Power System Voltage Stability Assessment Using Channel Components Transform

• Author / Creator

  Rahimi Pordanjani, Iraj

• This Thesis proposes a novel transform called “Channel Components Transform” and presents its application to power system voltage stability assessment. The transform is based on the following observation: a power network can be represented as a multi-node, multi-branch Thevenin circuit connecting the loads to the generators. If one applies eigen-decomposition on the Thevenin impedance matrix, the network can be decoupled into a set of single-branch equivalent circuits. These circuits are much easier to analyze and they carry valuable information of a power system. Similarly, if the variations of the transformed variables can be evaluated, one may be able to predict the complex behaviours of the actual network. The eigen-decomposition of the Thevenin impedance matrix and associated operations are named “Channel Components Transform” (CCT).

  The thesis shows that CCT can establish a framework to assess the voltage stability conditions of a power system. Techniques are developed to identify the critical modes (called channels) involved in voltage collapse, the associated critical buses, generators, and branches. These methods are tested using various test systems including an actual large power system. The results confirm that the developed methods are useful tools for assessing the voltage stability of a complex power system.

  A wide-area scheme for the online voltage stability monitoring based on the proposed CCT-based framework is proposed. A methodology for optimal placement of Phsor Measurement Units (PMUs) is also proposed in order to minimize the number of required PMUs and as a result, make the implementation procedure practical. A CCT-based algorithm to facilitate the planning of reactive power support is developed. Using the proposed algorithm, the optimal location and amount of reactive supports are determined in order to increase the voltage stability margin. The application of Singular Value Decomposition (SVD) in the proposed CCT is also investigated in this thesis.

• Subjects / Keywords

  • Power systems
  • Voltage stability
  • Channel Components Transform
  • Eigen decomposition

• Graduation date

  Fall 2013

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3WM1427F

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.