Patents by Inventor Mark Qin

Mark Qin 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).

  • Motor drive control including varying DC bus voltages, converter and inverter switching frequencies, and motor speed for thermal mitigation
    Patent number: 12631382
    Abstract: In other features, a refrigeration system is provided and includes a compressor motor, an inverter, a converter and a control module. The inverter is configured to convert a direct current (DC) bus voltage to an alternating current (AC) voltage and supply the AC voltage to the compressor motor. The converter is configured to convert a DC input voltage to the DC bus voltage. The control module is configured to obtain a parameter and in response to the parameter exceeding a predetermined threshold, reduce the DC bus voltage and at least one of (i) reduce a switching frequency, (ii) increase an amount of negative d-axis current of the compressor motor, or (iii) reduce a speed of the compressor motor.
    Type: Grant
    Filed: November 5, 2021
    Date of Patent: May 19, 2026
    Assignee: Copeland LP
    Inventors: Joseph G. Marcinkiewicz, Mark Qin, Nikhil R. Lakhkar, Robert Dziuba
  • Motor Drive Control Including Varying DC Bus Voltages, Converter and Inverter Switching Frequencies, And Motor Speed For Thermal Mitigation
    Publication number: 20230146546
    Abstract: In other features, a refrigeration system is provided and includes a compressor motor, an inverter, a converter and a control module. The inverter is configured to convert a direct current (DC) bus voltage to an alternating current (AC) voltage and supply the AC voltage to the compressor motor. The converter is configured to convert a DC input voltage to the DC bus voltage. The control module is configured to obtain a parameter and in response to the parameter exceeding a predetermined threshold, reduce the DC bus voltage and at least one of (i) reduce a switching frequency, (ii) increase an amount of negative d-axis current of the compressor motor, or (iii) reduce a speed of the compressor motor.
    Type: Application
    Filed: November 5, 2021
    Publication date: May 11, 2023
    Inventors: Joseph G. Marcinkiewicz, Mark Qin, Nikhil R. Lakhkar, Robert Dziuba