Patents by Inventor Sangsun Kim

Sangsun Kim 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: 10727673
    Abstract: A power system including a rectifier and an inverter. The rectifier has a plurality of phase input terminals and a plurality of rectifier output terminals that provide respective rectified outputs, rectifier circuitry that rectifies the signals on the phase input terminals to generate respective rectified outputs on the rectifier output terminals, a rectifier neutral to receive a power source neutral, and capacitors connected between the rectifier neutral and the rectifier output terminals. The inverter includes a respective plurality of inverter input terminals respectively connected to the rectifier output terminals, a plurality of inverter output terminals, and an inverter neutral. The rectifier neutral and the inverter neutral are coupled by a conductor to form a same neutral.
    Type: Grant
    Filed: August 26, 2019
    Date of Patent: July 28, 2020
    Assignee: Google LLC
    Inventors: Sangsun Kim, Anand Ramesh, Scott Aldous, John Zipfel
  • Publication number: 20190379207
    Abstract: A power system including a rectifier and an inverter. The rectifier has a plurality of phase input terminals and a plurality of rectifier output terminals that provide respective rectified outputs, rectifier circuitry that rectifies the signals on the phase input terminals to generate respective rectified outputs on the rectifier output terminals, a rectifier neutral to receive a power source neutral, and capacitors connected between the rectifier neutral and the rectifier output terminals. The inverter includes a respective plurality of inverter input terminals respectively connected to the rectifier output terminals, a plurality of inverter output terminals, and an inverter neutral. The rectifier neutral and the inverter neutral are coupled by a conductor to form a same neutral.
    Type: Application
    Filed: August 26, 2019
    Publication date: December 12, 2019
    Inventors: Sangsun Kim, Anand Ramesh, Scott Aldous, John Zipfel
  • Patent number: 10439399
    Abstract: A power system including a rectifier and an inverter. The rectifier has a plurality of phase input terminals and a plurality of rectifier output terminals that provide respective rectified outputs, rectifier circuitry that rectifies the signals on the phase input terminals to generate respective rectified outputs on the rectifier output terminals, a rectifier neutral to receive a power source neutral, and capacitors connected between the rectifier neutral and the rectifier output terminals. The inverter includes a respective plurality of inverter input terminals respectively connected to the rectifier output terminals, a plurality of inverter output terminals, and an inverter neutral. The rectifier neutral and the inverter neutral are coupled by a conductor to form a same neutral.
    Type: Grant
    Filed: May 1, 2018
    Date of Patent: October 8, 2019
    Assignee: Google LLC
    Inventors: Sangsun Kim, Anand Ramesh, Scott Aldous, John Zipfel
  • Patent number: 10327354
    Abstract: A server rack with vertically stacked shelves is disclosed. The shelves are used for housing loads (e.g. servers) and power supply units. Thus, both the power supply units and the servers are vertically stacked in the rack. An array of vertical and horizontal busses is secured to the back side of the server rack to electrically couple the servers with the power supply units. The arrangement of the PSUs and the busses provides for uniform current density across the server rack. The devices placed on the shelves are accessible and serviceable from the front of the server rack. The server rack can be placed within or secured to a device, system or a server room in a vertical orientation, a horizontal orientation or at an angle.
    Type: Grant
    Filed: March 1, 2019
    Date of Patent: June 18, 2019
    Assignee: Google LLC
    Inventors: Sangsun Kim, Honggang Sheng, Ken Krieger
  • Patent number: 10225948
    Abstract: A server rack with vertically stacked shelves is disclosed. The shelves are used for housing loads (e.g. servers) and power supply units. Thus, both the power supply units and the servers are vertically stacked in the rack. An array of vertical and horizontal busses is secured to the back side of the server rack to electrically couple the servers with the power supply units. The arrangement of the PSUs and the busses provides for uniform current density across the server rack. The devices placed on the shelves are accessible and serviceable from the front of the server rack. The server rack can be placed within or secured to a device, system or a server room in a vertical orientation, a horizontal orientation or at an angle.
    Type: Grant
    Filed: April 3, 2018
    Date of Patent: March 5, 2019
    Assignee: Google LLC
    Inventors: Sangsun Kim, Honggang Sheng, Ken Krieger
  • Publication number: 20180248377
    Abstract: A power system including a rectifier and an inverter. The rectifier has a plurality of phase input terminals and a plurality of rectifier output terminals that provide respective rectified outputs, rectifier circuity that rectifies the signals on the phase input terminals to generate respective rectified outputs on the rectifier output terminals, a rectifier neutral to receive a power source neutral, and capacitors connected between the rectifier neutral and the rectifier output terminals. The inverter includes a respective plurality of inverter input terminals respectively connected to the rectifier output terminals, a plurality of inverter output terminals, and an inverter neutral. The rectifier neutral and the inverter neutral are coupled by a conductor to form a same neutral.
    Type: Application
    Filed: May 1, 2018
    Publication date: August 30, 2018
    Inventors: Sangsun Kim, Anand Ramesh, Scott Aldous, John Zipfel
  • Patent number: 10033196
    Abstract: A method for converting alternating current (AC) power to direct current (DC) power in a non-isolated power converter includes receiving a three-phase power supply, transforming the three phase power supply into six voltage phases, half-wave rectifying the AC current, applying a power factor correction to achieve DC power, and outputting a DC power signal. The three-phase power supply has an AC current. The six voltage phase is transformed at a secondary side of a three-phase distribution transformer, which includes a center tap located at the secondary side of the three-phase distribution transformer and one or more AC wire conductors. The AC wire conductors carry the transformed power supply. The half-wave rectification occurs at the secondary side of the three-phase distribution transformer. An arrangement of rectifier diodes on the AC wire conductors accomplishes the half-wave rectification. The output DC power signal has an output voltage at a DC output.
    Type: Grant
    Filed: September 17, 2015
    Date of Patent: July 24, 2018
    Assignee: Google LLC
    Inventors: Sangsun Kim, Francisco Javier Elias, Cornelius Bendict O'Sullivan
  • Patent number: 9997917
    Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for non-isolated power conversion. In one aspect, a method includes generating first and second rectified outputs using a rectifier with a first input and a second input connected respectively to a first and second output of a power source, capacitively coupling the first and second rectified outputs to a neutral, generating first and second AC outputs from the first and second rectified outputs, and capacitively coupling the first and second AC outputs to the neutral. Other embodiments of this aspect include corresponding systems, apparatus, and computer programs, configured to perform the actions of the methods, encoded on computer storage devices.
    Type: Grant
    Filed: July 1, 2015
    Date of Patent: June 12, 2018
    Assignee: Google LLC
    Inventors: Sangsun Kim, Anand Ramesh, Scott Aldous, John Zipfel
  • Patent number: 9966761
    Abstract: In general, one innovative aspect of the subject matter described in this specification can be embodied in a load control system configured to perform load control operations comprising: measuring a voltage on an electrical grid at a plurality of times; determining, for each time of the plurality of times, a difference between a specified normal voltage and the respective measured voltage at that time; summing the differences between the specified normal voltage and the measured voltages to determine a curtailment level; determining whether the curtailment level exceeds a first threshold curtailment level; and in response to determining that the curtailment level exceeds the first threshold curtailment level, adjusting an amount of power drawn by a load.
    Type: Grant
    Filed: May 23, 2014
    Date of Patent: May 8, 2018
    Assignee: Google LLC
    Inventors: Sangsun Kim, Anand Ramesh, Ronald Scott Collyer, Jyoti Sastry, Arunava Majumdar
  • Patent number: 9967998
    Abstract: A server rack with vertically stacked shelves is disclosed. The shelves are used for housing loads (e.g. servers) and power supply units. Thus, both the power supply units and the servers are vertically stacked in the rack. An array of vertical and horizontal busses is secured to the back side of the server rack to electrically couple the servers with the power supply units. The arrangement of the PSUs and the busses provides for uniform current density across the server rack. The devices placed on the shelves are accessible and serviceable from the front of the server rack. The server rack can be placed within or secured to a device, system or a server room in a vertical orientation, a horizontal orientation or at an angle.
    Type: Grant
    Filed: June 10, 2016
    Date of Patent: May 8, 2018
    Assignee: Google LLC
    Inventors: Sangsun Kim, Honggang Sheng, Ken Krieger
  • Patent number: 9843221
    Abstract: Aspects of the disclosure relate generally to uninterruptible power supply units for systems requiring back up power. Each unit may include UPS circuitry for controlling charging and allowing discharging of a battery. The UPS circuitry may includes a controller and a plurality of metal-oxide semiconductor field effect transistors (“MOSFET”) switches. The MOSFETs may include charging and discharging MOSFETs arranged in series with the battery all driven by a single gate driver, such as a controller. In this regard, the controller may limit the charging current though all of the MOSFETs and charge the battery. The MOSFETs may be arranged such that if the charging MOSFET fails, the redundant charging MOSFET may continue to limit the charging current to the battery. Similarly, a redundant discharging MOSFET may be arranged in series with a discharging MOSFET in order to continue to provide discharging current if the discharging MOSFET fails.
    Type: Grant
    Filed: November 5, 2015
    Date of Patent: December 12, 2017
    Assignee: Google LLC
    Inventors: Sangsun Kim, William Leslie Dailey, Craig Kaneshiro, Shane R. Nay, Cornelius O'Sullivan
  • Publication number: 20170288454
    Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for controlling a battery power source. In one aspect, a system includes a first MOSFET having a first gate, a first source, and a first drain. A second MOSFET having a second gate, a second source, and a second drain. The first source is connected to the second source, and the second drain is coupled to a ground. A control circuit connected to the first gate and the second gate and that provides control signals to the first gate and the second gate that cause the first and second MOSFETS to operate in saturation regions during a first operational state to cause the first power source to discharge and the first MOSFET operates in a linear region during a second operational state to limit a charging current that charges the first power source.
    Type: Application
    Filed: June 15, 2017
    Publication date: October 5, 2017
    Inventors: Sangsun Kim, Anand Ramesh
  • Patent number: 9716408
    Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for controlling a battery power source. In one aspect, a system includes a first MOSFET having a first gate, a first source, and a first drain. A second MOSFET having a second gate, a second source, and a second drain. The first source is connected to the second source, and the second drain is coupled to a ground. A control circuit connected to the first gate and the second gate and that provides control signals to the first gate and the second gate that cause the first and second MOSFETS to operate in saturation regions during a first operational state to cause the first power source to discharge and the first MOSFET operates in a linear region during a second operational state to limit a charging current that charges the first power source.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: July 25, 2017
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Anand Ramesh
  • Patent number: 9712040
    Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for shaping grid currents output from parallel inverters in a power distribution system with virtual impedances. In one aspect, a method includes receiving a measurement of the current output from the inverter, processing the measurement of the current to extract a first current component having a particular frequency, obtaining a second current component based on the measurement of the current and the extracted first current component, weighing the first and second current components with respective first and second impedances to obtain respective first and second component voltages, the first impedance having a lower impedance amplitude than the second impedance, obtaining a shaped voltage based on the first and second component voltages, and outputting a control signal to the inverter, the control signal causing the inverter to output the shaped voltage to the power distribution bus.
    Type: Grant
    Filed: December 30, 2014
    Date of Patent: July 18, 2017
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Srinivasa Murthy Salapaka, Murti V. Salapaka, Subhrajit Roychowdhury
  • Patent number: 9692309
    Abstract: Devices and methods for monitoring and determining alternating current (AC) power system parameters are provided. In some implementations, the device can include a processor; and at least one non-transitory computer-readable medium storing computer-executable instructions for implementing a number of components. The components include a monitor configured to: sense an AC line voltage signal and an AC current voltage signal; filter the AC line voltage signal; calculate average AC line voltage and current values based, at least, on a DC voltage and current values corresponding to the AC line voltage and current signals, respectively; determine fundamental AC line voltage and current signals based, at least, on zero crossings of the respective average AC line voltage value and the average AC line current value; and determine one or more AC power system parameters based, at least, on the fundamental AC line voltage signal and the fundamental AC line current signal.
    Type: Grant
    Filed: December 14, 2016
    Date of Patent: June 27, 2017
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Eduardo M. Lipiansky
  • Patent number: 9667094
    Abstract: Methods and systems supply uninterrupted power to a load using a backup battery module. A driver circuit connects the load and the backup battery module such that the operational range of the load voltage is narrower than the operational range of the battery voltage. Different charging and discharging paths of the driver circuit may be used to limit the DC bus voltage to values lower than the battery voltage. The proposed systems and methods can increase power efficiency and decrease the cost of power supply and conversion operations.
    Type: Grant
    Filed: May 31, 2016
    Date of Patent: May 30, 2017
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Pascal Kam
  • Patent number: 9634512
    Abstract: An electronic uninterruptible power supply unit includes one or more battery connections. A bi-directional converter is in electrical communication with the one or more battery connections and arranged to (a) provide power at a first controlled voltage from the one or more battery connections as a boost converter when power is determined to not be available from a power source; and (b) provide charge to the one or more battery connections by providing power at a second controlled voltage that is different from the first controlled voltage when power is determined to be available from the power source. First and second MOSFET switches are connected in series with the one or more battery connections and arranged as a bi-directional switch that controls charging current for the one or more battery connections.
    Type: Grant
    Filed: December 3, 2013
    Date of Patent: April 25, 2017
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Mark R. Imbertson
  • Publication number: 20170047744
    Abstract: A method for converting alternating current (AC) power to direct current (DC) power in a non-isolated power converter includes receiving a three-phase power supply, transforming the three phase power supply into six voltage phases, half-wave rectifying the AC current, applying a power factor correction to achieve DC power, and outputting a DC power signal. The three-phase power supply has an AC current. The six voltage phase is transformed at a secondary side of a three-phase distribution transformer, which includes a center tap located at the secondary side of the three-phase distribution transformer and one or more AC wire conductors. The AC wire conductors carry the transformed power supply. The half-wave rectification occurs at the secondary side of the three-phase distribution transformer. An arrangement of rectifier diodes on the AC wire conductors accomplishes the half-wave rectification. The output DC power signal has an output voltage at a DC output.
    Type: Application
    Filed: September 17, 2015
    Publication date: February 16, 2017
    Applicant: Google Inc.
    Inventors: Sangsun Kim, Francisco Javier Elias, Cornelius Bendict O'Sullivan
  • Publication number: 20170025891
    Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for controlling a battery power source. In one aspect, a system includes a first MOSFET having a first gate, a first source, and a first drain. A second MOSFET having a second gate, a second source, and a second drain. The first source is connected to the second source, and the second drain is coupled to a ground. A control circuit connected to the first gate and the second gate and that provides control signals to the first gate and the second gate that cause the first and second MOSFETS to operate in saturation regions during a first operational state to cause the first power source to discharge and the first MOSFET operates in a linear region during a second operational state to limit a charging current that charges the first power source.
    Type: Application
    Filed: July 24, 2015
    Publication date: January 26, 2017
    Inventors: Sangsun Kim, Anand Ramesh
  • Patent number: 9548650
    Abstract: Devices and methods for monitoring and determining alternating current (AC) power system parameters are provided. In some implementations, the device can include a processor; and at least one non-transitory computer-readable medium storing computer-executable instructions for implementing a number of components. The components include a monitor configured to: sense an AC line voltage signal and an AC current voltage signal; filter the AC line voltage signal; calculate average AC line voltage and current values based, at least, on a DC voltage and current values corresponding to the AC line voltage and current signals, respectively; determine fundamental AC line voltage and current signals based, at least, on zero crossings of the respective average AC line voltage value and the average AC line current value; and determine one or more AC power system parameters based, at least, on the fundamental AC line voltage signal and the fundamental AC line current signal.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: January 17, 2017
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Eduardo Marcelo Lipiansky