System and method for sensing temperature of inverter for electric vehicle

Abstract

A system includes an inverter configured to convert DC power from a battery to AC power to drive a motor, where the inverter includes: a power module including a drain terminal and a source terminal; one or more phase switching elements, wherein the one or more phase switching elements are configured to control the current between the drain terminal and the source terminal; and a point of use controller, the point of use controller comprising two or more thermal sensors on the point of use controller, the point of use controller configured to determine a temperature of the one or more phase switches using the two or more thermal sensors.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 377,486 filed on September 28, 2022, U.S. Provisional Patent Application No. 63 / 377,501 filed on September 28, 2022, U.S. Provisional Patent Application No. 63 / 377,512 filed on September 28, 2022, U.S. Provisional Patent Application No. 63 / 378,601 filed on October 6, 2022, and U.S. Non-Provisional Patent Application No. 18 / 153,810 filed on January 12, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Various embodiments of the present disclosure relate generally to systems and methods for sensing temperature of an inverter for an electric vehicle, and more particularly to systems and methods for sensing temperature of a power module (including phase switching components) for an inverter for an electric vehicle. Background Art

[0004] Inverters, such as those used to drive motors in electric vehicles, are responsible for, for example, converting high voltage direct current (HVDC) to alternating current (AC) to drive the motor. In inverters, high temperatures can cause inverter inefficiencies.

[0005] The present disclosure is directed to overcoming one or more of these aforementioned challenges. Summary of the invention

[0006] In some aspects, the technology described herein relates to a system comprising: an inverter configured to convert DC power from a battery into AC power to drive a motor, wherein the inverter comprises: a power module comprising a drain terminal and a source terminal; one or more phase switching elements configured to control current between the drain terminal and the source terminal; and a point-of-use controller comprising two or more thermal sensors on the point-of-use controller, the point-of-use controller being configured to determine a temperature of the one or more phase switching elements using the two or more thermal sensors.

[0007] In some aspects, the technology described herein relates to a system in which the point-of-use controller is an application specific integrated circuit.

[0008] In some aspects, the technology described herein relates to a system in which the point-of-use controller is a gate driver for the one or more phase switching elements.

[0009] In some aspects, the technology described herein relates to a system wherein the one or more phase switches include one or more silicon carbide grains.

[0010] In some aspects, the technology described herein relates to a system in which each of the two or more thermal sensors includes a stack of diodes having a voltage drop with a negative temperature coefficient.

[0011] In some aspects, the technology described herein relates to a system in which a point-of-use controller is configured to determine the temperature of the one or more phase switching elements using the respective absolute temperatures of the two or more thermal sensors and a difference between the respective absolute temperatures of the two or more thermal sensors.

[0012] In some aspects, the technology described herein relates to a system in which a point-of-use controller is configured to determine the temperature of the one or more phase switches using a temperature gradient of the point-of-use controller using the two or more thermal sensors.

[0013] In some aspects, the technology described herein relates to a system that further includes a battery configured to supply DC power to the inverter and a motor configured to receive AC power from the inverter to drive the motor.

[0014] In some aspects, the technology described herein relates to a system comprising: a power module, the power module being for an inverter configured to convert DC power to AC power, the power module comprising a drain terminal and a source terminal; one or more phase switching elements, the one or more phase switching elements being configured to control current between the drain terminal and the source terminal; and a point-of-use controller, the point-of-use controller comprising two or more thermal sensors on the point-of-use controller, the point-of-use controller being configured to determine a temperature of the one or more phase switching elements using the two or more thermal sensors.

[0015] In some aspects, the techniques described herein relate to a system in which the point-of-use controller is an application specific integrated circuit gate driver for the one or more phase switches.

[0016] In some aspects, the technology described herein relates to a system wherein the one or more phase switches include one or more silicon carbide grains.

[0017] In some aspects, the technology described herein relates to a system in which each of the two or more thermal sensors includes a stack of diodes having a voltage drop with a negative temperature coefficient.

[0018] In some aspects, the technology described herein relates to a system in which a point-of-use controller is configured to determine the temperature of the one or more phase switching elements using the respective absolute temperatures of the two or more thermal sensors and a difference between the respective absolute temperatures of the two or more thermal sensors.

[0019] In some aspects, the technology described herein relates to a system in which a point-of-use controller is configured to determine the temperature of the one or more phase switches using a temperature gradient of the point-of-use controller using the two or more thermal sensors.

[0020] In some aspects, the technology described herein relates to a system comprising one or more controllers, the one or more controllers comprising: a first thermal sensor, the first thermal sensor being at a first location on the one or more controllers; and a second thermal sensor, the second thermal sensor being at a second location on the one or more controllers, wherein the one or more controllers are configured to determine a temperature of a component external to the one or more controllers using the first thermal sensor and the second thermal sensor.

[0021] In some aspects, the technology described herein relates to a system wherein the one or more controllers are configured to: determine a first temperature difference between a first thermal sensor and a second thermal sensor at a first time, determine a second temperature difference between the first thermal sensor and the second thermal sensor at a second time, and determine a temperature of a component based on the first temperature difference and the second temperature difference.

[0022] In some aspects, the technology described herein relates to a system wherein the one or more controllers are further configured to determine a temperature of a component based on a first temperature difference, a second temperature difference, and a slope of a gradient between the first temperature difference and the second temperature difference.

[0023] In some aspects, the technology described herein relates to a system wherein the one or more controllers are further configured to determine a temperature of a component based on a first temperature difference, a second temperature difference, a slope of a gradient between the first temperature difference and the second temperature difference, and a layout geometry of the component.

[0024] In some aspects, the technology described herein relates to a system wherein the one or more controllers are further configured to determine a temperature of a component based on a first temperature difference, a second temperature difference, and a rate of change between the first temperature difference and the second temperature difference.

[0025] In some aspects, the technology described herein relates to a system wherein the one or more controllers are further configured to determine a temperature of a component based on a temperature of a first thermal sensor, a first temperature difference, and a second temperature difference.

[0026] Other objects and advantages of the disclosed embodiments will be described in part in the following description, and in part will be obvious from the description, or can be understood by practicing the disclosed embodiments. The objects and advantages of the disclosed embodiments will be realized and achieved by means of the elements and combinations particularly pointed out in the appended claims.

[0027] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and, together with the description, serve to explain the principles of the disclosed embodiments.

[0029] Figure 1 An exemplary system infrastructure for a vehicle including a combined inverter and converter is depicted according to one or more embodiments.

[0030] Figure 2 Depicted is a method for providing a point-of-use switching controller according to one or more embodiments. Figure 1 An exemplary system infrastructure of a combined inverter and converter.

[0031] Figure 3 Describes a method for Figure 2 An exemplary system infrastructure for a controller of FIG.

[0032] Figure 4 Describes a method for Figure 2 An exemplary system infrastructure for a point-of-use switching controller.

[0033] Figure 5 Describes a method for Figure 4 An exemplary system infrastructure of an upper power module.

[0034] Figure 6 An exemplary system for a power module for an inverter according to one or more embodiments is depicted.

[0035] Figure 7 An exemplary system for sensing temperature of a power module for an inverter is depicted in accordance with one or more embodiments.

[0036] Figure 8 Depicted is an exemplary electrical schematic for sensing temperature of a power module for an inverter in accordance with one or more embodiments.

[0037] Fig. 9Depicted is a thermal simulation of an exemplary system for sensing temperature of a power module for an inverter according to one or more embodiments.

[0038] Fig.10 Depicted is the temperature sensing transient capability of an exemplary system for sensing temperature of a power module for an inverter according to one or more embodiments. DETAILED DESCRIPTION

[0039] Both the foregoing general description and the following detailed description are exemplary and explanatory only and do not constrain the claimed features. As used herein, the terms "comprises," "comprising," "has," "having," "includes," "including," or other variations thereof are intended to encompass non-exclusive inclusions such that a process, method, article, or device that includes a series of elements includes not only those elements, but may also include other elements that are not explicitly listed or inherent to such process, method, article, or device. In the present disclosure, unless otherwise stated, relative terms (such as, for example, "about," "substantially," and "approximately") are used to indicate possible ±10% variations in the stated values. In the present disclosure, unless otherwise stated, any numerical value may include possible ±10% variations in the stated values.

[0040] The terms used below may be interpreted in their broadest reasonable manner, although they are being used in conjunction with a detailed description of certain specific examples of the present disclosure. Indeed, certain terms may even be emphasized below; however, any term intended to be interpreted in any constrained manner will be explicitly and specifically defined as such in this detailed description. For example, in the context of the present disclosure, a switching device may be described as a switching element or device, but may refer to any device for controlling power flow in a circuit. For example, a switching element may be, for example, a metal oxide semiconductor field effect transistor (MOSFET), a bipolar junction transistor (BJT), an insulated gate bipolar transistor (IGBT) or a relay, or any combination thereof, but is not limited thereto.

[0041] Various embodiments of the present disclosure relate generally to systems and methods for sensing temperature of an inverter for an electric vehicle, and more particularly to systems and methods for sensing temperature of a power module (including phase switching components) for an inverter for an electric vehicle.

[0042] Inverters (such as those used to drive motors in electric vehicles) are responsible for converting high voltage direct current (HVDC) into alternating current (AC) to drive the motor. A three-phase inverter may include a bridge having six power device switches (e.g., power transistors such as IGBTs or MOSFETs) that are controlled by pulse width modulation (PWM) signals generated by a controller. The inverter may include three half-H-bridge switches to control phase voltages, upper and lower gate drivers to control the switches, a PWM controller, and glue logic between the PWM controller and the gate driver. The PWM controller may generate signals to define the expected state of the system. The gate driver may send signals from the PWM controller to the half-H-bridge switches. The half-H-bridge switches may drive the phase voltages. The inverter may include an isolation barrier between a low voltage plane and a high voltage plane. The signal may be passed from the PWM controller to the half-H-bridge switch by passing through the isolation barrier, which may employ optical, converter-based, or capacitor-based isolation. The PWM signal may be distorted when passing through the glue logic, which may include resistive, capacitive, or other types of filtering. Due to the electrical isolation barrier and other delays within the gate driver, the PWM signal may be distorted when passing through the gate driver. The PWM signal may be distorted when the signal is processed by the half-H switching element via the gate driver output.

[0043] Gate drivers withstand common-mode transients that occur during field effect transistor (FET) switching and when one side of a floating high voltage terminal is shorted to ground or subjected to electrostatic discharge. These voltage transients can cause fast edges that can form common-mode current bursts through electrical isolation. Gate drivers may need to demonstrate common-mode transient immunity (CMTI) in order to be effective and safe.

[0044] The gate driver may have a high voltage domain in common with the voltage plane of the associated FET. Further, the high voltage plane may be supplied by a flyback converter, which may be isolated from the low voltage plane by a transformer. The high voltage domain power supply may be used to provide power to such a circuit that sources and sinks gate current to drive the FET and can detect FET faults, thereby acting on the faults and / or transmitting the faults to the low voltage domain. The gate driver may include an electrical channel dedicated to FET commands, and one or more bidirectional or unidirectional electrical channels dedicated to FET communications.

[0045] High current switching transients can form strong electromagnetic (EM) fields that can couple into nearby metal traces. The magnitude and frequency of the coupled current can depend on the layout of the FET packaging solution and the direction and length of the metal traces between the FET and the control integrated circuit (IC). For example, a typical value for the coupled current can be up to 1A at an AC frequency of up to 100MHz. Typically, within the circuit, the gate driver IC can be placed far enough away from the FET so that the high EM field is not directly coupled into the internal metal traces within the gate driver IC. The gate driver is placed at a distance from the EM field so that the induced current within the circuit is below the level that will cause the gate driver to malfunction, or a metal shield is placed between the gate driver and the source of the EM field to protect the gate driver circuit. The output terminals of the gate driver connected to the FET are exposed to the EM field at a point where the output terminals are no longer covered by the shield. The gate driver switches large currents (e.g., such as 5A to 15A) through these exposed terminals. The large currents switched are usually larger in magnitude than the EM induced current. The gate driver can overdrive the induced current to maintain control of the FET. The gate driver and the high side of the FET may share a common ground and gate control signal trace, both of which may be susceptible to coupled currents.

[0046] The gate driver can turn on low resistance switches to source and sink gate current. Sometimes a series resistor can be added to limit the gate current. The switched gate current can be greater than the coupling current in order to maintain control of their respective FETs.

[0047] The gate driver may be able to sense the FET operating voltage or current in order to provide feedback and react to faults. An overcurrent fault may typically be detected by sensing the FET drain to source voltage and comparing the sensed voltage to a reference value. The sensed voltage may be heavily filtered to reject coupled currents. Filtering may slow the response to a fault condition, causing a delay in response. For example, the rate of current increase due to a low resistance short may reach damaging levels before being detected by a heavily filtered drain to source voltage detection strategy. The resulting short may damage the FET or the vehicle before being detected and cut off.

[0048] According to one or more embodiments, a FET driver circuit may provide fast overcurrent detection by shunt current sensing, or by diverting a portion of the load current through a parallel FET that may have a current sensing circuit. Utilizing either strategy may require a "point of use IC" in which the sensing circuit is very close to the FET. Even if the point of use IC and the remote controller are resistant to EM fields, the communication between the point of use IC and the remote controller is still susceptible to induced currents. Point of use ICs have been implemented in low EM field applications, such as smart FETs for automotive applications. However, point of use ICs have not yet been used in high EM field applications. High EM fields can be fields that (i) induce a current within the IC that exceeds the operating current of the IC and causes a malfunction, or (ii) induce a differential voltage within the IC that exceeds the operating differential voltage and causes a malfunction. High EM fields can be, for example, fields greater than about 10A or about 100V.

[0049] The point-of-use controller may be on a power module including a phase switch. The temperature of the phase switch and / or the power module may be an important factor in the control of the inverter. The phase switch may include, for example, one or more silicon carbide (SiC) grains. One or more embodiments may allow a temperature-dependent gate drive curve for the phase switch to reduce switching losses and extend battery range.

[0050] Some systems may use a thermistor to monitor the SiC die temperature. The thermistor may be located some distance away from the SiC die, so there may be a temperature difference between the die and the thermistor. For thermistors, the total error stack between the predicted actual temperature and the measured temperature may be between + / -15°C to + / -11°C. At lower temperatures, some systems with thermistors may lose the ability to measure temperature due to insufficient range of the measurement circuit.

[0051] For example, one or more embodiments may include a point-of-use controller, such as an integrated gate driver ASIC. The ASIC may use an on-chip integrated trimmed thermal sensor to accurately measure temperature. The on-chip thermal sensor may measure the absolute ASIC temperature to within a tolerance of + / - approximately 1.5°C. The thermal sensors on the ASIC may be arranged in a manner to measure a temperature gradient across the ASIC. One or more embodiments may use the absolute measured ASIC temperature in combination with the temperature gradient across the ASIC to accurately predict the SiC die temperature within a range of + / - approximately 5°C. One or more embodiments may use the rate of change of the temperature difference between the ASIC thermal sensors to improve the response time of the predicted SiC die temperature.

[0052] For example, relative to a thermistor-based system, one or more embodiments may provide a much tighter temperature measurement of the SiC die, such as within a range of + / - approximately 5°C. Relative to a thermistor-based system, one or more embodiments may require a reduced operating margin due to the tighter tolerance of the measured temperature, which may reduce the cost and / or complexity of the system. Relative to a thermistor-based system, one or more embodiments may allow the power module to operate at a higher average temperature. Relative to a thermistor-based system, one or more embodiments may provide a smaller total SiC die area and / or a lower cost heat sink.

[0053] One or more embodiments may allow for a modified gate drive curve based on SiC temperature, which may reduce switching losses and extend battery range. Both SiC gate threshold voltage and transconductance decrease with temperature. If the temperature of the SiC is determined, the gate drive curve may be modified to achieve lower switching losses at a given temperature. This curve modification may require a complex gate driver that can provide gate current breakpoints as a function of the drive gate to source voltage. The more accurately the temperature is measured, the better the gate drive curve can adapt to the temperature.

[0054] One or more embodiments may allow temperature-based control of the power module during bulk capacitor discharge. Bulk capacitor discharge at shutdown is a function in which the bulk capacitor is quickly discharged after the battery contactor is opened. The bulk capacitor discharge reduces the risk of contact with high voltage. Bulk capacitor discharge can transfer energy from the bulk capacitor (e.g., 700μF*800V2) to the power switching element and should be implemented in a controlled manner. Using the temperature of the SiC device during bulk capacitor discharge can reduce the discharge time while protecting the SiC device from excessive temperature rise.

[0055] One or more embodiments may provide a Vbe error of + / - approximately 1.6°C in the thermal sensor. One or more embodiments may provide a buffer error of + / - approximately 0.225°C from the thermal sensor. One or more embodiments may provide a GND error of + / - approximately 0.0625°C. One or more embodiments may provide a VDDL error of approximately 0.356°C from -40°C to 165°C in the thermal sensor. One or more embodiments may provide a VDDL transient error of + / - approximately 1.25°C. One or more embodiments may provide an ADC integral nonlinearity error of approximately 0.125°C from -40°C to 165°C. One or more embodiments may provide an ADC effective number of bits with twelve bits of accuracy, where 400uV equals + / - approximately 0.1°C. One or more embodiments may provide a trim and test error of + / - approximately 1.5°C. One or more embodiments may provide an error without the chuck and VDDL transient error and including an error of half the thermal sensor and integral nonlinearity error (expanded as a function of temperature transients) of + / - approximately 2.128°C. One or more embodiments may provide an error with chuck measurement error in addition to the above-mentioned error of + / - approximately 3.628°C.

[0056] Accurately knowing the SiC device temperature within a power module may allow for optimization of the reliability and efficiency of the power module. One or more embodiments may provide a power module that incorporates a SiC FET bare die and an integrated gate driver ASIC. Multiple thermal sensing points on the ASIC may be used to sense the absolute temperature of the ASIC and the thermal gradient between the thermal sensing points of the ASIC. The thermal sensing points may be arranged on the ASIC in an advantageous manner so that the absolute temperature and thermal gradient measurements may be used to estimate the temperature of adjacent SiC die. The rate of change of the thermal gradient with respect to time may also be used to improve the estimated response time.

[0057] Accurate temperature sensing of SiC FET bare die can allow optimization of overall system cost and efficiency. Some systems may use a thermistor placed within the power module. Thermistors allow the temperature to be measured in the physical location of the thermistor, which in the application may be up to 20°C cooler than the adjacent SiC die. In addition, there may be significant coupling occurring between high current and high voltage lines, and thermistors require significant filtering of the monitoring signal, which can greatly reduce response time.

[0058] One or more embodiments may provide an apparatus and method for accurately estimating the temperature of a SiC device within a power module. One or more embodiments may provide a gate driver ASIC that is integrated into a power module together with a bare die.

[0059] With an integrated ASIC gate driver IC, multiple thermal sensors can be positioned across the ASIC. The temperature of these on-die trimmed thermal sensors can be accurately measured. Furthermore, these thermal sensors can be placed across the ASIC in a manner that measures the temperature gradient across the die. One or more embodiments can use the absolute measured ASIC die temperature in conjunction with the temperature gradient across the ASIC to accurately predict the SiC die temperature within + / - approximately 5°C. Additionally, the rate of change of the temperature difference between the ASIC die sensors can be used to improve the response time of the predicted SiC die temperature.

[0060] One or more embodiments may provide an integrated gate driver within a power module. The integrated gate driver may be an ASIC. The ASIC may include two thermal sensors on the ASIC, which may be labeled TREF and TSENSE. The thermal sensor may be composed of a stack of diodes having a voltage drop with a negative temperature coefficient. However, the present disclosure is not limited thereto and may include other ways of constructing thermal sensors within the ASIC.

[0061] The temperature of the thermal sensor can be accurately measured at a known sampling rate. The absolute temperature of the sensor and the difference between the thermal sensor temperatures can be monitored. Equations 1 to 5 below can be used to predict the temperature of the adjacent SiC grain temperature.

[0062] Equation 1:

[0063] Equation 2: β M =(ΔT N -ΔT N-1 )*f s

[0064] Equation 3: S(β N )=αfor 0<|β N |

[0065] Equation 4: S(β N )=γfor|β N |>=A

[0066] Equation 5:

[0067] In equations 1 to 5 above, ΔT N can be the temperature gradient across the ASIC at a given sampling time N, may be the temperature recorded by the first temperature sensor at time N, can be the temperature recorded by the second temperature sensor at time N, β N can be the slope of the gradient from one temperature sample to the next with respect to time, f s ​may represent the sampling rate, α, γ, A, B, and C may be constants based on layout geometry and temperature, and It can be the predicted temperature of adjacent SiC grains.

[0068] One or more embodiments may provide a thermal measurement device including a diode stack and an analog-to-digital converter (ADC). However, the present disclosure is not limited thereto. One or more embodiments may provide a system for accurately estimating the temperature of adjacent SiC die located within a power module. One or more embodiments may provide a system for operating an average SiC die at a higher temperature, for example due to the ability to have a much tighter standard deviation than other systems (such as those using thermistors). One or more embodiments may provide a system with improved accuracy that may allow optimization of system design due to reduced error tolerances.

[0069] Figure 1 An exemplary system infrastructure for a vehicle including a combined inverter and converter according to one or more embodiments is depicted. In the context of the present disclosure, the combined inverter and converter may be referred to as an inverter. Figure 1 As shown, the electric vehicle 100 may include an inverter 110, a motor 190, and a battery 195. The inverter 110 may include a component for receiving electric power from an external source and outputting electric power to charge the battery 195 of the electric vehicle 100. For example, the inverter 110 may convert DC power from the battery 195 in the electric vehicle 100 into AC power to drive the motor 190 of the electric vehicle 100, but the embodiment is not limited thereto. For example, the inverter 110 may be bidirectional and may convert DC power into AC power, or convert AC power into DC power, such as during regenerative braking. The inverter 110 may be a three-phase inverter, a single-phase inverter, or a multi-phase inverter.

[0070] Figure 2 Depicted is a method for providing a point-of-use switching controller according to one or more embodiments. Figure 1 The electric vehicle 100 may include an inverter 110, a motor 190, and a battery 195. The inverter 110 may include an inverter controller 300 ( Figure 314). The inverter 110 may include a low voltage upper phase controller 120 separated from a high voltage upper phase controller 130 by an electrical isolator 150, and an upper phase power module 140. The upper phase power module 140 may include a point-of-use upper phase controller 142 and an upper phase switch 144. The inverter 110 may include a low voltage lower phase controller 125 separated from a high voltage lower phase controller 135 by an electrical isolator 150, and a lower phase power module 145. The lower phase power module 145 may include a point-of-use lower phase controller 146 and a lower phase switch 148. The upper phase switch 144 and the lower phase switch 148 may be connected to a motor 190 and a battery 195. The electrical isolator 150 may be one or more of optical, converter-based, or capacitor-based isolation. For example, the electrical isolator 150 may be one or more capacitors having a value from about 20 fF to about 100 fF, having a breakdown voltage from about 6 kV to about 12 kV. The electrical isolator 150 may include a pair of capacitors, wherein one capacitor in the pair carries an inverted data signal from the other capacitor in the pair to form a differential signal that is rejected for common mode noise. The electrical isolator 150 may include more than one capacitor in series. The electrical isolator 150 may include one capacitor located on a first IC, or may include a first capacitor located on a first IC and a second capacitor located on a second IC that communicates with the first IC.

[0071] The inverter 110 may include a low voltage region (e.g., where the voltage is typically less than 5V) and a high voltage region (e.g., where the voltage may exceed 500V). The low voltage region may be separated from the high voltage region by an electrical isolator 150. The inverter controller 300 may be in the low voltage region of the inverter 110, and may send a signal to and receive a signal from the low voltage upper phase controller 120. The low voltage upper phase controller 120 may be in the low voltage region of the inverter 110, and may send a signal to and receive a signal from the high voltage upper phase controller 130. The low voltage upper phase controller 120 may send a signal to and receive a signal from the low voltage lower phase controller 125. The high voltage upper phase controller 130 may be in the high voltage region of the inverter 110. Therefore, the signal between the low voltage upper phase controller 120 and the high voltage upper phase controller 130 passes through the electrical isolator 150. The high voltage upper phase controller 130 may send signals to and receive signals from a point-of-use upper phase controller 142 in the upper phase power module 140. The point-of-use upper phase controller 142 may send signals to and receive signals from an upper phase switch 144. The upper phase switch 144 may be connected to a motor 190 and a battery 195. For example, the upper phase switch 144 and the lower phase switch 148 may be used to transfer energy from the motor 190 to the battery 195, from the battery 195 to the motor 190, from an external source to the battery 195, or from the battery 195 to an external source. The lower phase system of the inverter 110 may be similar to the upper phase system described above.

[0072] Figure 3 Describes a method for Figure 2 FIG. 3 is an exemplary system infrastructure of an inverter controller 300 . The inverter controller 300 may include one or more controllers.

[0073] The inverter controller 300 may include a set of instructions that can be executed to cause the inverter controller 300 to perform any one or more of the methods or computer-based functions disclosed herein. The inverter controller 300 may operate as a standalone device, or may be connected to other computer systems or peripheral devices, for example using a network.

[0074] In a networked deployment, the inverter controller 300 can operate in the capacity of a server, or as a client in a server-client user network environment, or as a peer computer system in a peer (or distributed) network environment. The inverter controller 300 can also be implemented as or incorporated into various devices, such as a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile device, a palmtop computer, a laptop computer, a desktop computer, a communication device, a wireless phone, a landline phone, a control system, a camera, a scanner, a fax machine, a printer, a pager, a personal trusted device, a network device, a network router, a switch or bridge, or any other machine capable of executing a set of instructions (sequentially or otherwise) (the set of instructions specifies the actions to be taken by the machine). In a specific implementation, the inverter controller 300 can be implemented using an electronic device that provides voice, video or data communication. Further, although the inverter controller 300 is illustrated as a single system, the term “system” should also be understood to include any collection of systems or subsystems that individually or jointly execute one or more sets of instructions to perform one or more computer functions.

[0075] like Figure 3 As shown, the inverter controller 300 may include a processor 302, such as a central processing unit (CPU), a graphics processing unit (GPU), or both. The processor 302 may be a component in a variety of systems. For example, the processor 302 may be part of a standard inverter. The processor 302 may be one or more general-purpose processors, digital signal processors, application-specific integrated circuits, field programmable gate arrays, servers, networks, digital circuits, analog circuits, combinations thereof, or other devices now known or later developed for analyzing and processing data. The processor 302 may implement a software program, such as a manually generated (i.e., programmed) code.

[0076] The inverter controller 300 may include a memory 304 that can communicate via a bus 308. The memory 304 may be a main memory, a static memory, or a dynamic memory. The memory 304 may include, but is not limited to, computer-readable storage media, such as various types of volatile and non-volatile storage media, including but not limited to random access memory, read-only memory, programmable read-only memory, electrically programmable read-only memory, electrically erasable read-only memory, flash memory, tape or disk, optical media, etc. In one specific implementation, the memory 304 includes a cache or random access memory for the processor 302. In an alternative specific implementation, the memory 304 is separated from the processor 302, such as a cache memory, system memory, or other memory of the processor. The memory 304 may be an external storage device or database for storing data. Examples include a hard drive, a compact disk ("CD"), a digital video disk ("DVD"), a memory card, a memory stick, a floppy disk, a universal serial bus ("USB") storage device, or any other device operable to store data. The memory 304 is operable to store instructions that can be executed by the processor 302. The functions, actions, or tasks illustrated in the figures or described herein may be performed by the processor 302 executing instructions stored in the memory 304. The functions, actions, or tasks are not related to a particular type of instruction set, storage medium, processor, or processing strategy, and may be performed by software, hardware, integrated circuits, firmware, microcode, etc. operating alone or in combination. Likewise, processing strategies may include multi-processing, multi-tasking, parallel processing, etc.

[0077] As shown, the inverter controller 300 may further include a display 310, such as a liquid crystal display (LCD), an organic light emitting diode (OLED), a flat panel display, a solid state display, a cathode ray tube (CRT), a projector, a printer, or other display devices known now or later developed for outputting the determined information. The display 310 may serve as an interface for a user to view the operation of the processor 302, or specifically serve as an interface with the software stored in the memory 304 or in the drive unit 306.

[0078] Additionally or alternatively, the inverter controller 300 may include an input device 312 configured to allow a user to interact with any of the components of the inverter controller 300. The input device 312 may be a numeric keypad, a keyboard or a cursor control device (such as a mouse or a joystick), a touch screen display, a remote control, or any other device operable to interact with the inverter controller 300.

[0079] The inverter controller 300 may also or alternatively include a drive unit 306 implemented as a disk or optical drive. The drive unit 306 may include a computer-readable medium 322 in which one or more sets of instructions 324 (e.g., software) may be embedded. Further, the instructions 324 may embody one or more of the methods or logics described herein. The instructions 324 may reside completely or partially within the memory 304 and / or within the processor 302 during execution by the inverter controller 300. The memory 304 and the processor 302 may also include computer-readable media as described above.

[0080] In some systems, the computer-readable medium 322 includes instructions 324 or receives and executes instructions 324 in response to a propagated signal, so that a device connected to the network 370 can transmit voice, video, audio, images, or any other data through the network 370. Further, the instructions 324 can be transmitted or received through the network 370 and / or using the bus 308 via the communication port or interface 320. The communication port or interface 320 can be part of the processor 302 or can be an independent component. The communication port or interface 320 can be formed in software or can be a physical connector in hardware. The communication port or interface 320 can be configured to connect to the network 370, external media, display 310, or any other component in the inverter controller 300, or a combination thereof. The connection to the network 370 can be a physical connection (such as a wired Ethernet connection) or can be established wirelessly, as described below. Similarly, additional connections to other components of the inverter controller 300 can be physical connections or can be established wirelessly. The network 370 can alternatively be directly connected to the bus 308.

[0081] Although the computer-readable medium 322 is shown as a single medium, the term "computer-readable medium" may include a single medium or multiple media (such as a centralized or distributed database and / or associated caches and servers) that store one or more sets of instructions. The term "computer-readable medium" may also include any medium capable of storing, encoding, or carrying a set of instructions for execution by a processor or causing a computer system to perform any one or more of the methods or operations disclosed herein. The computer-readable medium 322 may be non-transitory and may be tangible.

[0082] Computer readable medium 322 may include solid-state memory, such as a memory card or other package that accommodates one or more non-volatile read-only memories. Computer readable medium 322 may be random access memory or other volatile rewritable memory. Additionally or alternatively, computer readable medium 322 may include magneto-optical or optical media, such as a disk or tape or other storage device for capturing carrier signals (such as signals transmitted through a transmission medium). Digital file attachments to emails or other self-contained information archives or archive sets may be considered distribution media as tangible storage media. Therefore, the present disclosure is considered to include any one or more of computer-readable media or distribution media and other equivalents and successor media in which data or instructions may be stored.

[0083] In alternative implementations, dedicated hardware implementations (such as application specific integrated circuits, programmable logic arrays, and other hardware devices) may be constructed to implement one or more of the methods described herein. Applications that may include the apparatus and systems of various implementations may broadly include a variety of electronic and computer systems. One or more implementations described herein may use two or more specific interconnected hardware modules or devices with associated control and data signals that may be transmitted between and through the modules or as part of an application specific integrated circuit to implement functionality. Thus, the present system encompasses software, firmware, and hardware implementations.

[0084] The inverter controller 300 may be connected to a network 370. The network 370 may define one or more networks, including wired or wireless networks. The wireless network may be a cellular telephone network, an 802.11, 802.16, 802.20, or WiMAX network. Further, such networks may include public networks (such as the Internet), private networks (such as intranets), or combinations thereof and may utilize a variety of networking protocols that are now available or later developed, including but not limited to TCP / IP-based networking protocols. The network 370 may include a wide area network (WAN) (such as the Internet), a local area network (LAN), a campus area network, a metropolitan area network, a direct connection (such as through a universal serial bus (USB) port), or any other network that allows data communication. The network 370 may be configured to couple one computing device to another computing device to enable data communication between devices. The network 370 may generally be enabled to use any form of machine-readable media to transmit information from one device to another. The network 370 may include a communication method by which information can travel between computing devices. The network 370 may be divided into subnetworks. A subnetwork may allow access to all other components connected to it, or a subnetwork may restrict access between components. Network 370 may be considered a public or private network connection and may include, for example, a virtual private network or encryption or other security mechanisms employed over the public Internet.

[0085] According to various implementations of the present disclosure, the methods described herein may be implemented by a software program that can be executed by a computer system. Further, in an exemplary non-limiting implementation, the implementation may include distributed processing, component or object distributed processing, and parallel processing. Alternatively, a virtual computer system process may be constructed to implement one or more of the methods or functionalities described herein.

[0086] Although this specification describes components and functions that can be implemented in a specific implementation with reference to specific standards and protocols, the present disclosure is not limited to such standards and protocols. For example, standards for Internet and other packet-switched network transmissions (e.g., TCP / IP, UDP / IP, HTML, HTTP) represent examples of the prior art. Such standards are periodically replaced by faster or more efficient equivalents having substantially the same functionality. Therefore, alternative standards and protocols having the same or similar functionality as those disclosed herein are considered equivalents thereof.

[0087] It will be appreciated that, in one embodiment, the operations of the methods discussed are performed by an appropriate processor (or processors) of a processing (i.e., computer) system executing instructions (computer readable code) stored in a storage device. It will also be appreciated that the present disclosure is not limited to any particular implementation or programming technique, and that the present disclosure may be implemented using any suitable technique for implementing the functionality described herein. The present disclosure is not limited to any particular programming language or operating system.

[0088] Figure 4 Describes a method for Figure 2 An exemplary system infrastructure of a point-of-use switching controller. For a three-phase inverter, each of the upper phase and the lower phase may include three phases related to phases A, B, and C. For example, the upper phase power module 140 may include an upper phase power module 140A for upper phase A, an upper phase power module 140B for upper phase B, and an upper phase power module 140C for upper phase C. The upper phase power module 140A may include a point-of-use upper phase A controller 142A and an upper phase A switching element 144A. The upper phase power module 140B may include a point-of-use upper phase B controller 142B and an upper phase B switching element 144B. The upper phase power module 140C may include a point-of-use upper phase C controller 142C and an upper phase C switching element 144C. Each of the upper phase A switching member 144A, the upper phase B switching member 144B, and the upper phase C switching member 144C may be connected to the motor 190 and the battery 195 . Figure 4 Details of the upper phase power module 140 are depicted. Although not shown, the lower phase power module 145 may include a similar structure as the upper phase power module 140 for the lower phases A, B, and C.

[0089] Figure 5 Describes a method for Figure 4 Example system infrastructure for the upper power module. For example, Figure 5 Additional details of upper phase power module 140A are provided. Although not shown, upper phase power module 140B, upper phase power module 140C, and respective lower phase power modules of lower phase power module 145 may include components related to Figure 5 The upper phase power module 140A shown in FIG. 1 is similar in structure to the upper phase power module 140A shown in FIG. 1. In addition, the terms "upper", "lower", "northern", and "southern" as used in this disclosure are used for reference only, do not limit the elements to a particular orientation, and are generally interchangeable throughout the text. For example, the upper phase power module 140 may be referred to as a lower phase power module, a northern phase power module, a southern phase power module, a first phase power module, or a second phase power module.

[0090] The upper phase power module 140A may include a point-of-use upper phase A controller 142A and an upper phase A switch 144A. The upper phase A switch 144A may include one or more sets of switches. Figure 5 As shown, the upper phase A switch 144A may include an upper phase A north switch 144A-N and an upper phase A south switch 144A-S. The point-of-use upper phase A controller 142A may include one or more memories, controllers, or sensors. For example, the point-of-use upper phase A controller 142A may include a communication manager 405, a functional safety controller 410, a test interface and controller 415, a north thermal sensor 420A, a south thermal sensor 420B, a self-test controller 425, a command manager 430, a waveform adjuster 435, a memory 440, a north switch control and diagnostic controller 450N, and a south switch control and diagnostic controller 450S. The point-of-use upper phase A controller 142A may include a controller 405, a functional safety controller 410, a test interface and controller 415, a north thermal sensor 420A, a south thermal sensor 420B, a self-test controller 425, a command manager 430, a waveform adjuster 435, a memory 440, a north switch control and diagnostic controller 450N, and a south switch control and diagnostic controller 450S. Figure 5 More or fewer components than those shown. For example, the point-of-use upper phase A controller 142A may include more or less than two switch controls and diagnostic controllers, and may include more than two thermal sensors.

[0091] The communication manager 405 may control inter-controller communications to and from the point-of-use upper phase A controller 142A and / or may control intra-controller communications between components of the point-of-use upper phase A controller 142A. The functional safety controller 410 may control safety functions of the point-of-use upper phase A controller 142A. For example, the test interface and controller 415 may control test functions of the point-of-use upper phase A controller 142A, such as end-of-line testing in manufacturing. The north thermal sensor 420A may sense the temperature at a first location in the point-of-use upper phase A controller 142A, and the south thermal sensor 420B may sense the temperature at a second location in the point-of-use upper phase A controller 142A. For example, the self-test controller 425 may control self-test functions of the point-of-use upper phase A controller 142A, such as during initialization of the point-of-use upper phase A controller 142A after an inverter 110 power-on event. The command manager 430 may control commands received from the communication manager 405 and issued to the north switch control and diagnostic controller 450N and the south switch control and diagnostic controller 450S. The waveform adjuster 435 may control the waveform timing and shape of the commands received from the communication manager 405 and issued to the north switch control and diagnostic controller 450N and the south switch control and diagnostic controller 450S. The memory 440 may include one or more volatile and non-volatile storage media for the operation of the point-of-use upper phase A controller 142A. The north switch control and diagnostic controller 450N may send one or more signals to the north switch 144A-N to control the operation of the north switch 144A-N, and may receive one or more signals from the north switch 144A-N that provide information about the north switch 144A-N. The south switch control and diagnostic controller 450S may send one or more signals to the south switches 144A-S to control the operation of the south switches 144A-S, and may receive one or more signals from the south switches 144A-S providing information about the south switches 144A-S. As described above, the terms "north" and "south" are used for reference only, and the north switch control and diagnostic controller 450N may send one or more signals to the south switches 144A-S, and the south switch control and diagnostic controller 450S may send one or more signals to the south switches 144A-N.

[0092] Figure 6 An exemplary system for a power module for an inverter according to one or more embodiments is depicted. Figure 6As shown, the power module 640A may include a point-of-use controller 642A and a phase switch 644A. For example, the point-of-use controller 642A may be an integrated gate driver and an application-specific integrated circuit (ASIC). The phase switch 644A may include one or more sets of switches, such as north phase switches 644A-N and south phase switches 644A-S. For example, each die of the north phase switches 644A-N may include a gate and a plurality of SiC FETs. Figure 6 As shown, the southern phase switch 644A-S includes four dies, wherein each of the four dies includes three SiC FETs. However, the present disclosure is not limited thereto, and the number of phase switches, dies, and SiC FET groups may vary, for example, depending on the application of the power module.

[0093] The power module 640A may be, for example, a specific implementation of the upper phase power module 140 upper phase power module 140A (which may be, for example, a specific implementation of the upper phase power module 140 or the lower phase power module 145). For example, the point of use controller 642A may be a specific implementation of the point of use upper phase A controller 142A (which may be a specific implementation of the point of use upper phase controller 142 or the upper phase switching element use point lower phase controller 146). For example, the phase switching element 644A is a specific implementation of the upper phase A switching element 144A (which may be a specific implementation of the upper phase switching element 144 or the lower phase switching element 148). The north phase switching element 644A-N and the south phase switching element 644A-S may be specific implementations of the upper phase A north switching element 144A-N and the upper phase A south switching element 144A-S.

[0094] The point-of-use controller 642A may include one or more memories, controllers, or sensors. Figure 7As shown, the point of use controller 642A may include a northern thermal sensor 720A and a southern thermal sensor 720B. The point of use controller 642A may include more than two thermal sensors. The northern thermal sensor 720A may sense the temperature at a first position in the point of use controller 642A, and the southern thermal sensor 720B may sense the temperature at a second position in the point of use controller 642A. The point of use controller 642A may send one or more signals to the northern phase switching element 644A-N to control the operation of the northern phase switching element 644A-N, and may receive one or more signals from the northern phase switching element 644A-N providing information about the northern phase switching element 644A-N. The point of use controller 642A may send one or more signals to the southern phase switching element 644A-S to control the operation of the southern phase switching element 644A-S, and may receive one or more signals from the southern phase switching element 644A-S providing information about the southern phase switching element 644A-S. As described above, the terms "north" and "south" are used for reference only. For example, the point-of-use controller 642A can receive power and send and receive signals through signal channels A, B, VPS, VMS, and SRC. The point-of-use controller 642A can control the north phase switching element 644A-N and the south phase switching element 644A-S to control the current passing between the drain and the source of the power module 640A. For example, during the operation of the north phase switching element 644A-N and the south phase switching element 644A-S, the point-of-use controller 642A can monitor the temperature of the power module 640A to adjust the operation of the power module 640A or assert a fault. The point-of-use controller 642A can use the north thermal sensor 720A and the south thermal sensor 720B to monitor the temperature of the power module 640A.

[0095] Figure 7 An exemplary system for sensing the temperature of a power module for an inverter according to one or more embodiments is depicted. Figure 7 As shown, the point of use controller 642A can use on-chip integrated trimmed thermal sensors (including north thermal sensor 720A and south thermal sensor 720B) to accurately measure temperature. The north thermal sensor 720A and the south thermal sensor 720B can measure the absolute point of use controller 642A temperature to within a tolerance range of + / - approximately 1.5°C. The north thermal sensor 720A and the south thermal sensor 720B on the point of use controller 642A can be arranged in a manner to measure the temperature gradient across the point of use controller 642A. One or more embodiments may use the absolute measured temperature of the point of use controller 642A in combination with the temperature gradient across the point of use controller 642A to accurately predict the die temperature 710(TM) of one or more adjacent die of the north phase switch 644A-N and the south phase switch 644A-S within a range of + / - approximately 5°C. Although Figure 7The grain temperature 710 located on the grain of the northern phase switch 644A-N is illustrated, but the grain temperature 710 may include one or more temperature estimates of any grain in the grains of the northern phase switch 644A-N and the southern phase switch 644A-S. One or more embodiments may use the rate of change of the temperature difference between the northern thermal sensor 720A and the southern thermal sensor 720B to improve the response time of the grain temperature 710. The temperature gradient across the grain is extrapolated to predict the temperature of the adjacent SiC grain. Using only the temperature gradient, the predicted temperature will lag behind the actual temperature during a fast transient event. Using the rate of change of the temperature gradient can significantly improve the transient response during a fast transient event. The rate of change of the temperature gradient of the temperature difference between the northern thermal sensor 720A and the southern thermal sensor 720B can indicate the amplitude of the applied power pulse.

[0096] For example, relative to a thermistor-based system, one or more embodiments may provide a much tighter temperature measurement of the die temperature 710, such as within a range of + / - approximately 5°C. Relative to a thermistor-based system, one or more embodiments may require a reduced operating margin due to the tighter tolerance of the measured temperature, which may reduce the cost and / or complexity of the system. Relative to a thermistor-based system, one or more embodiments may allow the power module 640A to operate at a higher average temperature.

[0097] Relative to thermistor-based systems, one or more embodiments may provide a smaller total SiC die area and / or a lower cost heat sink. The more accurately the temperature is measured, the smaller the tolerance required to withstand operation within a given temperature operating range. For example, if the temperature is measured to be within the range of + / -15C, and the SiC die should not exceed 175C, the system must be designed so that the nominal system does not exceed 160C (175C-15C). Due to potential thermal sensor errors, the nominal system may mistakenly measure the temperature as being at 175C and be shut down. This erroneous measurement may cause an increase in power that may be dissipated in the switching element to actually lose 15C. Therefore, if the temperature is more accurately measured to + / -5C, only a 5C tolerance is required. Therefore, for a given load requirement, the number of SiC die per power switching element can be reduced because the conduction losses can be higher (fewer SiC die) because the maximum temperature on the nominal device is 170C (175C-5C) instead of 160C (175C-15C). In terms of heat sink cost, the thermal system may allow for a nominal die rise of 10C (15C - 5C) if the same number of SiC dies are used. One or more embodiments may allow for a modified gate drive curve based on die temperature 710, which may reduce switching losses and extend battery range. One or more embodiments may allow for temperature-based control of the power module 640A during bulk capacitor discharge.

[0098] One or more embodiments may provide a Vbe error of + / - approximately 1.6°C in a thermal sensor (north thermal sensor 720A or south thermal sensor 720B). One or more embodiments may provide a buffer error of + / - approximately 0.225°C from a thermal sensor. One or more embodiments may provide a GND error of + / - approximately 0.0625°C. One or more embodiments may provide a VDDL error of approximately 0.356°C from -40°C to 165°C in a thermal sensor. One or more embodiments may provide a VDDL transient error of + / - approximately 1.25°C. One or more embodiments may provide an ADC integral nonlinearity error of approximately 0.125°C from -40°C to 165°C. One or more embodiments may provide an ADC effective number of bits with twelve bits of accuracy, where 400uV equals + / - approximately 0.1°C. One or more embodiments may provide a trim and test error of + / - approximately 1.5°C. One or more embodiments may provide an error without chuck and VDDL transient errors and including half of the thermal sensor and integral nonlinearity error (spread as a function of temperature transients) of + / - approximately 2.128°C. One or more embodiments may provide an error with chuck measurement error in addition to the above mentioned error of + / - approximately 3.628°C.

[0099] Accurately understanding the die temperature 710 within the power module 640A can allow the reliability and efficiency of the power module 640A to be optimized. One or more embodiments may provide a power module 640A incorporating a north phase switch 644A-N and a south phase switch 644A-S and a point of use controller 642A. Multiple thermal sensing points on the point of use controller 642A can be used to sense the absolute temperature of the point of use controller 642A and the thermal gradient between the north thermal sensor 720A and the south thermal sensor 720B. The north thermal sensor 720A and the south thermal sensor 720B can be arranged on the ASIC in an advantageous manner so that the absolute temperature and thermal gradient measurements can be used to estimate the temperature of the north phase switch 644A-N and the south phase switch 644A-S. The rate of change of the thermal gradient with respect to time can also be used to improve the estimated response time.

[0100] Accurate temperature sensing of the north phase switch 644A-N and the south phase switch 644A-S can allow for optimization of the overall system cost and efficiency. Some systems may use a thermistor placed within the power module. The thermistor allows for measurement of temperature in the physical location of the thermistor, which in an application may be up to 20°C cooler than the adjacent SiC die. In addition, there may be significant coupling occurring between high current and high voltage lines, and the thermistor requires significant filtering of the monitoring signal, which can greatly reduce response time.

[0101] One or more embodiments may provide an apparatus and method for accurately estimating the temperature of the north phase switches 644A-N and the south phase switches 644A-S within the point of use controller 642A. One or more embodiments may provide a point of use controller 642A that is integrated into the power module 640A along with the north phase switches 644A-N and the south phase switches 644A-S.

[0102] For the point of use controller 642A, multiple thermal sensors, such as the north thermal sensor 720A and the south thermal sensor 720B, may be positioned across the point of use controller 642A. The temperatures of these on-chip trimmed thermal sensors may be accurately measured. Furthermore, the north thermal sensor 720A and the south thermal sensor 720B may be arranged across the point of use controller 642A in a manner that measures a temperature gradient across the point of use controller 642A. One or more embodiments may use the absolute measured temperature of the point of use controller 642A die in combination with the temperature gradient across the point of use controller 642A to accurately predict the SiC die temperature within a range of + / - approximately 5°C. Additionally, the rate of change of the temperature difference between the north thermal sensor 720A and the south thermal sensor 720B may be used to improve the response time of the die temperature 710.

[0103] One or more embodiments may provide a point of use controller 642A located within the power module 640A. The point of use controller 642A may be an ASIC. The point of use controller 642A may include a north thermal sensor 720A (TREF) and a south thermal sensor 720B (TSENSE) on the point of use controller 642A. The north thermal sensor 720A and the south thermal sensor 720B may be composed of a stack of diodes having a voltage drop with a negative temperature coefficient. However, the present disclosure is not limited thereto and may include other ways of constructing thermal sensors within the point of use controller 642A.

[0104] For example, the temperatures of the north thermal sensor 720A and the south thermal sensor 720B may be accurately measured at a known sampling rate, such as 100 μs. The absolute temperature of the sensors and the difference between the thermal sensor temperatures may be monitored. Equations 1 to 5 below may be used to predict the die temperature 710.

[0105] Equation 1:

[0106] Equation 2: β N =(ΔT N -ΔT N-1 )*f s

[0107] Equation 3: S(β N )=αfor 0<|β N |

[0108] Equation 4: S(β N )=γfor|β N |>=A

[0109] Equation 5:

[0110] In equations 1 to 5 above, ΔT N may be the temperature gradient across the point-of-use controller 642A at a given sampling time N, may be the temperature recorded by the north thermal sensor 720A at time N, may be the temperature recorded by the south thermal sensor 720B at time N, β N can be the slope of the gradient from one temperature sample to the next with respect to time, f s may represent the sampling rate, α, γ, A, B, and C may be constants based on layout geometry and temperature, and ​may be the die temperature 710. For example, B may be an offset related to the power dissipated in the point-of-use controller 642A itself and may be equal to approximately 2. For example, C may be the slope without gradient slope prediction and may be equal to approximately 2.27. A may be a breakpoint for a piecewise linear fit for gradient slope compensation. For example, if the gradient slope is less than A, α may be equal to approximately 0.444. For example, if the gradient slope is greater than A, γ may be equal to approximately 0.0942. For example, the point-of-use controller 642A may be tested in an end-of-line test. The north thermal sensor 720A and the south thermal sensor 720B may be calibrated, and constants may be customized for a particular point-of-use controller 642A based on the different characteristics of each manufactured point-of-use controller 642A. For example, the constants may be stored in a memory of the point-of-use controller 642A.

[0111] Figure 8 An exemplary electrical schematic diagram for sensing the temperature of a power module for an inverter according to one or more embodiments is depicted. Figure 8 As shown, the point of use controller 642A may include a north thermal sensor 720A and a south thermal sensor 720B (which may include a diode stack) and a thermal monitor 801 including an analog to digital converter (ADC) 802. Figure 8 As shown, the point of use controller 642A may include a multiplexer for receiving the signal TSDin from the north thermal sensor 720A and the south thermal sensor 720B. For example, when ABIST_SEL<1:3> is equal to zero and OR(TSD_SEL<2:1>) is equal to one, the multiplexer may select TSDin. The point of use controller 642A may include additional Figure 8 The circuit shown or other circuits as required for the application. However, the present disclosure is not limited in this regard. The point-of-use controller 642A may provide a system for accurately estimating the die temperature 710 located within the point-of-use controller 642A (such as using constants stored in a memory of the point-of-use controller 642A and the above equation). The point-of-use controller 642A may provide a system for operating the north phase switches 644A-N and the south phase switches 644A-S at higher temperatures, for example due to the ability to have a much tighter standard deviation than other systems (such as those using thermistors). One or more embodiments may provide a system with improved accuracy that may allow optimization of the system design due to reduced error tolerances.

[0112] Fig. 9 Depicted is a thermal simulation of an exemplary system for sensing temperature of a power module for an inverter according to one or more embodiments. Fig. 9A thermal simulation 900 of a 150W response and a 225W response from a power module 640A is depicted, where the step response begins at 1.0 s. Fig. 9 As shown, at 150W, the predicted temperature 910 (eg, die temperature 710) can follow the actual measured temperature 905 with a small error. The system may use a slope compensation model (eg, such as β N ) to provide an even better predicted temperature 915, albeit with a small overshoot. Fig. 9 As shown, at 225 W, the predicted temperature 930 (eg, die temperature 710) may follow the actual measured temperature 925 with a small error. The system may use a slope compensation model (eg, such as β N ) to provide an even better predicted temperature 935, albeit with a small overshoot.

[0113] Fig.10 Depicted is the temperature sensing transient capability of an exemplary system for sensing temperature of a power module for an inverter according to one or more embodiments. Fig.10 A simulation 1000 of a 150W response from power module 640A is depicted, where the step response begins at 1.0 s. Fig.10 As shown, the predicted temperature 1010 (eg, the die temperature 710) may follow the actual measured temperature 1005 with a small error 1020. The system may use a slope compensation model (eg, such as β N ) to provide an even better predicted temperature 1015, albeit with a small overshoot. Using the slope compensation model, the error 1025 can quickly approach zero.

[0114] One or more embodiments may allow temperature-dependent gate drive curves for phase switching components to reduce switching losses and extend battery range. For example, one or more embodiments may include a point-of-use controller, such as an integrated gate driver ASIC. The ASIC may use an on-chip integrated trimmed thermal sensor to accurately measure temperature. The on-chip thermal sensor may measure the absolute ASIC temperature to a tolerance range of + / - approximately 1.5°C. The thermal sensors on the ASIC may be arranged in a manner to measure the temperature gradient across the ASIC. One or more embodiments may use the absolute measurement of the ASIC temperature in combination with the temperature gradient across the ASIC to accurately predict the SiC die temperature within a range of + / - approximately 5°C. One or more embodiments may use the rate of change of the temperature difference between the ASIC thermal sensors to improve the response time of the predicted SiC die temperature. For example, relative to a thermistor-based system, one or more embodiments may provide a much stricter temperature measurement of the SiC die, such as within a range of + / - approximately 5°C. Relative to a thermistor-based system, one or more embodiments may require a reduced operating tolerance due to a tighter tolerance for measuring temperature, which may reduce the cost and / or complexity of the system. Relative to a thermistor-based system, one or more embodiments may allow the power module to operate at a higher average temperature. One or more embodiments may provide a smaller total SiC die area and / or a lower cost heat sink relative to a thermistor-based system. One or more embodiments may allow for a modified gate drive curve based on SiC temperature, which may reduce switching losses and extend battery range. One or more embodiments may allow for temperature-based control of the power module during bulk capacitor discharge. With an integrated ASIC gate driver IC, multiple thermal sensors may be positioned across the ASIC. The temperature of these on-chip trimmed thermal sensors may be accurately measured. In addition, these thermal sensors may be arranged across the ASIC in a manner that measures the temperature gradient across the die. One or more embodiments may accurately predict the SiC die temperature within a range of + / - approximately 5°C using absolute measurements of the ASIC die temperature combined with the temperature gradient across the ASIC. In addition, the rate of change of the temperature difference between the ASIC die sensors may be used to improve the response time of the predicted SiC die temperature. One or more embodiments may provide a system that is used to operate an average SiC die at a higher temperature, for example, due to the ability to have a much tighter standard deviation than other systems (such as those using thermistors). One or more embodiments may provide a system with improved accuracy, which may allow optimization of the system design due to reduced error tolerances.

[0115] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

Claims

1. A system comprising: An inverter configured to convert DC power from a battery into AC power to drive a motor, wherein the inverter comprises: A power module, the power module comprising a drain terminal and a source terminal; one or more phase switches configured to control current flow between the drain terminal and the source terminal; and A point-of-use controller includes two or more thermal sensors on the point-of-use controller, the point-of-use controller being configured to determine a temperature of the one or more phase switching elements using the two or more thermal sensors.

2. The system of claim 1, wherein the point-of-use controller is an application specific integrated circuit. 3 . The system of claim 1 , wherein the point-of-use controller is a gate driver for the one or more phase switching elements. 4 . The system of claim 1 , wherein the one or more phase switching elements comprise one or more silicon carbide grains. 5 . The system of claim 1 , wherein each of the two or more thermal sensors comprises a stack of diodes having a voltage drop with a negative temperature coefficient.

6. The system of claim 1, wherein the point-of-use controller is configured to determine the temperature of the one or more phase switching elements using the respective absolute temperatures of the two or more thermal sensors and a difference between the respective absolute temperatures of the two or more thermal sensors.

7. The system of claim 1, wherein the point of use controller is configured to determine the temperature of the one or more phase switches using a temperature gradient of the point of use controller using the two or more thermal sensors.

8. The system of claim 1, further comprising: the battery, the battery being configured to supply the DC power to the inverter; as well as The motor is configured to receive the AC power from the inverter to drive the motor.

9. A system comprising: a power module for an inverter configured to convert DC power into AC power, the power module comprising a drain terminal and a source terminal; one or more phase switches configured to control current flow between the drain terminal and the source terminal; as well as A point-of-use controller includes two or more thermal sensors on the point-of-use controller, the point-of-use controller being configured to determine a temperature of the one or more phase switching elements using the two or more thermal sensors.

10. The system of claim 9, wherein the point-of-use controller is an application specific integrated circuit gate driver for the one or more phase switches.

11. The system of claim 9, wherein the one or more phase switching elements comprise one or more silicon carbide grains.

12. The system of claim 9, wherein each of the two or more thermal sensors comprises a stack of diodes having a voltage drop with a negative temperature coefficient.

13. The system of claim 9, wherein the point-of-use controller is configured to determine the temperature of the one or more phase switching elements using the respective absolute temperatures of the two or more thermal sensors and a difference between the respective absolute temperatures of the two or more thermal sensors.

14. The system of claim 9, wherein the point of use controller is configured to determine the temperature of the one or more phase switches using a temperature gradient of the point of use controller using the two or more thermal sensors.

15. A system comprising one or more controllers, the one or more controllers comprising: a first thermal sensor at a first location on the one or more controllers; as well as a second thermal sensor at a second location on the one or more controllers, Wherein the one or more controllers are configured to use the first thermal sensor and the second thermal sensor to determine a temperature of a component external to the one or more controllers.

16. The system of claim 15, wherein the one or more controllers are configured to: determining a first temperature difference between the first thermal sensor and the second thermal sensor at a first time, determining a second temperature difference between the first thermal sensor and the second thermal sensor at a second time, and The temperature of the component is determined based on the first temperature difference and the second temperature difference.

17. The system of claim 16, wherein the one or more controllers are further configured to: The temperature of the component is determined based on the first temperature difference, the second temperature difference, and a slope of a gradient between the first temperature difference and the second temperature difference.

18. The system of claim 16, wherein the one or more controllers are further configured to: The temperature of the component is determined based on the first temperature difference, the second temperature difference, a slope of a gradient between the first temperature difference and the second temperature difference, and a layout geometry of the component.

19. The system of claim 16, wherein the one or more controllers are further configured to: The temperature of the component is determined based on the first temperature difference, the second temperature difference, and a rate of change between the first temperature difference and the second temperature difference.

20. The system of claim 16, wherein the one or more controllers are further configured to: The temperature of the component is determined based on the temperature of the first thermal sensor, the first temperature difference, and the second temperature difference.

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