An Eliminating Congestion Algorithm Based On The Practical Quoted Price Settlement By Analyzing The Matrix Of Sensitivity

Power is an important resource of the development of human being. It isnecessary to push the electrical power industry to the market with the development ofeconomy. In our country, the first step to open up the Generation Market is carryingout. This paper is presented to study how to purchase electricity from power plantswith minimal cost on the premise of satisfying security constraints, electric energyquality and users' requirements. So this issue has some theoretical and practicalmeanings.The objective of the proposed algorithm is to eliminate congestion with theminimal cost of purchasing electricity from power plants. It is proposed to clear basedon the practical quoted price and make use of the Merit-order Method to solve theUnit Commitment problem. The feature of the Merit-order Method is fast and brief.Afterwards, Power Dispatch is determined by adopting Equal Bidding Price Methodconsidering the impact of power loss. But this Power Dispatch may cause overloadingin lines or transformers (It is called Congestion under Power Market condition.). Toensure a more secure power system, congestion must be eliminated. This paperdiscusses the transmission congestion management based on the analysis of thesensitivity and several algorithms. An algorithm of eliminating congestion based onthe analysis of matrix of sensitivity is proposed in this paper. The algorithm providesa solution according to all the overloading lines. Its equality constraints are theoverloads of the branches and the summation of the sensitivity of the elementmultiplying corresponding adjustment respectively. Its inequality constrains are theupper and lower limits of the units. The algorithm uses the method of finding extremevalue of Lagrangian function and the adjustment of each unit can be obtained bysolving a linear equation set only, the calculation is fast and simple.The results of the IEEE9 system and the IEEE30 system show that the presentedalgorithm is correct and effective.