Patents by Inventor Satish Rajagopalan

Satish Rajagopalan 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: 20150183330
    Abstract: A modular reconfigurable medium voltage transformer configured for data centers, VOLT/VAR control, AC and DC charging, and vehicle-to-grid applications is disclosed. The modular reconfigurable transformer includes a plurality of modules configured to be connected to or disconnected from each other to provide multiple transformer configurations.
    Type: Application
    Filed: December 30, 2013
    Publication date: July 2, 2015
    Applicant: Electric Power Research Institute, Inc.
    Inventors: Satish Rajagopalan, Arindam Maitra, Jih-Sheng Lai, Mark Duvall, Mark McGranaghan
  • Publication number: 20130134935
    Abstract: An apparatus for DC fast charging of an electric vehicle includes an active front end AC-DC converter and an isolated DC-DC converter. The active front end AC-DC converter is adapted to rectify a medium voltage alternating current (AC) from a utility grid to a high voltage direct current (DC). The isolated DC-DC converter is adapted to transform the high voltage DC to a low voltage DC for charging the electric vehicle.
    Type: Application
    Filed: May 24, 2012
    Publication date: May 30, 2013
    Applicant: ELECTRIC POWER RESEARCH INSTITUTE, INC.
    Inventors: Arindam Maitra, Satish Rajagopalan, Jih-Sheng Lai, Mark Duvall, Mark McGranaghan
  • Patent number: 8433672
    Abstract: A system and method for determining the health of a component includes retrieving measured health signatures from the component, retrieving component usage variables, estimating component health signatures using an aging model, determining an aging derivative using the aging model and calculating an aging error based on the estimated component health signatures, the aging derivative and the measured health signatures.
    Type: Grant
    Filed: February 17, 2010
    Date of Patent: April 30, 2013
    Assignee: GM Global Technology Operations LLC
    Inventors: Kwang-Keun Shin, Mutasim A. Salman, Yilu Zhang, Xidong Tang, Hong S. Bae, Mark N. Howell, Satish Rajagopalan
  • Patent number: 8334616
    Abstract: A photovoltaic (PV) integrated variable frequency drive system having a variable frequency drive and an energy source. The variable frequency drive having a back end inverter, a DC bus electrically connected to the back end inverter, and an active front end electrically connected to the DC bus to facilitate bi-directional power flow to and from a power grid. The energy source being electrically connected to the DC bus.
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: December 18, 2012
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Arshad Mansoor, Satish Rajagopalan, Jih-Sheng Lai, Faisal Habib Khan
  • Patent number: 8260493
    Abstract: A system and method for providing component and sub-system state of health prognosis in a complex system using fault models and component aging models. The method includes determining a current state of health value for a sub-system using fault signature test results and determining current state of health values for a plurality of components in the sub-system using the fault signature test results. The method also determines current state of health values for components in the system that cannot use fault signature test results using a first probability model and the current state of health values for the plurality of components. The method determines predicted future state of health values for the components in the sub-system using component aging models and determines a predicted future state of health value for the sub-system using a second probability model and the future state of health values of the components.
    Type: Grant
    Filed: February 17, 2010
    Date of Patent: September 4, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Yilu Zhang, Mutasim A. Salman, Kwang-Keun Shin, Satish Rajagopalan, Mark N. Howell, Xidong Tang, Hong S. Bae
  • Patent number: 8207840
    Abstract: An embodiment contemplates a method for determining belt slip in a vehicle. The vehicle includes an engine and an alternator rotatably coupled by an accessory drive belt. The accessory drive belt engaging a rotating member of the engine for driving a rotating member of the alternator. A battery voltage is measured. An estimated battery voltage is determined as a function of engine speed. The belt slip of the alternator is detected in response to a comparison of the estimated battery voltage and the measured battery voltage.
    Type: Grant
    Filed: July 6, 2009
    Date of Patent: June 26, 2012
    Assignee: GM Global Technology Operations LLC
    Inventors: Yilu Zhang, Satish Rajagopalan, Mutasim A. Salman
  • Patent number: 8078415
    Abstract: A system and method for monitoring the state of health of the connection between a generator and a battery includes detecting an interruption in power between the generator and the battery, incrementing a counter each time an interruption is detected, generating a trend of a number of interruptions over time based on a number of increments in the counter, monitoring a rate of increase in the number of interruptions over time and determining if the rate of increase in the number of interruptions over time is greater than a predetermined threshold.
    Type: Grant
    Filed: November 25, 2009
    Date of Patent: December 13, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Satish Rajagopalan, Yilu Zhang, Mutasim A. Salman
  • Publication number: 20110273917
    Abstract: The present invention relates to a photo-voltaic interface for integration of photo-voltaic modules in a power system. The photo-voltaic interface includes a power conversion system adapted to convert power to a pre-determined voltage and current type, a control and monitoring system adapted to allow monitoring and control of power flow to optimize grid operation, and a communications system adapted to allow remote monitoring of the photo-voltaic interface to detect defective components.
    Type: Application
    Filed: May 5, 2011
    Publication date: November 10, 2011
    Applicant: ELECTRIC POWER RESEARCH INSTITUTE, INC.
    Inventors: Arindam Maitra, Mark McGranaghan, Satish Rajagopalan, Jih-Sheng Lai
  • Patent number: 8055460
    Abstract: A method for monitoring the state of health (SOH) of a solenoid powered by a battery includes measuring a voltage and a current supplied to the solenoid by the battery, using a processor to determine each of an equivalent resistance and inductance of the solenoid using the voltage and the current, comparing the equivalent resistance and the equivalent inductance to a corresponding calibrated threshold, and recording deviations from the corresponding calibrated thresholds as a pair of SOH values. A trend of the SOH values is continuously monitored, and an appropriate control action is taken when either SOH value drops below a calibrated lower limit. A solenoid monitoring system includes a solenoid, voltage and current sensors, and a controller having an algorithm for continuously monitoring a state of health (SOH) of the solenoid as set forth above.
    Type: Grant
    Filed: February 20, 2009
    Date of Patent: November 8, 2011
    Assignee: GM Global Technology Operations LLC
    Inventors: Satish Rajagopalan, Mutasim A. Salman
  • Publication number: 20110202227
    Abstract: A system and method for providing component and sub-system state of health prognosis in a complex system using fault models and component aging models. The method includes determining a current state of health value for a sub-system using fault signature test results and determining current state of health values for a plurality of components in the sub-system using the fault signature test results. The method also determines current state of health values for components in the system that cannot use fault signature test results using a first probability model and the current state of health values for the plurality of components. The method determines predicted future state of health values for the components in the sub-system using component aging models and determines a predicted future state of health value for the sub-system using a second probability model and the future state of health values of the components.
    Type: Application
    Filed: February 17, 2010
    Publication date: August 18, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Yilu Zhang, Mutasim A. Salman, Kwang-Keun Shin, Satish Rajagopalan, Mark N. Howell, Xidong Tang, Hong S. Bae
  • Publication number: 20110202494
    Abstract: A system and method for determining the health of a component includes retrieving measured health signatures from the component, retrieving component usage variables, estimating component health signatures using an aging model, determining an aging derivative using the aging model and calculating an aging error based on the estimated component health signatures, the aging derivative and the measured health signatures.
    Type: Application
    Filed: February 17, 2010
    Publication date: August 18, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Kwang-Keun Shin, Mutasim A. Salman, Yilu Zhang, Xidong Tang, Hong S. Bae, Mark N. Howell, Satish Rajagopalan
  • Publication number: 20110125430
    Abstract: A system and method for monitoring the state of health of the connection between a generator and a battery includes detecting an interruption in power between the generator and the battery, incrementing a counter each time an interruption is detected, generating a trend of a number of interruptions over time based on a number of increments in the counter, monitoring a rate of increase in the number of interruptions over time and determining if the rate of increase in the number of interruptions over time is greater than a predetermined threshold.
    Type: Application
    Filed: November 25, 2009
    Publication date: May 26, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Satish Rajagopalan, Yilu Zhang, Mutasim A. Salman
  • Publication number: 20110000421
    Abstract: An embodiment contemplates a method for determining belt slip in a vehicle. The vehicle includes an engine and an alternator rotatably coupled by an accessory drive belt. The accessory drive belt engaging a rotating member of the engine for driving a rotating member of the alternator. A battery voltage is measured. An estimated battery voltage is determined as a function of engine speed. The belt slip of the alternator is detected in response to a comparison of the estimated battery voltage and the measured battery voltage.
    Type: Application
    Filed: July 6, 2009
    Publication date: January 6, 2011
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Yilu Zhang, Satish Rajagopalan, Mutasim A. Salman
  • Publication number: 20100217545
    Abstract: A method for monitoring the state of health (SOH) of a solenoid powered by a battery includes measuring a voltage and a current supplied to the solenoid by the battery, using a processor to determine each of an equivalent resistance and inductance of the solenoid using the voltage and the current, comparing the equivalent resistance and the equivalent inductance to a corresponding calibrated threshold, and recording deviations from the corresponding calibrated thresholds as a pair of SOH values. A trend of the SOH values is continuously monitored, and an appropriate control action is taken when either SOH value drops below a calibrated lower limit. A solenoid monitoring system includes a solenoid, voltage and current sensors, and a controller having an algorithm for continuously monitoring a state of health (SOH) of the solenoid as set forth above.
    Type: Application
    Filed: February 20, 2009
    Publication date: August 26, 2010
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: Satish Rajagopalan, Mutasim A. Salman
  • Publication number: 20100073969
    Abstract: A photovoltaic (PV) integrated variable frequency drive system having a variable frequency drive and an energy source. The variable frequency drive having a back end inverter, a DC bus electrically connected to the back end inverter, and an active front end electrically connected to the DC bus to facilitate bi-directional power flow to and from a power grid. The energy source being electrically connected to the DC bus.
    Type: Application
    Filed: September 19, 2008
    Publication date: March 25, 2010
    Inventors: Satish Rajagopalan, Arshad Mansoor, Jih-Sheng Lai, Faisal Khan