Patents by Inventor Liyu Cao

Liyu Cao 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: 11621134
    Abstract: A driver circuit for driving a solenoid, and related method, are described. A power supply charges one or more capacitors to a high voltage level sufficient to over-drive the solenoid. A switch is connected to the one or more capacitors and the solenoid. When the switch is on, the switch connects the one or more capacitors to the solenoid. When the switch is off, the switch disconnects the one or more capacitors from the solenoid. Control circuitry turns the switch on, and turns the switch off in response to sensing current through the solenoid reaches a defined maximum current.
    Type: Grant
    Filed: February 25, 2021
    Date of Patent: April 4, 2023
    Assignee: Smart Wires Inc.
    Inventors: Liyu Cao, Amrit Iyer, Arthur Kelley, Govind Chavan
  • Patent number: 11469015
    Abstract: A filter network is insertable into a power transmission line, to handle disturbances in the power transmission line. A first circuit has an RC network in parallel with a surge arrestor, to bypass high frequency disturbances of the power transmission line. A second circuit has inductors for carrying low-frequency power to and from impedance injection units.
    Type: Grant
    Filed: March 10, 2021
    Date of Patent: October 11, 2022
    Assignee: Smart Wires Inc.
    Inventors: Liyu Cao, Haroon Inam, Amrit Iyer, Hamed Khalilinia, Zbigniew Wolanski
  • Patent number: 11303110
    Abstract: A system and method using thyristors to protect a series-connected Flexible AC Transmission Systems (FACTS) device from surge currents are disclosed. According to some embodiments, the system includes a thyristor connected in shunt with the FACTS device to be protected. The system further includes control circuitry coupled to the thyristor to drive a gate of the thyristor with a direct current (DC) signal and turn on the thyristor in a time span on order of microseconds. The system and method can be used to protect any series-connected FACTS device that is in danger of being exposed to surge current such as a reclose after a deadline.
    Type: Grant
    Filed: July 7, 2020
    Date of Patent: April 12, 2022
    Assignee: Smart Wires Inc.
    Inventors: Amrit Iyer, Govind Chavan, Liyu Cao, Brock Petersen, Haroon Inam, Antonio Ginart
  • Publication number: 20220005633
    Abstract: A filter network is insertable into a power transmission line, to handle disturbances in the power transmission line. A first circuit has an RC network in parallel with a surge arrestor, to bypass high frequency disturbances of the power transmission line. A second circuit has inductors for carrying low-frequency power to and from impedance injection units.
    Type: Application
    Filed: March 10, 2021
    Publication date: January 6, 2022
    Inventors: Liyu Cao, Haroon Inam, Amrit Iyer, Hamed Khalilinia, Zbigniew Wolanski
  • Patent number: 7502697
    Abstract: An AC power supply includes a digital feedback loop for output regulation. The feedback loop generates an RMS control signal that is mixed with a desired waveform to produce an input for a feedback loop that generates an instantaneous control signal. The instantaneous control signal is used to regulate power supply output.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: March 10, 2009
    Assignee: Programmable Division of Xantrex Technology, Inc.
    Inventors: Gunnar R. Holmquist, Liyu Cao, Daniel D. Zuck
  • Publication number: 20080082277
    Abstract: An AC power supply includes a digital feedback loop for output regulation. The feedback loop generates an RMS control signal that is mixed with a desired waveform to produce an input for a feedback loop that generates an instantaneous control signal. The instantaneous control signal is used to regulate power supply output.
    Type: Application
    Filed: September 28, 2006
    Publication date: April 3, 2008
    Inventors: Gunnar R. Holmquist, Liyu Cao, Daniel D. Zuck
  • Publication number: 20080080218
    Abstract: A power supply includes a feedback loop allowing user control of bandwidth and output impedance. The feedback may combine both voltage feedback and current feedback. Control of power supply bandwidth and impedance allows legacy power supply emulation in automated test systems.
    Type: Application
    Filed: November 22, 2006
    Publication date: April 3, 2008
    Inventors: Gunnar R. Holmquist, Liyu Cao
  • Publication number: 20080079406
    Abstract: A power supply with digital feedback loop that is configured to generate a digital voltage error signal and a digital current error signal and to select one of the digital voltage error signal and the digital current error signal for regulating one or both of power supply output voltage and power supply output current.
    Type: Application
    Filed: September 28, 2006
    Publication date: April 3, 2008
    Inventors: Gunnar R. Holmquist, Liyu Cao, Daniel D. Zuck