With the increasing attentions to environmental protection in China

during regional dispatch for thermal and power cogeneration

besides saving the operation costs

pollutant emission reduction has also drawn more and more attentions. Against this dual objective minimization problem of economy and environment

using the conventional ε-constraint method can not effectively optimize the revenue matrix

so the non-dominated solution can not be ensured. To solve this problem

this paper proposes to adopt the lexicographic optimization method

it updates the income matrix gradually based on the ε expectations formed in the previous optimization process so as to reduce the search scope. By introducing slack variables

the e sub-problems are transformed into a standard linear programming model

and the primal-dual interior point algorithm is used to solve it to improve the global search ability. In addition

the fuzzy decision technique is used to provide a quantitative solution for determining satisfactory solutions. Finally

two examples are analyzed by the proposed method and the weighting coefficient adjustment method. The results verifies that

both the quality of pareto solution and the computational speed of the proposed method are better.