Patents by Inventor Mohammed Khorshed ALAM

Mohammed Khorshed ALAM has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 10173534
    Abstract: A vehicle power system may include a gate driver configured to drive a traction gate and a generator gate corresponding to switches of a variable voltage controller such that the gates have alternating pulse width modulation ON periods. The gates may be driven in response to a throughput magnitude falling below a threshold. The gate driver may be further configured to drive the gates such that a duty cycle of one of the gates is zero in response to the throughput exceeding the threshold.
    Type: Grant
    Filed: January 12, 2017
    Date of Patent: January 8, 2019
    Assignee: Ford Global Technologies, LLC
    Inventors: Fan Xu, Shuitao Yang, Yan Zhou, Mohammed Khorshed Alam, Lihua Chen
  • Publication number: 20180366970
    Abstract: A vehicle powertrain includes a power inverter and a controller. The power inverter includes a load switch monolithically integrated with a mirror switch, and a current sensor configured to measure current through the load switch to provide current feedback for vector control of a motor. The controller may be configured to, responsive to a difference between a mirror current of the mirror switch and an output of the current sensor resulting from temperature changes of the load switch, operate the power inverter to reduce a temperature of the load switch.
    Type: Application
    Filed: June 20, 2017
    Publication date: December 20, 2018
    Inventors: Yan Zhou, Shuitao Yang, Fan Xu, Lihua Chen, Mohammed Khorshed Alam, Baoming Ge
  • Publication number: 20180354372
    Abstract: A powertrain for a vehicle may include a variable voltage converter (VVC), and a controller. The VVC may include an inductor, a bus capacitor and a flying capacitor. The controller may be configured to, in response to a power demand signal exceeding a threshold, modulate switches of the VVC such that an inductor current created by a collapsing field of the inductor is directed into the flying capacitor or the bus capacitor such that a bus capacitor voltage exceeds a flying capacitor voltage, and in response to the power demand signal dropping below the threshold, modulate switches such that the flying capacitor and the bus capacitor are coupled in parallel.
    Type: Application
    Filed: June 9, 2017
    Publication date: December 13, 2018
    Inventors: Shuitao Yang, Yan Zhou, Lihua Chen, Baoming Ge, Fan Xu, Mohammed Khorshed Alam
  • Patent number: 10144296
    Abstract: A vehicle powertrain includes a switch configured to provide a drive current to an electric machine and coupled with a diode array and a gate driver. The gate driver may be configured to, in response to a voltage across the array exceeding a threshold while providing the drive current in a presence of a turn-off request, confine operation of a resistive switch to a linear region to decrease a rate of change of the drive current proportional to the voltage.
    Type: Grant
    Filed: December 1, 2016
    Date of Patent: December 4, 2018
    Assignee: Ford Global Technologies, LLC
    Inventors: Fan Xu, Shuitao Yang, Yan Zhou, Lihua Chen, Mohammed Khorshed Alam
  • Publication number: 20180302019
    Abstract: A system of one or more computers can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions. One general aspect includes a series-parallel electric vehicle drive system, including a controller commutatively coupled to at least one inverter circuit with a serial insulated gate bipolar transistor (IGBT) and a parallel IGBT. The system includes a dc power source connected to an inverter circuit and a winding of a motor connected to an output of the invert circuit, wherein the inverter circuit generates a motor control signal.
    Type: Application
    Filed: April 18, 2017
    Publication date: October 18, 2018
    Inventors: Shuitao Yang, Lihua Chen, Yan Zhou, Mohammed Khorshed Alam, Fan Xu, Baoming Ge
  • Publication number: 20180281600
    Abstract: A vehicle powertrain includes a monolithically integrated load switch, mirror switch, and temperature array, and a gate driver. The gate driver includes a first comparator configured to filter a current level of the mirror switch, and a second comparator configured to provide a reference to the first comparator based on temperature array output such that a gate discharge rate of the switch, enabled by the first comparator, varies proportionally with a temperature adjusted filtered current level.
    Type: Application
    Filed: March 29, 2017
    Publication date: October 4, 2018
    Inventors: Yan Zhou, Lihua Chen, Shuitao Yang, Fan Xu, Mohammed Khorshed Alam, Baoming Ge
  • Patent number: 10090792
    Abstract: A powertrain includes a first and second switch coupled in parallel to drive an electric machine and a gate driver. The gate driver may be configured to, in response to a transition request while a first temperature of the first switch exceeds a second temperature of the second switch, inject a current onto a gate of the second switch to drive rates of change of current through the first and second switch to the electric machine to a same value.
    Type: Grant
    Filed: December 8, 2016
    Date of Patent: October 2, 2018
    Assignee: Ford Global Technologies, LLC
    Inventors: Fan Xu, Yan Zhou, Shuitao Yang, Mohammed Khorshed Alam, Lihua Chen
  • Publication number: 20180215269
    Abstract: A vehicle powertrain includes a variable voltage converter, a bypass diode and a controller. The bypass diode may be coupled in parallel with the converter and configured to clamp an output of the converter to a battery voltage. The controller may be configured to, while in a boost mode and in response to a rate of change of a converter inductor current exceeding a boost threshold, open switches of the converter to divert propulsive energy through the bypass diode. The controller may also be configured to, while in buck mode and in response to a magnitude of a converter inductor current exceeding a buck threshold, open switches of the converter to divert regenerative energy through the bypass diode, while reversed biased, to the battery.
    Type: Application
    Filed: January 31, 2017
    Publication date: August 2, 2018
    Inventors: Mohammed Khorshed Alam, Yan Zhou, Shuitao Yang, Fan Xu, Lihua Chen
  • Publication number: 20180219546
    Abstract: A gate driver of a power device includes a power supply and a resonant circuit. The power supply may have a positive potential and a negative potential. The resonant circuit may include an inductor and be configured to recirculate charge during turn-off by inducing a first field based on a positive charge from a gate caused by the positive potential, and in response to reversal of a voltage across the inductor, collapsing the first field to draw charge from the gate.
    Type: Application
    Filed: January 31, 2017
    Publication date: August 2, 2018
    Inventors: Shuitao Yang, Fan Xu, Yan Zhou, Lihua Chen, Mohammed Khorshed Alam
  • Publication number: 20180194234
    Abstract: A vehicle power system may include a gate driver configured to drive a traction gate and a generator gate corresponding to switches of a variable voltage controller such that the gates have alternating pulse width modulation ON periods. The gates may be driven in response to a throughput magnitude falling below a threshold. The gate driver may be further configured to drive the gates such that a duty cycle of one of the gates is zero in response to the throughput exceeding the threshold.
    Type: Application
    Filed: January 12, 2017
    Publication date: July 12, 2018
    Inventors: Fan Xu, Shuitao Yang, Yan Zhou, Mohammed Khorshed Alam, Lihua Chen
  • Publication number: 20180198401
    Abstract: A variable voltage converter for an electric drive system has upper and lower switching devices in series between positive and negative buses. An inductance couples a junction between the switching devices to a DC battery. A controller is configured to drive the switches according to PWM gate signals based on an expected boost ratio of the converter. The PWM gate signals have a nominal dead-time insertion for both the upper and lower switching devices when the expected boost ratio is greater than a predetermined boost ratio. In order to extend a range of achievable boost ratios during regeneration operation, the PWM gate signals are without dead-time insertion for the upper switching device and the lower switching device remains continuously off when the expected boost ratio is less than the predetermined boost ratio.
    Type: Application
    Filed: January 12, 2017
    Publication date: July 12, 2018
    Inventors: JOGENDRA S. THONGAM, SHUITAO YANG, MOHAMMED KHORSHED ALAM, LIHUA CHEN, FAN XU, YAN ZHOU
  • Publication number: 20180167013
    Abstract: A powertrain includes a first and second switch coupled in parallel to drive an electric machine and a gate driver. The gate driver may be configured to, in response to a transition request while a first temperature of the first switch exceeds a second temperature of the second switch, inject a current onto a gate of the second switch to drive rates of change of current through the first and second switch to the electric machine to a same value.
    Type: Application
    Filed: December 8, 2016
    Publication date: June 14, 2018
    Inventors: Fan XU, Yan ZHOU, Shuitao YANG, Mohammed Khorshed ALAM, Lihua CHEN
  • Publication number: 20180154784
    Abstract: A vehicle powertrain includes a switch configured to provide a drive current to an electric machine and coupled with a diode array and a gate driver. The gate driver may be configured to, in response to a voltage across the array exceeding a threshold while providing the drive current in a presence of a turn-off request, confine operation of a resistive switch to a linear region to decrease a rate of change of the drive current proportional to the voltage.
    Type: Application
    Filed: December 1, 2016
    Publication date: June 7, 2018
    Inventors: Fan Xu, Shuitao Yang, Yan Zhou, Lihua Chen, Mohammed Khorshed Alam
  • Publication number: 20180154787
    Abstract: A powertrain includes a DC-DC converter, an electric machine, and a controller. The DC-DC converter may be configured to output a bus voltage. The controller may be configured to, in response to a torque request exceeding an available torque of the electric machine, command the converter to boost the bus voltage to a discrete step value selected from a predetermined number of available discrete step values, that changes in response to a selected operating mode of the powertrain changing, to increase the available torque.
    Type: Application
    Filed: December 1, 2016
    Publication date: June 7, 2018
    Inventors: Lihua Chen, Yan Zhou, Shuitao Yang, Mohammed Khorshed Alam, Fan Xu
  • Publication number: 20180099574
    Abstract: A vehicle includes an electric machine configured to provide propulsive force to the vehicle, and a power inverter configured to supply power from a traction battery to the electric machine using a first and second switch configured as a half-bridge, wherein the first switch is controlled by a gate driver. The gate driver is configured to operate in a soft turn-off mode when a load current exceeds a threshold for a time period defined by a mask timer, operate in a fast turn-off mode when the load current is below the threshold, and in response to a turn-off request received prior to expiration of the mask timer after the load current exceeds the threshold, enable the soft turn-off mode.
    Type: Application
    Filed: October 12, 2016
    Publication date: April 12, 2018
    Inventors: Yan Zhou, Shuitao Yang, Lihua Chen, Fan Xu, Mohammed Khorshed Alam
  • Patent number: 9931944
    Abstract: A vehicle powertrain includes a bypass diode and a controller. The bypass diode is configured to clamp an inverter DC terminal voltage to a battery voltage. The controller is configured to, while the terminal voltage is within a predetermined range of the battery voltage, maintain off a lower IGBT of a DC-DC converter while in a propulsion mode, and modulate the lower IGBT to increase the terminal voltage to maintain the bypass diode reverse biased while in a regenerative mode.
    Type: Grant
    Filed: March 22, 2016
    Date of Patent: April 3, 2018
    Assignee: Ford Global Technologies, LLC
    Inventors: Mohammed Khorshed Alam, Lihua Chen, Yan Zhou, Fan Xu
  • Publication number: 20180079315
    Abstract: A DC link capacitor in a drive system for an electric vehicle is quickly discharged using only local action within an inverter module and without any extra components to dissipate the charge. The inverter has a phase leg comprising an upper switching device and a lower switching device coupled across the capacitor. A gate driver is coupled to the phase leg to alternately switch the switching devices to ON state according to a PWM signal during pulse-width modulation of the drive system. The gate driver is configured to discharge the link capacitor during a discharge event by simultaneously activating the upper and lower switching devices to transitional states. Thus use of transitional states ensures that the switching devices provide an impedance that dissipates the capacitor charge while protecting the devices from excessive temperature.
    Type: Application
    Filed: September 19, 2016
    Publication date: March 22, 2018
    Inventors: SHUITAO YANG, YAN ZHOU, FAN XU, MOHAMMED KHORSHED ALAM, LIHUA CHEN
  • Patent number: 9855850
    Abstract: A voltage converter includes a switch having a switching loss that decreases as a switching frequency of the switch decreases. The voltage converter further includes a controller programmed to vary the switching frequency based on a duty cycle of the switch and a current input to the switch to reduce switching losses or reduce a ripple current magnitude.
    Type: Grant
    Filed: December 14, 2015
    Date of Patent: January 2, 2018
    Assignee: Ford Global Technologies, LLC
    Inventors: Lihua Chen, Shailesh Shrikant Kozarekar, Yan Zhou, Mohammed Khorshed Alam, Shahram Zarei, Fazal Urrahman Syed
  • Patent number: 9834206
    Abstract: A hybrid drive system has a battery and a combustion engine for energy sources. The system has a traction motor, a generator, a variable voltage converter (VVC), a motor inverter, a generator inverter, a bus coupling the VVC to the inverters, and a controller. The controller regulates engine speed, motor torque, and generator torque. The engine speed is determined according to a driver torque demand. In normal conditions, 1) the controller regulates the engine speed by modifying a generator torque command, and 2) the bus voltage is regulated using the VVC and battery. When the controller detects a fault in which the battery and VVC become unavailable for regulating the bus voltage, then the controller regulates a motor inverter power output to match a sum of a generator inverter power output and an estimated power loss of the inverters in order to regulate the bus voltage.
    Type: Grant
    Filed: March 29, 2017
    Date of Patent: December 5, 2017
    Assignee: FORD GLOBAL TECHNOLOGIES, LLC
    Inventors: Shuitao Yang, Yan Zhou, Kevin L. Newman, Lihua Chen, Fan Xu, Mohammed Khorshed Alam
  • Publication number: 20170274777
    Abstract: A vehicle powertrain includes a bypass diode and a controller. The bypass diode is configured to clamp an inverter DC terminal voltage to a battery voltage. The controller is configured to, while the terminal voltage is within a predetermined range of the battery voltage, maintain off a lower IGBT of a DC-DC converter while in a propulsion mode, and modulate the lower IGBT to increase the terminal voltage to maintain the bypass diode reverse biased while in a regenerative mode.
    Type: Application
    Filed: March 22, 2016
    Publication date: September 28, 2017
    Inventors: Mohammed Khorshed Alam, Lihua Chen, Yan Zhou, Fan Xu