A Bidding Algorithm With Minimum Cost Of Eliminating The Congestion In Power Market Based On Unified Marginal Price Settlement Method

In the generation electricity market mode, the net companies will minimize the cost of purchasing electricity while shill ensuring the security of the system operation and power quality. It is important for power system operation in power market. So this issue has some theoretical and practical meaning.It is proposed in this paper to solve the unit commitment by adopting merit-order method and to pre-dispatch the power among the units using the equal bidding price method. To eliminate the congestion that might be occurred, a kind of method that minimizing the adjustment of the output is discussed. It is realized by adopting the method of adjustment of equal and opposite quantities output of each unit according to its sensitivities to the overload branch. Based on the discussing, a new method that squaring the cost according to the unified marginal price and minimizing the cost increment of the adjustment to eliminate the congestion is proposed: the output increment of each unit is determined by the same price based on its sensitivity and the bidding curve. Thus both eliminating the congestion and minimizing the cost of network power are guaranteed. Compared with the method of minimizing the adjustment of the output of the units, this method can decrease the total cost. Using the formula of DC Flow and matrixof FDLF that could easily cooperate with power analysis in calculating sensitivity, the calculation is greatly simplified and therefore becomes relatively simple. Test samples have shown the validity of the proposed method.