Patents by Inventor Ravisekhar Nadimpalli Raju

Ravisekhar Nadimpalli Raju 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: 20160181947
    Abstract: A method for use in reducing an inductance of a circuit including a commutation loop defined at least in part by a source conductor and a return conductor between a first component and a second component is described. The method includes disposing a conductive inductance reducer within the commutation loop. The conductive inductance reducer includes an electrically conductive material and an insulator.
    Type: Application
    Filed: December 23, 2014
    Publication date: June 23, 2016
    Inventors: Ravisekhar Nadimpalli Raju, Manoj Ramprasad Shah
  • Patent number: 9343897
    Abstract: A circuit breaker device includes plural bridges conductively coupled parallel to each other between plural terminals that are configured to be conductively coupled with a power source and a load. The bridges include first and second outer bridges each having plural switches and at least an impedance bridge. The switches of the first and second outer bridges are configured to be closed to conduct electric current between the power source and the load and at least one switch in each of the first and second outer bridges are configured to be opened while at least one other switch in each of the first and second outer bridges are configured to remain closed to prevent conduction of the electric current between the power source and the load and to direct the electric current into the impedance bridge.
    Type: Grant
    Filed: August 8, 2014
    Date of Patent: May 17, 2016
    Assignee: General Electric Company
    Inventors: Luis Jose Garces, Rui Zhou, Ravisekhar Nadimpalli Raju, Satish Prabhakaran, Philip Michael Cioffi
  • Patent number: 9306391
    Abstract: A direct current (DC) transmission and distribution (T&D) system includes a plurality of DC-to-DC converter devices defining a plurality of isolatable portions of the DC T&D system. The DC T&D system also includes a DC T&D control system coupled to the DC-to-DC converter devices. The DC T&D control system includes a plurality of current sensors. At least one of the current sensors is positioned at one of the DC-to-DC converter devices. The current sensor is configured to transmit signals representative of a value of DC electric current transmission through the DC-to-DC converter device. The DC T&D control system also includes a plurality of processors. At least one processor is coupled to the current sensor and the DC-to-DC converter device. The processor is configured to regulate DC current transmission through the DC-to-DC converter device as a function of the value of DC current transmission through the DC-to-DC converter device.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: April 5, 2016
    Assignee: General Electric Company
    Inventors: Nilanjan Ray Chaudhuri, Ranjan Kumar Gupta, Rajib Datta, Ravisekhar Nadimpalli Raju
  • Publication number: 20160082907
    Abstract: A power system for a marine ship includes a plurality of protection zones, wherein at least two protection zones are coupled to each other via at least one bus-tie converter. Each of the protection zones includes a plurality of direct current (DC) buses and a plurality of power converters. The bus-tie converter includes at least two converter legs coupled by at least one inductor. Each converter leg includes a first branch connected with a snubber circuit by an intermediate switching device. The first branch includes two outer switching devices and at least one inner switching device connected between the two outer switching devices. The snubber circuit includes a combination of a diode, a resistor and a capacitor. A controller controls the operation of the plurality of power converters and the at least one bus-tie converter.
    Type: Application
    Filed: July 1, 2015
    Publication date: March 24, 2016
    Inventors: Dong Dong, Ravisekhar Nadimpalli Raju
  • Publication number: 20160072375
    Abstract: A system and method for series connecting electronic power devices are disclosed. In one embodiment, a switching device system includes a first upper arm electrically coupled to a first lower arm and a second upper arm electrically coupled to a second lower arm. Each of the arms include a plurality of low voltage sub-modules connected in series and each plurality of low voltage sub-modules includes an auxiliary switching device, a series switching device, and a capacitor. Each plurality of low voltage sub-modules is configured to be sequentially switched using the auxiliary switching device and the series switching device separately in the upper arms and the respective lower arms to control change in voltage over time (dV/dt) while selectively blocking a desired high voltage. Further, a capacitor voltage balancing (sorting or rotating) algorithm may be used to actively balance voltage across each plurality of low voltage sub-modules.
    Type: Application
    Filed: September 10, 2014
    Publication date: March 10, 2016
    Inventors: Rui Zhou, Luis Jose Garces, Ravisekhar Nadimpalli Raju, Rixin Lai, Di Zhang
  • Publication number: 20160065081
    Abstract: A multi-level DC-DC converter includes an input side to receive a DC power having an input voltage and current, an output side to provide power to a load at a desired output voltage and current, and a plurality of tranformer-isolated DC-DC converters connected between the input and output sides, with the tranformer-isolated DC-DC converters being connected in series on one side and connected in parallel on another side. Each of the tranformer isolated DC-DC converters further includes a power transformer having a primary winding and a secondary winding, and a plurality of switching devices each selectively operable in one of an On state and an Off state. Operating the switching devices in a complementary On state and Off state alternately at a controlled switching frequency provides for engaging the tranformer isolated DC-DC converter and operating the switching devices in a simultaneously On state bypasses the transformer isolated DC-DC converter.
    Type: Application
    Filed: August 26, 2014
    Publication date: March 3, 2016
    Inventors: Ravisekhar Nadimpalli Raju, Rajib Datta, Xu She
  • Publication number: 20160009354
    Abstract: A power system for a marine ship includes a plurality of protection zones, wherein at least two protection zones are coupled to each other via at least one bus-tie converter. Each of the protection zones includes a plurality of direct current (DC) buses; wherein DC buses which do not have same DC voltage are coupled to each other via at least one DC to DC converter. Furthermore, at least one energy source is coupled to at least one DC bus via a power electronic converter.
    Type: Application
    Filed: July 11, 2014
    Publication date: January 14, 2016
    Inventors: Rixin Lai, Di Zhang, Dong Dong, Konrad Roman Weeber, Ravisekhar Nadimpalli Raju, Steven Michael Mankevich
  • Publication number: 20160006238
    Abstract: A circuit breaker device includes plural bridges conductively coupled parallel to each other between plural terminals that are configured to be conductively coupled with a power source and a load. The bridges include first and second outer bridges each having plural switches and at least an impedance bridge. The switches of the first and second outer bridges are configured to be closed to conduct electric current between the power source and the load and at least one switch in each of the first and second outer bridges are configured to be opened while at least one other switch in each of the first and second outer bridges are configured to remain closed to prevent conduction of the electric current between the power source and the load and to direct the electric current into the impedance bridge.
    Type: Application
    Filed: August 8, 2014
    Publication date: January 7, 2016
    Inventors: LUIS JOSE GARCES, RUI ZHOU, RAVISEKHAR NADIMPALLI RAJU, SATISH PRABHAKARAN, PHILIP MICHAEL CIOFFI
  • Publication number: 20150256093
    Abstract: A hybrid HVDC converter system includes at least one alternating current (AC) conduit, at least one transformer coupled to said at least one AC conduit, and at least one direct current (DC) conduit. The hybrid HVDC converter system also includes at least one capacitor commutated converter (CCC) configured to convert AC voltages and AC currents to a DC voltage and DC current. The at least one CCC is coupled to the at least one AC conduit through the at least one transformer. The hybrid HVDC converter system further includes at least one self-commutated converter (SCC) configured to convert AC voltages and AC currents to a regulated DC voltage and DC current. The at least one SCC includes at least one AC/DC stage and at least one DC/DC stage coupled to the at least one AC/DC stage.
    Type: Application
    Filed: March 7, 2014
    Publication date: September 10, 2015
    Applicant: General Electric Company
    Inventors: Ranjan Kumar Gupta, Luis Jose Garces, Ravisekhar Nadimpalli Raju
  • Publication number: 20150070939
    Abstract: An electric power conversion system is coupled to a high voltage direct current (HVDC) transmission system. The electric power conversion system includes a plurality of power conversion modules. At least one of the power conversion modules includes at least one power converter coupled to at least one DC power terminal. The power conversion module also includes at least one isolation device coupled to the at least one power converter. The at least one power converter and the at least one isolation device at least partially define an isolatable portion of the electric power conversion system. The at least one isolation device is configured to remove the isolatable portion from service. The at least one power converter is configured to decrease electric current transmission through the isolatable portion prior to opening the at least one isolation device.
    Type: Application
    Filed: September 6, 2013
    Publication date: March 12, 2015
    Applicant: General Electric Company
    Inventors: Ranjan Kumar Gupta, Ravisekhar Nadimpalli Raju, Rahul Shantilal Chokhawala
  • Publication number: 20140347898
    Abstract: A power converter module is provided. The power converter module includes a first converter leg and a second converter leg. The first converter leg includes a first switching unit and a second switching unit coupled in series. The second switching unit is disposed in a reverse orientation with respect to an orientation of the first switching unit. The second converter leg includes a third switching unit and a diode coupled in series. The third switching unit is disposed in a reverse orientation with respect to the orientation of the first switching unit. The power converter also includes a first energy storage device operatively coupled between the first converter leg and the second converter leg. The power converter module further includes a second energy storage device operatively coupled between the first converter leg and the second converter leg.
    Type: Application
    Filed: August 7, 2014
    Publication date: November 27, 2014
    Inventors: Ravisekhar Nadimpalli Raju, Luis Jose Garces, Ranjan Kumar Gupta, Di Zhang, Andrew Allen Rockhill
  • Publication number: 20140265583
    Abstract: A direct current (DC) transmission and distribution (T&D) system includes a plurality of DC-to-DC converter devices defining a plurality of isolatable portions of the DC T&D system. The DC T&D system also includes a DC T&D control system coupled to the DC-to-DC converter devices. The DC T&D control system includes a plurality of current sensors. At least one of the current sensors is positioned at one of the DC-to-DC converter devices. The current sensor is configured to transmit signals representative of a value of DC electric current transmission through the DC-to-DC converter device. The DC T&D control system also includes a plurality of processors. At least one processor is coupled to the current sensor and the DC-to-DC converter device. The processor is configured to regulate DC current transmission through the DC-to-DC converter device as a function of the value of DC current transmission through the DC-to-DC converter device.
    Type: Application
    Filed: March 15, 2013
    Publication date: September 18, 2014
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Nilanjan Ray Chaudhuri, Ranjan Kumar Gupta, Rajib Datta, Ravisekhar Nadimpalli Raju
  • Publication number: 20140092660
    Abstract: A power converter includes at least one leg with a first string including a plurality of controllable semiconductor switches, a first connecting node, and a second connecting node, wherein the first string is operatively coupled across a first bus and a second bus. The at least one leg also includes a second string operatively coupled to the first string via the first connecting node and the second connecting node, wherein the second string includes a plurality of switching units. The first string includes a first branch and a second branch, wherein the second branch is operatively coupled to the first branch via a third connecting node and the third connecting node is coupled to a ground connection.
    Type: Application
    Filed: July 29, 2013
    Publication date: April 3, 2014
    Inventors: Di Zhang, Luis José Garcés Rivera, Ravisekhar Nadimpalli Raju, Rixin Lai, Andrew Allen Rockhill
  • Publication number: 20140092661
    Abstract: A power converter is presented. The power converter includes at least one leg, the at least one leg includes a first string, where the first string includes a plurality of controllable semiconductor switches, a first connecting node, and a second connecting node, and where the first string is operatively coupled across a first bus and a second bus. Furthermore, the at least one leg includes a second string operatively coupled to the first string via the first connecting node and the second connecting node, where the second string includes a plurality of switching units. A method for power conversion is also presented.
    Type: Application
    Filed: September 28, 2012
    Publication date: April 3, 2014
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Di Zhang, Luis Jose Garces, Rajib Datta, Ravisekhar Nadimpalli Raju
  • Patent number: 8644037
    Abstract: An AC-AC Converter for an AC source which in one embodiment has a first rectifier section rectifying the AC source into a first pulsed DC link voltage signal and a high frequency modulating section coupled to the first pulsed DC link voltage signal and producing a high frequency AC voltage signal. A high frequency transformer is coupled to the high frequency AC voltage signal producing a transformed high frequency AC signal. There is a second rectifier section coupled to the transformed high frequency AC signal and producing a second pulsed DC voltage signal and an unfolder section coupled to the second pulsed DC voltage signal and producing an output AC signal.
    Type: Grant
    Filed: July 15, 2008
    Date of Patent: February 4, 2014
    Assignee: General Electric Company
    Inventors: Ravisekhar Nadimpalli Raju, Richard S. Zhang, Ljubisa Dragolijub Stevanovic, Jeffrey Neal Slotnick, Robert Louis Steigerwald, Luis Jose Garces
  • Publication number: 20130343089
    Abstract: An electronics power system includes a plurality of substantially identical power electronic modules. Each power electronic module includes a single-phase DC/AC inverter having an output side. Each power electronic module further includes a medium/high-frequency-isolated DC/DC current-to-voltage converter having an input side. The medium/high-frequency-isolated DC/DC current-to-voltage converter drives the single-phase DC/AC inverter. Each DC/DC converter and its corresponding DC/AC inverter are connected back-to-back sharing a common DC-link. The plurality of power electronics modules is stacked together in series at the input side and in parallel or series/parallel at the output side.
    Type: Application
    Filed: June 25, 2012
    Publication date: December 26, 2013
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Ranjan Kumar Gupta, Ravisekhar Nadimpalli Raju, Rajib Datta, Mohammed Agamy
  • Publication number: 20130322142
    Abstract: An AC-DC power converter is provided. The power converter includes an electrical terminal including a positive node and a negative node. The power converter also includes a first switch coupled across the positive node and the negative node and a second switch coupled in a reverse orientation relative to the first switch and in parallel to the first switch forming a first path and a second path. The power converter further includes a first electrical storage device situated in the first path and a second electrical storage device situated in the second path.
    Type: Application
    Filed: May 31, 2012
    Publication date: December 5, 2013
    Applicant: GENERAL ELECTRIC COMPANY
    Inventor: Ravisekhar Nadimpalli Raju
  • Publication number: 20130313906
    Abstract: A load bypass switch enables continuous power to remote loads in the event of 1) failure of one or more remote loads, or 2) faults within the remote loads, within a dc power system. The bypass switch utilizes the passive components of the dc loads or inverters and therefore reduces overall component count. A black start method for the remote dc system uses the same passives present inside the loads/inverters and simultaneously uses some of the features of the bypass switch. A bypass-module-yard uses multiple bypass switches enabling continuous power to the remote loads in the event of failure of one or more power distribution cables (in-feed to the remote loads) located remotely in the dc system.
    Type: Application
    Filed: May 23, 2012
    Publication date: November 28, 2013
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Ranjan Kumar Gupta, Christof Martin Sihler, Satish Sivarama Gunturi, Stefan Schroeder, Joseph Song Manguelle, Ravisekhar Nadimpalli Raju, Rajib Datta
  • Publication number: 20130162239
    Abstract: A multi-phase electronic power transformer includes a set of primary windings, wherein each primary winding is configured to couple with an input voltage. The transformer includes a pair of primary switching devices that includes a first primary switching device coupled to a first end of each primary winding and a second primary switching device coupled to a second end of each primary winding distinct from the first end of each primary winding. The transformer includes a set of secondary windings, wherein each secondary winding is configured to inductively couple with a respective primary winding and to output a voltage. The transformer includes a pair of secondary switching devices that includes a first secondary switching device coupled to a first end of each secondary winding and a second secondary switching device coupled to a second end of each secondary winding distinct from the first end of the each secondary winding.
    Type: Application
    Filed: December 22, 2011
    Publication date: June 27, 2013
    Applicant: General Electric Company
    Inventor: Ravisekhar Nadimpalli Raju
  • Publication number: 20130051091
    Abstract: A power conversion system includes a power transformer for receiving AC power at a first voltage from an input side and for delivering AC power at a second voltage to an output side. A power converter is also included in the power conversion system wherein the power converter includes an input side converter on the input side and an output side converter on the output side coupled through a plurality of DC links. A converter controller in the power converter provides control signals to the input side converter and the output side converter for regulating an active power and a reactive power flow through the power converter. Each of the input side converters and the output side converters includes at least two power converter transformers coupled between respective power converter bridges coupled to the plurality of DC links and the input side or to the plurality of DC links and the output side.
    Type: Application
    Filed: August 29, 2011
    Publication date: February 28, 2013
    Applicant: GENERAL ELECTRIC COMPANY
    Inventors: Rajib Datta, Ravisekhar Nadimpalli Raju