Patents by Inventor Shizhong Ji

Shizhong Ji 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).

  • Publication number: 20210058019
    Abstract: A compressor and a control method thereof are provided. The compressor includes a motor with a rotor of a permanent magnet. According to embodiments, the method of controlling the compressor includes: applying a detection current to the motor in response to a command of starting the compressor; detecting whether there is demagnetization of the permanent magnet of the rotor according to a response of the motor to the applied detection current; resetting an operating parameter of the compressor if there is the demagnetization; and starting the compressor according to the reset operating parameters. According to embodiments of the present disclosure, when the compressor is to be started, demagnetization is detected first, and the operating parameter are set accordingly, so as to suppress or avoid performance degeneration due to the demagnetization.
    Type: Application
    Filed: July 29, 2020
    Publication date: February 25, 2021
    Inventors: Shizhong Ji, Li Yao, Wanzhen Liu
  • Publication number: 20210036651
    Abstract: The present disclosure provides a parameter control system for a motor, comprising: a current acquisition circuit connected to the motor, so as to acquire a current output by the motor; an arithmetic processor configured to determine whether to adjust a parameter of the motor according to the current acquired, and generate a new parameter when it is determined to adjust the parameter of the motor; and an output circuit configured to output the new parameter generated by the arithmetic processor to a control device of the motor. The present disclosure also provides a motor including the parameter control system.
    Type: Application
    Filed: July 29, 2020
    Publication date: February 4, 2021
    Inventors: Shizhong Ji, Li Yao, Yingke Sun, Qingyue Meng
  • Publication number: 20200186057
    Abstract: Embodiments of the present invention provide a method for controlling compressor braking, a frequency converter and a variable speed compressor. The method includes steps of: determining to brake a compressor, wherein a brake circuit includes three switching units and the three switching units are respectively electrically connected to three phases of windings of a motor of the compressor; actuating two of the three switching units to short-circuit two phases of windings of the motor. The two phases of windings of the motor are short-circuited by controlling the three switching units to generate braking torque, such that the compressor is braked without introducing a DC voltage, and thus the braking energy consumption is reduced. Besides, by turning on only two switches at a time, the switching abrasion is reduced, and the overall service life of the three switching units is effectively improved.
    Type: Application
    Filed: December 3, 2019
    Publication date: June 11, 2020
    Inventors: Shizhong Ji, Li Yao, Yingke Sun, Qingyue Meng