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).

  • Publication number: 20170005471
    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: Application
    Filed: July 1, 2015
    Publication date: January 5, 2017
    Inventors: Sangsun Kim, Anand Ramesh, Scott Aldous, John Zipfel
  • Patent number: 9515520
    Abstract: The subject innovation relates to providing battery backup for a power supply (e.g., a power supply implemented within a distributed power architecture where multiple power supplies are coupled together) based at least in part on voltage feed-forward control. A backup converter is coupled to a battery and a primary power converter. The backup converter delivers power from the battery to a load when a primary power failure is detected in the primary power converter. A controller controls an output current level of the backup converter based on an output voltage level of the battery.
    Type: Grant
    Filed: August 3, 2012
    Date of Patent: December 6, 2016
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Ken Krieger
  • Patent number: 9490663
    Abstract: Systems and methods for providing an uninterruptible power supply are disclosed herein. The system includes a power converter component that concurrently provides power to a load and charges a battery by using a primary power source. The system also includes a backup component that delivers power from the battery to the load during a primary power failure. Additionally, a set of series transistors are coupled to the battery to control charging current and discharging current of the battery.
    Type: Grant
    Filed: July 16, 2012
    Date of Patent: November 8, 2016
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Ken Krieger
  • Patent number: 9490720
    Abstract: An electric power supply unit includes a primary stage having an electric converter arranged to increase a frequency of AC power provided to an input of the power supply unit; a transformer stage connected to receive AC power from the primary stage and to reduce a voltage level of the AC power; and a secondary stage connected to receive the AC power at the reduced voltage level and the increased frequency and having a rectifier and power factor correction circuit arranged to convert the AC power to DC power and to provide power factor correction for power entering the power supply unit.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: November 8, 2016
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Jimmy Clidaras, Cornelius B. O'Sullivan, Anand Ramesh
  • Patent number: 9479077
    Abstract: An electric three-phase power supply system includes a primary stage arranged to receive an input of three-phase alternating current power; a transformer stage arranged to receive power from the primary stage and to reduce the three-phase AC power in voltage level, the transformer stage include an independent secondary winding for each of the phases in the alternating current power; a power factor correction (PFC) stage having a plurality of PFC units that each receive AC power for one of the phases in the alternating current power from the transformer stage; and a pair of output terminals that receive power form the PFC units, wherein output terminals of each of the PFC units are tied to each other, and ground terminals of each of the PFC units are tied to a common ground.
    Type: Grant
    Filed: December 31, 2013
    Date of Patent: October 25, 2016
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Francisco J. Elias
  • Patent number: 9439327
    Abstract: Systems and methods are provided for cooling electronic equipment in a data center. Ambient air is vertically circulated from a workspace across a plurality of rack-mounted electronic devices. The electronic devices are located in a plurality of trays such that each tray has a major plane that is substantially parallel to a side plane of the rack. The circulated air is cooled with a heat exchanger that is connected to a vertical end of the rack via a sealed interface. Multiple racks can be arrayed in a distributed cooling arrangement, which increases reliability and scalability of the data center.
    Type: Grant
    Filed: January 20, 2015
    Date of Patent: September 6, 2016
    Assignee: Google Inc.
    Inventors: Honggang Sheng, Sangsun Kim
  • Patent number: 9413221
    Abstract: A power conversion unit includes power converters arranged sequentially to each other to convert input power that is provided at an input of the power conversion unit to output power. A set of first capacitors are arranged in series with each other and include, for each power converter, a first capacitor that is arranged in parallel with an associated power converter. Each first capacitor is also arranged to store a portion of the input power. A set of second capacitors are connected in series with each other and include a second capacitor connected between each pair of sequential power converters in the sequence. The set of second capacitors are arranged to balance the portion of the input power stored by each first capacitor.
    Type: Grant
    Filed: December 4, 2013
    Date of Patent: August 9, 2016
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Di Xu, Anand Ramesh
  • Patent number: 9392720
    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 13, 2013
    Date of Patent: July 12, 2016
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Honggang Sheng, Ken Krieger
  • Patent number: 9373977
    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 18, 2015
    Date of Patent: June 21, 2016
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Pascal Kam
  • Patent number: 9335774
    Abstract: In many aspects, the systems and methods described herein include circuitry for an intermediate bus converter for use in a datacenter. The systems and methods described herein describe an intermediate bus converter comprising power stage circuitry, comprising a non-isolated converter, configured to convert a DC source voltage to one or more DC output voltages, wherein the DC source voltage is received from a front-end AC-to-DC converter. The intermediate bus converter further comprising controller circuitry configured to receive both the DC source voltage and the DC output voltage, and generate an at least one control signal to control the operation of the power stage circuitry.
    Type: Grant
    Filed: May 9, 2012
    Date of Patent: May 10, 2016
    Assignee: Google Inc.
    Inventors: Honggang Sheng, Sangsun Kim, Cornelius B. O'Sullivan
  • Patent number: 9225202
    Abstract: System for providing AC power control is disclosed. The system includes a primary power source (e.g., AC power source or backup generator power source), a backup power source (e.g., battery in power supply unit), and a control component. The control component powers the load with the primary power source when output voltage of the primary power source is above a predetermined threshold. The control component is configured to power the load concurrently with both the primary power and the backup power if the output voltage of the primary power source falls below a predetermined threshold. The control component is also configured to disable the primary power source and power the load with only the backup power source, upon detection of a fault condition at the primary power source. Upon resolution of the fault condition, the primary power is ramped up and the backup power is simultaneous ramped down.
    Type: Grant
    Filed: May 3, 2012
    Date of Patent: December 29, 2015
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Neilus O'Sullivan
  • Patent number: 9214833
    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: September 14, 2012
    Date of Patent: December 15, 2015
    Assignee: Google Inc.
    Inventors: Sangsun Kim, William Dailey, Craig Kaneshiro, Shane R. Nay, Cornelius O'Sullivan
  • Patent number: 9166423
    Abstract: Aspects of the disclosure relate generally to uninterruptible power supply (“UPS”) units for systems requiring back up power. The UPS units include circuitry for controlling charging and allowing discharging of a battery. The circuitry includes a controller as well as a pair of metal-oxide semiconductor field effect transistors (“MOSFET”) switches. The pair of MOSFET switches includes a charging and a discharging MOSFET switches in series with the battery operating as a bidirectional switch. A UPS unit may be charged and subsequently stored for period of time. During this time, plurality of features may prevent current leakage from the batteries. For example, PNP bipolar transistors and additional MOSFET switches may be used to prevent current leakage. These features alone or in combination may allow for long term storage of the uninterruptible power supply units without current leakage.
    Type: Grant
    Filed: August 17, 2012
    Date of Patent: October 20, 2015
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Jianshui Wang
  • Patent number: 9166410
    Abstract: System for providing AC line balancing includes a three-phase power source, a monitoring component and a control component. Three AC lines from the three-phase power source are coupled to a first set of loads and a set of transfer switches. Additionally, the set of transfer switches are configured to be coupled to a second set of loads. The monitoring component is configured to detect current provided by the three AC lines to identify the AC lines providing the highest and the lowest levels of currents to the first and second sets of loads. The control component is configured to configure at least one transfer switch in the set of transfer switches to decouple the AC line providing the highest level of current to a load of the second set of loads and couple the AC line providing the lowest level of current to that load.
    Type: Grant
    Filed: March 14, 2012
    Date of Patent: October 20, 2015
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Anthony Tonizzo
  • Patent number: 9065277
    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: February 29, 2012
    Date of Patent: June 23, 2015
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Pascal Kam
  • Patent number: 9035609
    Abstract: Aspects relate generally to hot swap control in uninterruptible power supply units for systems requiring backup power. A unit may include a pair of MOSFET switches configured as a bidirectional switch for battery charging and discharging current control. This configuration allows the unit to limit inrush current when the unit is connected to a DC power bus of a power system and also allows the unit to eliminate any current flow when it is disconnected. Upon insertion and extraction of the unit, the MOSFET switches are disabled to prevent any disturbances on the DC power bus. Hot swapping in the unit ensures that the overall power system, including the unit and the DC bus, operates reliably.
    Type: Grant
    Filed: August 17, 2012
    Date of Patent: May 19, 2015
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Craig Kaneshiro, William Dailey
  • Patent number: 9032250
    Abstract: A power delivery system includes a power supply unit, a secondary power unit, a controller, and a monitor. The power supply unit is configured to receive primary power and provide operating DC power to a DC load. The secondary power unit is configured to store energy from the primary power. The controller is configured to control the secondary power unit during a testing period such that the secondary power unit uses the stored energy to provide secondary DC power to the load instead of the operating DC power. The monitor is configured to monitor the operation of the secondary power unit during the testing period and provide a signal indicative of whether the secondary power unit operated within defined parameters during the testing period.
    Type: Grant
    Filed: November 5, 2012
    Date of Patent: May 12, 2015
    Assignee: Google Inc.
    Inventors: Ken Krieger, Sangsun Kim
  • Patent number: 8964374
    Abstract: Systems and methods are provided for cooling electronic equipment in a data center. Ambient air is vertically circulated from a workspace across a plurality of rack-mounted electronic devices. The electronic devices are located in a plurality of trays such that each tray has a major plane that is substantially parallel to a side plane of the rack. The circulated air is cooled with a heat exchanger that is connected to a vertical end of the rack via a sealed interface. Multiple racks can be arrayed in a distributed cooling arrangement, which increases reliability and scalability of the data center.
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: February 24, 2015
    Assignee: Google Inc.
    Inventors: Honggang Sheng, Sangsun Kim
  • Patent number: 8872484
    Abstract: Aspects relate to utilizing power factor correction to compensate for a leading power factor produced mainly due to electromagnetic interference (EMI) capacitors in front of a power factor correction stage. Provided is a power supply that includes a power factor correction circuit that includes a second harmonic generator component. The harmonic generator component includes a filter component and an integrator component. The filter component is configured to receive a rectified voltage and a power factor correction current and block a direct current component. The integrator component is configured to receive an alternating current component from the filter component and produce a harmonic that causes an angle of the power factor correction current to change from a leading power factor to a unity power factor or to a lagging power factor.
    Type: Grant
    Filed: August 17, 2011
    Date of Patent: October 28, 2014
    Assignee: Google Inc.
    Inventor: Sangsun Kim
  • Patent number: 8810273
    Abstract: Provided is an apparatus that includes sensors configured to ascertain two or more alternating current voltage signals. In some aspects, a first AC voltage is sensed at a resistor branch and a second AC voltage is sensed at a resistor-capacitor branch. A processor is configured to transform the two alternating current voltage signals into two instantaneous direct current voltage values. Analysis of at least one direct current value is performed to determine whether or not the instantaneous RMS line voltage is within or outside the range of the required (or expected) RMS line voltage. If the direct current value indicates that the line voltage is outside the expected RMS voltage value, it is determined that an alternating current line fault has occurred or is occurring.
    Type: Grant
    Filed: November 15, 2011
    Date of Patent: August 19, 2014
    Assignee: Google Inc.
    Inventors: Sangsun Kim, Ho Kong Mah