Patents by Inventor Roland Zuelch

Roland Zuelch 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).

  • Patent number: 11621650
    Abstract: A method provides current limitation in the event of transient voltage variations at an AC output of a multilevel inverter that includes a bridge circuit with a first DC input, a second DC input, a neutral terminal and a bridge output, as well as a line filter with a choke connected between the bridge output and the AC output, and a capacitor connected between the AC output and the neutral terminal. In the method, depending on the voltage at the capacitor, when a first current threshold is exceeded by the choke current, a regular operating mode is interrupted and measures for current limitation are initiated. A multilevel inverter is further disclosed including a control circuit that is configured to carry out such a method.
    Type: Grant
    Filed: August 25, 2021
    Date of Patent: April 4, 2023
    Assignee: SMA Solar Technology AG
    Inventors: Uwe Stickelmann, Roland Zuelch
  • Publication number: 20210384818
    Abstract: A method provides current limitation in the event of transient voltage variations at an AC output of a multilevel inverter that includes a bridge circuit with a first DC input, a second DC input, a neutral terminal and a bridge output, as well as a line filter with a choke connected between the bridge output and the AC output, and a capacitor connected between the AC output and the neutral terminal. In the method, depending on the voltage at the capacitor, when a first current threshold is exceeded by the choke current, a regular operating mode is interrupted and measures for current limitation are initiated. A multilevel inverter is further disclosed including a control circuit that is configured to carry out such a method.
    Type: Application
    Filed: August 25, 2021
    Publication date: December 9, 2021
    Inventors: Uwe Stickelmann, Roland Zuelch