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Stochastic Transmission Capacity Expansion Planning Considering Thyristor Controlled Series Capacitor Placement and Network Topology Control

Omid Ziaee, University of Nebraska - Lincoln


Appropriate design and efficient operation of components of a power system reduce the cost of electric power generation and distribution and benefit consumers. A vital component of a power system is its transmission network. The cost of electricity increases when power flow congestion and bottlenecks appear in the transmission network. In recent years, the probability of having a power flow congestion in the network has increased. This increase is primarily due to a) restructuring of the power system toward a deregulated market-oriented system, b) high penetration and scattered locations of non-dispatchable renewable energy sources, and c) an anticipated increase in power consumption. The increase in instances of power flow congestion has accentuated the power flow limitations of the existing transmission network. An obvious but costly choice for mitigating these bottlenecks is to expand the network by building additional transmission lines. However, more economical alternatives to building new transmission lines exist that could enhance the operational capacity of an existing transmission network. These alternatives include installing fast switching equipment and associated communication infrastructure on certain lines, such that those lines could be switched on and off frequently, or installing series flexible AC transmission systems (FACTS) devices on selected lines, i.e., thyristor controlled series capacitor (TCSC), to control the power flow over the network. These alternative enhancement approaches, when applicable for a network, are economically preferable to the expansion option because of the smaller capital investment and shorter implementation time. Since the electric power flow through the network is governed by the kirchoff's law that is linked to the topology of the network, finding the optimal transmission line in order to either switch it off or compensate it have to be performed through a mathematical program. In this dissertation, the benefit of combining topology control and compensating the transmission line by installing TCSCs while considering the uncertainty associated with load and generation are investigated. This combined problem has not been addressed in the literature although it is a natural extension of the network enhancement options. The main reason of either network topology control or TCSC placement is to expand the feasible solution space of the optimal power flow to obtain the results that are not feasible in the conventional system. Numerical results verify that combining the network topology control with TCSC placement provides better economical results.

Subject Area

Electrical engineering|Operations research

Recommended Citation

Ziaee, Omid, "Stochastic Transmission Capacity Expansion Planning Considering Thyristor Controlled Series Capacitor Placement and Network Topology Control" (2016). ETD collection for University of Nebraska-Lincoln. AAI10248362.