• Thermal limit: -The maximum amount of electrical energy that transmit on transmission line without overheating.
• Voltage limit: - System voltage and change in voltage must be maintained with the range of acceptable deviation. …show more content…
However the electric power that can be transmitted between two locations on a transmission network is limited by several transfer limits such as thermal limits, voltage limits, & stability limits with the most restrictive applying at a given time. If any such limit reached, the system is said to be congested. Congestion in a transmission system whether in vertically integrated or unbundled electric system cannot be tolerated except for a short time, since this may cause outages with uncontrolled loss of load. The chances of congestion in a deregulated market are quite high since the customers would like to purchase electricity from cheapest available resources. Congestion management, is that, is controlling the transmission system so that transfer limits are observed, is perhaps the fundamental transmission management problem. The methods are generally adapted to manage congestion include rescheduling generators outputs, supplying reactive power support or physically curtail …show more content…
Imagine a two area system with cheaper generation in area 1 and relatively costlier generation in area 2. Buyers in both the areas would prefer the generation in area 1 and eventually the tie-lines between the two areas would start operating at full capacity such that no further power transfer from area 1 to 2 is possible. The sellers in area 2 are then said to possess market power. By exercising market power, these sellers can charge higher price to buyers if the loads are inelastic. Thus, congestion may lead to market power which ultimately results in market