In view of the uncertainty problem of the input data due to renewable energy injection and load changes

a new constrained power flow model based on the interval algorithm is proposed. First

the input data changes are expressed in an interval form

and then the traditional power flow equations are converted into an optimization model considering voltage and reactive power constraints. In the solving process

the interval comparative concept is introduced

and the uncertain constrained optimization problem is decomposed into two deterministic subproblems

or the upper bound and lower bound problem. Finally

the two subproblems are solved by the modern interior point algorithm to obtain the upper and lower bound solutions. Extensive numerical simulations on IEEE 14bus

57bus

118bus systems and South China 703bus system

have demonstrated the effectiveness and rapidity of the proposed method as compared to affine arithmetic and Monte Carlo simulation. This work is supported by National Basic Research Program of China (973 Program) (No. 2013CB228205) and National Natural Science Foundation of China (No. 51167001).