electrode of the voltage source 62 and a second switch (i.e., a “low” switch) 70, 72, and 74 having a second terminal coupled to a negative electrode of the voltage source 62 and having a first terminal coupled to a second terminal of the respective first switch 64, 66, and 68.
Although not shown, the DC/AC inverter 28 may also include an inverter control module, which may be implemented within the electronic control system 18 (
The BDC 32 and the inverter 28 may also include a plurality of power module devices, each including a semiconductor substrate, or a plurality of (i.e., one or more) electronic die, each with an integrated circuit formed thereon, amongst which the switches 40-46 and 64-74 are distributed, as is commonly understood.
The semiconductor substrate 80 includes a high electron mobility transistor (HEMT), such as a FET 82, as is commonly understood, formed thereon. In the depicted embodiment, the FET 82 includes, amongst other components, conductive emitter regions (e.g., having a P-dopant type) 84 formed in a first surface (e.g., upper surface) of the substrate 80, a conductive collector layer (e.g., having a N+-dopant type) 86 formed in a second surface (e.g., a lower surface) of the substrate 80, and a conductive gate 88 formed over the first surface and extending between the emitter regions 84. An epitaxial drift region (e.g., having an N-dopant type) 90 interconnects the emitter regions 84 and the collector layer (or substrate) 86, as shown in
Referring again to
Referring again to
During operation, still referring to
One advantage of the use of the wide band gap transistors is that the frequencies at which the inverter 28 and/or the BDC 26 is operated may be significantly increased when compared to conventional silicon based transistors, while providing improved efficiency. For example, in one simulation, gallium nitride based transistors operated at both 10 kilohertz (kHz) and 100 kHz demonstrated an improvement in efficiency when compared to silicon based transistors operated at 10 kHz. The increased frequency of operation of the inverter 28 reduces the ripple current in the AC waveform that is provided to the electric motor 20 which improves the efficiency of the electric motor 20, when compared to lower frequency operation of the inverter when using conventional silicon based transistors, which reduces power consumption, and in the case of a hybrid electric vehicle, decreases fuel consumption.
Another advantage is that because of the increased operating frequencies, smaller and lighter components may be used in the inverter 28 and/or the BDC. For example, the mass of the converter inductor (e.g., inductor 48) used in the BDC 26 may be reduced as the frequency is increased when compared to that used in a converter using conventional silicon transistors. As a result, manufacturing costs are reduced, and power consumption is even further decreased.
A further advantage is that because the wide band gap operate at temperatures higher than conventional silicon based transistors, a single loop cooling system, such as that shown in
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention as set forth in the appended claims and the legal equivalents thereof.
