Study Of A Long-dated Electric Agreement And Its Unit Commitment Arithmetic In Power Market

The innovation to power industry is an inevitable trend of power development. In China this innovation has begun, in which it is a key to introduce market economy. And it is a field to study how to set up and develop power market and what will affect the traditional power industry. Thus no other than after the theory of power market is analyzed intensively, the material and essential steps could be brought into effect.The electric bargaining market with an agreement is an important part of power market and the electric bargaining market with a long-dated agreement occupies 70 percent of the electric bargaining market. It gave a model of the agreement about long-dated electric bargaining, which is a relatively integrated electric bargaining model. As the quoted price data from power corporations should be fit for the competition principle in a market, to pursue optimal benefit will bring on a benefit equilibrium in participant power corporations. Here,game theory can be introduced to analyze the process of price competition in units and thus power corporations can use game theory for instituting their proper quoted price curve.In base of the content to be prescribed in an agreement, the bargaining center carries unit commitment.The model of economical distribution to power in units has two target functions: the one is to minimize purchasing power expenses which is balanced according to marginal cost; the other is to minimize purchasing power expenses which is balanced according to real quoted price from generating units. This model to price competing includes three restrictions: of power and capability, of time and of power network's security and so on.The major of the price competition in independent generating units is about units' optimal commitment. By setting up units commitment model in power market, it analyzed and studied the arithmetic of unit commitment. And merit-order method and dynamic programming method are the used methods in conventional unit commitment. The former has the quick computing speed and small memory and not to find the optimal solution but to satisfy general demand; the latter is a math method to solute the optimization of multistage decision-making process and has the following characteristics: it is the arithmetic to optimize unit commitment that has no special demand to the character of target function and can findthe holistic optimal solution, but its computing quantity is huge to a big system with more units, when it is simplified by approximate methods and thus the optimal solution will easily lose. The dynamic programming method requests unit commitment process has obvious phases and thus hard considers the restrictions of time and climbing speed and so on.We combined the dynamic programming method with the conditional merit-order method to gain an improved dynamic programming method, which integrated their both advantages and could avoid their disadvantages.An example of 4 units system demonstrated how to set down quoted price curve from power units and how to carry through units' commitment according to the quoted price curve. The results are compared to find that game theory is advantage to analyze quoted price and the improved arithmetic can give an applied and convenient effect.