(School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150001, China)

Power systems optimization considering operational constraints should be oriented to a time period, a demand the regular optimal power flow model focusing on single time span is unable to meet. This paper presents an integral optimal power flow model for the time period. To further increase the calculation efficiency, a characteristic optimal power flow model for time period is then proposed, which employs three different load characteristic patterns to respectively represent the objective function and operational constraints. This model is able to guarantee the systems’ optimality on the premise of satisfying all operational constraints in the whole time period. Numerical tests based on 14-bus and 118-bus experimental systems have demonstrated the validity of the proposed models, and the results show that the characteristic optimal power flow model is able to effectively guarantee system security and economy.