Mitigating Congestion in a Power System and Role of FACTS Devices

Abstract

Congestion management refers to avoiding or relieving congestion. In transmission lines, congestion management is one of the most important issues for the reliable operation of power system in the deregulated environment. Restructuring has brought considerable changes in all possible domains including electric supply industry. By virtue of restructuring, electricity has now become a commodity and has converted into a deregulated one. The traditional regulated power system has now become a competitive power market. In the present scenario, the real time transmission congestion is the operating condition in which the transfer capability to implement all the traded transactions simultaneously is not enough due to either some expected contingencies or market settlement. Thus, congestion is associated with one or more violations of the physical, operational, and policy constraints under which grids operate. Thus, congestion management is about managing the power transmission and distribution among valuable consumers priority-wise. Placement of FACTS (Flexible Alternating Current Transmission System) devices for generation rescheduling and load-shedding play a crucial role in congestion management. FACTS devices are used to enhance the maximum load ability of the transmission system. FACTS increases the flexibility of power system, makes it more controllable, and allows utilization of existing network closer to its thermal loading capacity without jeopardizing the stability. FACTS technology can boost the transfer capability in stability limited systems by 20-30%. As a result, more power can reach consumers with a shorter project implementation time and a lower investment cost. This review work unites the various publications on congestion management in past few decades.

A survey on recent advances in transmission congestion management

“…FACTS can improve the loadability, and network efficiency, reduce system losses, reduce production costs, and handle the network's power flow requirements. FACTS devices improve existing transmission network capacity and reduce congestion costs by regulating the voltage, controlling reactive power, and power stabilization [11]. Activation of traditional compensation devices, phase shifters, the setting of transformer taps, and application of FACTS devices are coming under cost-free measures.…”

Modelling Demand Response to Alleviate Congestion in Active Power Market

“…Usually, each system operator manages it by applying their own guidelines and rules, and employing a certain physical or financial mechanism. In certain situations, it can be eased by cost-free methods such as the utilization of Flexible Alternating Current Transmission System (FACTS) devices [3], [4], [5], [6], the implementation of network reconfiguration [7], [8], [9], [10], [11], and transformer tap operation [12]. However, sometimes these methods are not effective and time consuming.…”

Optimal power flow based congestion management using enhanced genetic algorithms

“…Reference [4] proposes a CM approach based on an ac power flow method with the help of Flexible AC Transmission System (FACTS) devices in the power system. A detailed review on CM, by considering the conventional methods of CM and the important discussions on each topic are presented in [5]. Reference [6] proposes a single and multiobjective optimization approaches for optimal choice, location and size of FACTS controllers in deregulated power system to minimize congestion, improve voltage stability and reduce the transmission line losses.…”