Optimal Allocation of TCSC and DG Unit for Congestion Management in Deregulated Power Systems

Transmission network congestion is an important issue in deregulated power systems, whenever the physical or operational constraints in a transmission network become active, the system is said to be in a state of congestion. Congestion management (CM) is a mechanism to prioritize the transactions and commit to such a schedule that will not overload the network. This paper presents relieving transmission network congestion in two ways, one is without disturbing the existing transactions by optimal placement of thyristor controlled series capacitor (TCSC) and, another is rescheduling generators including optimal placement of distribution generation (DG) unit. Congestion in a transmission system can result in very high locational prices for electricity determined by marginal costs from optimal power flow (OPF) based CM problems. The problem is solved by particle swarm optimization (PSO) and genetic algorithm (GA) for fast convergence ratio and minimizes production cost; compare its results with each other for finding a good economical solution method among them. The considerable cost of TCSC and better performance of DG unit, it is necessary to find their optimal location, where sensitivity methods are suggested to determine the optimal placement of these devices. The proposed approach is tested on a standard IEEE 30 bus test system.