Li, Yishan (2005-12). Short-term and long-term reliability studies in the deregulated power systems. Doctoral Dissertation. Thesis uri icon

abstract

  • The electric power industry is undergoing a restructuring process. The major goals of the change of the industry structure are to motivate competition, reduce costs and improve the service quality for consumers. In the meantime, it is also important for the new structure to maintain system reliability. Power system reliability is comprised of two basic components, adequacy and security. In terms of the time frame, power system reliability can mean short-term reliability or long-term reliability. Short-term reliability is more a security issue while long-term reliability focuses more on the issue of adequacy. This dissertation presents techniques to address some security issues associated with short-term reliability and some adequacy issues related to long-term reliability in deregulated power systems. Short-term reliability is for operational purposes and is mainly concerned with security. Thus the way energy is dispatched and the actions the system operator takes to remedy an insecure system state such as transmission congestion are important to shortterm reliability. Our studies on short-term reliability are therefore focused on these two aspects. We first investigate the formulation of the auction-based dispatch by the law of supply and demand. Then we develop efficient algorithms to solve the auction-based dispatch with different types of bidding functions. Finally we propose a new Optimal Power Flow (OPF) method based on sensitivity factors and the technique of aggregation to manage congestion, which results from the auction-based dispatch. The algorithms and the new OPF method proposed here are much faster and more efficient than the conventional algorithms and methods. With regard to long-term reliability, the major issues are adequacy and its improvement. Our research thus is focused on these two aspects. First, we develop a probabilistic methodology to assess composite power system long-term reliability with both adequacy and security included by using the sequential Monte Carlo simulation method. We then investigate new ways to improve composite power system adequacy in the long-term. Specifically, we propose to use Flexible AC Transmission Systems (FACTS) such as Thyristor Controlled Series Capacitor (TCSC), Static Var Compensator (SVC) and Thyristor Controlled Phase Angle Regulator (TCPAR) to enhance reliability.
  • The electric power industry is undergoing a restructuring process. The major goals
    of the change of the industry structure are to motivate competition, reduce costs and
    improve the service quality for consumers. In the meantime, it is also important for the
    new structure to maintain system reliability. Power system reliability is comprised of
    two basic components, adequacy and security. In terms of the time frame, power system
    reliability can mean short-term reliability or long-term reliability. Short-term reliability
    is more a security issue while long-term reliability focuses more on the issue of
    adequacy. This dissertation presents techniques to address some security issues
    associated with short-term reliability and some adequacy issues related to long-term
    reliability in deregulated power systems.
    Short-term reliability is for operational purposes and is mainly concerned with
    security. Thus the way energy is dispatched and the actions the system operator takes to
    remedy an insecure system state such as transmission congestion are important to shortterm
    reliability. Our studies on short-term reliability are therefore focused on these two
    aspects. We first investigate the formulation of the auction-based dispatch by the law of
    supply and demand. Then we develop efficient algorithms to solve the auction-based
    dispatch with different types of bidding functions. Finally we propose a new Optimal
    Power Flow (OPF) method based on sensitivity factors and the technique of aggregation
    to manage congestion, which results from the auction-based dispatch. The algorithms
    and the new OPF method proposed here are much faster and more efficient than the
    conventional algorithms and methods. With regard to long-term reliability, the major issues are adequacy and its
    improvement. Our research thus is focused on these two aspects. First, we develop a
    probabilistic methodology to assess composite power system long-term reliability with
    both adequacy and security included by using the sequential Monte Carlo simulation
    method. We then investigate new ways to improve composite power system adequacy in
    the long-term. Specifically, we propose to use Flexible AC Transmission Systems
    (FACTS) such as Thyristor Controlled Series Capacitor (TCSC), Static Var
    Compensator (SVC) and Thyristor Controlled Phase Angle Regulator (TCPAR) to
    enhance reliability.

publication date

  • December 2005