Harmonic

Quantum mechanics

Control (management)

Voltage

Linearization

Engineering

Three-phase

Voltage source

Image impedance

Damping factor

Computer science

Acoustics

Harmonic analysis

Quarter-wave impedance transformer

Input impedance

Electrical impedance

Physics

Nonlinear system

Impedance bridging

Output impedance

Electronic engineering

Artificial intelligence

Control theory (sociology)

Converters

Electrical engineering

Total harmonic distortion

IEEE Transactions on Power Electronics

The impedance-based stability analysis of single-phase voltage source converters (VSCs) emphasizes the precise impedance modeling. Considering the complexity of dq-frame impedance modeling and measurement, this paper proposes a mirror-frequency impedance modeling and measurement approach of single-phase VSCs in the stationary frame based on harmonic linearization. First, the mirror frequency definition is put forward and the dynamics of the second-order generalized phase-locked loop considering the mirror-frequency effects is validated by simulations. Next, the impedance model considering the mirror-frequency effects and dc-link voltage control loops is compared with the conventional one-dimension impedance model and a mirror-frequency impedance measurement method is presented, which are verified by experiments on the hardware-in-the-loop platform. The results indicate that the mirror-frequency impedance model considering the dc-link voltage control is more accurate and better captures the cross-coupling dynamics of VSCs. Finally, the different bandwidths of dc-link voltage control loops and different capacitances are designed to study the impacts of dc-link voltage control loops and ripples on impedance. The experiments and impedance-based analysis illustrate that the wider bandwidth of dc-link voltage control loops or the less capacitance with high dc-link voltage ripple will expand the frequency range of negative impedance in the low frequency.

Input Impedance Modeling and Verification of Single-Phase Voltage Source Converters Based on Harmonic Linearization