Research On Unit Commitment Based On Improved Immune Algorithm

Unit commitment (UC) plays an important part of the power system economic dispatch, and it is a preparation of short generate scheduling problem to be solved first. It has an important significance to the power system and the national economy. Unit commitment is a mathematical problem which is high-dimensional, discrete, nonlinear, and mixed integer.This paper describes the immune algorithm for solving unit commitment idea, solution methods and types of operating indicators. According to the characteristics of unit commitment, particularly the characteristics of security constraints, this paper propose an UC algorithm based on improved immune algorithm:First, using an antibody segment to represent a unit state in the scheduling, and store the information of good antibody in the form of antibody memory library. Second, we proposed a clonal selection method based on antibody concentration and affinity, which effectively inhibit the antibody premature. Furthermore, an optimization mutation based on group search is adopted to reduce the blindness of random mutation.This paper made the following improvements on security constraints:first, a pre-proposed method is adopted to judge the working unit, greatly reducing the number of variables. Then we propose a fast solution method for the robustness of the actual power requirements of the algorithm. Finally, adding the information of the active security constraints as part of antibody and form security constraints memory, which works as an artificial selection of active constraints during economic dispatching in ISO. It can reduce the number of constraints and calculate of scale effectively.On the basis of the above, we apply the improved immune algorithm to hydrothermal short-term scheduling.The relationship between the power head, water flow and power output is linearized based on the minimum error. Considering the range of non-continuous operation, minimum switch time constraints and other factors, we establish the improved immune algorithm model which is suitable for hydrothermal scheduling.Several cases are used to analyze the validity and rationality of the proposed method.