Impedance scanning with chirps for single-phase converters
Chapter
Accepted version
Permanent lenke
https://hdl.handle.net/11250/3045157Utgivelsesdato
2022Metadata
Vis full innførselSamlinger
- Institutt for elkraftteknikk [2499]
- Institutt for teknisk kybernetikk [3787]
- Publikasjoner fra CRIStin - NTNU [38685]
Originalversjon
10.23919/IPEC-Himeji2022-ECCE53331.2022.9806874Sammendrag
Impedance scanning of single-phase AC-DC converters is challenging due to frequency couplings, which map one injection frequency to a multiple of output frequencies. Single-tone injections are often preferred over wideband signals, as spectral overlap negates the benefits provided by quick-to-implement wideband scans. In this paper we take advantage of the time-frequency properties of chirp excitation signals, and develop a model so that a single chirp sweep can provide the impedance frequency response - formulated as a Harmonic Transfer Matrix, which takes into account the frequency couplings. Though we concentrate on single-phase AC-DC converters, the general HTM formulation extends application to any linear time-periodic and linear time-invariant system. Numerical impedance measurements are presented for a single-phase grid-connected converter, operating in grid-forming mode with dispatchable Virtual Oscillator Control.