Patents by Inventor RAJENDRA PRASAD KANDULA

RAJENDRA PRASAD KANDULA 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: 20240120739
    Abstract: An exemplary embodiment of the present disclosure provides a power converter system comprising a power converter. The power converter system can comprise a power converter electrically connected to a local power supply and an electrical utility grid. The power converter can comprise an output configured to exchange electrical power with the electrical utility grid. The power converter can be further configured to monitor one or more electrical parameters of the electrical utility grid over a period of time and alter one or more electrical parameters of the output of the power converter based on the monitored one or more electrical parameters of the electrical utility grid in real time using a deep learning neural network.
    Type: Application
    Filed: February 9, 2022
    Publication date: April 11, 2024
    Inventors: Mohammadreza Miranbeigi, Rajendra Prasad Kandula, Deepak M. Divan
  • Publication number: 20240113526
    Abstract: A universal control (UniCon) scheme for grid-connected converters is presented herein that allows operation automatically in grid-following, grid-firming, and grid-forming modes. The converter does not need information on the grid or connected sources and loads. The converter can set its own operating point based on local measurements. The converter can operate over a wide range of typically encountered steady-state, transient, and fault conditions. UniCon realizes a universal control strategy for converters on the grid, allowing operation in distinct modes, including dispatch in grid connected mode, and automatic load sharing in islanded or microgrid mode. Under transient conditions, the converters provide inertial support and improve damping to stabilize and reduce disturbances. Multiple converters on the system do not require detailed system knowledge or low-latency communications for fast coordination, using communications when available for slow coordination and system level optimization.
    Type: Application
    Filed: February 9, 2022
    Publication date: April 4, 2024
    Inventors: Mohammadreza Miranbeigi, Rajendra Prasad Kandula, Deepak M. Divan
  • Publication number: 20240039388
    Abstract: An exemplary embodiment of the present disclosure provides a resonant module and sensing circuits for use with a soft-switching current source converter. The resonant module comprises a resonant switch, a resonant inductor, and a resonant capacitor. The resonant inductor is connected in electrical series with the resonant switch. The resonant capacitor is connected in parallel with the serially connected resonant switch and resonant capacitor. The resonant module further comprises first and second sensing circuits. The first sensing circuit is configured to generate a first sensing signal indicative of when the time derivative of a voltage across the resonant capacitor is negative. The second sensing circuit is configured to generate a second sensing signal indicative of when a voltage across the resonant capacitor is less than or equal to a predetermined threshold value.
    Type: Application
    Filed: August 20, 2021
    Publication date: February 1, 2024
    Inventors: Mickael J. Mauger, Rajendra Prasad Kandula, Deepak M. Divan
  • Publication number: 20240014749
    Abstract: The present disclosure relates to current source inverters (CSIs), and in particular to soft-switching current source inverters (SSCSIs). An exemplary CSI comprises a first CSI bridge, a second CSI bridge, a DC-link inductor, and a resonant tank. The first CSI bridge can be operatively connected to a first power bank. The second CSI bridge can be operatively connected to a second power bank. The DC-link inductor can be connected in series between the first and second CSI bridges. The resonant tank can be connected in parallel with the DC-link inductor.
    Type: Application
    Filed: August 26, 2020
    Publication date: January 11, 2024
    Inventors: Mickael J. Mauger, Rajendra Prasad Kandula, Deepak M. Divan
  • Publication number: 20230406126
    Abstract: An embodiment of the disclosure provides a flexible multiport energy routing system comprising a first port configured to connect to an AC grid, a plurality of second ports configured to connect to a plurality of devices, a step-down transformer, a power converter stack, and a third port. The step-down transformer can a high voltage side electrically coupled to the first port and a low voltage side. The power converter stack can comprise a plurality of power converter modules each having a first converter bridge connected to the low voltage side of the step-down transformer and a second converter bridge connected to one or more of the plurality of second ports. Each of the power converter modules can have a converter transformer connected between the first and second converter bridges. The first and second converter bridges can bidirectionally manage AC and DC power flows between the first, second, and third ports.
    Type: Application
    Filed: November 10, 2021
    Publication date: December 21, 2023
    Inventors: Mickael J. Mauger, Rajendra Prasad Kandula, Deepak M. Divan
  • Publication number: 20230336088
    Abstract: A synchronous reverse blocking switch for a soft-switching current source converter (SSCSC), the switch comprising: a first controlled switch; a second controlled switch connected in series to the first controlled switch; and a delay generation circuit configured to control: the second controlled switch to turn on after a delay (t_dON) from the first controlled switch turning on, and the second controlled switch to turn off after a delay (t_dOFF) from the first controlled switch turning off.
    Type: Application
    Filed: June 21, 2021
    Publication date: October 19, 2023
    Inventors: Aniruddh Marellapudi, Mickael J. Mauger, Rajendra Prasad Kandula, Deepakraj M. Divan
  • Publication number: 20230271524
    Abstract: An exemplary embodiment of the present disclosure provides a method for charging electric vehicles using service transformers on an electric utility grid. The method can comprise monitoring one or more electrical and/or thermal properties of a plurality of service transformers on an electric utility grid, and based on the monitored one or more electrical and/or thermal properties, determining that one or more of the plurality of service transformers have capacity to charge an electric vehicle.
    Type: Application
    Filed: June 18, 2021
    Publication date: August 31, 2023
    Inventors: Shreyas B. Kulkarni, Rajendra Prasad Kandula, Deepakraj M. Divan
  • Patent number: 11309802
    Abstract: A soft-switching solid-state power transformer, including: a high-frequency (HF) transformer comprising first and second winding connections; a first auxiliary resonant circuit coupled to the first winding connection, the first auxiliary resonant circuit comprising: a resonant capacitor coupled across the first winding connection, a resonant inductor coupled across the first winding connection in parallel with the resonant capacitor, and a damping feature coupled across the first winding connection in series with the resonant capacitor and the resonant inductor; a first current-source inverter (CSI) bridge coupled to the first auxiliary resonant circuit, the first CSI bridge comprising reverse blocking switches configured to conduct current in one direction and block voltage in both directions; a second auxiliary resonant circuit coupled to the second winding connection; and a second CSI bridge coupled to the second auxiliary resonant circuit, the second CSI bridge comprising reverse blocking switches.
    Type: Grant
    Filed: July 23, 2019
    Date of Patent: April 19, 2022
    Assignee: Georgia Tech Research Corporation
    Inventors: Liran Zheng, Deepakraj M. Divan, Rajendra Prasad Kandula, Karthik Kandasamy
  • Patent number: 11159091
    Abstract: Various examples are provided for isolated voltage optimization and control. In one example, a stackable isolated voltage optimization module (SIVOM) includes a transformer having a turns ratio between a primary winding and a secondary winding; a switching circuit configured to energize the secondary winding with a voltage provided from the three-phase power system or short the secondary winding; and a connection block configured to couple the switching circuitry to the first phase and a neutral, or to second and third phases of the three-phase power system. In another example, a system includes a SIVOM coupled to each phase of a three-phase power system, where each SIVOM comprises: a transformer and a switching circuit configured to boost or buck a voltage or change a phase angle of the phase coupled to that SIVOM by energizing a secondary winding of the transformer with a voltage provided from the three-phase power system.
    Type: Grant
    Filed: May 17, 2017
    Date of Patent: October 26, 2021
    Assignee: Georgia Tech Research Corporation
    Inventors: Deepakraj M. Divan, Rajendra Prasad Kandula
  • Publication number: 20210273574
    Abstract: A soft-switching solid-state power transformer, including: a high-frequency (HF) transformer comprising first and second winding connections; a first auxiliary resonant circuit coupled to the first winding connection, the first auxiliary resonant circuit comprising: a resonant capacitor coupled across the first winding connection, a resonant inductor coupled across the first winding connection in parallel with the resonant capacitor, and a damping feature coupled across the first winding connection in series with the resonant capacitor and the resonant inductor; a first current-source inverter (CSI) bridge coupled to the first auxiliary resonant circuit, the first CSI bridge comprising reverse blocking switches configured to conduct current in one direction and block voltage in both directions; a second auxiliary resonant circuit coupled to the second winding connection; and a second CSI bridge coupled to the second auxiliary resonant circuit, the second CSI bridge comprising reverse blocking switches.
    Type: Application
    Filed: July 23, 2019
    Publication date: September 2, 2021
    Inventors: Liran Zheng, Deepakraj M. Divan, Rajendra Prasad Kandula, Karthik Kandasamy
  • Patent number: 11004596
    Abstract: Embodiments of the present disclosure can include a hybrid transformer system comprising an electrical voltage transformer comprising: a high-voltage winding, the high-voltage winding comprising a first end and a second end, the first end having a lower voltage than the second end; a plurality of taps disposed proximate the first end of the high-voltage winding; a multi-level converter coupleable to the plurality of taps of the electrical voltage transformer, the multi-level converter configured to simultaneously control voltage injection and VAR injection to the high-voltage winding of the electrical voltage transformer; and a controller electrically coupleable to the multi-level converter, such that when the multi-level converter is coupled to the plurality of taps of the electrical voltage transformer, the controller is configured to selectively inject at least one of VARs or voltage to the high-voltage winding of the electrical voltage transformer.
    Type: Grant
    Filed: March 16, 2018
    Date of Patent: May 11, 2021
    Assignee: Georgia Tech Research Corporation
    Inventors: Deepakraj M. Divan, Rajendra Prasad Kandula
  • Publication number: 20200321882
    Abstract: Various examples are provided for isolated voltage optimization and control. In one example, a stackable isolated voltage optimization module (SIVOM) includes a transformer having a turns ratio between a primary winding and a secondary winding; a switching circuit configured to energize the secondary winding with a voltage provided from the three-phase power system or short the secondary winding; and a connection block configured to couple the switching circuitry to the first phase and a neutral, or to second and third phases of the three-phase power system. In another example, a system includes a SIVOM coupled to each phase of a three-phase power system, where each SIVOM comprises: a transformer and a switching circuit configured to boost or buck a voltage or change a phase angle of the phase coupled to that SIVOM by energizing a secondary winding of the transformer with a voltage provided from the three-phase power system.
    Type: Application
    Filed: May 17, 2017
    Publication date: October 8, 2020
    Inventors: DEEPAKRAJ M. DIVAN, RAJENDRA PRASAD KANDULA
  • Publication number: 20200013546
    Abstract: Embodiments of the present disclosure can include a hybrid transformer system comprising an electrical voltage transformer comprising: a high-voltage winding, the high-voltage winding comprising a first end and a second end, the first end having a lower voltage than the second end; a plurality of taps disposed proximate the first end of the high-voltage winding; a multi-level converter coupleable to the plurality of taps of the electrical voltage transformer, the multi-level converter configured to simultaneously control voltage injection and VAR injection to the high-voltage winding of the electrical voltage transformer; and a controller electrically coupleable to the multi-level converter, such that when the multi-level converter is coupled to the plurality of taps of the electrical voltage transformer, the controller is configured to selectively inject at least one of VARs or voltage to the high-voltage winding of the electrical voltage transformer.
    Type: Application
    Filed: March 16, 2018
    Publication date: January 9, 2020
    Inventors: Deepakraj M. Divan, Rajendra Prasad Kandula
  • Patent number: 9325171
    Abstract: Power flow controllers based on Imputed DC Link (IDCL) cells are provided. The IDCL cell is a self-contained power electronic building block (PEBB). The IDCL cell may be stacked in series and parallel to achieve power flow control at higher voltage and current levels. Each IDCL cell may comprise a gate drive, a voltage sharing module, and a thermal management component in order to facilitate easy integration of the cell into a variety of applications. By providing direct AC conversion, the IDCL cell based AC/AC converters reduce device count, eliminate the use of electrolytic capacitors that have life and reliability issues, and improve system efficiency compared with similarly rated back-to-back inverter system.
    Type: Grant
    Filed: February 1, 2013
    Date of Patent: April 26, 2016
    Assignee: GEORGIA TECH RESEARCH CORPORATION GEORGIA INSTITUTE OF TECHNOLOGY
    Inventors: Deepakraj M. Divan, Anish Prasai, Jorge Hernendez, Rohit Moghe, Amrit Iyer, Rajendra Prasad Kandula
  • Publication number: 20160099653
    Abstract: A power flow controller with a fractionally rated back-to-back (BTB) converter is provided. The power flow controller provide dynamic control of both active and reactive power of a power system. The power flow controller inserts a voltage with controllable magnitude and phase between two AC sources at the same frequency; thereby effecting control of active and reactive power flows between the two AC sources. A transformer may be augmented with a fractionally rated bi-directional Back to Back (B TB) converter. The fractionally rated BTB converter comprises a transformer side converter (TSC), a direct-current (DC) link, and a line side converter (LSC). By controlling the switches of the BTB converter, the effective phase angle between the two AC source voltages may be regulated, and the amplitude of the voltage inserted by the power flow controller may be adjusted with respect to the AC source voltages.
    Type: Application
    Filed: December 15, 2015
    Publication date: April 7, 2016
    Applicant: Varentec, Inc.
    Inventors: DEEPAKRAJ M. DIVAN, RAJENDRA PRASAD KANDULA, ANISH PRASAI
  • Patent number: 9281756
    Abstract: A power flow controller with a fractionally rated back-to-back (BTB) converter is provided. The power flow controller provide dynamic control of both active and reactive power of a power system. The power flow controller inserts a voltage with controllable magnitude and phase between two AC sources at the same frequency; thereby effecting control of active and reactive power flows between the two AC sources. A transformer may be augmented with a fractionally rated bi-directional Back to Back (BTB) converter. The fractionally rated BTB converter comprises a transformer side converter (TSC), a direct-current (DC) link, and a line side converter (LSC). By controlling the switches of the BTB converter, the effective phase angle between the two AC source voltages may be regulated, and the amplitude of the voltage inserted by the power flow controller may be adjusted with respect to the AC source voltages.
    Type: Grant
    Filed: November 9, 2012
    Date of Patent: March 8, 2016
    Assignee: VARENTEC, INC.
    Inventors: Deepakraj M. Divan, Rajendra Prasad Kandula, Anish Prasai
  • Publication number: 20140009980
    Abstract: A power flow controller with a fractionally rated back-to-back (BTB) converter is provided. The power flow controller provide dynamic control of both active and reactive power of a power system. The power flow controller inserts a voltage with controllable magnitude and phase between two AC sources at the same frequency; thereby effecting control of active and reactive power flows between the two AC sources. A transformer may be augmented with a fractionally rated bi-directional Back to Back (BTB) converter. The fractionally rated BTB converter comprises a transformer side converter (TSC), a direct-current (DC) link, and a line side converter (LSC). By controlling the switches of the BTB converter, the effective phase angle between the two AC source voltages may be regulated, and the amplitude of the voltage inserted by the power flow controller may be adjusted with respect to the AC source voltages.
    Type: Application
    Filed: November 9, 2012
    Publication date: January 9, 2014
    Applicant: VARENTEC, INC.
    Inventors: Deepakraj M. Divan, Rajendra Prasad Kandula, Anish Prasai
  • Publication number: 20130207471
    Abstract: Power flow controllers based on Imputed DC Link (IDCL) cells are provided. The IDCL cell is a self-contained power electronic building block (PEBB). The IDCL cell may be stacked in series and parallel to achieve power flow control at higher voltage and current levels. Each IDCL cell may comprise a gate drive, a voltage sharing module, and a thermal management component in order to facilitate easy integration of the cell into a variety of applications. By providing direct AC conversion, the IDCL cell based AC/AC converters reduce device count, eliminate the use of electrolytic capacitors that have life and reliability issues, and improve system efficiency compared with similarly rated back-to-back inverter system.
    Type: Application
    Filed: February 1, 2013
    Publication date: August 15, 2013
    Inventors: DEEPAKRAJ M. DIVAN, ANISH PRASAI, JORGE HERNENDEZ, ROHIT MOGHE, AMRIT LYER, RAJENDRA PRASAD KANDULA