Abstract
Three-phase voltage source converters (VSC) 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 VSC to enter line-frequency instability region. In this paper, a line-frequency instability phenomenon in three-phase voltage-source converters is reported. The converter can also be regarded as exhibiting a Hopf-type bifurcation in which the dc output voltage oscillates at about 130 Hz, and large amount of harmonics appear on the line current. We develop an averaged model of the VSC and non-ideal power grid which can predict the Hopf-type bifurcation. The effects of circuit and grid parameters can be studied with this model, and are verified though cycle-by-cycle simulations. The simulations also provide design-oriented boundaries of operation.
Original language | English |
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Title of host publication | ISCAS 2012 - 2012 IEEE International Symposium on Circuits and Systems |
Pages | 213-216 |
Number of pages | 4 |
DOIs | |
Publication status | Published - 28 Sep 2012 |
Event | 2012 IEEE International Symposium on Circuits and Systems, ISCAS 2012 - Seoul, Korea, Republic of Duration: 20 May 2012 → 23 May 2012 |
Conference
Conference | 2012 IEEE International Symposium on Circuits and Systems, ISCAS 2012 |
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Country | Korea, Republic of |
City | Seoul |
Period | 20/05/12 → 23/05/12 |
ASJC Scopus subject areas
- Hardware and Architecture
- Electrical and Electronic Engineering