Low Voltage Ride Through Control for the Brushless Doubly-Fed Induction Generators
S. Zhang (TU Delft - Electrical Engineering, Mathematics and Computer Science)
H. Polinder – Mentor
J. Dong – Mentor
U. Shipurkar – Mentor
M. Gholizadeh – Mentor
Milos Cvetković – Graduation committee member
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Stability and security of the grid are two vital aspects of energy supply. To keep the grid stable, it is necessary that the electricity plant can control and protect the mechanism. In the past, traditional plants could meet these requirements. Nowadays, the share of sustainable power sources in total electricity generation has become so important that these sources must keep the grid stable. A significant part of these requirements is the Low Voltage Ride Through (LVRT) capability of the sustainable energy plant. When some large loads are connected to the grid or as a result of grid faults like lightning strikes or short circuits, short–term voltage dip may occur. This low voltage dip condition plans to be simulated and the behaviours of Brushless Doubly-Fed Induction Generator (B-DFIG) should be improved in this situation. This thesis is going to realize this goal that after the improvement, when low voltage dip occurs, it is not necessary to disconnect the generator from the grid.
The thesis is organized as follows: Firstly, the B-DFIG modelling is implemented, including the steady state modelling by equivalent circuits and the dynamic modelling by differential equations. The steady and transient state characteristic of B-DFIG can be studied by equivalent circuits and dynamic models respectively. Secondly, the control algorithm is added to the power electronic converter to control the machine in a stable and responsive manner. Thirdly, simulations of both full voltage and low voltage dip conditions are done to compare B-DFIG behaviours between these two different simulation conditions. Unexpected performance like large transient current will occur under low voltage dip condition. Fourthly, the LVRT control algorithm is added to the controller of B-DFIG for improving the behaviours of B-DFIG in low voltage dip condition based on some constraints and assumptions. Finally, experiments are executed to verify this result.
Index Terms — Brushless Doubly-Fed Induction Generator, Low Voltage Ride Through, security, stability