Patents by Inventor Vahid Dargahi

Vahid Dargahi 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: 20220149746
    Abstract: A pyramid-type multilevel converter for converting DC voltage to AC voltage waveforms, and vice versa. An example device can use modular building blocks to form a selector stage, a converter stage, and at least one intermediate stage if the number of converters within the converter stage is greater than or equal to 3, with the converter stage switching at high-frequency PWM to chop the DC voltages. The modular building blocks are connected in a symmetric or asymmetric pyramid configuration having a base of using the converter stage and an apex of the selector stage.
    Type: Application
    Filed: January 26, 2022
    Publication date: May 12, 2022
    Applicant: The Regents of the University of California
    Inventors: Vahid Dargahi, Keith A. Corzine
  • Patent number: 11171575
    Abstract: A Modular Multilevel Converter (MMC) circuit for converting DC power to AC and vice versa. At each respective connection to the AC power-source/load, the MMC circuit uses one Pulse Width Modulation Insulated Gate Bipolar Transistor (PWM IGBT) to control the switching between upper and lower arms of sub-modules. The circuit eliminates the inter-phase inductors often used in MMCs, and replaces the inductors by two complementary-gated PWM IGBTs, thereby eliminating circulating current. Moreover, the multilevel converter topology disclosed herein requires less number of components including PWM IGBTs and capacitors. In fact, at least two submodules per-phase are eliminated: one submodule in the upper arm and one submodule in the lower arm. In other words, the MMC topology not only mitigates the circulating current but also eliminates at least one submodule in the upper arm and at least one submodule in the lower arm per-phase.
    Type: Grant
    Filed: April 22, 2020
    Date of Patent: November 9, 2021
    Assignee: The Regents of the University of California
    Inventors: Keith Corzine, Vahid Dargahi
  • Publication number: 20200350833
    Abstract: A pyramid-type multilevel converter for converting DC voltage to AC voltage waveforms, and vice versa. An example device can use modular building blocks to form a selector stage, a converter stage, and at least one intermediate stage if the number of converters within the converter stage is greater than or equal to 3, with the converter stage switching at high-frequency PWM to chop the DC voltages. The modular building blocks are connected in a symmetric or asymmetric pyramid configuration having a base of using the converter stage and an apex of the selector stage.
    Type: Application
    Filed: May 1, 2020
    Publication date: November 5, 2020
    Applicant: The Regents of the University of California
    Inventors: Keith A. Corzine, Vahid Dargahi
  • Publication number: 20200336083
    Abstract: A Modular Multilevel Converter (MMC) circuit for converting DC power to AC and vice versa. At each respective connection to the AC power-source/load, the MMC circuit uses one Pulse Width Modulation Insulated Gate Bipolar Transistor (PWM IGBT) to control the switching between upper and lower arms of sub-modules. The circuit eliminates the inter-phase inductors often used in MMCs, and replaces the inductors by two complementary-gated PWM IGBTs, thereby eliminating circulating current. Moreover, the multilevel converter topology disclosed herein requires less number of components including PWM IGBTs and capacitors. In fact, at least two submodules per-phase are eliminated: one submodule in the upper arm and one submodule in the lower arm. In other words, the MMC topology not only mitigates the circulating current but also eliminates at least one submodule in the upper arm and at least one submodule in the lower arm per-phase.
    Type: Application
    Filed: April 22, 2020
    Publication date: October 22, 2020
    Applicant: The Regents of the University of California
    Inventors: Keith A. Corzine, Vahid Dargahi