Thesis - Contributions to cascade linear control strategies applied to grid-connected voltage-source converters - Group of Electronic Engineering Applied to Renewable Energy Systems
 

Group of Electronic Engineering Applied to Renewable Energy Systems

  • Full Screen
  • Wide Screen
  • Narrow Screen
  • Increase font size
  • Default font size
  • Decrease font size
Publications PhD. Thesis

Contributions to cascade linear control strategies applied to grid-connected voltage-source converters

Research Area: Uncategorized
Status: Finished Degree: Phd
Directors: Emilio Bueno; A. García Students: Ana Rodríguez
Proposed end date: 2013-09-15
Description:

Among the existing techniques for implementing the current control for harmonic compensation, two of the most used are resonant and repetitive controllers both in stationary and synchronous reference frames. A thorough study of different existing structures to implement them is carried out, showing the frequency-adaptive algorithm for each of these structures and analyzing their computational load. Basic guidelines for the programming of such controllers are given. The current control scheme is studied and characterized in order to establish a comparison among the different structures.

After studying in depth the current control of a grid-connected VSC, the second control to analyze is the PCC voltage controller. The presence of an unbalanced voltage at the PCC results in the appearance of a negative sequence current component, which deteriorates the control performance when applying conventional control techniques. STATCOMs are wellknown to be a power application capable of carry out the PCC voltage regulation in distribution lines that may suffer from grid disturbances. This Thesis proposes a novel voltage controller in synchronous reference frame to compensate an unbalanced PCC voltage by means of a STATCOM, allowing an independent control of both positive and negative voltage sequences. Several works have been proposed in this line but they were not able to compensate an unbalance in the PCC voltage. Furthermore, this novel controller includes aspects as antiwindup and droop control to improve the control-system performance.

Several experimental tests have been carried out to analyze the performance of the current controllers discussed in the Thesis. All of them have been tested under the same conditions of power, voltage and current. These tests aim at characterizing the transient response, steadystate response, behavior under frequency jumps and computational load of the current controllers.

You are here: Publications PhD. Thesis