There are some differences between congestion problem in transmission networks and distribution networks. One difference is that transmission systems are operated ring, not rural. The other difference is that – considering deregulation in power system - in transmission network the congestion management is considered as an economical problem than a technical problem. For example in congestion management of a transmission network it is required to consider locational marginal price in problem formulation, but in distribution system the electricity price is equal all over the network. Moreover, It is generally necessary to control actions intended to relieve transmission network overloads do not jeopardise the system N−1 security level. However, in distribution system usually it is not required to take this level of security in account.