Abstract
Three-phase power-factor-correction (PFC) power supplies are commonly used to convert ac power from a three-phase grid to a regulated dc voltage with unity input power factor. The output voltage regulation is normally achieved by an outer voltage feedback loop and a sinusoidal pulse-width-modulated (SPWM) inner current loop. However, the non-ideal power grid may drive the converter to enter a low-frequency instability region. In this paper, a low-frequency instability phenomenon in three-phase PFC power supplies is reported. The converter can also be regarded as exhibiting a Hopf-type bifurcation in which the dc output voltage oscillates at 150 Hz, and a large amount of harmonics appear on the line current. We develop an averaged model of the grid-converter system to predict the low-frequency instability. The effects of circuit and grid parameters can be studied with this model. Additionally, as a result of the emergence of low-frequency oscillation, the stability boundary leading to a catastrophic bifurcation changes dramatically. Simulation results also provide design-oriented boundaries of operation. This phenomenon is confirmed by experimental measurement.
| Original language | English |
|---|---|
| Article number | 6605630 |
| Pages (from-to) | 3328-3340 |
| Number of pages | 13 |
| Journal | IEEE Transactions on Circuits and Systems I: Regular Papers |
| Volume | 60 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 1 Dec 2013 |
Keywords
- Catastrophic bifurcation
- grid interaction
- Hopf bifurcation
- low-frequency instability
- three-phase voltage source converter
ASJC Scopus subject areas
- Electrical and Electronic Engineering