Patent ID: 11901730
Assignee: SIEMENS AKTIENGESELLSCHAFT
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G  Y | IPC G  H

Claim 9:
10. A method for estimation of grid impedance in a power converter controller, comprising:
injecting an injection current while operating online and coupled to a power grid at a point of common coupling (PCC), the injection current being benign to an operating current of the power converter;
regulating input voltage of the power converter;
determining parameters for the injection current including injection interval and duration, current magnitude, current frequency, and symmetrical component;
extracting measurements of current and voltage at the PCC at an operating point shifted from a previous operating point in response to the injection current;
extracting symmetrical components of current and voltage measurements; and
computing an estimated grid impedance based on the extracted symmetrical components.