Patents by Inventor Venkata Giri Venkataramanan
Venkata Giri Venkataramanan 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).
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Patent number: 10879812Abstract: A semiconductor switch includes four diodes, two transistors, and a capacitor. The capacitor includes a fourth terminal and a fifth terminal. An anode of a third diode is connected to a third terminal of a first transistor. A cathode of the third diode is connected to a first terminal of the first transistor and to an anode of a first diode. An anode of a fourth diode is connected to a third terminal of a second transistor. A cathode of the fourth diode is connected to a first terminal of the second transistor and to an anode of the second diode. A cathode of the first diode is connected to a cathode of the second diode and to the fourth terminal of the capacitor. An anode of the third diode is connected to the anode of the fourth diode and to the fifth terminal of the capacitor.Type: GrantFiled: April 9, 2019Date of Patent: December 29, 2020Assignee: Wisconsin Alumni Research FoundationInventor: Venkata Giri Venkataramanan
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Publication number: 20200328690Abstract: A semiconductor switch includes four diodes, two transistors, and a capacitor. The capacitor includes a fourth terminal and a fifth terminal. An anode of a third diode is connected to a third terminal of a first transistor. A cathode of the third diode is connected to a first terminal of the first transistor and to an anode of a first diode. An anode of a fourth diode is connected to a third terminal of a second transistor. A cathode of the fourth diode is connected to a first terminal of the second transistor and to an anode of the second diode. A cathode of the first diode is connected to a cathode of the second diode and to the fourth terminal of the capacitor. An anode of the third diode is connected to the anode of the fourth diode and to the fifth terminal of the capacitor.Type: ApplicationFiled: April 9, 2019Publication date: October 15, 2020Inventor: Venkata Giri Venkataramanan
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Patent number: 10243447Abstract: A controller controls power between a source and a load with a link capacitor. (a) A switch vector is selected based on load and source values, a capacitor voltage value, and a switch state selection mode. The switch vector identifies an on or off configuration for load and source switches during a subcycle that allow or do not allow current flow between the link capacitor and the load switch or source switch. (b) The state of the load and source switches is controlled in the on configuration or in the off configuration based on the selected switch vector. (c) It is determined that it is time to select a next switch vector. (a) to (c) are repeated for each subcycle of the determined number of switching subcycles. At least one load switch and at least one source switch are simultaneously in the on configuration during at least one subcycle.Type: GrantFiled: February 2, 2017Date of Patent: March 26, 2019Assignee: WISCONSIN ALUMNI RESEARCH FOUNDATIONInventors: Venkata Giri Venkataramanan, Mahima Gupta
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Publication number: 20190036449Abstract: A power converter provides a pyramidal structure of switches communicating between a capacitive divider at the base of the pyramid and a terminal at the top of the pyramid to provide a transformation of a relationship between current and voltage in power transferred between the capacitive divider and the terminal at the top of the pyramid while providing reduced electrical interference and electrical rate of change (dv/dt).Type: ApplicationFiled: July 26, 2017Publication date: January 31, 2019Inventors: Venkata Giri Venkataramanan, Mahima Gupta, Daniel Ludois, Robert Mark Cuzner
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Patent number: 10193440Abstract: A power converter provides a pyramidal structure of switches communicating between a capacitive divider at the base of the pyramid and a terminal at the top of the pyramid to provide a transformation of a relationship between current and voltage in power transferred between the capacitive divider and the terminal at the top of the pyramid while providing reduced electrical interference and electrical rate of change (dv/dt).Type: GrantFiled: July 26, 2017Date of Patent: January 29, 2019Assignee: WISCONSIN ALUMNI RESEARCH FOUNDATIONInventors: Venkata Giri Venkataramanan, Mahima Gupta, Daniel Ludois, Robert Mark Cuzner
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Publication number: 20180219468Abstract: A controller controls power between a source and a load with a link capacitor. (a) A switch vector is selected based on load and source values, a capacitor voltage value, and a switch state selection mode. The switch vector identifies an on or off configuration for load and source switches during a subcycle that allow or do not allow current flow between the link capacitor and the load switch or source switch. (b) The state of the load and source switches is controlled in the on configuration or in the off configuration based on the selected switch vector. (c) It is determined that it is time to select a next switch vector. (a) to (c) are repeated for each subcycle of the determined number of switching subcycles. At least one load switch and at least one source switch are simultaneously in the on configuration during at least one subcycle.Type: ApplicationFiled: February 2, 2017Publication date: August 2, 2018Inventors: Venkata Giri Venkataramanan, Mahima Gupta
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Patent number: 9954427Abstract: A controller selects a first switch vector based on a current, voltage, or power of a multi-phase load or power source. The first switch vector identifies a first state for each of a plurality of half-bridges of a converter as on or as off during a first interval. A second switch vector is selected based on the current, voltage, or power of the multi-phase load or power source. The second switch vector identifies a second state for each of the half-bridges as on or as off during a second interval. The first interval is computed based on the selected first switch vector. The second interval is computed based on the selected second switch vector. Each of the plurality of half-bridges is controlled as on or as off during the first interval based on the selected first switch vector and during the second interval based on the selected second switch vector.Type: GrantFiled: November 6, 2015Date of Patent: April 24, 2018Assignee: Wisconsin Alumni Research FoundationInventors: Venkata Giri Venkataramanan, Mahima Gupta
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Publication number: 20170133922Abstract: A controller selects a first switch vector based on a current, voltage, or power of a multi-phase load or power source. The first switch vector identifies a first state for each of a plurality of half-bridges of a converter as on or as off during a first interval. A second switch vector is selected based on the current, voltage, or power of the multi-phase load or power source. The second switch vector identifies a second state for each of the half-bridges as on or as off during a second interval. The first interval is computed based on the selected first switch vector. The second interval is computed based on the selected second switch vector. Each of the plurality of half-bridges is controlled as on or as off during the first interval based on the selected first switch vector and during the second interval based on the selected second switch vector.Type: ApplicationFiled: November 6, 2015Publication date: May 11, 2017Inventors: Venkata Giri Venkataramanan, Mahima Gupta
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Patent number: 7919879Abstract: A wind turbine 36 has a back-to-back AC/DC/AC power electronic converter chain in which the grid side converter 48 is connected in series with DFIG stator windings 64. The machine side converter 56 is fed from the rotor windings 54 of the DFIG 44. Series connection of the grid side converter 48 enables voltage sag ride-through capability via control of the stator flux. In the event of a grid voltage sag, the series converter allows for a controlled response in the stator flux and electromagnetic shaft torque, protects the machine side converter and enables continued power delivery to the grid.Type: GrantFiled: May 31, 2007Date of Patent: April 5, 2011Assignee: Wisconsin Alumni Research FoundationInventors: Patrick S. Flannery, Venkata Giri Venkataramanan
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Patent number: 7595687Abstract: An apparatus and method for reducing EMI generated by a power conversion device, as well as a power conversion device employing such apparatus or method (and/or devices employing such a power conversion device) are disclosed. In at least some embodiments, the apparatus includes a hybrid filter for use in reducing EMI. The hybrid filter includes a passive filtering component, and an active filtering component coupled at least indirectly to the passive filtering component. The active filtering component includes a voltage controlled voltage source, and the hybrid filter operates to reduce a level of a common mode current, whereby the EMI generated due to the common mode current is reduced.Type: GrantFiled: July 31, 2006Date of Patent: September 29, 2009Assignee: Wisconsin Alumni Research FoundationInventors: Nicolai B. Mortensen, Venkata Giri Venkataramanan
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Publication number: 20080024951Abstract: An apparatus and method for reducing EMI generated by a power conversion device, as well as a power conversion device employing such apparatus or method (and/or devices employing such a power conversion device) are disclosed. In at least some embodiments, the apparatus includes a hybrid filter for use in reducing EMI. The hybrid filter includes a passive filtering component, and an active filtering component coupled at least indirectly to the passive filtering component. The active filtering component includes a voltage controlled voltage source, and the hybrid filter operates to reduce a level of a common mode current, whereby the EMI generated due to the common mode current is reduced.Type: ApplicationFiled: July 31, 2006Publication date: January 31, 2008Inventors: Nicolai B. Mortensen, Venkata Giri Venkataramanan
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Publication number: 20070278797Abstract: A wind turbine 36 has a back-to-back AC/DC/AC power electronic converter chain in which the grid side converter 48 is connected in series with DFIG stator windings 64. The machine side converter 56 is fed from the rotor windings 54 of the DFIG 44. Series connection of the grid side converter 48 enables voltage sag ride-through capability via control of the stator flux. In the event of a grid voltage sag, the series converter allows for a controlled response in the stator flux and electromagnetic shaft torque, protects the machine side converter and enables continued power delivery to the grid.Type: ApplicationFiled: May 31, 2007Publication date: December 6, 2007Inventors: Patrick S. Flannery, Venkata Giri Venkataramanan
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Patent number: 6982890Abstract: A three-phase AC to AC frequency converter has a transformer with a three-phase input and n sets of three-phase secondary outputs, where n is three or more, the voltages at each set of secondary output terminals being one or more multiples of 360°/n out of phase with the voltages at the other sets of secondary output terminals. The sets of secondary output terminals are connected to three single pole, n throw switches, the poles of which are connected to the three output terminals of the frequency converter. Each switch may have n semiconductor switching devices, each connected to the common pole and separately connected to one of the output terminals in each of the sets of secondary output terminals.Type: GrantFiled: October 9, 2003Date of Patent: January 3, 2006Assignee: Wisconsin Alumni Research FoundationInventor: Venkata Giri Venkataramanan